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Plant communities and plant production in the western Queen Elizabeth Islands

Plant communities and plant production in the western Queen Elizabeth Islands L. C. Bliss and J. Svoboda Bliss. L. C. and Svnboda, 1. 1984. Plant communities and plant production in the western Ouccn Elizabeth Islands. - Holarcl. Ecol. 7: 325-344. A study of soils, plant communities, and net annual plant production was conducted with 41 stands at 3 sites on 3 arctic islands. Twelve additional sites were sludied in less detail on Ellef Ringnes. King Christian and Melville islands and on four other islands. Through polar ordination five groupings were recognized. Alopecurus and Puccinellia barrens on sand to silty soils and on silty soils, high in sodium salts respectively. Species richness averaged 2.6 ± 2.0 and total plant cover 6.H + 2.7%. The Phippsia barrens occur on sheet eroded surfaces and in gulleys with deep winter snow. Speeies richness was 9.8 ± 5.0 and total plant cover 14.8 ± 9.6%. The graminoid steppes on sandy soils averaged 7.6 ± 2.4 species and total plant cover 40.0 ± 2.8%. Eight stands were dominated by moss-graminoids, mostly on loam soils. Species richness was 24.9 ± 3.4 and total plant cover 77.7 ± 16.1%. Plant producion was S.O g m"^ in a Puccinellia barren and 9.4 g m- in a Luzula confu.sa graminoid steppe. Net annual production ranged from IS.8 to 58.7 in 6 other stands. The 13 stands within the cryptogam-herb community complex occur on sandy loam to clay-loam soils. Species richness averaged 26.3 ± 6.2 and total planl cover 61.2 ± 24.7%. Mosses and lichens play a significant role in the establishment and maintenance of communities with a greater speeies richness and plant production of vascular plant species. The ability of mosses to hold moisture and the presence of limited bluegreen algae that fix nitrogen appear essential to [he maintenance of greater species richness, plant cover and plant production compared with the barren polar deserts that are often nearby. L. C. Btixs. Dept of Botany. Univ. of Wa.shington, Seattle, WA 9fiJ9S, USA. J. Svoboda. Dept of Botany, Erindale College, Univ. of Toronto, Mississauga, Ontario, Canada L5L IC6. Introduction By temperate region standards, the Canadian High Aretic is a barren landseape. often termed a polar desert. While large areas of the High Aretic are polar desert (< 5% total plant cover), other areas limited in extent, have considerable vegetation. These lands have been termed polar semi-desert and wet sedge-moss tundra (Bliss et al. 1973, Bliss 197.5, 1981). Polar semi-deserts typieally have a 5 to 2(1% cover of vascular plants with lichens, mostly crustose and foliose species, and bryophytes adding 20 to 80% cover. These arctic landscapes can have a vascular plant cover dominated by Accepted 25 May 1983 © HOLARCTEC ECOLOGY cushion plants of Dryas integrifolia and Saxifraga opposilifolia mats of Salix arctica. small rosette clumps of Draba, Minuiirtia, and scattered dry site sedges (Svoboda 1973. 1977), orby Luzula, Alopecurus and rosette speeies, termed a polar steppe by Beschel (1973). This study was concentrated on Melville. King Christian, and Ellef Ringnes Islands in the western Queen Elizabeth Islands. Additional data were gathered and general observations made from visits of short duration to twelve additional sites on these three islands and on four other islands (Fig. 1). The objeetives were: (1) to determine the plant community patterns and relate HOLARCTIC ECOLOGY T.i (1984) • Major Study Slli Fig. 1. Ujcation of the three intensive and the 12 extensive study sites in the High Arctic. them to topography and soils; (2) to determine the Standing crop and annual plant production of representative communities; (3) and to relate these findings to other high arctic landscapes, especially to the intensive research sites of the Truelove Lowland, Devon Island ecosystem study (Bliss 1977) in order to determine how widely those ecosystem data can be extrapolated. Study areas Geology The islands in this study are within the Sverdrup Lowland Division of the Inuitian Region. The Sverdrup Basin is superimposed on deformed rocks of the Franklinian Geosyncline; most of the exposed roeks are sandstones, siltstones, and shales of Paleozoic and Mesozoic Age (Tozer and Thornsteinsson 1964). These islands have rolling, scarped surfaces of low relief, prominent dendritic patterns, and rocks showing little deformation. Streams and rivers carry large sediment loads during spring runoff, but, due to reduced flow, they transport little material in mid and late summer. Lakes are generally a minor feature, though small ponds and lakes occur near Rea Point and other locations on Melville Island. At Rea Point, Melville Island, grey marine and nonmarine sandstones, siltstones, and shales of the midDevonian Weatherall Formation predominate. Just to the north, a band of white, yellow, and red sandstones of the Hecia Bay Formation (mid and upper Devonian) outcrops. Our lower slope studies were confined to unconsolidated sands and silt loams derived from the Weatherall Formation and the upland stands (75-90 m) were on loam soils derived from siltstones of the same formation. King Christian Island (ca. 26 x 39 km) has a low domal profile with long, low scarps and gentle slopes. Based upon the descriptions of Stott (1969) and Balkwill and Roy (1977), most of the island consists of alternating beds of sandstone, mudstone, and shale from Christopher and Isachsen Formations of Lower Cretaceous age. A limited amount of shale of the Deer Bay Formation, of Upper Jurassic- Lower Cretaceous age, outcrops near the Panarctic Oils Camp, this formation and much of the Isachsen Formation are covered with recent marine sediments within 3--4 km of the shoreline. Most of the sampling was confined to the sandy loam and silt-loam soils of these coastal sediments. On Ellef Ringnes Island our study was conducted on the slopes of Malloch Dome, a gypsum plug of Pennsylvanian or Permian Age (Greincr in Fortier et a!. 1963). Sampling was done on silty loam soils next to the dome and eastward across sandy and silty alluvium derived from the Cretaceous age beds. Tozer and Thornsteinsson (1964) pointed out that vegetation is largely controlled by rock formations. As will be brought out in this paper, much of this results from soil texture and the ability of the soils, which are mostly developed from siltstones and shales, to hold adequate moisture in what are otherwise polar deserts. Pleistocene events have not been fully established on King Christian Island and are little known on Ellef Ringnes Island. It is unclear whether these islands were glaciated in Wisconsinan time. Much of the late Quaternary history has been obscured by frost action, desiccation processes, and the nature of the underlying bedrock (Prest 1969, Hodgson 1982). Relict "beach ridges", resulting from isostatic rebound, occur at 22 to 33 m on the south and west-central coasts of Ellef Ringnes (Prest 1969), and at 30 m levels on King Christian. The upper limit of these recent marine features occurs at 70 m on eastern Melville Island. Henoch (1964) postulated the existence of an ice cap on the Sabine Peninsula in Wisconsinan Time and that Laurentide ice depressed the south coast of the island. Climate Although polar high pressure systems are centered over Siberia and the Mackenzie-Yukon area in winter and over the polar ice pack in summer, the Queen Elizabeth Islands are characterized by: (1) infrequency of cyclonic storms; (2) shallow pressure gradients in summer; and (3) a lack of atmospheric moisture. Collectively they result in a cold polar desert (Courtin in Bliss et al. 1973, Barry and Hare 1974). The region is marked by persistent rather than extreme cold in winter. Winds, while strong in storms, are generally light in winter. Cloud cover averages 40% and calm air 30% of all observaHOLARCnC ECOLOGY 7:3 (1984) tions in winter (Barry and Hare 1974). Infrequent occurrence of cyck>nic activity is reflected in only 10% of the winds averaging 13 m s'' (at 10 m). Maxwell (1981) divides the Canadian Arctic Archipelago into five climatic regions based upon the climatic control of cyclonic activity, sea ice-water regime, broad scale physiographic features, and net radiation. Region 1 includes the islands in this study, a region of maximum anticyclonic activity and no major relief features. Annual net radiation is in the range of 5-10 kly and mean annual temperature range is extreme (3H-40°C). Climatic data are presented for Rea Pt., Melville Island. Mould Bay, Prince Patrick Island (320 km west of Rea Pt.,), and Isachsen, Ellef Ringnes Island (110km and 75 km northwest of King Christian Island and Malloch Dome respectively) (Tab. i). Based upon summer data, the climate of King Christian is very similar to that of Isachsen (Addison and Bliss 1980). Cloud cover averages 72-84% from June through August at Rea Pt. and 78-89% ;,t Isachsen (1970-76). Summer temperature is well coupled with solar radiation and time of snowmelt at these latitudes. Courtin and Labine (1977) reported that over 50% of total radiation is received at these latitudes (Truelove Lowland. Devon Island 75°33'N) before snowmelt is complete, usually the end of June, and therefore the growing season (45-50 d, snowmelt to autumn leaf coloration) is concurrent with decreasing solar radiation. Summers with higher mean monthly temperatures (1971) than the 1970-75 or 1941-1970 means are also summers with greater hours of sunshine. The short term means of 1975-79 were generally l . T to 2 . 2 T lower per "summer" month than the long term means of 1941-1970 at Mould Bay and Isachsen. One of the single best measures of summer temperature regime is the accumulated degree day value ( > 0°C). The accumulated degree days for 1970-1976 at Rea Point average 208°C, with the coldest sumtner (1972) 13% lower and the warmest summer (1973) 25% higher. The figures for Mould Bay are 216°C, 26% lower for the coldest summer (1972) and 34% higher for the warmest summer (1971) and for Isachsen 152°C, 47% and 45% respectively. Temperatures have been generally lower and precipitation higher in the 1970s at these northwestern high arctic sites than in previous years. In fact. Maxwell (1981) points out a general cooling trend in this climatic region (Northwestern Islands) has been underway since the early 196O's with 1972 and 1973 being the coldest years. On the basis of data from 11 stations since 1950, of the eight warmest years, five were before 1963 and of the seven coldest years, six have been since 1963. The impact of these climatic shifts on plant growth and vegetation pattern is not yet known. Soils Soils in these western Queen Elizabeth Islands are of residual, glacial and marine origin and show little horizon development, little incorporation of organic matter, and low nutrient levels (Tedrow et al. 1968, Everett 1968. Pawluk and Brewer 1976, Bell and Bliss 1978). Many of the sites near Malloch Dome and the lower slopes at Rea Point are on fine textured sands to silty loams, while silty-clay loams and clay loams predominate on the marine sediments on King Christian Island. Plant communities General information on floristics and plant communities, but without supporting quantitative data, are available for the Landing Lake area, near Mould Bay, Prince Patrick Island (Bird 1975), and Isachsen, Ellef Tab. I. Climatic data for selected high arctic stations in the vicinity of polar semi-desert areas. Data are for 1970-79 with comparisons for the 1941-7U period. Station ("N) Latitude Jun Mould Bay Rea Pt. Isachsen' Station Jun Mould Bay Rea Pt. Isachsen 1970-79 Temperature ("C) Mean monthly Jul Aug 3.8 4.0 2.6 0.8 0.9 0.3 Degree days Precipitation (mm) above 0°C Jun-Aug Annual Mean annual -17.7 -17.6 -19.2 209 210 161 39 26 53 102 62 127 Cloud Cover (%) Jun-Aug -0.6 -L2 -1.5 Departure from means 1970-74 1975-79 Jul Aug Jun Jul 0.7 -0.2 -0.1 -0.5 -2. 2 -1. 1 -2.3 -LI Temperature Long term means 1941-1970 Aug Jun Jul Aug -1.6 -2.1 -0.4 -0.9 3.6 3.3 1.7 1.1 Days above 0°C 1970-74 1975-79 Jun-Aug Jun-Aug 0.2 — 'Station closed 1978, 1979. HOLARCnC ECOLOGY 7:3 (1984) Ringnes Island (Saville 1961). Wein and Rencz (1976) gathered data at two locations on Melville Island for sampling efficiency of plant cover and standing crop (phytomass) estimates. Methods Study sites were established immediately to the west of the Panarctic Oils Ltd. camp at Rea Point, Melville Island (75°22'N. 105°42'W); south and west of the Panarctic Oils Ltd. camp near Cape Abernethy (77°45'N, lO(r53'W); and in the vicinity of the Panarctic Oils Ltd. camp near Malloch Dome. Ellef Ringnes Island (78°12'N. lOrW). Soils generally within 20% for the most important species, litter and bare soil within a stand. Cover data are presented in the tables to permit comparison with other studies. Similarity coefficients (C = 2w/(a-l-b) x 100) between stands were computed. Species were not adjusted in relation to their maximum values of frequency and cover as in Bray and Curtis (1957). Dissimilarity values (1 - C) were computed and used for the construction of a two-dimensional, polar ordination (ORDIFLEX H. G. Gauch, Cornell University). This permitted the grouping of stands into community types discussed later. Nomenclature for lichens follows Hale and Culberson (1970). for bryophytes, Vitt (1975) and for vascular plants, Porsild (1964) unless otherwise given. Standing crop Within eight of the stands sampled for community composition, 5 (20 X 50 cm) plots out of the 30 measured for cover were randomly chosen and harvested. In sandy and gravelly soils, individual plants were extracted with most of the roots. A known portion of the soil to a depth of 30 cm (general lower limit for root development) was taken to estimate the remaining roots. In fine textured soils, plants were cut at ground level, lichens and mosses removed and bagged, and the root block prewashed to remove much of the soil. Soil sieves (2 mm and 0.75 mm mesh) were used to collect small roots and fine organic matter. Samples were kept cold in the field prior to air freight shipment to the laboratory. Here samples were frozen until analysed. Material was sorted into mosses, lichens, and vascular plants. The latter were separated by species into green. live-brown, and standing dead shoot material. Roots, where possible, were separated by species. Root fragments, fibrous organic matter and surface litter were combined to form organic matter standing erop. Samples were dried at 8O''C and weighed (0.001 g). In some instances mean cover values of the sampled plots (n ^ 5) differed substantially from the community mean cover value {n = 30), In such cases the standing crop data were adjusted: SC, = X D,. (1) Soils were examined by means of soil pits in most of the stands sampled. Since these soils have little if any profile development, a single composite sample of the top 15 cm was collected for analyses. When present, the cryptogam mat was removed and only the mineral soil was collected. Soil texture was estimated in the field and rooting pattern was described within the pit at all stands. The soils were analyzed by Northwest Soil Research, Ltd., Edmonton. Organic matter was determined by the Walkley and Black (1934) method. Exchangeable cations were extracted with neutral N ammonium acetate and determined by atomic absorption spectrophotometry. Nitrogen was determined by the phenoldisulfonic method and phosphorus by the combined nitric acid-vanadate-molybdate colormetric method. Soil color was determined on moist soil using the Munsell Color Charts in natural light. Plant communities At all sites general reeonnaissance of topography and plant community patterning preceded sampling. Relatively uniform stands (topography, floHstics and plant structure) were selected for sampling within a larger plant community. Stand as used here refers to a particular example of vegetation that was sampled and plant community or community type to a grouping of similar stands based upon a two-dimensional ordination (discussed below). Each stand, roughly 5 x 8 m, was sampled with thirty 20 x 50 cm quadrats by a stratified random technique (Bliss 1963). Cover estimates were made for all species of vascular plants, lichens, mosses litter, bare soil and pebbles by projecting plants to the surface within the quadrat frame, grided into 1 dm squares. Only one stratum was recognized. Each stand was surveyed for additional species; no more than 2 or 3 species of vascular plants were ever found. Frequency and average cover for each species were calculated and converted to prominence values by multiplying cover by the square root of frequency for each species in the stand. Standard error of the mean was Where SC^ is adjusted standing erop (g). C, is cover (%) of 5 harvested plots, C2 mean cover of 30 plots and D, is mean dry weight (g) of harvested plots. Where given error estimates are standard error. Net plant production Most plant communities were sampled at their seasonal peak of growth. This made possible the use of peak green phytomass as a basis for calculating net annual production. An accurate estimate of annual production HOLARCTIC ECOLOGY 7:3 (1984) includes green tissue formed that year, "brown" leaves or their parts produced earlier in the season, "brown" non-photosynthetic shoots produced that year, and an estimate of current root growth. It is virtually impossible, without phcnological studies of dominant species, to determine the proper ratios of green shoot:brown shoot and shoot:root production (Andreyev 1971, Flower-Ellis 1973, Muc 1977). Production estimates considering green tissues only (Parker 1975) or including estimates of annual decomposition (Wielgolaski 1975) will result in significant errors. Many species maintain some green leaf tissue over winter (Bell and Bliss 1977) and plant decomposition does not occur the same year as production in the same plant tissue. Correction terms for decomposition and litter fall should only be used when indirect estimates of plant production are based upon phytomass harvests alone. Valid approximations can be made since there is a strong correlation between the seasonal production of photosynthetic (shoots) and non-photosynthetic (shoots and roots) tissue. This ratio, although changing with age for long lived plants and differing between various plant groups, can be considered a constant for species with convergent morphology in an arctic ecosystem. If the peak green standing crop and net annual green production are known for a "master species" of a given growth form (sedge, grass, cushion, rosette), then total production of the convergent group can be fairly estimated (Svoboda 1977). Standing crop refers to all plant material living and dead, phytomass to living material, and net production to material produced the current year. Based upon these assumptions, the following techniques were applied in the calculation of annual aboveground and belowground production. nal green shoot growth, plus 25% of this value for nonphotosynthetic stems (diameter growth) and 50% of the green shoot growth for root production. Graminoids The rushess Luzuia confusa, L. nivaiis and the grasses Alopecurus aipinus and Puccineliia vaginata are the most impotant species. All green tissue was included as annual production although annual green carry-over is about 20%. hut is matched by 10-20% of seasonal leaf browning. Root production was assumed to equal green .shoot production, an overestimate for Luzuia spp. but an underestimate for the grasses (Bell and Bliss 1978). Herbs Few true herbs were found in the studied communities. All green tissue was counted as annual production plus 50% of this value for root production. The small carryover of basal shoot green tissue (10%) is matched by seasonal dieback. Rosettes The species of Draba, Saxifraga, and Cerastium along with Papavcr radicatum and a few others retain their green leaves for at least 2 yr (Bell and Bliss 1977). After careful examination, the leaves produced during the current year could be identified and separated from those produced in previous years. Root production was assumed to be 50% of shoot production. Results Soils Soils presented are only from King Christian Island and Rea Pt., Melville Island. Soil color ranged from brown Dwarf shrubs Annual production for Satix arctica included all seaso- (10 YR 4/4) to dull yellowish brown - dull yellow orange (10 YR 5/3-6/4). Tab. 2. Soil ehemistry for soils from polar semi-desert vegetation on King Christian and Melville islands. All data are from 0-15 cm soil depth. Stand # pH Organic matter N (%) P (ppm) Ca Mg Exchangeable cations (meq 100 g-i) Na K Total exchange capacity 2.8 4.8 2 Herb-lichen ?• Herb-lichen 5a* Herb-lichen 5b Herb-lichen 7 Wet griiminoid l l a + Herb-lichen l i b Herb-lichen 17 Phippsia barrens . . . 22 Graminoid barrens . 32 Herb-lichen 35 graminoid-moss 36 Phipp.na b a r r e n s . . . 0.9 1.6 1.6 2,8 2.3 2.3 3.0 1.8 1.2 1.6 1.8 0.07 O.OI 0.01 0.16 0.12 0.09 0.12 0.10 O.tM 0.03 0.U8 0.18 0.41 0.38 0.23 0.31 0.26 0.21 0.56 0.10 0.23 0.36 * 5a soil polygon center, 5b soil polygon edge. + 11a soil stripe center, l i b soil stripe edge. 22 HOLARCnC ECOLOGY 7:3 (1984) The soils at Rea Pt. were sandy loams to loamy sands on the outwash from the hills (stands #1-3). clay loams on the hill top (+4-6); loams predominated in the graminoid wetlands (#7). At Cape Abernathy the soils were generally sandy loams to clay loams derived from recent marine deposits. At higher elevations sands and sandy gravels, derived from the Isachsen formation, predominate. In general soil pH is near neutral with the exception of the wet sedge-grass-moss meadow (+7) at Rea Pt., moss covered soil stripes at King Christian Island (#11), and the quite acid (4.4 to 4.8 pH) silty-clay loam soils at stands #35, 36. Other pH measurements from these fine-textured soils, often with sheet erosion patterns with only scattered plants of Phippsia algida predominating, also indicate quite acid soils (4.5 to 3.5 pH, Nancy Gruike 1983) in the absence of acid-forming mosses. Soil organic matter in general reflected the low cover of vascular plants and their limited root systems. Soils from nearly bare surfaces (stands #5a, 11a) have lower percentages of organic matter and nitrogen than do the moss-covered edges of these vegetation polygons and stripes (Tab. 2). At all sites nitrogen levels were low (0.01 to 0.16%) and phosphorus was equally low (4 to 8 ppm). Calcium and magnesium were low in all soils; the highest values were in stand 5 on the upland 2 km west of the Rea Pt. Base Camp. Sodium levels were generally 0.2 to 0.6 meq 100 g ' soil with the exception of the small salty-clay pans of King Christian Island (3.2 meq 100 g"' soil) where Puccinellia vaginata predominated. Potassium was also highest at this stand (#22), 0.56 vs. 0.10 to 0.41 meq 1(X) g'' soil elsewhere. Roots are mostly within the upper 5 to 10 cm, but a few can be found to 25+ cm. There is considerable detail on rooting pattern of the dominant species on King Christian Island (Bell and Bliss 1978). Plant communities •"• ^ : : . . . \ C.H. •" AI.B. "' .. Ph.B. M.G. 1* , • is' Fig. 2. Polar ordination of the 41 stands sampled for plant cover and fequency. The stands are ordered into five groupings. They range from Puccinellia and Alopecurus barrens (Pu. Al B), and Phippsia barrens (Ph B) in sites with limited soil moisture and few cryptogams to a gradient of graminoid and herb communities with an abundance of cryptogams, the mossgraminoid meadows (M.G.). graminoid steppe (GS), and the cryptogam-herb meadows (C.H.). these sites with their annual spring floods and shifting sands (Tab. 3). On terraces 2-4 m above the main river fan. Alopecurus alpinus predominated in medium textured sands (#40. 41); plant cover averaged 5-12% over large areas (Fig. 4). The rhizomatous growth form of Alopecurus enables the species to keep pace with accumulating sand, the only bryophyte present was Pogonatitrii alpinum. but only in one stand. Near the upper limit of tbe coastal marine sediments and the soils derived from the Isachsen Formation on King Christian Island, there were small sandy loam pans The polar ordination of 41 stands resulted in five major groupings of communities (Fig. 2). In most communities, vascular plants contributed 5 to 20% cover; lichens and bryophytes collectively provided 20 to HOTo cover. Only in the sheet erosion surfaces on King Christian island and the sandy outwash soils of Ellef Ringnes were cryptograms < 5% cover. In most sites the cover of crustoe lichens was greatest. Graminoid dominated communities Puccinellia and Alopecurus barrens. In the finegrained sands and silts of the river delta near Malloch Dome. Ellef Ringnes Island, scattered clumps of Puccinellia vaginata predominated (stands # 3 8 , 39). There were often salt crusts on the surface late in the summer (Fig. 3). In a few places there were widely spaced clumps of Alopecurus alpinus and scattered plants of Cochlearia officinale. Cryptogams were absent from 330 Fig. 3. Puccinellia vaginata on a salt pan near Malloch Dome. Ellef Ringnes Island (lens cap 5 cm). HOLARCnC ECOLOGY 7:3 (1984) Tab. 3. Prominence values (cover x square root of frequency) for the PuccinelUa and Alopecurus barrens and Phippsia barrens community types. KCI = King Christian Island. ER = Ellef Ringnes Island. Species Puccinellia & Alopecurus Barrens Stand # Phippsia Barrens 22 KCI 38 ER Puccinellia vaginata Ahpecurm alpinus Phippsia algida Papaver radicatum 39 ER 4() BR 41 ER 60.0 - 9 KCI 13 KCI 14 KCI 17 KCI 21 KCI 36 KCI 29.9 1.2 - 0.2 72.0 105.0 - 18,6 43,0 _ _ _ _ _ 30,0 0.3 _ _ _ _ _ 2.7 Cochlearia officinalis.... Saxifraga cernua Saxifraga nivalis Ci-raxtiitm arcticum Draha subcapitata Drtihu alpina (ladonia gracilis _ _ _ _ 3.4 20,7 3,1 _ _ _ 6.8 58.4 _ _ _ _ _ _ Lepraria ne^lecta Dermatocurpon hepaticum C 'etraria islandica Ci'traria delisei — — — — 23.0 11,7 Gymnomitrion corallioides Other species 2 Total species 6 Total vascular plant cover (%) 5.4 Total bryophyte cover (%) 0.0 Total lichen cover ( % ) , . 0.2 Litter cover (%) 0.0 Bare soil and pebble eover(%) 94.4 2 3.8 0.0 0,0 0,0 96.2 — 0 I 6.0 0.0 0,0 0,0 0,0 0,0 6 3.2 0.5 0.6 0,3 95.4 — _ 7 13 5,9 0,0 3.2 0.4 4.3 1,5 90.6 6.5 10,0 5.0 0.0 78.5 0.0 71,4 0,0 94.0 (5-20 m across) dominated by Puccinellia vaginata. Associated scattered individuals of Phippsia algida, ('ochlcaria officinalis. and small patches of lichens were present (stand #22). These small pans contained high levels of sodium salts which form salt crystals during dry periods in summer as in 1977. Species richness was higher at this site (6) but averaged 2.6 ± 2.0 in the five stands; total plant cover averaged only 6,8 ± 2.7%, Phippsia barrens. Near the contact of the Isachsen Formation sandstones and the thin cover (50-150 cm) of i .,L - . .-.;...; ciink-iJ siiiliiccs wiili I'hipjiMn ul^utu and Puc- cmeliut vaginala barrens. The vegetated area at the shovel and the slopes beyond are dominated by Luzula confusa, Alopecurus alpinus, Rkacomitrium lanuginosum and Gymnomitrion coralliodes. a moss-graminoid community on King Christian Island. iiju'i \it]i\ ii/jniiii-< i n i iin.-Lliimi IfMuK'il s.iiuts km of Malloch Dome, Ellef Ringness Islands- CrypU)gams are absent from this graminoid barrens community. HOLARCTIC ECOLOGY 7:3 (1984) marine sediments on King Christian Island, the surface of the latter sediments erode with spring snowmelt. This results in many gentle slopes (5-8°) having little or no plant cover other than scattered small plants of Phippsia algida and remnants of formally stable surfaces with their cover of lichens-bryophytes-vascular plants (Fig- 5). The bare soil surfaces, hectares in area, were colonized by Phippsia algida with small numbers of Papaver radicatum (stands #9, 13-14) (Tab. 3). The lichens Der~ matocarpon hepaticum and Lepraria neglecta were present in small amounts. The greater cover of the liverwort Gymnomiirion corallioides Nees, and several species of lichens, from less eroded surfaces, would have placed this stand into the bryophyte-graminoid group except for the abundance of Phippsia algida (Stand #36) (Tab. 3), Mosses were generally very minor (< 1% cover) consisting mostly of Polytrichum piliferum and Ditrichum flexicaule. These silty loam and clay-loam surfaces were very wet and sticky following snowmelt, but by mid-July the surfaces were often baked dry. provided the summer had periods of sunny days as in 1976, 1977, Fig. 6. Raised center polygons (4-6 cm across) with Alopecurus alpinus dominating the tops and Luzula confusa and Lepraria and 1979. The guileys contain deep snowbanks {2-A m) which neglecta the troughs about 3 km northeast of Malloch dome, Ellef Ringnes Island, frequently melt out in early to mid-July. Phippsia algida was usually the dominant vascular species although PaGraminoid steppe. The rolling terrain on southern paver radicatum, Draba alpina, D. subcapitata, Saxifraga cernua, S. nivalis, and Cerastium arcticum com- Ellef Ringnes Island beyond the influence of the outprised considerable cover (stands #17, 21). Bryophytes wash channels of the river was dominated by floristically were generally minor but crustose lichen species, such simple communities of Luzula cotifusa and Alopecurus as Dermatocarpon hepaticum and Lepraria neglecta alpinus. Where there were large raised center polygons were usually present, especially on the upper slopes that 4 to 6 m across, Alopecurus and Pogonatum alpinum dominated on the tops (stands #24, 26). Luzula confusa melt out earlier. These Phippsia barrens have a greater number of and Lepraria neglecta dominated the troughs (stands species (9.8 ± 5.0) and total plant cover (14.8 ± 9.6%). #25, 27) which were 50 to 150 cm deep; the soils conTab. 4. Prominence values (cover x square root of frequency) for the graminoid steppe community type, M = Melville Island, ER = Ellef Ringnes Island. Species 7 M 24 ER 25 ER 26 ER Stand # 27 ER 28 ER 29 ER 30 ER 31 ER Dupontia fischeri Eriophorutn triste Ranunculus sulphureus Saxifraga cernua Luzula confusa Luzula nivaiis Alopecurus alpinus Orihothecium chryseum Polytrichum juniperinum PhiUmotis fontana Campylium arcticum Aulacomnium turqidum Drepanocladus revolvens Pogonatum alpinum Ditrichum flexicaule Rhacomitrium sudeticum Lepraria neglecta Solorina crocea Daciylina arctica Peltigera aphthosa Other species Total species Total vascular plant cover (%), 180.0 37.7 4.6 3.0 10.7 _ 73.0 213,0 40.1 18,9 14,8 9.3 2.5 25.7 03 . — 76,0 01 . _ _ 1 7 94 . 35 , 77 , 13.0 55,3 _ 40.0 81.9 17 , 19.7 718 01 , 79 , 106.0 16,8 14,6 _ _ 51,2 13 . _ 78.0 03 . _ _ 30,2 20.1 01 . _ — 0 T - 76.8 03 . _ 23.2 13 . _ _ 10.7 64 . 80 . 10,2 64,7 Total bryophyte eover (%) Total lichen cover (%) Litter cover (7o) Total bare soil and pebbles (%) 10.6 77,8 10.9 79 , 29 . 36 . 150.7 _ _ 71.0 16.0 _ _ 1 7 80 . 15.3 10.2 _ _ 64.0 76 . _ _ 0 4 12,3 _ 82 . 17.2 1, 17 49.5 434.0 25.0 38 , 31 , 10.7 2 10 16.8 52.1 79 , 17,7 28,5 88 , 569,0 46.3 22.2 78 . 63 . 4 12 13.6 64.4 11.5 62 . 4,3 HOLARCTIC ECOLOGY 7:3 (1984) Kij;. 7, tjramlnoid sleppe doniinaled l\v Luztila vanfusa. Atopccurus alpinus wilh sniull iimounts of Saxifraga cernua, Saxifraga cacspiiosa, and Draba corymbosa, 2 km from Malloch Dome, Ellef Ringnes Island. taincd more moisture than those of the polygonal tops (Fig. 6). Total vascular plant cover averaged only 5 to n% and species richness was low (7.6 ± 2.4) in these uplands, yet ihe clumps of Luzula and Alopecurus gave the appearance of an arctic grassland. The sandy soils were derived from the Eureka Formation sandstones. Most surfaces were covered with desiccation polygons (10 to 25 cm diameter) without raised rims or centers; there were limited amounts of Lepraria ne^lecia and Pogonaium alpinum. There also appeared to be an early establishment stage of Dermatocarpon hepaticum on the soils. Bare ground accounted for 50 to 70"/li of the total cover (Tab. 4). While vascular plant cover averaged only 4.0 ± 3.4%. total plant cover (40 ± 28%) was significantly higher than in the previous communities. Moss-graminoid meadow. Eight stands from King Christian and Ellef Ringnes islands have been grouped under this heading. Al! stands were characterized by the Tab. 5. Prominence values (eover x square root of frequeney) for the moss-graminoid community type. KCI = King Christian Island. Species Luzula nivalis Luzula confusa Alopecurus alpinus Phippsia algida ruciinellia vaginala Sifllaria crassipes I'apavcr radicatum Drahii corymhosa Draha utpina Drabu siihcapitata Stixifrafia cernua Cerastium arcticum Cardamine helliilifolia (iymnt)initrion corallioides Rhacomitrium sudeticum Rhacomitrium lanuginosum Atitacomnium turgidum I'olytrichum juniperinum Ditrichuin flexicaule Dicranoweisia crispa Scliistidium holmenianum lomenthypnum nitens Distichum capillaceum Philonotis fontana ('ftraria islandica ('etraria delisei ('ludonui gracilis Thamnolia subuliformis Dactytina arciica Oactylina ranudosa Lepraria neglecta Parmetia omphalodes Dermatocarpon hepaticum Olher species Total species Total vascular plant eover (%) . . . lotal bryophyte cover (%) Total lichen cover (%) Litter eover (%) Bare soil and pebble cover ( % ) . . 8 KCI 23.8 0.2 20.0 3.8 14.7 2.6 8.2 4.5 6.8 3.6 64.5 40.1 84.5 18.6 36.9 6.7 6.6 ~ 2.4 1.0 0,4 0.7 1.0 23.1 5 28 11.1 29.6 5.1 32.7 21.5 10 KCI 15 KCI 16 KCI 18 KCI 19 KCI 35 KCI 37 KCI 47.3 31.0 03 . 80 . 01 . 51 . 80 . t).l 50.2 485.0 14.6 11.6 21.9 — 38.1 33 . 79 . 26.0 16.5 - 84.0 03 . 39.0 02 . 57 . 23 . 96 . - 40.2 _ 10.2 55 . 03 . 01 . 01 . 34.8 41.9 _ 41.1 17.9 05 . 53.0 81 . 68 . _ 17.0 04 . 55 . 416.0 39.9 34.5 24.3 14.3 20.6 13.5 02 . 65.0 03 . — 14 . _ 01 . 12.1 78 . 13 . 40.5 — 03 . — — — — 03 . 348.0 — — 43 . — _ — _ — 38 . 27.3 63 . _ _ 05 . 56.2 21.2 — 5 19 23 . 01 . _ 13 . 593.0 62 . _ 27.1 39.5 49.9 70.2 19.5 _ 56 . _ _ 09 . — _ — 01 . 548.0 _ 10.9 19.6 27 . _ 12.0 91 . 07 . — — — 10.9 51.2 — 05 . 10.0 24.6 O.I 05 . 03 . 58 . 83.0 4 26 11.2 56.5 14.5 54 . 12.4 63 . 08 . 14.4 46.8 - HOI ARCTIC ECOLOGY 7:3 (1984) Fig. 8. Close up of previous community with Pogonatum alpinnm. vascular plant dominance of Aiopecurus aipinus or Luzuia nivaiis or L. confusa, the presence of several rosette species, and the overall dominance of bryophytcs (Figs 7-8, Tab. 5). The silty loam and silty-clay loam soils of stands +8, 10, 15-16. and 18-19 on King Christian and stands *35 and 37, 12 km SE of Malloch Dome on Ellef Ringness were characterized by varying combinations of Rhacomitrium lanuginosum, Schistidium holmenianum, Aulacomnium turgidum, Polytrichum juniperum, and Ditrichum flexicalue. On clay-loam soils that appear to be wetter near the soil surface all summer, the liverwort Gymnomitrion corallioides predominated, typically accounting for 40 to 60% of the total cover at six of the sites. The graminoids reach their greatest cover in these communities which typically have higher soil-moisture levels. Stands #8 and 10 fit within this grouping due to the importance of Alopecurus, a mixture of forbs, and the high cover of mosses but low cover of Gymnomitrion. The "wettest sites" have a greater cover of Gymnomitrion and little if any Papaver radicatum (Tab. 5). Fig. 10. Cryptogam-herb community at Rea Point. Melville Island. The community is dominated by Saxifraga oppositifolia and the lichen Dermatocarpon hepaticum with lesser amounts of Draba corymhosa, Alopecurus aipinus. ainl Juncus uli)escetis. Species richness is much greater in this community (24.9 ± 3.4), as is total plant cover (77.7 ± 16.1%). Wet graminoid-moss meadow. Only one site of wetland grasses and sedges was sampled, and that one at Rea Point, Melville Island. Floristically this stand was very different from the others (#7, Fig. 2. Tab. 4). The dominant vascular species was Dupontia fisheri with lesser amounts of Eriophorum triste (Fig. 9). Carex stans and Eriophorum scheuchzeri were found near the pond margins and Pieuropogon subinei in the shallow waters. These three species were not sampled in stand #7. Although eleven other species of vascular plants were sampled, none provided a cover of more than 0.7%. Four species were not sampled elsewhere. Of the ten species of bryophytes. Orthofhecium chryseum, Polytrichum juniperinum, Aulacomnium turgidum. Philonotis fontana var. pumita, and Campytium arcticum provided 40% of the total cover. Nostoc commune was found throughout the stand as small mats; lichens were very minor (2 spp, 1.3% cover). This stand is within a 5O-1(K) ha area of wetland that receives discharge water during much of the summer, which prevents surface drying. The soils are sands to loams with little peat accumulation (1-2 cm). The surface is covered with polygons (1 to 5 m diameter) and there is some patterning of species, Eriophorum triste, E. scheuchzeri and Carex stans occupy the rather bare mud boils (l.(t-1.5 m diameter) and pond margins, while Dupontia fisheri is found on the moss mats that form the rims (3 to 5 cm high). Herb dominated communities Cryptogam-herb. This grouping of stands includes six from Rea Point, one from Malloch Dome, and six from Cape Abernethy. They all have in common the presence of Alopecurus aipinus, Luzuia confusa or L. nivaiis, numerous rosette species, and an abundance of cnistose and some fruticose lichen species (Tab. 6). The HOLARCnC ECOLOGY 7:3 (1W4) Fig. 9. Wet graminoid-moss meadow at Rea Point, Melville island. Dupontia fisheri and Eriophorum irisle dominate the foreground with Carex sians near the pond and Pieuropogon sahinei in the water. Tiih. 6- Prominence values (cover x square root of frequency) for Ihe cryptogam-herb community type. M = Melville Island, KCl = King Christian Island, and ER = Ellef Ringnes Island. Species lM .Ahpecurus atpinus Liizula confusa / uzula nivutis I'liainelliu vaginata Papaver radicalum Saxifraga caespitosa Saxifraaa cernua Saxifraga opposilifolia 2.1 0.5 6.9 17.0 0.9 19.6 2M 11.7 14.9 13.2 5.6 51.9 3M 0.3 0.6 3.1 0.6 O.I 26.2 4M 36.5 5.5 5.2 13.5 11.1 9.8 5M 4.9 23.8 4.1 2.1 I.O 0.6 6M Stand + 11 KCI12 KCI20 KCI23 KCl 32 KCl 33 KCI 34 KCI 26.8 24.7 57 . 10.1 _ _ 46 . 12.1 27 . _ _ 22 . 12.4 _ - 19.7 23.8 95 . 08 . 79 . _ — _ 25 . 16.4 _ 64 . ~ 22 . _ 27 . 63 . _ - 52 . 19.7 14 . 24 . _ 19 . 26 . 23 . 68 . 51 . 74 . 11 . 57 . 11.2 30 . 73 . 14 . _ — _ . 36 . 03 . _ 16 . 86 . 10.3 12.2 01 . - Saxifraga flagellaris Saxifraga hieracifolia Saxifraga tricuspidata Saxifraga nivalis Draba corvmhosa tyraba subcapitata Draha alpina lestuca hrachyphylla Cerastium arclivum (eraslium alpinum Jutu-us albescem Juncus biglumis Oxyria digyna Salix arciica Ranunculus .sulphureus Ranunculus sabinei Minuartia rubella Minuartia rossii Siellaria cras.sipes Sieilaria humifusa Potentillii hyparclica Ditrichum flexicaule liryum algovicum Volvtrichum juniperinum lorluta ruralis Rluunmiirium sudeticitm Khacomitrium lanuginosum ... 0.3 4.2 2.7 6.9 54.2 35.7 l.J 9.8 0.1 13.9 2.2 - 3.3 12.8 4.0 5.9 17.9 19.3 8.4 3.0 0.3 3.6 23.1 15.1 - 3.4 0.3 0.4 0.5 8.9 7.3 86.2 0.1 0.3 0.2 64.4 0.2 3.3 11.0 - 8.5 1.6 0.8 14.0 3.7 1.2 7.2 3.8 3.2 5.7 2.2 110.2 7.7 5.7 - 0.6 5.1 0.8 0.3 2.4 11.4 20.1 58.4 0.1 0.3 3.6 0.1 117.6 1.7 14.5 - 32 . 31 . 24 . 10 . 78 . 60 . _ 10 . 45 . _ 37 , 53 . 01 . 03 . 60 . 80 . 16 . 10.9 05 . 32 . 03 . - 13 . _ 26 . 24 . 13 . _ 28 . 73 . 50 . _ 33 . _ 01 . 01 . _ _ 39 . - 1. 19 56 . 24 . _ 11 . 11 . - 17 . — — _ 02 . 07 . _ 50 . I _ -5 1 . 91 . _ I.3 I I 5 - 134.8 48.1 — _ _ 55 . 78 . 02 . 73 . 1 25 15.4 16.8 35 . 46 . 59.7 78.1 35 . 36 . - I -4 3 . Tottwnihyphum iiiiens Autacomnium turgidum Schisiidium homenianum Dicranoweisia crispa Dermatocarpon hepaticum .... Lepraria neglecta (etraria islandica ( etraria cucullaia Sicreocaulon arenarium Ihamnolia subuliformis Daviylina arciica Other species Tolal species Total vascular plant cover (%) Total bryophyte cover ( % ) . . . . Total lichen cover (%) l.ittereover (%) Bare soil and pebbles (%) . . . . 64.0 05 . 05 . 18 . 52 . 11.9 249.0 29.4 56.3 67.0 161.0 17.9 02 . 53 . 10 . 93 . 22.8 1 23 14.4 24.1 16.1 _ 03 . 05 . 1 22 14.9 14.2 32.1 12.5 26.3 _ 70 . 12 38 13.9 13.1 48.9 40 . 20.1 113.0 12.1 — — 35.4 21.8 — 318.0 324.0 lOl.O _ 0 2 119.0 . 01 . 19.0 4 30 25.2 29.9 34.0 98 . 11 . I _ - I - I _ -3 4 . _ 29.5 - I.5 2 40,0 I1 0 . soils range from sandy loams to sandy-clay loams and clay loams. The summer climate at Rea Point. Melville Island is warmer and Uinger (see climate section) than that on King Christian and Ellef Ringnes islands. This is supported by a more diverse flora and robust vegetation. In stands #1 to 6 there were 18 ± 1.8 species of vascular HOLARCTIC ECOLOGY 7;3 (1984) plants, compared with the stands on the two northern islands (15 ± 5.7 species). On the sandy lower slopes Saxifraga opposiufolia averaged 3 to 7% cover (Fig. 10). Associated species included Oxyria digyna, Juncus albesceris, Papaver radicatum. Saxifraga caespitosa, and Draha corymbosa. On the clay loams and loams of the upland beyond, Luzula confusa and Alopecurus alpinus 335 only erustose lichens of any importance, although a few other species were present. In nearby microsites with soils of finer texture and higher soil moisture levels, there were small clumps of Luzula confusa with scattered plants of Alopecurus alpinus, Papaver radicatum, and Minuartia rubella, there was a nearly complete cover of Dermatocarpon hepaticum in sharp contrast with the slightly more exposed sites with some sheet erosion as described above. Total species richness (26.3 ± 6,2) and vascular plant richness (16.8 ± 4.7) were highest in this community type. Total plant cover averaged 61.2 ± 24,7% and vascular plant cover was highest (15.9 ± 6.5%). The only sites with a diversity of vascular plant species and a preponderance of crustose lichens and mosses Fig. 11. Close up of cryplogam-herb community near Cape on southern Ellef Ringness Island were the lower slopes Abernethy, King Christian Island, Species present include Luzula confusa. Alopecurus alpinus, Papaver radicatum. Saxiof the gypsum plug, Malloch Dome, Loam to silty-clay fraga cernua. Saxifraga nivalis, Saxifraga flagellaris. Ranunloam soils predominated, with the surface composed of culus sabinei and the lichens Dermatocarpon hepaticum and soil hummocks 15 to 25 cm across as in the guUeys on Lepraria neglecla. King Christian Island. Of the 20 species of vascular plants sampled, Luzula confusa, L. nivalis, Papaver radicatum, Saxifraga caespitosa, and Oxyria digyna were more important. Here (stands +5, 6) and on the were most important. Lichen cover was again domieastfacing slope, mats of Sali.x arctica occurred and on nated by Dermatocarpon hepaticum with small amounts the slope there were small, local populations of Dryas of Thamnolia suhuliformis and the bryophytes intcgrifolia. Mosses were generally minor, except for Pogonatum alpinum, Hylocomnium splcndcns, DiDitrichum flexicaule, Bryum algovicum and Tortula cranoweisia crispula, Orthothecium chryseum, Diruralis in a few stands. Crustose lichens were prominent trichum flexicalue, and Rhacomitrium lanuginosum. in stands #1 to 3 and 5. dominated by Dermatocarpon On steeper (10 to 15°) slopes, facing south and east, hepaticum and Lepraria neglecta with smaller amounts there were mats of Salix arctica and Saxifraga opof Thamnolia subuliformis. positifolia 20 to 50 cm diameter, each species providing Three stands on King Christian (#11. 12, 33) oc- 3 to 8% cover. Associated species, though less in cover, curred on sandy loams and sandy-clay loams of the include Papaver radicatum, Fotcntilla hyparctica, P. recent marine sediments. All stands had 14 to 17% ruhricaulis. Ranunculus sulphureus, Festuca cover of vascular plants; lichens provided 16 to 32% hrachyphylla, and several species each of Draba, Saxcover. Although Alopecurus alpinus or Luzula confiLta ifraga, and Minuartia. had the highest cover for an individual species, cover provided by the rosette forbs Papaver radicatum, Draba corymbosa. Saxifraga cernua, S. nivalis, and Cerastium Standing crop arcticum dominated (Fig. 11). The crustose lichens Der- Owing to the time, cost, manpower, and logistic factors. tnatocarpon hepaticum, and Lepraria neglecta were the determination of standing crop was restricted to most important although Cetraria islandica, Dactylina proportions that could be handled. Yet 20% of the arctica, and Thamnolia subuliformis contributed some stands measured for community composition and cover cover in one or more stands. The only mosses of impor- were also analysed for standing crop and net annual tance were Schistidium holmenianum, Rhacomitrium production. lanuginosum, and Tomenthypnum nitens. In terms of biomass, composition, and physical strucTwo stands (#32. 34). 2.5 km apart, were located 20 ture the polar semi-desert communities ean be characm upslope of the limit of the coastal marine sediments, terized by several common features. The structured upon soils derived from Isachsen Formation sandstones standing crop (i.e. fine organic matter and surface litter and siltstones. The soils were sands and loamy sands excluded) is low (1156 ± 270 gm"-), bryophytes being with small silty-loam pans containing Puccinellia va- the major contributors (ca. 85%, with the exception of ginata in low density and eover (0.5 to 1.0%), This was the graminoid barrens community). Lichens contribthe only graminoid species found in these wind-swept uted the least amount (0.6%) (Tab. 7). (little winter snow cover), well-drained sites. The roseIn the vascular plant component, monocots prevail tte species Papaver radicatum, Draba corymbosa, Ce- (75'yo). followed by forbs (14%) and woody species rastium arcticum and Minuiirtia rubella comprised most (11%). Salix arctica, the only true woody species, was of the vascular plant cover of these habitats. Der- listed in only 4 of the 41 measured stands of which only matocarpon hepaticum and Lepraria neglecta were the two had significant cover (> 2.5%). HOLARCnC ECOLOGY 7:3 (I9R4) and D, respectively). These were not significant at the level of sampling. Also correlations between prominence values and biomass were generally less significant than those calculated directly from cover data. Net production As with standing crop, net annual production varied from a few grams in graminoid barrens to 52 and 59 g m ' y ' in cryptogam-herb and graminoid steppe communities respectively, The mean total production (i.e. bryophyte and liehen production included) estimated on the basis of the living portion of the standing crop harvested was 30.8 ± 6.7 g m ' y', To this total the vaseular plants contributed 15.9 ± 4.2 gm-^y-'(51.6%), bryophytes 14.7 ± 4.3 g m ' y ' (47.7%) and lichens 0.67 ± 0.02 g m^' y-' (0.7%). Monocots, forbs and woody species shared the vascular plant production with 52.0, 23.2 and 24.8% respectively but these values varied greatly from stand to stand. Discussion Soils Fig. 12. Regression analysis for (A) total vascular plant cover vs. tolal vascular plant standing crop, aboveground (Y = 8.6 X -.Vi-6); (B) total vascular plant cover vs. total vascular plant slanding crop (Y = 18.0 X -55.9); (C) total plant cover vs. lotiil above ground standing erop (Y = 10.7 x -1-448.4); and (D) lotal plant cover vs. total plant standing crop (Y = 13.5 x + 385.7). The standing and attached dead represented 78% of the aboveground vascular standing crop. Phytomass of the vascular plants consists of the "green", photosynthetic tissue, "brown" woody or semi-woody {Saxifraga opposilifolia) stems and approximately one-half of the identifiable roots. Ibgether this accounts for only 38% of the total vascular standing crop. The green portion alone represented only 5.4% of the total phytomass. The identifiable root standing crop was 40% higher than the total vascular aboveground standing crop (root:shoot ratio = 1.4) wilh monocots again contributing most (88%). Litter and the remaining beiowground organie matter varied greatly and represented only a fraetion of the total structured standing erop. 1 he low number of replicated samples did not allow for the differentiation of eommtmities on the basis of standing crop data. However a significant correlation was found between vaseular plant cover and aboveground standing crop (Fig. 12A). This suggests that a good estimate of standing erop can be obtained from cover data followed by partial sampling of standing crop. Other correlations attempted included: cover vs. total vascular plant standing crop; cover vs. total aboveground standing crop (mosses and lichens included), and cover vs. total standing crop (Figs 12B, C HOLARCTIC ECOLOGY 7:3 (1984) Soils within the High Arctic, as with vegetation, have generally been referred to as polar desert. Tedrow (1977) has reported six genetic soil groups for the polar desert zone (lands north of Baffin. Prince of Wales, Victoria and Banks islands. The soils from all but stand #7 (tundra soils) fit within the polar desert and polar desert-tundra interjacence genetic groups of soils (Tedrow 1970. 1977). The Canadian soil classification system would designate these as Regosolic Static Cryosols (after Walker and Peters 1977). The soils at stands 30, 31 on Ellef Ringnes and the gulleys on King Christian (#17. 21) are on hummocky ground. All of these soils have low levels of organic matter. N, P, Ca. K, and total exchange capacity. This is in agreement with previous data from King Christian Island (Pawiuk and Brewer 1975. Bell and Bliss 1978). Prince Patrick Island (Tedrow and Thompson 1969) and Cameron Island (McMillan 1960). At all sites examined there is little indication that the prevailing plant communities provide much influence on soil development (Figs 13. 14). Topographic position and drainage characteristics are of fundamental importance (Tedrow 1977). Plant communities These polar semi-desert landscapes, as with those in the Low Aretic, present a constantly changing pattern of groups of species. The ecological tolerance range of most speeies is broad. While no two stands are identical, the grouping of species is sufficiently repetitive to permit a general grouping of sampled stands into community types (Fig. 2). 337 O S a. <n Tt TT ini (2. r-i d C1 c in rn C r-; 'T d -^ dd o — ov o 5 fN Q.7.' O Tt a: T3 (; (2 d— oT d oo" fN — d d —d — in d --J od — — •—fN (238 (238 ,00- — S^ xQ " rt -T d -t 1 1 ' ^ \D 00 i n oo 1243 :220. in to" fN TT . 3 — :i co • 3 .^2 '5 £ E C *.. c: II c > JS Cfl 0 ^ ^ w o i« •d'_; n c/3 I:Q hri FU ^s£ HOLARCTIC ECOLOGY 7:3 (WtM) q o o rr •* 00 O Tf 1- O — » ,0 — r^ - d— " 00 — l- 25 00 ~; r j in r i O 06 » Fig. 13. Soil profile below a cryptogam-herb plant community (stand 3). Re;i PoinI, Melvilic Ishind. Soils are medium textured sands. ^ 06 -- o o> I I I ( C^ \O Ov IN r ; ^ fn rn « —• o 00 Fig. 14. Soil profile below a cryptogam-herb plant community. Cape Abernethy, King Christian Island. The soils developed from recent marine sediments are silty-clay loam. -t r- — wS o *c CQ-JP HOLARCTIC ECOLOGY 7:3 (1984) There is a pattern of increased numbers of vascular plant species and total plant cover in going from sandy soils, to clay loams, and to loams. If tbe stands on sbeeteroded surfaces are deleted (#9, 13, 14, 35, 36) vascular species (12,7 ± 1.9 vs. 13.0 ± 1.4) and percent cover (15.3 ± 2.0 vs. 14.7 ± 1.5) are very similar on the loams and clay-loam soils respectively. Bryophyte cover is greatest on the clay-loam soils, while lichen cover is greatest on the loam soils. Bare soil, pebbles, and litter generally account for more cover than do the vascular plants, bryopbytes, and lichens. When the surfaceeroded stands are excluded, total plant cover is greatest on the clay loams and least on the sands. The number of vascular plant species is significantly correlated with vascular plant cover (r^ = 0.84. P < 0.01). Tbe number of vascular plant species and their percent cover are both correlated with total cover of bare ground, pebbles, and litter (r- = 0.33. P < 0.05. r^ = 0.51. P < 0.01). However, there is no significant correlation between the cover of vascular plants and that of bryophytes or lichens, nor between the eover of these plant groups and soil texture. Graminoid and herb barrens The ten stands sampled within this grouping have in common a low percentage of vascular plant cover (3 to 10%). few species (1 to 4) and very limited bryophyte and lichen plant cover, generally 0 to 10%. They occur on soils ranging from outwash sands on Melville and Ellef Ringnes islands, and loamy sands of the Isachsen Formation on King Christian Island, to clay loams and silty-eiay loams, subject to intense surface erosion, on the same island. Plant cover and plant structure approach that of a true polar desert, though floristically these stands are different because of the dominance of Fig. 15. Graminoid burrcns dominated graminoids. Lichen cover is significant only in Stand on Christopher shale near Drake Point.by Alopecurus aipinus Melville Island, #32 where Dermatocarpon hepaticum predominates in contrast with its minor role in polar deserts. Sand deposition on the outwash plain at Malloch Dome favors the scattered plants of Papaver radicatum, Cerastium rhizomatous grass Alopecurus aipinus. Tbis grass has a arcticum, Stellaria longipes, Draba corymbosa, D. albroad ecological amplitude, for it dominates in soils that pina, Saxifraga nivaiis and S. cernua (Fig. 15). These range from medium sands to clay loams. communities on Christopher shale have few lichens or Puccineliia vuginata predominates on loamy sands bryophytes on the loam lo the siity-clay loam soils; soils with small silt pans and their higher salt content. A that remain moist to wet much of the summer. Commuclosely related species is generally the only one of im- nities with a similar fioristic composition and plant portance along with a few scattered forbs in the polar structure have been described from Axel Heiberg (Bedeserts (Bliss et al. 1984). schei 1969). northern Ellef Ringnes (Saville 1961). and Phippsia algida is the dominant vascular plant on the Prince Patrick islands (Bird 1975). and Lougheed Island sheet erosion surfaces of clay loam soils on King Chris- (Edlund 1980). tian Island. This species is especially well adapted for these surfaces because of its high levels of seed produc- Moss graminoid meadows tion, ease of seedling establishment, and spiraled roots Large areas on the younger coastal marine sediments which permit it to occupy unstable sites with soil churn- and the Christopher shales of inland King Christian, ing (Bell and Bliss 1978, 198(1, Gruike 1983). Phippsia Christopher shale and Kanguk shale on southern Ellef also occupies sites of late-lying snow, sites with little if Ringnes. and Christopher shale on the Sabine Peninsula any soil movement and often with little bare soil for new support varying amounts of Alopecurus and/or Luzuia plant establishment. Stands #17 and 21 represent this confusa. The most important bryophytes are habitat along with other numerous sites examined on Hhacomitrium kmuginosum, Schistidium holmenianum, King Christian. Ellef Ringnes, and Melville islands. At Aulacomnium turgidum, and Ditrichum flexicaule. The Marie Bay on western Melville Island. Phippsia is a liverwort Gymnomitrion corallioides often predomicomponent of a closed community in which Alopecurus nates on fine textured soils. This species is also imporaipinus, Luzuia nivaiis and numerous liehens and tant at several sites at Mould Bay, Prince Patrick Island mosses predominate. Its ability to invade bare soil has (Bird 1975). There is a broad range of associated forbs. permitted it to provide 10-15% cover on the bare soils generally including Papaver radicatum, Draba corymof an adjacent well and camp site cleaned up in 1971. Phippsia also predominates at old well sites on King bosa, D. alpina, Stellaria longipes. Cerastium arcticum. Saxifraga cernua, S. nivaiis, and Ranunculus sabinei. Christian Island. In central King Christian Island, numerous valleys are dominated by Alopecurus aipinus with smaller Graminoid steppes amounts of Papaver radicatum, Saxifraga cernua, S. On the rolling uplands above the outwash channels at caespitosa, S. nivaiis, Cerastium arcticum and Draba Malloch Dome, comnwinitics of Alopecurus aipinus and alpina. There is little Luzuia confusa or L. nivaiis presLuzuia confusa predominate with limited eover of ent. Mo.sses provide 50 to 80% cover, mostly bryophytes and lichens (6 to 25%). Large areas on Orthothecium chryseum, Tomenthypnum nitens, southern and western King Christian Island, along the Aulacomnium turgidum, Ditrichum flaxicaule and DiHoodoo River. Ellef Ringnes Island, and north of cranoweisia crispula. Gymnomitrion corallioides is Drake Poini, Melville Island are occupied by Al- minor on these silty-clay soils that are sensitive to earth opecurus aipinus "meadows" with 5 to 10% cover, a few flows (Hamilton and Bliss, unpubl.). HOLARCnC ECOLOGY 7:3 09M) Wet graminoid-moss meadows Lowlands with lakes, ponds, and wet marshes are an uncommon feature oi these northwestern islands. Thus wetlands with sedges and grasses are minor as are large herbivores, whieh depend on them except on Melville Island. A feature of all of these areas is the presence of standing water in the depressed-center polygons (5 to 8 ni) for most of the summer. The wetland sampled at Rea Point is dominated by Dupontiii fisheri (18% eover) with lesser amounts of F.riophorum triste (4.3%). Though not sampled, small amounts of Carex stans, Eriophorum scheuchzeri and Arctagrostis latifolia are psesent. The shallow ponds contain Pleuropogon sabinei. In the transition to cryptogam-herb meadows, the soil boils {I to 1.5 m diameter) have 3 to 8% eover of Eriophorum with Dupontia on the moss mats of the raised rims. Salix arctica, Rammculus sulphureus, and Saxifraga cernua are eommon associates. Here and elsewhere the dominant mosses include Orthothecium chryseum, Tomenthypnum nitens, Philonotis fontatia, Drepanocladus revolvens, and Aulacotnnium turgidum. Wet meadows with Carex stans dominant are uncommon except on southern Melville Island. This speeies does predominate in the Sabine Lowlands (Fig. I) (25% cover) and at Mould Bay (45% cover) (Bird 1975). Elsewhere at Sherard Bay and on Cameron Island the wet meadows are dominated by Dupontia fisheri (8 to 15% cover), the mosses listed above, and a few scattered forbs. Five small meadows dominated by Dupontia fisheri, Eriophorum scheuchzeri, Pleuropogon sahinei. and Juncus biglumis have been reported from Isachsen. Ellef Ringnes Island (Saville 1961). In all eases total plant cover averages 100% except where small soil polygons occur. nivalis and Alopecurus alpinus dominated poorlydrained silts and clays. Associated species of Saxifraga, Draba, Papaver radicatum, and Potentitia hyparctica oeeurrcd on better-drained slopes. These communities were found on soils developed from the Hassel Formation. Weathered shales developed from the Kanguk Formation were very acid and devoid of vegetation. On the islands to the nortb and west. Salix arctica and Dryas integrifolia are limited to specialized warmer microsites. Both species occur in small amounts at Mould Bay, Prince Patrick Island (Bird 1975). Salix arctica is limited to only a few warm inland valleys on moss mats with Saxifraga oppositifolia on King Christian Island. Both species occur in limited amounts on the warmer east and south slopes of Malloch Dome, Ellef Ringnes Island. Both species, along with Dryas, are quite common on warm slopes and inland valleys on southern and southwestern portions of Melville Island, in areas with wet meadows of Carex stans and Dupontia fisheri. These relatively lush and diverse habitats support large populations of muskox and Peary's caribou. Characlerislics ur polar semi-deserts In her book on the geobotanical areas of the Arctic and Antarctic, Aleksandrova (1980) plaeed Melville Island within the Parry Archipelago District of the Arctic Tundra Subregion. This results from placing what Bliss (1975. 1979) and others have called the Low Arctic, with its preponderance of shrub species of Salix, Betula and Alnus, in the Subarctic Tlindra Subregion of the Arctic Tundras. Using terminology of Aleksandrova (198(1). the sedge-moss, sedgc-grass-moss meadows (mires), and the Dryas and Satix arctica tundras are part of the arctic tundra complex. The more barren lands of Cameron, King Christian, and Ellef Ringnes. along with other northwestern islands, were placed within the Cryptogam-herb meadows At Rea Point the broad lowlands west of the camp and Canadian Province of the Arctic Polar Deserts. The present authors prefer to recognize the grassthe slopes and uplands of the ridges beyond are dominated by the crustose liehens Dematocarpon hepaticum moss and sedge-moss meadows (mires) as the northern and Lepraria neglecta, and Thamnolia subuliformis, es- extension of the sedge-moss tundras of the Low Arctic. pecially in the coarser textured soils. On fincr-tcxtured The rest of the eommunity types better fit within the soils of the uplands, mosses increase in importance. A polar semi-desert complex of moss-graminoid. grammixture of vascular species predominate, but of the 10 inoid steppe and the cryptogam-herb group of commuto 15 common ones, Saxifraga oppositifolia, S. nities of the High Aretic. In general the plant commucaespitosa. Ranunculus sulphureus, Juncus albsecens, nities described here {Puccinellia, Alopecurus and Papaver radicatum, Draba corymbosa, Salix arctica, Phippsia barrens are the exception) are eharacterized and Oxyria digyna are most common. Luzula confusa by crustose lichens and mosses with scattered vascular and Alopecurus alpinus increase in importance on the plants. The flowering plants are a combination of gramfiner-textured soils. South-facing slopes, with late-lying inoids and rosette plants such a Papaver and various snow, may have small patches (2(M0 cm across) domi- species of Draba, Saxifraga, Cerastium and Minuartia. nated by Cassiope tetragona. On tbe steeper slopes (15° In the eastern and southern High Arctic, cushion plant to 18") that face east, south, or west, there are small communities dominated by Dryas integrifolia, Salix areas of Dryas integrifolia, usually with more mosses arctica. Saxifraga oppositifolia, a few rosette species, dry site sedges and numerous mosses and lichens domithan lichens. Ediund (1980) reported L«z«/a-dominated commu- nate the polar semi-desert landscapes (Svoboda 1977, nities were the most common ones on Lougheed Island. Svoboda and Bliss unpubl.). The real polar deserts are Luzula confusa occurred on drier aspects while Luzula far more depauperate in plant cover (< 5%) and vascuHOLARCnC ECOLOGY 7:3 (1984) lar plants with cryptogams playing a minor role except in snowflush communities (Bliss et al. 1984). Luzula confusa is one of the two most important graminoids in these northwestern islands. The plants are long-lived {> 100 yr), seldom produce viable seed, and are quite sensitive to moisture stress (Addison and Bliss 1984). Consequently, they are seldom encountered within the polar deserts except in snowflush sites. From several studies, there is growing evidence that crustose lichens and mosses play significant roles in the thermal and water regimes of these areas (Addison 1977, Addison and Bliss 1980) and thus in seedling establishment (Bell and Bliss 1980, Sohlberg and Bliss 1984). Soil lichens are not as effective as moss mats in reducing evaporation from moist surfaces. When dry surfaces predominate, lichens are more effective in further reducing evaporation. This helps to explain the presence of moist soils below surfaces covered with cryptogams in numerous sites. The studies by Bell and Bliss (1980) and Sohlberg and Bliss (1984) show that seedling establishment for many species is such higher on moss mats and in desiccation cracks with mosses. There appear to be a large number of seeds within these cryptogam mats, but seed germination and seedling establishment are not abundant in these communities (Bell and Bliss 1980). Seeds are transported over the snow to a limited extent, and the number of seeds contained in the lower crusted layers of snow in spring reflect, in general, vascular plant density and seed production within cryptogam-herb and graminoid barren communities (Grulke and Bliss 1983). crop, and net annual plant production, the present data indicate that these landscapes, dominated by cryptogams with scattered vascular plants, are intermediate between the lush sedge-moss meadows and other communities of the Low Arctic, and the very barren polar deserts. It is for these reasons that the name polar semidesert has been chosen for these landscapes. This concept was first advanced for communities dominated by cushion plants on the Truelove Lowland (Svoboda 1973). Standing crop and net production There arc few data in the literature for a comparison of standing crop and net annual production in similar higharctic plant communities. At Maria Pronchitsheva Bay, USSR (76''N), Matveyeva et al. (1975) reported aboveground phytomass of 30-33 g m ' and a net annual production of 27 g m"-^ in a cushion plant-moss community. Phytomass and net production were 68 and 72 g m- respectively in an herb-moss community at the same site. Aleksandrova (1969) reported a biomass of 6 g m for vascular plants, 123 g m- for mosses and lichens and 29 g m ' belowground for a moss-lichen polygonal desert community on Alexandra Land Island, USSR. This plant community and the herb-moss community data from Maria Pronchitscheva Bay may be communities somewhat simitar to the cryptogam-herb meadows reported here. Wein and Renez (1976) reported aboveground standing crop (including dead plants) data of 3427 g m- and 4078 g m ' for two sedge-moss meadows. They present other standing crop data ranging from 154 to 1045 g m- but do not provide species or community names. As stated earlier, the soils of these plant communities are deficient in nitrogen and phosphorus. In the mossgraminoid and cryptogam-herb communities there are often small mats of Nostoc commune following spring In our study, standing crop (aboveground plus bemelt. However, for much of the summer these colonies lowground) ranged from 27 g m % in the Puccinella and are dry. and therefore unable to fix nitrogen. Prelimin- Alopecurus barrens on Ellef Ringnes Island to the more ary studies indicate that some sites with moist soils representative 900 to 23(H) g m - in various cryptogamcovered by the liverwort Gymnomitrion corallioides herb and graminoid meadows. In all but the graminoid have higher rates of nitrogen fixation than nearby sites barrens and one graminoid meadow community, mosses without this species (Dawson, pers. comm.). Further contribute 85-98% of aboveground standing crop (exresearch is necessary to determine the organisms re- cluding litter). Although lichens may be conspicuous, sponsible for fixation and the magnitude of the fixation they contribute little biomass. rates. Total plant production above and beiowground Soil texture and available soil moisture during the ranged from 19 to 59 g m"^ in the cryptogam-herb, mossinfrequent, drier summers appear important in the lim- graminoid, and graminoid steppe communities. These ited sorting of species into community types. The wet- data are similar to those reported by Svoboda (1977) in lands with Dupontia and Eriophorum and the dry wing- polar semi-deserts dominated by cushion plants on the swept ridges with Saxifraga oppositifolia, S, caespiiosa, Truelove Lowland, Devon Island (20 to 50 g m""). and Draba corymbosa are obvious extremes in the landscape, more subtle is the patterning within the cryp- Acknowledgements - Logistic and field aimp support were togam-herb and moss-graminoid grouping of "commu- provided by Panarctic Oils Ltd. Other field support was funded nities". The importance of soil texture and soil moisture from consulting fees provided to the senior author from the Protection Canadian Gas in the patterning of communities was also recognized by EnvironmentalN.S.F. GrantBoard of thefunded the Arcticwork Project, Ltd. #79-13421 field Ediund (1980) on Lougheed Island. the past three years and the ordination runs and map preparaOn the basis of detailed physiological and microen- tion by Linda Kunze. Laboratory analyses of plant material vironmental studies on King Christian Island and the were made possible by N.R.C. grants to both authors. Dwight Bliss prepared with the field work. extensive studies of soils, plant communities, standing Christine Woo the geology and helpedsamples and Bonnie sorted ihe biomass 342 HOLARCnC ECOLOGY Bergsma tabulated the data. Soil analyses were made by Northwcsi Soil Research. Ltd.. Edttionton.,Lichens were identified by 1. M. Brodo and bryophytes by D. H. Vitt. Kcrcrences Addison, P. A. 1977. Studies on evapotranspiration and energy budgets on Trueiove Lowland. - In: Bliss, L. C. (ed.), Truclove Lowland, Devon Island. Canada: A high arctic ecosystem. University of Alberta Press, Edmonton, pp. 281-300. - and Bliss, L. C. 1980. Summer climate, microclimate and energy budget of polar semi-desert on King Christian Island, N.W.T. Arct. Alp. Res. 12: 161-178. - and Bliss, L. C. iyS4. Adaptations of Luzula confusa to the polar semi desert environment. - Arctic 37 (in press). Alcksandrova, V. D. lMW). The Arctic and Antarctic: Their Division Into Geohotanical Areas. - Cambridge Univ. [*rcss. 247 pp. Andreyev, V. N. 1971. Methodsof determining above-ground phytomass on vast territories in the Subarctic, - Report KL'VO Subarctic Research Station 8: 3-11. Balkwill, R. H. and Roy, K. J. 1977. Geology of King Christian Island, District of Franklin (map 1445A). - Geol. Surv. Can. Memoir 386, 28 pp. Barry, R. 0. and Hare, F. K. 1974. Arctic climate. - In: Ives, J. D. and Barry. R. G. (eds), Arctic and alpine environments. Methucn, London, pp. 17-54. Bell. K. L. and Bliss. L. C. 1977. Overwintering phenology in a polar semi-desert. - Arctic 30: 118-121. - JIIKI Bliss, L. C. 1978. Root growth in a polar semi-desert environment. - Can. J. Botany 56: 2470-2490. - and Bliss. L, C. 1980. Plant reproduction in a high arctic environment. - Arcl. Alp. Res. 12: 1-UI. Bcschel. R. E. 1969. Floristic correlation on the Nearctic Islands. - Bolanicheskii Zhurnal 54: 872-891 (in Russian). Bird, C. D. 1975. The lichen, bryophyte, and vascular plant flora and vegetation of the Landing Lake area. Prince Patrick Island, Arctic Canada. - Can. J. Botany 5.1: 719-744. Bliss. L. C. 1963. Alpine plant communities of the Presidential Range, New Hampshire. - Ecology 44: 678-697. - 1975. Tundra grasslands, herblands and shrublands and the role of herbivores. - Geoscience and Man 10: 51-79. - 1979. Vascular plant vegetation of the Southern Circumpolar Region in relation to antarctic, alpine, and arctic vegetation. - Can. J. Botany 57: 2167-2178. - 1981. North Atticrican and Scandinavian tundras and polar deserts. - In: Bliss, L. C . Heal, O. W. and Moore. J. J. " (eds). Tundra ecosystems: A comparative analysis. Cambridge Univ. Press, pp. 8-24. - . Courtin, G. M., Pattie, D. L.. Riewe. R. R., Whitfield. D. W. A. and Widden, P. 1973. Arctic tundra ecosystems. Ann. Rev. Ecol. Syst. 4: 359-399. - . Svoboda. J. and Bliss. D. I. 1984. Polar deserts, their plant cover and plant production in the Canadian High Arctic. - Holarct. Ecol. 7: 301-320. Bray. J. R. and Curtis, J. T. 1957. An ordination of the upland forest communities of Southern Wisconsin. - Ecol. Monogr. 27: 32.V349. Courlin, G. M. and l.abine. C. L. 1977. Microclimatological studies of the Trueiove Lowland, - In: Bliss, L. C. (ed.), Trueiove Lowland. Devon Island, Canada: A high arctic ecosystem. Univ. of Alberta Press. Edmonton, pp. 7J-I06. Edlund. S. A. 1980, Vegetation of Lougheed island. District of Tranklin. - In: Current Research, Part A, Geol. Surv. Can. Paper 8()-lA: 329-333. Everett, K. R. 1968. Soil development in the Mould Bay and Isachsen areas. Queen Elizabeth Islands. N.W.T.. Canada. - Institute of Polar Studies. Ohio State Univ. Rept. 24. 75 pp. Flower-Ellis, J. G. K. 1973. Growth and morphology in the evergreen dwarf shrubs Empetrum hertnaphroditum and Andromeda polifolia at Stordalen. - In: Bliss, L. C. and Wielgolaski, F. E. (eds). Proceedings of the Conference on Primary Production and Production Processes. Tundra Biome Steering Committee, Edmonton, pp. 123-135. Freedman. B. and Svoboda. J. 1981. Regional survey of plant communities. - In: Svoboda. J. and Freedman. B. (eds). Ecology of a High Arctic Lowland Oasis. Alexandra Fiord (78''53'N. 75''65'W). Ellcsmerc Island. NWT. Canada. 1981 Progress Report, Univ. of Toronto, pp. 216-220. Greiner. H. R. 1963. Malloch Dome and vicinity. Ellef Ringnes Island. - In: Forticr et al. (eds). Geology of the North Central Part of the Arctic Archipelago. NWT (Operation Franklin). Geol. Surv. Can. Memoir No. 320, pp. 563-57L Gruike, N. 1983. Comparative ecophysiology and life history characteristics of two high arctic grasses, NWT, Canada. Ph.D. Thesis. The University of Washington. Seattle. - and Bliss. L. C. 1983. Winter seed rain the High Arctic. Arct. Alp. Res. l.S: 261-265. Hale. M. E. and Culberson. W, L. 1970. A fourth checklist of the lichens of continental United States and Canada. Bryologist 73: 499-543. Henock. W. E. S. 1964. Postglacial marine submergence and emergence of Melville Island. Northwest Territories. Geol. Bull. Can. 22: 105-126. Henry, G. 1981. Synecology and production of sedge-dominated communities. - In: Svoboda. J. and Freedman, B. (eds). Ecology of a High Arctic Lowland Oasis. Alexandra Fiord (78''53'N, 75°65'W). Ellesmere Island, NWT. Canada. 1981 Progress Report. Univ. of Toronto, pp. 38-49. McMillan. N. J. 1968. Soils of the Queen Elizabeth Islands (Canadian Arctic). - J. Soil Science U: 131-139. Maxwell. J. B. 1981. Climatic regions of the Canadian Arctic islands. - Arctic 34: 225-240. Muc. M. 1977. Ecology and primary production of the Truelove Lowland sedge-moss meadow communities. - In: Bliss, L. C. (cd.), Trueiove Lowland. Devon Island. Canada: a high arctic ecosystem. Univ. Alberta Press. Edmonton, pp. 157-184. Nams, M. L. N. 1982. Ecology of Cassiope tetragona at a high arctic lowland, Alexandra Fiord, Ellesmere Island, NWT. MSC. thesis. Department of Biology, Dalhousie University. Parker, G. R. 1975. An investigation of caribou range on Southanmpton Island. N.W.T. - Canadian Wildlife Service Report Series 33. 83 pp. Porsild, A. E. 1964. Illustrated Flora of the Canadian Arctic Archipelago. - National Museum of Canada. Ottawa. Bulletin No. 218pp. Pawluk. S. and Brewer. R. 1975. Micromorphological and analytical characteristics of some soils from Devon and King Christian Islands. N.W.T. - Can. J. Soil Science 55: 349-361. Prest. V, K. 1969. Retreat of Wisconsin and recent ice in North America. Map 125F-A. - Can. Geol. Surv. Ottawa. Reznicek, S. A. and Svoboda. J. 1982. Tundra communities along a microenvironmental gradient. Coral Harbour. Southampton Island. NWT. - La Naturaiiste Canadian 109: 583-595. Hodgson, D. A. 1982. Surficial materials and geomorphic processes, western Sverdrup and adjacent islands. District of Franklin. - Geol. Surv. Can., Paper 81-89, 44 pp. Savilte, D. B. O. 1961. The botany of the northwestern Queen Elizabeth Islands. - Can. J. Botany 39: 909-942. Sohlberg. E. H. and Bliss. L. C. 1984. Microscale pattern of vascular plant distribution in two high arctic plant communities. - Can. J. Bot. 61 (in press). Stott. D. F. 1969. Ellef Ringnes Island. Canadian Arctic Archipelago. - Geol, Surv. Can. 68-16. 44 pp. HOLARCTIC ECOLOGY 7:3 (1984) Svoboda, J. 1973. Primary production of plant communities of the Tnielove Lowland, Devon Island, Canada - beach ridges. - In: Bliss, L. C. and Wielgolaski, F. E. (eds). Proceedings of the Conference on Primary Production and Production Processes. Tundra Biome Steering Committee, Edmonton, pp. 15-26. - 1977. Ecology and primary production of raised beach communities, Trueiove Lowland. - In: Bliss, L. C. (ed.). Ttiielove Lowland, Devon Island. Canada: A high arctic ecosystem. Univ. Alberta Press, Edmonton, pp. 185-216. Tedrow, J. C. F. 1970. Soils of the subarctic regions. - In: Ecology of the Subarctic Regions. Proceedings UNESCO Helsinki Symposium. UNESCO Paris, pp. 189-205. - 1977. Soils of the Polar Landscapes. - Rutgers Uni. Press. New Brunswick, 638 pp. - , Bruggemann, P. F. and Walton, G. F. 1968. Soils of Prince Patrick Island. - Arctic Institute of North America. Research Paper 44. 82 pp. - and Thompson, C. C. 1969. Chemical composition of polar soils. - Blulletin Peryglacjalny (Lodz) 18: 169-181. Tozer, E. T- and Thorsteinsson, R. 1964. Western Queen Elizabeth Islands. Arctic Archipelago. - Geol. Surv. Can. Memoir No. 332. Vitt, D. H. 1975. A key and synopsis of the moss flora of the northern lowlands of Devon Islands, N.W.T. Canada. Can. J. Botany 53: 2158-2197. Walker, B. D. and Peters, T. W. 1977. Soils of Truelowe Lowland and plateau. - In: Bliss, L. C. (ed.), Truelove Lowland, Devon Island, Canada: A high arctic ecosystem. Univ. Alberta Press, Edmonton, pp. 31-62. Wcin, R. W. and Rencz, A. N. 1976. Plant cover and standing crop sampling procedures for the Canadian High Arctic. Arct. Alp. Res. 8: 139-150. HOLARCnC ECOLOGY 7:3 119B41 http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Ecography Wiley

Plant communities and plant production in the western Queen Elizabeth Islands

Ecography , Volume 7 (3) – Sep 1, 1984

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Copyright © 1984 Wiley Subscription Services, Inc., A Wiley Company
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1600-0587
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Abstract

L. C. Bliss and J. Svoboda Bliss. L. C. and Svnboda, 1. 1984. Plant communities and plant production in the western Ouccn Elizabeth Islands. - Holarcl. Ecol. 7: 325-344. A study of soils, plant communities, and net annual plant production was conducted with 41 stands at 3 sites on 3 arctic islands. Twelve additional sites were sludied in less detail on Ellef Ringnes. King Christian and Melville islands and on four other islands. Through polar ordination five groupings were recognized. Alopecurus and Puccinellia barrens on sand to silty soils and on silty soils, high in sodium salts respectively. Species richness averaged 2.6 ± 2.0 and total plant cover 6.H + 2.7%. The Phippsia barrens occur on sheet eroded surfaces and in gulleys with deep winter snow. Speeies richness was 9.8 ± 5.0 and total plant cover 14.8 ± 9.6%. The graminoid steppes on sandy soils averaged 7.6 ± 2.4 species and total plant cover 40.0 ± 2.8%. Eight stands were dominated by moss-graminoids, mostly on loam soils. Species richness was 24.9 ± 3.4 and total plant cover 77.7 ± 16.1%. Plant producion was S.O g m"^ in a Puccinellia barren and 9.4 g m- in a Luzula confu.sa graminoid steppe. Net annual production ranged from IS.8 to 58.7 in 6 other stands. The 13 stands within the cryptogam-herb community complex occur on sandy loam to clay-loam soils. Species richness averaged 26.3 ± 6.2 and total planl cover 61.2 ± 24.7%. Mosses and lichens play a significant role in the establishment and maintenance of communities with a greater speeies richness and plant production of vascular plant species. The ability of mosses to hold moisture and the presence of limited bluegreen algae that fix nitrogen appear essential to [he maintenance of greater species richness, plant cover and plant production compared with the barren polar deserts that are often nearby. L. C. Btixs. Dept of Botany. Univ. of Wa.shington, Seattle, WA 9fiJ9S, USA. J. Svoboda. Dept of Botany, Erindale College, Univ. of Toronto, Mississauga, Ontario, Canada L5L IC6. Introduction By temperate region standards, the Canadian High Aretic is a barren landseape. often termed a polar desert. While large areas of the High Aretic are polar desert (< 5% total plant cover), other areas limited in extent, have considerable vegetation. These lands have been termed polar semi-desert and wet sedge-moss tundra (Bliss et al. 1973, Bliss 197.5, 1981). Polar semi-deserts typieally have a 5 to 2(1% cover of vascular plants with lichens, mostly crustose and foliose species, and bryophytes adding 20 to 80% cover. These arctic landscapes can have a vascular plant cover dominated by Accepted 25 May 1983 © HOLARCTEC ECOLOGY cushion plants of Dryas integrifolia and Saxifraga opposilifolia mats of Salix arctica. small rosette clumps of Draba, Minuiirtia, and scattered dry site sedges (Svoboda 1973. 1977), orby Luzula, Alopecurus and rosette speeies, termed a polar steppe by Beschel (1973). This study was concentrated on Melville. King Christian, and Ellef Ringnes Islands in the western Queen Elizabeth Islands. Additional data were gathered and general observations made from visits of short duration to twelve additional sites on these three islands and on four other islands (Fig. 1). The objeetives were: (1) to determine the plant community patterns and relate HOLARCTIC ECOLOGY T.i (1984) • Major Study Slli Fig. 1. Ujcation of the three intensive and the 12 extensive study sites in the High Arctic. them to topography and soils; (2) to determine the Standing crop and annual plant production of representative communities; (3) and to relate these findings to other high arctic landscapes, especially to the intensive research sites of the Truelove Lowland, Devon Island ecosystem study (Bliss 1977) in order to determine how widely those ecosystem data can be extrapolated. Study areas Geology The islands in this study are within the Sverdrup Lowland Division of the Inuitian Region. The Sverdrup Basin is superimposed on deformed rocks of the Franklinian Geosyncline; most of the exposed roeks are sandstones, siltstones, and shales of Paleozoic and Mesozoic Age (Tozer and Thornsteinsson 1964). These islands have rolling, scarped surfaces of low relief, prominent dendritic patterns, and rocks showing little deformation. Streams and rivers carry large sediment loads during spring runoff, but, due to reduced flow, they transport little material in mid and late summer. Lakes are generally a minor feature, though small ponds and lakes occur near Rea Point and other locations on Melville Island. At Rea Point, Melville Island, grey marine and nonmarine sandstones, siltstones, and shales of the midDevonian Weatherall Formation predominate. Just to the north, a band of white, yellow, and red sandstones of the Hecia Bay Formation (mid and upper Devonian) outcrops. Our lower slope studies were confined to unconsolidated sands and silt loams derived from the Weatherall Formation and the upland stands (75-90 m) were on loam soils derived from siltstones of the same formation. King Christian Island (ca. 26 x 39 km) has a low domal profile with long, low scarps and gentle slopes. Based upon the descriptions of Stott (1969) and Balkwill and Roy (1977), most of the island consists of alternating beds of sandstone, mudstone, and shale from Christopher and Isachsen Formations of Lower Cretaceous age. A limited amount of shale of the Deer Bay Formation, of Upper Jurassic- Lower Cretaceous age, outcrops near the Panarctic Oils Camp, this formation and much of the Isachsen Formation are covered with recent marine sediments within 3--4 km of the shoreline. Most of the sampling was confined to the sandy loam and silt-loam soils of these coastal sediments. On Ellef Ringnes Island our study was conducted on the slopes of Malloch Dome, a gypsum plug of Pennsylvanian or Permian Age (Greincr in Fortier et a!. 1963). Sampling was done on silty loam soils next to the dome and eastward across sandy and silty alluvium derived from the Cretaceous age beds. Tozer and Thornsteinsson (1964) pointed out that vegetation is largely controlled by rock formations. As will be brought out in this paper, much of this results from soil texture and the ability of the soils, which are mostly developed from siltstones and shales, to hold adequate moisture in what are otherwise polar deserts. Pleistocene events have not been fully established on King Christian Island and are little known on Ellef Ringnes Island. It is unclear whether these islands were glaciated in Wisconsinan time. Much of the late Quaternary history has been obscured by frost action, desiccation processes, and the nature of the underlying bedrock (Prest 1969, Hodgson 1982). Relict "beach ridges", resulting from isostatic rebound, occur at 22 to 33 m on the south and west-central coasts of Ellef Ringnes (Prest 1969), and at 30 m levels on King Christian. The upper limit of these recent marine features occurs at 70 m on eastern Melville Island. Henoch (1964) postulated the existence of an ice cap on the Sabine Peninsula in Wisconsinan Time and that Laurentide ice depressed the south coast of the island. Climate Although polar high pressure systems are centered over Siberia and the Mackenzie-Yukon area in winter and over the polar ice pack in summer, the Queen Elizabeth Islands are characterized by: (1) infrequency of cyclonic storms; (2) shallow pressure gradients in summer; and (3) a lack of atmospheric moisture. Collectively they result in a cold polar desert (Courtin in Bliss et al. 1973, Barry and Hare 1974). The region is marked by persistent rather than extreme cold in winter. Winds, while strong in storms, are generally light in winter. Cloud cover averages 40% and calm air 30% of all observaHOLARCnC ECOLOGY 7:3 (1984) tions in winter (Barry and Hare 1974). Infrequent occurrence of cyck>nic activity is reflected in only 10% of the winds averaging 13 m s'' (at 10 m). Maxwell (1981) divides the Canadian Arctic Archipelago into five climatic regions based upon the climatic control of cyclonic activity, sea ice-water regime, broad scale physiographic features, and net radiation. Region 1 includes the islands in this study, a region of maximum anticyclonic activity and no major relief features. Annual net radiation is in the range of 5-10 kly and mean annual temperature range is extreme (3H-40°C). Climatic data are presented for Rea Pt., Melville Island. Mould Bay, Prince Patrick Island (320 km west of Rea Pt.,), and Isachsen, Ellef Ringnes Island (110km and 75 km northwest of King Christian Island and Malloch Dome respectively) (Tab. i). Based upon summer data, the climate of King Christian is very similar to that of Isachsen (Addison and Bliss 1980). Cloud cover averages 72-84% from June through August at Rea Pt. and 78-89% ;,t Isachsen (1970-76). Summer temperature is well coupled with solar radiation and time of snowmelt at these latitudes. Courtin and Labine (1977) reported that over 50% of total radiation is received at these latitudes (Truelove Lowland. Devon Island 75°33'N) before snowmelt is complete, usually the end of June, and therefore the growing season (45-50 d, snowmelt to autumn leaf coloration) is concurrent with decreasing solar radiation. Summers with higher mean monthly temperatures (1971) than the 1970-75 or 1941-1970 means are also summers with greater hours of sunshine. The short term means of 1975-79 were generally l . T to 2 . 2 T lower per "summer" month than the long term means of 1941-1970 at Mould Bay and Isachsen. One of the single best measures of summer temperature regime is the accumulated degree day value ( > 0°C). The accumulated degree days for 1970-1976 at Rea Point average 208°C, with the coldest sumtner (1972) 13% lower and the warmest summer (1973) 25% higher. The figures for Mould Bay are 216°C, 26% lower for the coldest summer (1972) and 34% higher for the warmest summer (1971) and for Isachsen 152°C, 47% and 45% respectively. Temperatures have been generally lower and precipitation higher in the 1970s at these northwestern high arctic sites than in previous years. In fact. Maxwell (1981) points out a general cooling trend in this climatic region (Northwestern Islands) has been underway since the early 196O's with 1972 and 1973 being the coldest years. On the basis of data from 11 stations since 1950, of the eight warmest years, five were before 1963 and of the seven coldest years, six have been since 1963. The impact of these climatic shifts on plant growth and vegetation pattern is not yet known. Soils Soils in these western Queen Elizabeth Islands are of residual, glacial and marine origin and show little horizon development, little incorporation of organic matter, and low nutrient levels (Tedrow et al. 1968, Everett 1968. Pawluk and Brewer 1976, Bell and Bliss 1978). Many of the sites near Malloch Dome and the lower slopes at Rea Point are on fine textured sands to silty loams, while silty-clay loams and clay loams predominate on the marine sediments on King Christian Island. Plant communities General information on floristics and plant communities, but without supporting quantitative data, are available for the Landing Lake area, near Mould Bay, Prince Patrick Island (Bird 1975), and Isachsen, Ellef Tab. I. Climatic data for selected high arctic stations in the vicinity of polar semi-desert areas. Data are for 1970-79 with comparisons for the 1941-7U period. Station ("N) Latitude Jun Mould Bay Rea Pt. Isachsen' Station Jun Mould Bay Rea Pt. Isachsen 1970-79 Temperature ("C) Mean monthly Jul Aug 3.8 4.0 2.6 0.8 0.9 0.3 Degree days Precipitation (mm) above 0°C Jun-Aug Annual Mean annual -17.7 -17.6 -19.2 209 210 161 39 26 53 102 62 127 Cloud Cover (%) Jun-Aug -0.6 -L2 -1.5 Departure from means 1970-74 1975-79 Jul Aug Jun Jul 0.7 -0.2 -0.1 -0.5 -2. 2 -1. 1 -2.3 -LI Temperature Long term means 1941-1970 Aug Jun Jul Aug -1.6 -2.1 -0.4 -0.9 3.6 3.3 1.7 1.1 Days above 0°C 1970-74 1975-79 Jun-Aug Jun-Aug 0.2 — 'Station closed 1978, 1979. HOLARCnC ECOLOGY 7:3 (1984) Ringnes Island (Saville 1961). Wein and Rencz (1976) gathered data at two locations on Melville Island for sampling efficiency of plant cover and standing crop (phytomass) estimates. Methods Study sites were established immediately to the west of the Panarctic Oils Ltd. camp at Rea Point, Melville Island (75°22'N. 105°42'W); south and west of the Panarctic Oils Ltd. camp near Cape Abernethy (77°45'N, lO(r53'W); and in the vicinity of the Panarctic Oils Ltd. camp near Malloch Dome. Ellef Ringnes Island (78°12'N. lOrW). Soils generally within 20% for the most important species, litter and bare soil within a stand. Cover data are presented in the tables to permit comparison with other studies. Similarity coefficients (C = 2w/(a-l-b) x 100) between stands were computed. Species were not adjusted in relation to their maximum values of frequency and cover as in Bray and Curtis (1957). Dissimilarity values (1 - C) were computed and used for the construction of a two-dimensional, polar ordination (ORDIFLEX H. G. Gauch, Cornell University). This permitted the grouping of stands into community types discussed later. Nomenclature for lichens follows Hale and Culberson (1970). for bryophytes, Vitt (1975) and for vascular plants, Porsild (1964) unless otherwise given. Standing crop Within eight of the stands sampled for community composition, 5 (20 X 50 cm) plots out of the 30 measured for cover were randomly chosen and harvested. In sandy and gravelly soils, individual plants were extracted with most of the roots. A known portion of the soil to a depth of 30 cm (general lower limit for root development) was taken to estimate the remaining roots. In fine textured soils, plants were cut at ground level, lichens and mosses removed and bagged, and the root block prewashed to remove much of the soil. Soil sieves (2 mm and 0.75 mm mesh) were used to collect small roots and fine organic matter. Samples were kept cold in the field prior to air freight shipment to the laboratory. Here samples were frozen until analysed. Material was sorted into mosses, lichens, and vascular plants. The latter were separated by species into green. live-brown, and standing dead shoot material. Roots, where possible, were separated by species. Root fragments, fibrous organic matter and surface litter were combined to form organic matter standing erop. Samples were dried at 8O''C and weighed (0.001 g). In some instances mean cover values of the sampled plots (n ^ 5) differed substantially from the community mean cover value {n = 30), In such cases the standing crop data were adjusted: SC, = X D,. (1) Soils were examined by means of soil pits in most of the stands sampled. Since these soils have little if any profile development, a single composite sample of the top 15 cm was collected for analyses. When present, the cryptogam mat was removed and only the mineral soil was collected. Soil texture was estimated in the field and rooting pattern was described within the pit at all stands. The soils were analyzed by Northwest Soil Research, Ltd., Edmonton. Organic matter was determined by the Walkley and Black (1934) method. Exchangeable cations were extracted with neutral N ammonium acetate and determined by atomic absorption spectrophotometry. Nitrogen was determined by the phenoldisulfonic method and phosphorus by the combined nitric acid-vanadate-molybdate colormetric method. Soil color was determined on moist soil using the Munsell Color Charts in natural light. Plant communities At all sites general reeonnaissance of topography and plant community patterning preceded sampling. Relatively uniform stands (topography, floHstics and plant structure) were selected for sampling within a larger plant community. Stand as used here refers to a particular example of vegetation that was sampled and plant community or community type to a grouping of similar stands based upon a two-dimensional ordination (discussed below). Each stand, roughly 5 x 8 m, was sampled with thirty 20 x 50 cm quadrats by a stratified random technique (Bliss 1963). Cover estimates were made for all species of vascular plants, lichens, mosses litter, bare soil and pebbles by projecting plants to the surface within the quadrat frame, grided into 1 dm squares. Only one stratum was recognized. Each stand was surveyed for additional species; no more than 2 or 3 species of vascular plants were ever found. Frequency and average cover for each species were calculated and converted to prominence values by multiplying cover by the square root of frequency for each species in the stand. Standard error of the mean was Where SC^ is adjusted standing erop (g). C, is cover (%) of 5 harvested plots, C2 mean cover of 30 plots and D, is mean dry weight (g) of harvested plots. Where given error estimates are standard error. Net plant production Most plant communities were sampled at their seasonal peak of growth. This made possible the use of peak green phytomass as a basis for calculating net annual production. An accurate estimate of annual production HOLARCTIC ECOLOGY 7:3 (1984) includes green tissue formed that year, "brown" leaves or their parts produced earlier in the season, "brown" non-photosynthetic shoots produced that year, and an estimate of current root growth. It is virtually impossible, without phcnological studies of dominant species, to determine the proper ratios of green shoot:brown shoot and shoot:root production (Andreyev 1971, Flower-Ellis 1973, Muc 1977). Production estimates considering green tissues only (Parker 1975) or including estimates of annual decomposition (Wielgolaski 1975) will result in significant errors. Many species maintain some green leaf tissue over winter (Bell and Bliss 1977) and plant decomposition does not occur the same year as production in the same plant tissue. Correction terms for decomposition and litter fall should only be used when indirect estimates of plant production are based upon phytomass harvests alone. Valid approximations can be made since there is a strong correlation between the seasonal production of photosynthetic (shoots) and non-photosynthetic (shoots and roots) tissue. This ratio, although changing with age for long lived plants and differing between various plant groups, can be considered a constant for species with convergent morphology in an arctic ecosystem. If the peak green standing crop and net annual green production are known for a "master species" of a given growth form (sedge, grass, cushion, rosette), then total production of the convergent group can be fairly estimated (Svoboda 1977). Standing crop refers to all plant material living and dead, phytomass to living material, and net production to material produced the current year. Based upon these assumptions, the following techniques were applied in the calculation of annual aboveground and belowground production. nal green shoot growth, plus 25% of this value for nonphotosynthetic stems (diameter growth) and 50% of the green shoot growth for root production. Graminoids The rushess Luzuia confusa, L. nivaiis and the grasses Alopecurus aipinus and Puccineliia vaginata are the most impotant species. All green tissue was included as annual production although annual green carry-over is about 20%. hut is matched by 10-20% of seasonal leaf browning. Root production was assumed to equal green .shoot production, an overestimate for Luzuia spp. but an underestimate for the grasses (Bell and Bliss 1978). Herbs Few true herbs were found in the studied communities. All green tissue was counted as annual production plus 50% of this value for root production. The small carryover of basal shoot green tissue (10%) is matched by seasonal dieback. Rosettes The species of Draba, Saxifraga, and Cerastium along with Papavcr radicatum and a few others retain their green leaves for at least 2 yr (Bell and Bliss 1977). After careful examination, the leaves produced during the current year could be identified and separated from those produced in previous years. Root production was assumed to be 50% of shoot production. Results Soils Soils presented are only from King Christian Island and Rea Pt., Melville Island. Soil color ranged from brown Dwarf shrubs Annual production for Satix arctica included all seaso- (10 YR 4/4) to dull yellowish brown - dull yellow orange (10 YR 5/3-6/4). Tab. 2. Soil ehemistry for soils from polar semi-desert vegetation on King Christian and Melville islands. All data are from 0-15 cm soil depth. Stand # pH Organic matter N (%) P (ppm) Ca Mg Exchangeable cations (meq 100 g-i) Na K Total exchange capacity 2.8 4.8 2 Herb-lichen ?• Herb-lichen 5a* Herb-lichen 5b Herb-lichen 7 Wet griiminoid l l a + Herb-lichen l i b Herb-lichen 17 Phippsia barrens . . . 22 Graminoid barrens . 32 Herb-lichen 35 graminoid-moss 36 Phipp.na b a r r e n s . . . 0.9 1.6 1.6 2,8 2.3 2.3 3.0 1.8 1.2 1.6 1.8 0.07 O.OI 0.01 0.16 0.12 0.09 0.12 0.10 O.tM 0.03 0.U8 0.18 0.41 0.38 0.23 0.31 0.26 0.21 0.56 0.10 0.23 0.36 * 5a soil polygon center, 5b soil polygon edge. + 11a soil stripe center, l i b soil stripe edge. 22 HOLARCnC ECOLOGY 7:3 (1984) The soils at Rea Pt. were sandy loams to loamy sands on the outwash from the hills (stands #1-3). clay loams on the hill top (+4-6); loams predominated in the graminoid wetlands (#7). At Cape Abernathy the soils were generally sandy loams to clay loams derived from recent marine deposits. At higher elevations sands and sandy gravels, derived from the Isachsen formation, predominate. In general soil pH is near neutral with the exception of the wet sedge-grass-moss meadow (+7) at Rea Pt., moss covered soil stripes at King Christian Island (#11), and the quite acid (4.4 to 4.8 pH) silty-clay loam soils at stands #35, 36. Other pH measurements from these fine-textured soils, often with sheet erosion patterns with only scattered plants of Phippsia algida predominating, also indicate quite acid soils (4.5 to 3.5 pH, Nancy Gruike 1983) in the absence of acid-forming mosses. Soil organic matter in general reflected the low cover of vascular plants and their limited root systems. Soils from nearly bare surfaces (stands #5a, 11a) have lower percentages of organic matter and nitrogen than do the moss-covered edges of these vegetation polygons and stripes (Tab. 2). At all sites nitrogen levels were low (0.01 to 0.16%) and phosphorus was equally low (4 to 8 ppm). Calcium and magnesium were low in all soils; the highest values were in stand 5 on the upland 2 km west of the Rea Pt. Base Camp. Sodium levels were generally 0.2 to 0.6 meq 100 g ' soil with the exception of the small salty-clay pans of King Christian Island (3.2 meq 100 g"' soil) where Puccinellia vaginata predominated. Potassium was also highest at this stand (#22), 0.56 vs. 0.10 to 0.41 meq 1(X) g'' soil elsewhere. Roots are mostly within the upper 5 to 10 cm, but a few can be found to 25+ cm. There is considerable detail on rooting pattern of the dominant species on King Christian Island (Bell and Bliss 1978). Plant communities •"• ^ : : . . . \ C.H. •" AI.B. "' .. Ph.B. M.G. 1* , • is' Fig. 2. Polar ordination of the 41 stands sampled for plant cover and fequency. The stands are ordered into five groupings. They range from Puccinellia and Alopecurus barrens (Pu. Al B), and Phippsia barrens (Ph B) in sites with limited soil moisture and few cryptogams to a gradient of graminoid and herb communities with an abundance of cryptogams, the mossgraminoid meadows (M.G.). graminoid steppe (GS), and the cryptogam-herb meadows (C.H.). these sites with their annual spring floods and shifting sands (Tab. 3). On terraces 2-4 m above the main river fan. Alopecurus alpinus predominated in medium textured sands (#40. 41); plant cover averaged 5-12% over large areas (Fig. 4). The rhizomatous growth form of Alopecurus enables the species to keep pace with accumulating sand, the only bryophyte present was Pogonatitrii alpinum. but only in one stand. Near the upper limit of tbe coastal marine sediments and the soils derived from the Isachsen Formation on King Christian Island, there were small sandy loam pans The polar ordination of 41 stands resulted in five major groupings of communities (Fig. 2). In most communities, vascular plants contributed 5 to 20% cover; lichens and bryophytes collectively provided 20 to HOTo cover. Only in the sheet erosion surfaces on King Christian island and the sandy outwash soils of Ellef Ringnes were cryptograms < 5% cover. In most sites the cover of crustoe lichens was greatest. Graminoid dominated communities Puccinellia and Alopecurus barrens. In the finegrained sands and silts of the river delta near Malloch Dome. Ellef Ringnes Island, scattered clumps of Puccinellia vaginata predominated (stands # 3 8 , 39). There were often salt crusts on the surface late in the summer (Fig. 3). In a few places there were widely spaced clumps of Alopecurus alpinus and scattered plants of Cochlearia officinale. Cryptogams were absent from 330 Fig. 3. Puccinellia vaginata on a salt pan near Malloch Dome. Ellef Ringnes Island (lens cap 5 cm). HOLARCnC ECOLOGY 7:3 (1984) Tab. 3. Prominence values (cover x square root of frequency) for the PuccinelUa and Alopecurus barrens and Phippsia barrens community types. KCI = King Christian Island. ER = Ellef Ringnes Island. Species Puccinellia & Alopecurus Barrens Stand # Phippsia Barrens 22 KCI 38 ER Puccinellia vaginata Ahpecurm alpinus Phippsia algida Papaver radicatum 39 ER 4() BR 41 ER 60.0 - 9 KCI 13 KCI 14 KCI 17 KCI 21 KCI 36 KCI 29.9 1.2 - 0.2 72.0 105.0 - 18,6 43,0 _ _ _ _ _ 30,0 0.3 _ _ _ _ _ 2.7 Cochlearia officinalis.... Saxifraga cernua Saxifraga nivalis Ci-raxtiitm arcticum Draha subcapitata Drtihu alpina (ladonia gracilis _ _ _ _ 3.4 20,7 3,1 _ _ _ 6.8 58.4 _ _ _ _ _ _ Lepraria ne^lecta Dermatocurpon hepaticum C 'etraria islandica Ci'traria delisei — — — — 23.0 11,7 Gymnomitrion corallioides Other species 2 Total species 6 Total vascular plant cover (%) 5.4 Total bryophyte cover (%) 0.0 Total lichen cover ( % ) , . 0.2 Litter cover (%) 0.0 Bare soil and pebble eover(%) 94.4 2 3.8 0.0 0,0 0,0 96.2 — 0 I 6.0 0.0 0,0 0,0 0,0 0,0 6 3.2 0.5 0.6 0,3 95.4 — _ 7 13 5,9 0,0 3.2 0.4 4.3 1,5 90.6 6.5 10,0 5.0 0.0 78.5 0.0 71,4 0,0 94.0 (5-20 m across) dominated by Puccinellia vaginata. Associated scattered individuals of Phippsia algida, ('ochlcaria officinalis. and small patches of lichens were present (stand #22). These small pans contained high levels of sodium salts which form salt crystals during dry periods in summer as in 1977. Species richness was higher at this site (6) but averaged 2.6 ± 2.0 in the five stands; total plant cover averaged only 6,8 ± 2.7%, Phippsia barrens. Near the contact of the Isachsen Formation sandstones and the thin cover (50-150 cm) of i .,L - . .-.;...; ciink-iJ siiiliiccs wiili I'hipjiMn ul^utu and Puc- cmeliut vaginala barrens. The vegetated area at the shovel and the slopes beyond are dominated by Luzula confusa, Alopecurus alpinus, Rkacomitrium lanuginosum and Gymnomitrion coralliodes. a moss-graminoid community on King Christian Island. iiju'i \it]i\ ii/jniiii-< i n i iin.-Lliimi IfMuK'il s.iiuts km of Malloch Dome, Ellef Ringness Islands- CrypU)gams are absent from this graminoid barrens community. HOLARCTIC ECOLOGY 7:3 (1984) marine sediments on King Christian Island, the surface of the latter sediments erode with spring snowmelt. This results in many gentle slopes (5-8°) having little or no plant cover other than scattered small plants of Phippsia algida and remnants of formally stable surfaces with their cover of lichens-bryophytes-vascular plants (Fig- 5). The bare soil surfaces, hectares in area, were colonized by Phippsia algida with small numbers of Papaver radicatum (stands #9, 13-14) (Tab. 3). The lichens Der~ matocarpon hepaticum and Lepraria neglecta were present in small amounts. The greater cover of the liverwort Gymnomiirion corallioides Nees, and several species of lichens, from less eroded surfaces, would have placed this stand into the bryophyte-graminoid group except for the abundance of Phippsia algida (Stand #36) (Tab. 3), Mosses were generally very minor (< 1% cover) consisting mostly of Polytrichum piliferum and Ditrichum flexicaule. These silty loam and clay-loam surfaces were very wet and sticky following snowmelt, but by mid-July the surfaces were often baked dry. provided the summer had periods of sunny days as in 1976, 1977, Fig. 6. Raised center polygons (4-6 cm across) with Alopecurus alpinus dominating the tops and Luzula confusa and Lepraria and 1979. The guileys contain deep snowbanks {2-A m) which neglecta the troughs about 3 km northeast of Malloch dome, Ellef Ringnes Island, frequently melt out in early to mid-July. Phippsia algida was usually the dominant vascular species although PaGraminoid steppe. The rolling terrain on southern paver radicatum, Draba alpina, D. subcapitata, Saxifraga cernua, S. nivalis, and Cerastium arcticum com- Ellef Ringnes Island beyond the influence of the outprised considerable cover (stands #17, 21). Bryophytes wash channels of the river was dominated by floristically were generally minor but crustose lichen species, such simple communities of Luzula cotifusa and Alopecurus as Dermatocarpon hepaticum and Lepraria neglecta alpinus. Where there were large raised center polygons were usually present, especially on the upper slopes that 4 to 6 m across, Alopecurus and Pogonatum alpinum dominated on the tops (stands #24, 26). Luzula confusa melt out earlier. These Phippsia barrens have a greater number of and Lepraria neglecta dominated the troughs (stands species (9.8 ± 5.0) and total plant cover (14.8 ± 9.6%). #25, 27) which were 50 to 150 cm deep; the soils conTab. 4. Prominence values (cover x square root of frequency) for the graminoid steppe community type, M = Melville Island, ER = Ellef Ringnes Island. Species 7 M 24 ER 25 ER 26 ER Stand # 27 ER 28 ER 29 ER 30 ER 31 ER Dupontia fischeri Eriophorutn triste Ranunculus sulphureus Saxifraga cernua Luzula confusa Luzula nivaiis Alopecurus alpinus Orihothecium chryseum Polytrichum juniperinum PhiUmotis fontana Campylium arcticum Aulacomnium turqidum Drepanocladus revolvens Pogonatum alpinum Ditrichum flexicaule Rhacomitrium sudeticum Lepraria neglecta Solorina crocea Daciylina arctica Peltigera aphthosa Other species Total species Total vascular plant cover (%), 180.0 37.7 4.6 3.0 10.7 _ 73.0 213,0 40.1 18,9 14,8 9.3 2.5 25.7 03 . — 76,0 01 . _ _ 1 7 94 . 35 , 77 , 13.0 55,3 _ 40.0 81.9 17 , 19.7 718 01 , 79 , 106.0 16,8 14,6 _ _ 51,2 13 . _ 78.0 03 . _ _ 30,2 20.1 01 . _ — 0 T - 76.8 03 . _ 23.2 13 . _ _ 10.7 64 . 80 . 10,2 64,7 Total bryophyte eover (%) Total lichen cover (%) Litter cover (7o) Total bare soil and pebbles (%) 10.6 77,8 10.9 79 , 29 . 36 . 150.7 _ _ 71.0 16.0 _ _ 1 7 80 . 15.3 10.2 _ _ 64.0 76 . _ _ 0 4 12,3 _ 82 . 17.2 1, 17 49.5 434.0 25.0 38 , 31 , 10.7 2 10 16.8 52.1 79 , 17,7 28,5 88 , 569,0 46.3 22.2 78 . 63 . 4 12 13.6 64.4 11.5 62 . 4,3 HOLARCTIC ECOLOGY 7:3 (1984) Kij;. 7, tjramlnoid sleppe doniinaled l\v Luztila vanfusa. Atopccurus alpinus wilh sniull iimounts of Saxifraga cernua, Saxifraga cacspiiosa, and Draba corymbosa, 2 km from Malloch Dome, Ellef Ringnes Island. taincd more moisture than those of the polygonal tops (Fig. 6). Total vascular plant cover averaged only 5 to n% and species richness was low (7.6 ± 2.4) in these uplands, yet ihe clumps of Luzula and Alopecurus gave the appearance of an arctic grassland. The sandy soils were derived from the Eureka Formation sandstones. Most surfaces were covered with desiccation polygons (10 to 25 cm diameter) without raised rims or centers; there were limited amounts of Lepraria ne^lecia and Pogonaium alpinum. There also appeared to be an early establishment stage of Dermatocarpon hepaticum on the soils. Bare ground accounted for 50 to 70"/li of the total cover (Tab. 4). While vascular plant cover averaged only 4.0 ± 3.4%. total plant cover (40 ± 28%) was significantly higher than in the previous communities. Moss-graminoid meadow. Eight stands from King Christian and Ellef Ringnes islands have been grouped under this heading. Al! stands were characterized by the Tab. 5. Prominence values (eover x square root of frequeney) for the moss-graminoid community type. KCI = King Christian Island. Species Luzula nivalis Luzula confusa Alopecurus alpinus Phippsia algida ruciinellia vaginala Sifllaria crassipes I'apavcr radicatum Drahii corymhosa Draha utpina Drabu siihcapitata Stixifrafia cernua Cerastium arcticum Cardamine helliilifolia (iymnt)initrion corallioides Rhacomitrium sudeticum Rhacomitrium lanuginosum Atitacomnium turgidum I'olytrichum juniperinum Ditrichuin flexicaule Dicranoweisia crispa Scliistidium holmenianum lomenthypnum nitens Distichum capillaceum Philonotis fontana ('ftraria islandica ('etraria delisei ('ludonui gracilis Thamnolia subuliformis Dactytina arciica Oactylina ranudosa Lepraria neglecta Parmetia omphalodes Dermatocarpon hepaticum Olher species Total species Total vascular plant eover (%) . . . lotal bryophyte cover (%) Total lichen cover (%) Litter eover (%) Bare soil and pebble cover ( % ) . . 8 KCI 23.8 0.2 20.0 3.8 14.7 2.6 8.2 4.5 6.8 3.6 64.5 40.1 84.5 18.6 36.9 6.7 6.6 ~ 2.4 1.0 0,4 0.7 1.0 23.1 5 28 11.1 29.6 5.1 32.7 21.5 10 KCI 15 KCI 16 KCI 18 KCI 19 KCI 35 KCI 37 KCI 47.3 31.0 03 . 80 . 01 . 51 . 80 . t).l 50.2 485.0 14.6 11.6 21.9 — 38.1 33 . 79 . 26.0 16.5 - 84.0 03 . 39.0 02 . 57 . 23 . 96 . - 40.2 _ 10.2 55 . 03 . 01 . 01 . 34.8 41.9 _ 41.1 17.9 05 . 53.0 81 . 68 . _ 17.0 04 . 55 . 416.0 39.9 34.5 24.3 14.3 20.6 13.5 02 . 65.0 03 . — 14 . _ 01 . 12.1 78 . 13 . 40.5 — 03 . — — — — 03 . 348.0 — — 43 . — _ — _ — 38 . 27.3 63 . _ _ 05 . 56.2 21.2 — 5 19 23 . 01 . _ 13 . 593.0 62 . _ 27.1 39.5 49.9 70.2 19.5 _ 56 . _ _ 09 . — _ — 01 . 548.0 _ 10.9 19.6 27 . _ 12.0 91 . 07 . — — — 10.9 51.2 — 05 . 10.0 24.6 O.I 05 . 03 . 58 . 83.0 4 26 11.2 56.5 14.5 54 . 12.4 63 . 08 . 14.4 46.8 - HOI ARCTIC ECOLOGY 7:3 (1984) Fig. 8. Close up of previous community with Pogonatum alpinnm. vascular plant dominance of Aiopecurus aipinus or Luzuia nivaiis or L. confusa, the presence of several rosette species, and the overall dominance of bryophytcs (Figs 7-8, Tab. 5). The silty loam and silty-clay loam soils of stands +8, 10, 15-16. and 18-19 on King Christian and stands *35 and 37, 12 km SE of Malloch Dome on Ellef Ringness were characterized by varying combinations of Rhacomitrium lanuginosum, Schistidium holmenianum, Aulacomnium turgidum, Polytrichum juniperum, and Ditrichum flexicalue. On clay-loam soils that appear to be wetter near the soil surface all summer, the liverwort Gymnomitrion corallioides predominated, typically accounting for 40 to 60% of the total cover at six of the sites. The graminoids reach their greatest cover in these communities which typically have higher soil-moisture levels. Stands #8 and 10 fit within this grouping due to the importance of Alopecurus, a mixture of forbs, and the high cover of mosses but low cover of Gymnomitrion. The "wettest sites" have a greater cover of Gymnomitrion and little if any Papaver radicatum (Tab. 5). Fig. 10. Cryptogam-herb community at Rea Point. Melville Island. The community is dominated by Saxifraga oppositifolia and the lichen Dermatocarpon hepaticum with lesser amounts of Draba corymhosa, Alopecurus aipinus. ainl Juncus uli)escetis. Species richness is much greater in this community (24.9 ± 3.4), as is total plant cover (77.7 ± 16.1%). Wet graminoid-moss meadow. Only one site of wetland grasses and sedges was sampled, and that one at Rea Point, Melville Island. Floristically this stand was very different from the others (#7, Fig. 2. Tab. 4). The dominant vascular species was Dupontia fisheri with lesser amounts of Eriophorum triste (Fig. 9). Carex stans and Eriophorum scheuchzeri were found near the pond margins and Pieuropogon subinei in the shallow waters. These three species were not sampled in stand #7. Although eleven other species of vascular plants were sampled, none provided a cover of more than 0.7%. Four species were not sampled elsewhere. Of the ten species of bryophytes. Orthofhecium chryseum, Polytrichum juniperinum, Aulacomnium turgidum. Philonotis fontana var. pumita, and Campytium arcticum provided 40% of the total cover. Nostoc commune was found throughout the stand as small mats; lichens were very minor (2 spp, 1.3% cover). This stand is within a 5O-1(K) ha area of wetland that receives discharge water during much of the summer, which prevents surface drying. The soils are sands to loams with little peat accumulation (1-2 cm). The surface is covered with polygons (1 to 5 m diameter) and there is some patterning of species, Eriophorum triste, E. scheuchzeri and Carex stans occupy the rather bare mud boils (l.(t-1.5 m diameter) and pond margins, while Dupontia fisheri is found on the moss mats that form the rims (3 to 5 cm high). Herb dominated communities Cryptogam-herb. This grouping of stands includes six from Rea Point, one from Malloch Dome, and six from Cape Abernethy. They all have in common the presence of Alopecurus aipinus, Luzuia confusa or L. nivaiis, numerous rosette species, and an abundance of cnistose and some fruticose lichen species (Tab. 6). The HOLARCnC ECOLOGY 7:3 (1W4) Fig. 9. Wet graminoid-moss meadow at Rea Point, Melville island. Dupontia fisheri and Eriophorum irisle dominate the foreground with Carex sians near the pond and Pieuropogon sahinei in the water. Tiih. 6- Prominence values (cover x square root of frequency) for Ihe cryptogam-herb community type. M = Melville Island, KCl = King Christian Island, and ER = Ellef Ringnes Island. Species lM .Ahpecurus atpinus Liizula confusa / uzula nivutis I'liainelliu vaginata Papaver radicalum Saxifraga caespitosa Saxifraaa cernua Saxifraga opposilifolia 2.1 0.5 6.9 17.0 0.9 19.6 2M 11.7 14.9 13.2 5.6 51.9 3M 0.3 0.6 3.1 0.6 O.I 26.2 4M 36.5 5.5 5.2 13.5 11.1 9.8 5M 4.9 23.8 4.1 2.1 I.O 0.6 6M Stand + 11 KCI12 KCI20 KCI23 KCl 32 KCl 33 KCI 34 KCI 26.8 24.7 57 . 10.1 _ _ 46 . 12.1 27 . _ _ 22 . 12.4 _ - 19.7 23.8 95 . 08 . 79 . _ — _ 25 . 16.4 _ 64 . ~ 22 . _ 27 . 63 . _ - 52 . 19.7 14 . 24 . _ 19 . 26 . 23 . 68 . 51 . 74 . 11 . 57 . 11.2 30 . 73 . 14 . _ — _ . 36 . 03 . _ 16 . 86 . 10.3 12.2 01 . - Saxifraga flagellaris Saxifraga hieracifolia Saxifraga tricuspidata Saxifraga nivalis Draba corvmhosa tyraba subcapitata Draha alpina lestuca hrachyphylla Cerastium arclivum (eraslium alpinum Jutu-us albescem Juncus biglumis Oxyria digyna Salix arciica Ranunculus .sulphureus Ranunculus sabinei Minuartia rubella Minuartia rossii Siellaria cras.sipes Sieilaria humifusa Potentillii hyparclica Ditrichum flexicaule liryum algovicum Volvtrichum juniperinum lorluta ruralis Rluunmiirium sudeticitm Khacomitrium lanuginosum ... 0.3 4.2 2.7 6.9 54.2 35.7 l.J 9.8 0.1 13.9 2.2 - 3.3 12.8 4.0 5.9 17.9 19.3 8.4 3.0 0.3 3.6 23.1 15.1 - 3.4 0.3 0.4 0.5 8.9 7.3 86.2 0.1 0.3 0.2 64.4 0.2 3.3 11.0 - 8.5 1.6 0.8 14.0 3.7 1.2 7.2 3.8 3.2 5.7 2.2 110.2 7.7 5.7 - 0.6 5.1 0.8 0.3 2.4 11.4 20.1 58.4 0.1 0.3 3.6 0.1 117.6 1.7 14.5 - 32 . 31 . 24 . 10 . 78 . 60 . _ 10 . 45 . _ 37 , 53 . 01 . 03 . 60 . 80 . 16 . 10.9 05 . 32 . 03 . - 13 . _ 26 . 24 . 13 . _ 28 . 73 . 50 . _ 33 . _ 01 . 01 . _ _ 39 . - 1. 19 56 . 24 . _ 11 . 11 . - 17 . — — _ 02 . 07 . _ 50 . I _ -5 1 . 91 . _ I.3 I I 5 - 134.8 48.1 — _ _ 55 . 78 . 02 . 73 . 1 25 15.4 16.8 35 . 46 . 59.7 78.1 35 . 36 . - I -4 3 . Tottwnihyphum iiiiens Autacomnium turgidum Schisiidium homenianum Dicranoweisia crispa Dermatocarpon hepaticum .... Lepraria neglecta (etraria islandica ( etraria cucullaia Sicreocaulon arenarium Ihamnolia subuliformis Daviylina arciica Other species Tolal species Total vascular plant cover (%) Total bryophyte cover ( % ) . . . . Total lichen cover (%) l.ittereover (%) Bare soil and pebbles (%) . . . . 64.0 05 . 05 . 18 . 52 . 11.9 249.0 29.4 56.3 67.0 161.0 17.9 02 . 53 . 10 . 93 . 22.8 1 23 14.4 24.1 16.1 _ 03 . 05 . 1 22 14.9 14.2 32.1 12.5 26.3 _ 70 . 12 38 13.9 13.1 48.9 40 . 20.1 113.0 12.1 — — 35.4 21.8 — 318.0 324.0 lOl.O _ 0 2 119.0 . 01 . 19.0 4 30 25.2 29.9 34.0 98 . 11 . I _ - I - I _ -3 4 . _ 29.5 - I.5 2 40,0 I1 0 . soils range from sandy loams to sandy-clay loams and clay loams. The summer climate at Rea Point. Melville Island is warmer and Uinger (see climate section) than that on King Christian and Ellef Ringnes islands. This is supported by a more diverse flora and robust vegetation. In stands #1 to 6 there were 18 ± 1.8 species of vascular HOLARCTIC ECOLOGY 7;3 (1984) plants, compared with the stands on the two northern islands (15 ± 5.7 species). On the sandy lower slopes Saxifraga opposiufolia averaged 3 to 7% cover (Fig. 10). Associated species included Oxyria digyna, Juncus albesceris, Papaver radicatum. Saxifraga caespitosa, and Draha corymbosa. On the clay loams and loams of the upland beyond, Luzula confusa and Alopecurus alpinus 335 only erustose lichens of any importance, although a few other species were present. In nearby microsites with soils of finer texture and higher soil moisture levels, there were small clumps of Luzula confusa with scattered plants of Alopecurus alpinus, Papaver radicatum, and Minuartia rubella, there was a nearly complete cover of Dermatocarpon hepaticum in sharp contrast with the slightly more exposed sites with some sheet erosion as described above. Total species richness (26.3 ± 6,2) and vascular plant richness (16.8 ± 4.7) were highest in this community type. Total plant cover averaged 61.2 ± 24,7% and vascular plant cover was highest (15.9 ± 6.5%). The only sites with a diversity of vascular plant species and a preponderance of crustose lichens and mosses Fig. 11. Close up of cryplogam-herb community near Cape on southern Ellef Ringness Island were the lower slopes Abernethy, King Christian Island, Species present include Luzula confusa. Alopecurus alpinus, Papaver radicatum. Saxiof the gypsum plug, Malloch Dome, Loam to silty-clay fraga cernua. Saxifraga nivalis, Saxifraga flagellaris. Ranunloam soils predominated, with the surface composed of culus sabinei and the lichens Dermatocarpon hepaticum and soil hummocks 15 to 25 cm across as in the guUeys on Lepraria neglecla. King Christian Island. Of the 20 species of vascular plants sampled, Luzula confusa, L. nivalis, Papaver radicatum, Saxifraga caespitosa, and Oxyria digyna were more important. Here (stands +5, 6) and on the were most important. Lichen cover was again domieastfacing slope, mats of Sali.x arctica occurred and on nated by Dermatocarpon hepaticum with small amounts the slope there were small, local populations of Dryas of Thamnolia suhuliformis and the bryophytes intcgrifolia. Mosses were generally minor, except for Pogonatum alpinum, Hylocomnium splcndcns, DiDitrichum flexicaule, Bryum algovicum and Tortula cranoweisia crispula, Orthothecium chryseum, Diruralis in a few stands. Crustose lichens were prominent trichum flexicalue, and Rhacomitrium lanuginosum. in stands #1 to 3 and 5. dominated by Dermatocarpon On steeper (10 to 15°) slopes, facing south and east, hepaticum and Lepraria neglecta with smaller amounts there were mats of Salix arctica and Saxifraga opof Thamnolia subuliformis. positifolia 20 to 50 cm diameter, each species providing Three stands on King Christian (#11. 12, 33) oc- 3 to 8% cover. Associated species, though less in cover, curred on sandy loams and sandy-clay loams of the include Papaver radicatum, Fotcntilla hyparctica, P. recent marine sediments. All stands had 14 to 17% ruhricaulis. Ranunculus sulphureus, Festuca cover of vascular plants; lichens provided 16 to 32% hrachyphylla, and several species each of Draba, Saxcover. Although Alopecurus alpinus or Luzula confiLta ifraga, and Minuartia. had the highest cover for an individual species, cover provided by the rosette forbs Papaver radicatum, Draba corymbosa. Saxifraga cernua, S. nivalis, and Cerastium Standing crop arcticum dominated (Fig. 11). The crustose lichens Der- Owing to the time, cost, manpower, and logistic factors. tnatocarpon hepaticum, and Lepraria neglecta were the determination of standing crop was restricted to most important although Cetraria islandica, Dactylina proportions that could be handled. Yet 20% of the arctica, and Thamnolia subuliformis contributed some stands measured for community composition and cover cover in one or more stands. The only mosses of impor- were also analysed for standing crop and net annual tance were Schistidium holmenianum, Rhacomitrium production. lanuginosum, and Tomenthypnum nitens. In terms of biomass, composition, and physical strucTwo stands (#32. 34). 2.5 km apart, were located 20 ture the polar semi-desert communities ean be characm upslope of the limit of the coastal marine sediments, terized by several common features. The structured upon soils derived from Isachsen Formation sandstones standing crop (i.e. fine organic matter and surface litter and siltstones. The soils were sands and loamy sands excluded) is low (1156 ± 270 gm"-), bryophytes being with small silty-loam pans containing Puccinellia va- the major contributors (ca. 85%, with the exception of ginata in low density and eover (0.5 to 1.0%), This was the graminoid barrens community). Lichens contribthe only graminoid species found in these wind-swept uted the least amount (0.6%) (Tab. 7). (little winter snow cover), well-drained sites. The roseIn the vascular plant component, monocots prevail tte species Papaver radicatum, Draba corymbosa, Ce- (75'yo). followed by forbs (14%) and woody species rastium arcticum and Minuiirtia rubella comprised most (11%). Salix arctica, the only true woody species, was of the vascular plant cover of these habitats. Der- listed in only 4 of the 41 measured stands of which only matocarpon hepaticum and Lepraria neglecta were the two had significant cover (> 2.5%). HOLARCnC ECOLOGY 7:3 (I9R4) and D, respectively). These were not significant at the level of sampling. Also correlations between prominence values and biomass were generally less significant than those calculated directly from cover data. Net production As with standing crop, net annual production varied from a few grams in graminoid barrens to 52 and 59 g m ' y ' in cryptogam-herb and graminoid steppe communities respectively, The mean total production (i.e. bryophyte and liehen production included) estimated on the basis of the living portion of the standing crop harvested was 30.8 ± 6.7 g m ' y', To this total the vaseular plants contributed 15.9 ± 4.2 gm-^y-'(51.6%), bryophytes 14.7 ± 4.3 g m ' y ' (47.7%) and lichens 0.67 ± 0.02 g m^' y-' (0.7%). Monocots, forbs and woody species shared the vascular plant production with 52.0, 23.2 and 24.8% respectively but these values varied greatly from stand to stand. Discussion Soils Fig. 12. Regression analysis for (A) total vascular plant cover vs. tolal vascular plant standing crop, aboveground (Y = 8.6 X -.Vi-6); (B) total vascular plant cover vs. total vascular plant slanding crop (Y = 18.0 X -55.9); (C) total plant cover vs. lotiil above ground standing erop (Y = 10.7 x -1-448.4); and (D) lotal plant cover vs. total plant standing crop (Y = 13.5 x + 385.7). The standing and attached dead represented 78% of the aboveground vascular standing crop. Phytomass of the vascular plants consists of the "green", photosynthetic tissue, "brown" woody or semi-woody {Saxifraga opposilifolia) stems and approximately one-half of the identifiable roots. Ibgether this accounts for only 38% of the total vascular standing crop. The green portion alone represented only 5.4% of the total phytomass. The identifiable root standing crop was 40% higher than the total vascular aboveground standing crop (root:shoot ratio = 1.4) wilh monocots again contributing most (88%). Litter and the remaining beiowground organie matter varied greatly and represented only a fraetion of the total structured standing erop. 1 he low number of replicated samples did not allow for the differentiation of eommtmities on the basis of standing crop data. However a significant correlation was found between vaseular plant cover and aboveground standing crop (Fig. 12A). This suggests that a good estimate of standing erop can be obtained from cover data followed by partial sampling of standing crop. Other correlations attempted included: cover vs. total vascular plant standing crop; cover vs. total aboveground standing crop (mosses and lichens included), and cover vs. total standing crop (Figs 12B, C HOLARCTIC ECOLOGY 7:3 (1984) Soils within the High Arctic, as with vegetation, have generally been referred to as polar desert. Tedrow (1977) has reported six genetic soil groups for the polar desert zone (lands north of Baffin. Prince of Wales, Victoria and Banks islands. The soils from all but stand #7 (tundra soils) fit within the polar desert and polar desert-tundra interjacence genetic groups of soils (Tedrow 1970. 1977). The Canadian soil classification system would designate these as Regosolic Static Cryosols (after Walker and Peters 1977). The soils at stands 30, 31 on Ellef Ringnes and the gulleys on King Christian (#17. 21) are on hummocky ground. All of these soils have low levels of organic matter. N, P, Ca. K, and total exchange capacity. This is in agreement with previous data from King Christian Island (Pawiuk and Brewer 1975. Bell and Bliss 1978). Prince Patrick Island (Tedrow and Thompson 1969) and Cameron Island (McMillan 1960). At all sites examined there is little indication that the prevailing plant communities provide much influence on soil development (Figs 13. 14). Topographic position and drainage characteristics are of fundamental importance (Tedrow 1977). Plant communities These polar semi-desert landscapes, as with those in the Low Aretic, present a constantly changing pattern of groups of species. The ecological tolerance range of most speeies is broad. While no two stands are identical, the grouping of species is sufficiently repetitive to permit a general grouping of sampled stands into community types (Fig. 2). 337 O S a. <n Tt TT ini (2. r-i d C1 c in rn C r-; 'T d -^ dd o — ov o 5 fN Q.7.' O Tt a: T3 (; (2 d— oT d oo" fN — d d —d — in d --J od — — •—fN (238 (238 ,00- — S^ xQ " rt -T d -t 1 1 ' ^ \D 00 i n oo 1243 :220. in to" fN TT . 3 — :i co • 3 .^2 '5 £ E C *.. c: II c > JS Cfl 0 ^ ^ w o i« •d'_; n c/3 I:Q hri FU ^s£ HOLARCTIC ECOLOGY 7:3 (WtM) q o o rr •* 00 O Tf 1- O — » ,0 — r^ - d— " 00 — l- 25 00 ~; r j in r i O 06 » Fig. 13. Soil profile below a cryptogam-herb plant community (stand 3). Re;i PoinI, Melvilic Ishind. Soils are medium textured sands. ^ 06 -- o o> I I I ( C^ \O Ov IN r ; ^ fn rn « —• o 00 Fig. 14. Soil profile below a cryptogam-herb plant community. Cape Abernethy, King Christian Island. The soils developed from recent marine sediments are silty-clay loam. -t r- — wS o *c CQ-JP HOLARCTIC ECOLOGY 7:3 (1984) There is a pattern of increased numbers of vascular plant species and total plant cover in going from sandy soils, to clay loams, and to loams. If tbe stands on sbeeteroded surfaces are deleted (#9, 13, 14, 35, 36) vascular species (12,7 ± 1.9 vs. 13.0 ± 1.4) and percent cover (15.3 ± 2.0 vs. 14.7 ± 1.5) are very similar on the loams and clay-loam soils respectively. Bryophyte cover is greatest on the clay-loam soils, while lichen cover is greatest on the loam soils. Bare soil, pebbles, and litter generally account for more cover than do the vascular plants, bryopbytes, and lichens. When the surfaceeroded stands are excluded, total plant cover is greatest on the clay loams and least on the sands. The number of vascular plant species is significantly correlated with vascular plant cover (r^ = 0.84. P < 0.01). Tbe number of vascular plant species and their percent cover are both correlated with total cover of bare ground, pebbles, and litter (r- = 0.33. P < 0.05. r^ = 0.51. P < 0.01). However, there is no significant correlation between the cover of vascular plants and that of bryophytes or lichens, nor between the eover of these plant groups and soil texture. Graminoid and herb barrens The ten stands sampled within this grouping have in common a low percentage of vascular plant cover (3 to 10%). few species (1 to 4) and very limited bryophyte and lichen plant cover, generally 0 to 10%. They occur on soils ranging from outwash sands on Melville and Ellef Ringnes islands, and loamy sands of the Isachsen Formation on King Christian Island, to clay loams and silty-eiay loams, subject to intense surface erosion, on the same island. Plant cover and plant structure approach that of a true polar desert, though floristically these stands are different because of the dominance of Fig. 15. Graminoid burrcns dominated graminoids. Lichen cover is significant only in Stand on Christopher shale near Drake Point.by Alopecurus aipinus Melville Island, #32 where Dermatocarpon hepaticum predominates in contrast with its minor role in polar deserts. Sand deposition on the outwash plain at Malloch Dome favors the scattered plants of Papaver radicatum, Cerastium rhizomatous grass Alopecurus aipinus. Tbis grass has a arcticum, Stellaria longipes, Draba corymbosa, D. albroad ecological amplitude, for it dominates in soils that pina, Saxifraga nivaiis and S. cernua (Fig. 15). These range from medium sands to clay loams. communities on Christopher shale have few lichens or Puccineliia vuginata predominates on loamy sands bryophytes on the loam lo the siity-clay loam soils; soils with small silt pans and their higher salt content. A that remain moist to wet much of the summer. Commuclosely related species is generally the only one of im- nities with a similar fioristic composition and plant portance along with a few scattered forbs in the polar structure have been described from Axel Heiberg (Bedeserts (Bliss et al. 1984). schei 1969). northern Ellef Ringnes (Saville 1961). and Phippsia algida is the dominant vascular plant on the Prince Patrick islands (Bird 1975). and Lougheed Island sheet erosion surfaces of clay loam soils on King Chris- (Edlund 1980). tian Island. This species is especially well adapted for these surfaces because of its high levels of seed produc- Moss graminoid meadows tion, ease of seedling establishment, and spiraled roots Large areas on the younger coastal marine sediments which permit it to occupy unstable sites with soil churn- and the Christopher shales of inland King Christian, ing (Bell and Bliss 1978, 198(1, Gruike 1983). Phippsia Christopher shale and Kanguk shale on southern Ellef also occupies sites of late-lying snow, sites with little if Ringnes. and Christopher shale on the Sabine Peninsula any soil movement and often with little bare soil for new support varying amounts of Alopecurus and/or Luzuia plant establishment. Stands #17 and 21 represent this confusa. The most important bryophytes are habitat along with other numerous sites examined on Hhacomitrium kmuginosum, Schistidium holmenianum, King Christian. Ellef Ringnes, and Melville islands. At Aulacomnium turgidum, and Ditrichum flexicaule. The Marie Bay on western Melville Island. Phippsia is a liverwort Gymnomitrion corallioides often predomicomponent of a closed community in which Alopecurus nates on fine textured soils. This species is also imporaipinus, Luzuia nivaiis and numerous liehens and tant at several sites at Mould Bay, Prince Patrick Island mosses predominate. Its ability to invade bare soil has (Bird 1975). There is a broad range of associated forbs. permitted it to provide 10-15% cover on the bare soils generally including Papaver radicatum, Draba corymof an adjacent well and camp site cleaned up in 1971. Phippsia also predominates at old well sites on King bosa, D. alpina, Stellaria longipes. Cerastium arcticum. Saxifraga cernua, S. nivaiis, and Ranunculus sabinei. Christian Island. In central King Christian Island, numerous valleys are dominated by Alopecurus aipinus with smaller Graminoid steppes amounts of Papaver radicatum, Saxifraga cernua, S. On the rolling uplands above the outwash channels at caespitosa, S. nivaiis, Cerastium arcticum and Draba Malloch Dome, comnwinitics of Alopecurus aipinus and alpina. There is little Luzuia confusa or L. nivaiis presLuzuia confusa predominate with limited eover of ent. Mo.sses provide 50 to 80% cover, mostly bryophytes and lichens (6 to 25%). Large areas on Orthothecium chryseum, Tomenthypnum nitens, southern and western King Christian Island, along the Aulacomnium turgidum, Ditrichum flaxicaule and DiHoodoo River. Ellef Ringnes Island, and north of cranoweisia crispula. Gymnomitrion corallioides is Drake Poini, Melville Island are occupied by Al- minor on these silty-clay soils that are sensitive to earth opecurus aipinus "meadows" with 5 to 10% cover, a few flows (Hamilton and Bliss, unpubl.). HOLARCnC ECOLOGY 7:3 09M) Wet graminoid-moss meadows Lowlands with lakes, ponds, and wet marshes are an uncommon feature oi these northwestern islands. Thus wetlands with sedges and grasses are minor as are large herbivores, whieh depend on them except on Melville Island. A feature of all of these areas is the presence of standing water in the depressed-center polygons (5 to 8 ni) for most of the summer. The wetland sampled at Rea Point is dominated by Dupontiii fisheri (18% eover) with lesser amounts of F.riophorum triste (4.3%). Though not sampled, small amounts of Carex stans, Eriophorum scheuchzeri and Arctagrostis latifolia are psesent. The shallow ponds contain Pleuropogon sabinei. In the transition to cryptogam-herb meadows, the soil boils {I to 1.5 m diameter) have 3 to 8% eover of Eriophorum with Dupontia on the moss mats of the raised rims. Salix arctica, Rammculus sulphureus, and Saxifraga cernua are eommon associates. Here and elsewhere the dominant mosses include Orthothecium chryseum, Tomenthypnum nitens, Philonotis fontatia, Drepanocladus revolvens, and Aulacotnnium turgidum. Wet meadows with Carex stans dominant are uncommon except on southern Melville Island. This speeies does predominate in the Sabine Lowlands (Fig. I) (25% cover) and at Mould Bay (45% cover) (Bird 1975). Elsewhere at Sherard Bay and on Cameron Island the wet meadows are dominated by Dupontia fisheri (8 to 15% cover), the mosses listed above, and a few scattered forbs. Five small meadows dominated by Dupontia fisheri, Eriophorum scheuchzeri, Pleuropogon sahinei. and Juncus biglumis have been reported from Isachsen. Ellef Ringnes Island (Saville 1961). In all eases total plant cover averages 100% except where small soil polygons occur. nivalis and Alopecurus alpinus dominated poorlydrained silts and clays. Associated species of Saxifraga, Draba, Papaver radicatum, and Potentitia hyparctica oeeurrcd on better-drained slopes. These communities were found on soils developed from the Hassel Formation. Weathered shales developed from the Kanguk Formation were very acid and devoid of vegetation. On the islands to the nortb and west. Salix arctica and Dryas integrifolia are limited to specialized warmer microsites. Both species occur in small amounts at Mould Bay, Prince Patrick Island (Bird 1975). Salix arctica is limited to only a few warm inland valleys on moss mats with Saxifraga oppositifolia on King Christian Island. Both species occur in limited amounts on the warmer east and south slopes of Malloch Dome, Ellef Ringnes Island. Both species, along with Dryas, are quite common on warm slopes and inland valleys on southern and southwestern portions of Melville Island, in areas with wet meadows of Carex stans and Dupontia fisheri. These relatively lush and diverse habitats support large populations of muskox and Peary's caribou. Characlerislics ur polar semi-deserts In her book on the geobotanical areas of the Arctic and Antarctic, Aleksandrova (1980) plaeed Melville Island within the Parry Archipelago District of the Arctic Tundra Subregion. This results from placing what Bliss (1975. 1979) and others have called the Low Arctic, with its preponderance of shrub species of Salix, Betula and Alnus, in the Subarctic Tlindra Subregion of the Arctic Tundras. Using terminology of Aleksandrova (198(1). the sedge-moss, sedgc-grass-moss meadows (mires), and the Dryas and Satix arctica tundras are part of the arctic tundra complex. The more barren lands of Cameron, King Christian, and Ellef Ringnes. along with other northwestern islands, were placed within the Cryptogam-herb meadows At Rea Point the broad lowlands west of the camp and Canadian Province of the Arctic Polar Deserts. The present authors prefer to recognize the grassthe slopes and uplands of the ridges beyond are dominated by the crustose liehens Dematocarpon hepaticum moss and sedge-moss meadows (mires) as the northern and Lepraria neglecta, and Thamnolia subuliformis, es- extension of the sedge-moss tundras of the Low Arctic. pecially in the coarser textured soils. On fincr-tcxtured The rest of the eommunity types better fit within the soils of the uplands, mosses increase in importance. A polar semi-desert complex of moss-graminoid. grammixture of vascular species predominate, but of the 10 inoid steppe and the cryptogam-herb group of commuto 15 common ones, Saxifraga oppositifolia, S. nities of the High Aretic. In general the plant commucaespitosa. Ranunculus sulphureus, Juncus albsecens, nities described here {Puccinellia, Alopecurus and Papaver radicatum, Draba corymbosa, Salix arctica, Phippsia barrens are the exception) are eharacterized and Oxyria digyna are most common. Luzula confusa by crustose lichens and mosses with scattered vascular and Alopecurus alpinus increase in importance on the plants. The flowering plants are a combination of gramfiner-textured soils. South-facing slopes, with late-lying inoids and rosette plants such a Papaver and various snow, may have small patches (2(M0 cm across) domi- species of Draba, Saxifraga, Cerastium and Minuartia. nated by Cassiope tetragona. On tbe steeper slopes (15° In the eastern and southern High Arctic, cushion plant to 18") that face east, south, or west, there are small communities dominated by Dryas integrifolia, Salix areas of Dryas integrifolia, usually with more mosses arctica. Saxifraga oppositifolia, a few rosette species, dry site sedges and numerous mosses and lichens domithan lichens. Ediund (1980) reported L«z«/a-dominated commu- nate the polar semi-desert landscapes (Svoboda 1977, nities were the most common ones on Lougheed Island. Svoboda and Bliss unpubl.). The real polar deserts are Luzula confusa occurred on drier aspects while Luzula far more depauperate in plant cover (< 5%) and vascuHOLARCnC ECOLOGY 7:3 (1984) lar plants with cryptogams playing a minor role except in snowflush communities (Bliss et al. 1984). Luzula confusa is one of the two most important graminoids in these northwestern islands. The plants are long-lived {> 100 yr), seldom produce viable seed, and are quite sensitive to moisture stress (Addison and Bliss 1984). Consequently, they are seldom encountered within the polar deserts except in snowflush sites. From several studies, there is growing evidence that crustose lichens and mosses play significant roles in the thermal and water regimes of these areas (Addison 1977, Addison and Bliss 1980) and thus in seedling establishment (Bell and Bliss 1980, Sohlberg and Bliss 1984). Soil lichens are not as effective as moss mats in reducing evaporation from moist surfaces. When dry surfaces predominate, lichens are more effective in further reducing evaporation. This helps to explain the presence of moist soils below surfaces covered with cryptogams in numerous sites. The studies by Bell and Bliss (1980) and Sohlberg and Bliss (1984) show that seedling establishment for many species is such higher on moss mats and in desiccation cracks with mosses. There appear to be a large number of seeds within these cryptogam mats, but seed germination and seedling establishment are not abundant in these communities (Bell and Bliss 1980). Seeds are transported over the snow to a limited extent, and the number of seeds contained in the lower crusted layers of snow in spring reflect, in general, vascular plant density and seed production within cryptogam-herb and graminoid barren communities (Grulke and Bliss 1983). crop, and net annual plant production, the present data indicate that these landscapes, dominated by cryptogams with scattered vascular plants, are intermediate between the lush sedge-moss meadows and other communities of the Low Arctic, and the very barren polar deserts. It is for these reasons that the name polar semidesert has been chosen for these landscapes. This concept was first advanced for communities dominated by cushion plants on the Truelove Lowland (Svoboda 1973). Standing crop and net production There arc few data in the literature for a comparison of standing crop and net annual production in similar higharctic plant communities. At Maria Pronchitsheva Bay, USSR (76''N), Matveyeva et al. (1975) reported aboveground phytomass of 30-33 g m ' and a net annual production of 27 g m"-^ in a cushion plant-moss community. Phytomass and net production were 68 and 72 g m- respectively in an herb-moss community at the same site. Aleksandrova (1969) reported a biomass of 6 g m for vascular plants, 123 g m- for mosses and lichens and 29 g m ' belowground for a moss-lichen polygonal desert community on Alexandra Land Island, USSR. This plant community and the herb-moss community data from Maria Pronchitscheva Bay may be communities somewhat simitar to the cryptogam-herb meadows reported here. Wein and Renez (1976) reported aboveground standing crop (including dead plants) data of 3427 g m- and 4078 g m ' for two sedge-moss meadows. They present other standing crop data ranging from 154 to 1045 g m- but do not provide species or community names. As stated earlier, the soils of these plant communities are deficient in nitrogen and phosphorus. In the mossgraminoid and cryptogam-herb communities there are often small mats of Nostoc commune following spring In our study, standing crop (aboveground plus bemelt. However, for much of the summer these colonies lowground) ranged from 27 g m % in the Puccinella and are dry. and therefore unable to fix nitrogen. Prelimin- Alopecurus barrens on Ellef Ringnes Island to the more ary studies indicate that some sites with moist soils representative 900 to 23(H) g m - in various cryptogamcovered by the liverwort Gymnomitrion corallioides herb and graminoid meadows. In all but the graminoid have higher rates of nitrogen fixation than nearby sites barrens and one graminoid meadow community, mosses without this species (Dawson, pers. comm.). Further contribute 85-98% of aboveground standing crop (exresearch is necessary to determine the organisms re- cluding litter). Although lichens may be conspicuous, sponsible for fixation and the magnitude of the fixation they contribute little biomass. rates. Total plant production above and beiowground Soil texture and available soil moisture during the ranged from 19 to 59 g m"^ in the cryptogam-herb, mossinfrequent, drier summers appear important in the lim- graminoid, and graminoid steppe communities. These ited sorting of species into community types. The wet- data are similar to those reported by Svoboda (1977) in lands with Dupontia and Eriophorum and the dry wing- polar semi-deserts dominated by cushion plants on the swept ridges with Saxifraga oppositifolia, S, caespiiosa, Truelove Lowland, Devon Island (20 to 50 g m""). and Draba corymbosa are obvious extremes in the landscape, more subtle is the patterning within the cryp- Acknowledgements - Logistic and field aimp support were togam-herb and moss-graminoid grouping of "commu- provided by Panarctic Oils Ltd. Other field support was funded nities". The importance of soil texture and soil moisture from consulting fees provided to the senior author from the Protection Canadian Gas in the patterning of communities was also recognized by EnvironmentalN.S.F. GrantBoard of thefunded the Arcticwork Project, Ltd. #79-13421 field Ediund (1980) on Lougheed Island. the past three years and the ordination runs and map preparaOn the basis of detailed physiological and microen- tion by Linda Kunze. Laboratory analyses of plant material vironmental studies on King Christian Island and the were made possible by N.R.C. grants to both authors. Dwight Bliss prepared with the field work. extensive studies of soils, plant communities, standing Christine Woo the geology and helpedsamples and Bonnie sorted ihe biomass 342 HOLARCnC ECOLOGY Bergsma tabulated the data. Soil analyses were made by Northwcsi Soil Research. Ltd.. Edttionton.,Lichens were identified by 1. M. Brodo and bryophytes by D. H. Vitt. Kcrcrences Addison, P. A. 1977. Studies on evapotranspiration and energy budgets on Trueiove Lowland. - In: Bliss, L. C. (ed.), Truclove Lowland, Devon Island. Canada: A high arctic ecosystem. 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Journal

EcographyWiley

Published: Sep 1, 1984

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