"Wetlands"

Tolliver, Kathryn S.;Martin, David W.;Young, Donald R.

doi: 10.1007/BF03160714pmid: N/A

Abstract Flood sensitivity of five woody species common to barrier island swale habitats was quantified in a glasshouse study to examine potential mechanisms affecting observed small-scale distribution patterns. Differential response to short-term (30 d duration) freshwater and saltwater flooding occurred among the five species. OnlyBaccharis halimifolia was sensitive to freshwater flooding. At both low (2 and 5 g L−1) and mid-range (10 g L−1) salinity,Myrica cerifera, Pinus taeda, andB. halimifolia were more sensitive thanJuniperus virginiana orIva frutescens. At low salinity, stomatal conductance was significantly reduced forM. cerifera, P. taeda, andB. halimifolia, although recovery occurred and there was no mortality. At midrange salinity, all five species showed reduced stomatal conductance, but recovery differed. Mortality was highest forM. cerifera andB. halimifolia (60%), followed byP. taeda (40%),I. frutescens (25%), andJ. virginiana (20%). In contrast, 100% mortality occurred for all species in high salinity treatments of 20 and 30 g L−1. Interspecific differences in response to flooding may be a mechanism affecting small-scale distribution patterns of woody species in barrier island swales.

Lent, Robert M.;Weiskel, Peter K.;Lyford, Forest P.;Armstrong, David S.

doi: 10.1007/BF03160715pmid: N/A

Abstract Two sets of hydrologic indices were developed to characterize the water-budget components of nontidal wetlands. The first set consisted of six water-budget indices for input and output variables, and the second set consisted of two hydrologic interaction indices derived from the water-budget indices. The indices then were applied to 19 wetlands with previously published water-budget data. Two trilinear diagrams for each wetland were constructed, one for the three input indices and another for the three output indices. These two trilinear diagrams then were combined with a central quadrangle to form a Piper-type diagram, with data points from the trilinear diagrams projected onto the quadrangle. The quadrangle then was divided into nine fields that summarized the water-budget information. Two quantitative “interaction indices” were calculated from two of the six water-budget indices (precipitation and evapotranspiration). They also were obtained graphically from the water-budget indices, which were first projected to the central quadrangle of a Piper-type diagram from the flanking trilinear plots. The first interaction index (I) defines the strength of interaction between a wetland and the surrounding ground- and surface-water system. The second interaction index (S) defines the nature of the interaction between the wetland and the surrounding ground- and surface-water system (source versus sink). Evaluation of these indices using published wetland water-budget data illustrates the usefulness of the technique.

Miller, Deborah L.;Smeins, Fred E.;Webb, James W.;Longnecker, Michael T.

doi: 10.1007/BF03160716pmid: N/A

Abstract Interaction of herbivory by wintering lesser snow geese (Anser caerulescens caerulescens), environmental conditions, and burning were investigated in a mid-Texas coastal marsh dominated byScirpus americanus (Olney bulrush). Goose grubbing and use ofS. americanus rhizomes and roots initially produced a patchwork of denuded and vegetated areas on a recently burned area. Regrowth occurred by reestablishment of uprooted shoot complexes; regeneration from seed was not observed. Regrowth was dependent on intensity of use and post-herbivory environmental conditions. After three years of varying levels of goose use and environmental conditions, lowest foliar cover and standing crop occurred in areas with a high frequency and intensity of goose use followed by spring drought and high salinities. Greatest growth was associated with low frequency and intensity of use followed by normal spring freshwater inflows and low salinities. Burning did not significantly affect the response ofS. americanus. Continued frequent and intense snow goose use, coupled with high salinity and extended periods with water levels below the marsh surface, can produce denuded mudflats subject to accelerated soil erosion. Management strategies to reduce the impact of these combined events could be implemented. Hydroperiod and salinity conditions should be routinely monitored, and goose populations should be temporally and spatially directed to reduce the potential for conversion of marsh to permanent mudflats.

Johnson, David L.;Lynch, William E.;Morrison, Todd W.

doi: 10.1007/BF03160717pmid: N/A

Abstract Most (84%) of Ohio’s remaining Lake Erie wetlands are diked to maximize food production and habitat for migrating waterfowl. Typically these wetlands are partially drained during spring and refilled the following fall. Fish populations have not been managed extensively, probably because few quantitative data are available on fish communities in diked wetlands and on how water-level manipulations affect these communities. We used trap nets to sample fish monthly (April–August) in diked West Marsh and in the formerly diked Muddy Creek Bay. We compared fish communities on the basis of species richness, composition, and equitability; relative abundance; and mean length and body condition of species common to both areas. We collected 23 species from the diked area and 40 species from the undiked area. Although there were more species collected in the undiked area, species equitability was greater in the diked wetland. The five most abundant species in the diked wetland were white crappiePomoxis annularis, brown bullheadAmieurus nebulosus, black bullheadA. melas, goldfishCarassius auratus, and common carpCyprinis carpio. The dominant species in the undiked area were white perchMorone americana, gizzard shadDorosoma cepedianum, white crappie, brown bullhead, and yellow perchPerca flavescens. Neither area contained a classical, diverse wetland fish community. Mean lengths of white crappie, common carp, goldfish, and brown bullhead were significantly greater from the undiked area during all months. Body condition indices of > 150 mm white crappies and > 225 mm brown bullheads were significantly greater in the undiked area after June The large differences in length and condition indices indicate that fish communities in the diked wetland may be biologically isolated from those in the adjacent undiked area. This has management implications given that an almost complete exchange of water occurs annually and could result in extensive movement of fish in and out of the diked wetland. Management strategies compatible with or enhancing existing wildlife management strategies need to be developed for improving fish communities in diked wetlands and enhancing their contribution to Lake Erie.

Spencer, David F.;Ksander, Gregory G.

doi: 10.1007/BF03160718pmid: N/A

Abstract Vegetative propagules ofPotamogeton pectinatus, P. gramineus, andHydrilla verticillata were exposed to aerobic or anaerobic atmospheres for 7, 14, or 21 days in the dark at 18°C or 7°C. There were no differences in the proportion of propagules sprouting due the presence or absence of oxygen. However, propagules exposed to an anaerobic atmosphere at 18°C sprouted sooner than those exposed to an aerobic atmosphere. This effect was less apparent when exposure to anaerobic conditions was at 7°C. In field experiments,Potamogeton gramineus winter buds were buried at 4 depths in Byrnes Canal sediment. Those buried for 25 days at 25 cm (where sediment redox potential is < 50 mV and conditions are likely hypoxic) showed discoloration consistent with sulfide deposition, and they sprouted more rapidly than winter buds buried at 5 or 15 cm. As the duration of burial in Byrnes Canal sediment increased, propagule sprouting time decreased. Predicting the timing of propagule sprouting in habitats with fluctuating water levels may benefit from information on seasonal changes in the oxygen status of the sediments.

Knott, David M.;Wenner, Elizabeth L.;Wendt, Priscilla H.

doi: 10.1007/BF03160719pmid: N/A

Abstract We examined the recovery of vegetation and salt marsh macrofauna in a pipeline construction corridor at two locations where it intersected intertidal salt marshes near Charleston, SC. The impacts of construction were evaluated prior to construction and for subsequent periods of 34 and 46 months at the two sites using aerial photography and three field sampling methods. Quadrats were used to estimate densities of selected salt marsh invertebrates, as well as stem densities and aboveground wet-weight biomass ofSpartina alterniflora; pit traps were employed to simulate natural tidal pools for sampling small, motile epibenthic macrofauna that remained on the marsh surface at low tide; and flume nets were used to sample the natant macrofauna that used the marsh edge at high tide. The analyses of vegetation by quadrat and aerial imagery clearly showed that the recovery ofSpartina was more rapid and complete at the Ashley River site (88%) than at Wappoo Creek (48%). In contrast to this apparent, if partial, vegetative recovery, several salt marsh invertebrates, including,Littorina irrorata andGeukensia demissa, were eliminated from the corridor during construction and showed scant recovery by the end of our study. Differences in species composition and abundance of natant organisms in the flume net collections also supported the conclusion that faunal recovery was incomplete after 3–4 years at these sites. The recovery of functional equivalency of the excavations, compared with natural marshes, was not evaluated during our study, but we speculate that their functioning may equilibrate over time, since preexisting hydrologic conditions are more or less intact, seedstock forSpartina revegetation is nearby, and macrofauna will probably eventually reestablish themselves from adjacent areas.

Nuttle, William K.

doi: 10.1007/BF03160720pmid: N/A

Abstract The pattern of water-level fluctuations in a wetland is its hydroperiod. Characterization of this pattern cannot be accomplished by measuring a single parameter, but some means of measuring hydroperiod is needed so that comparisons can be made both between wetlands and within a single wetland over time Harmonic analysis can be used to characterize hydroperiod quantitatively by obtaining the amplitude and timing of the dominant periodic component in a time series of water levels. The utility of this method is demonstrated by investigating the link between water management in South Florida and nesting failure by wood storks in the Everglades wetland. With the quantitative measures of hydroperiod derived by harmonic analysis, I am able to demonstrate statistically the relationships between water management and hydroperiod in the Everglades and between hydroperiod and the probability of nesting failure. The simplicity and directness by which these results are achieved suggests the potential for harmonic analysis of hydroperiod as a general tool for wetland science.

Stauffer, Aura L.;Brooks, Robert P.

doi: 10.1007/BF03160721pmid: N/A

Abstract To evaluate the efficiency of different methods of wetland plant establishment and different soil amendments, 16 experimental plots in 4 treatment groups were established at a 6-ha created palustrine wetland in Tipton, PA. Response of vegetation, soil, and hydrology were evaluated. The first objective of the study was to determine if salvaged marsh surface (SMS) from a donor wetland can be used to effectivly vegetate experimental plots. The results were compared with control plots. In addition, the possibility of using a non-toxic organic waste (leaf litter compost) as a soil amendment to created wetland projects was examined. Lurid sedge (Carex lurida) tubers were hand-planted in the leaf litter plots and in the existing mineral soils of the remaining experimental plots. SMS plots had significantly greater plant species richness, total vegetative coverage, and diversity than control plots. SMS plots contained more hydrophytic vegetation and less undesirable vegetation than control plots. SMS added significant amounts of organic matter and soil nutrients (e.g., nitrogen) to the soils in treated plots. Survivorship of hand-plantedCarex was greater (79.0 ±5.0 % for both July and August 1992) on plots treated with leaf litter compost than on plots with existing mineral soils (45.0±20.0% in July and 38.0±20.0% in August 1992). Organic matter, pH, total N, and N03 levels were all significantly greater on leaf litter plots than on hand-planted plots after the 1991 growing season. At the end of the 1992 growing season, organic matter, pH, NO3, and NH4 levels were significantly greater on leaf litter plots than on hand-planted plots. The results of the study suggest that SMS can be used as a method to successfully revegetate created wetlands. Also, the addition of leaf litter compost to experimental plots helped to retain soil moisture and provide nutrients that enhanced survivorship of hand-plantedCarex.

Euliss, Ned H.;Jarvis, Robert L.;Gilmer, David S.

doi: 10.1007/BF03160722pmid: N/A

Abstract We examined carcass composition and proximate food composition of ruddy ducks (Oxyura jamaicensis), northern shovelers (Anas clypeata), and northern pintails (Anas acuta) wintering on agricultural drainwater ponds in California during 1983–84. Lipids varied seasonally in northern shovelers and northern pintails. Protein did not fluctuate except in ruddy ducks whose protein mass increased over winter, suggesting that some protein was catabolized prior to arrival on wintering areas or that a buildup of protein occurred prior to spring migration. Waterfowl diets varied among species and time, but the nutritional composition of the diets was relatively stable. Ruddy ducks and shovelers consumed mostly animal foods rich in protein (53–60%) and low in Nitrogen Free Extract (NFE)(1–7%). Pintail diets contained more NFE (23–38%) and less protein (14–38%) because of greater consumption of plant foods. Nutritional composition of pintail diets varied with lower protein consumption occurring from November through January.