"Wetlands"

Finlayson, C. M.;Davies, Gillian T.;Moomaw, William R.;Chmura, G. L.;Natali, Susan M.;Perry, J. E.;Roulet, N.;Sutton-Grier, Ariana E.

doi: 10.1007/s13157-018-1064-zpmid: N/A

Abstract The Second Warning to Humanity provides a clarion call for wetland researchers and practitioners given the loss and degradation of wetlands, the declining availability of fresh water, and the likely consequences of climate change. A coordinated response and approach to policies has the potential to prevent further degradation and support resilient wetlands that can provide a range of ecosystem services, including buffering wetlands from climate impacts, and avoiding major climate amplification from temperature-induced release of additional carbon dioxide and methane while addressing the causes and consequences of global climate change. The Warning to Humanity also provides an opportunity for organisations such as the Society of Wetland Scientists to raise the profile of wetlands and to initiate a discussion on how to respond and change direction from the destructive development trajectory that led to wetland loss and degradation. It also provides a signal for a reappraisal of the effectiveness of the implementation of the Ramsar Convention on Wetlands as an international mechanism for ensuring the sustainability of wetlands.

Popov, Igor;Sinelshikova, Alexandra;Markovets, Mikhail;Bulyuk, Victor

doi: 10.1007/s13157-018-1018-5pmid: N/A

Abstract The wetlands of Central Asia, including many of high ecological value, are poorly studied and poorly represented in international conservation activities. The Sorokaoziorki (“Forty Lakelets”) complex of wetlands, located in the arid Koibalskaya steppe (Republic of Khakassia, Russian Federation), falls into this category. We documented the origin of the complex’s wetlands, patterns of land use and economic activities, and use of the area by multiple bird, mammal, and fish species. The “lakelets” of the Sorokaoziorki originated from a dried river bed that refilled relatively recently with water introduced from irrigation activities. The resultant wetlands and surrounding wet grasslands within the Sorokaoziorki complex represent a refuge for wildlife, while the surrounding steppe has been turned to pasture. Located at a crossroads of bird flyways, at least 140 bird species use the Sorokaoziorki complex to nest or as a stop-over point during migration. Additionally, we documented the occurrence of seven fish, one lamprey, and seven mammal (including three bat) species within the complex. The planting of sea-buckthorn (Hippophaё rhamnoides) and the restriction of grazing around the edges of the wetlands in the Sorokaoziorki wetland complex has contributed to the conservation of this ecologically important area.

Correll, Maureen D.;Hantson, Wouter;Hodgman, Thomas P.;Cline, Brittany B.;Elphick, Chris S.;Shriver, W. Gregory;Tymkiw, Elizabeth L.;Olsen, Brian J.

doi: 10.1007/s13157-018-1028-3pmid: N/A

Abstract Salt marshes of the northeastern United States are dynamic landscapes where the tidal flooding regime creates patterns of plant zonation based on differences in elevation, salinity, and local hydrology. These patterns of zonation can change quickly due to both natural and anthropogenic stressors, making tidal marshes vulnerable to degradation and loss. We compared several remote sensing techniques to develop a tool that accurately maps high- and low-marsh zonation to use in management and conservation planning for this ecosystem in the northeast USA. We found that random forests (RF) outperformed other classifier tools when applied to the most recent National Agricultural Imagery Program (NAIP) imagery, NAIP derivatives, and elevation data between coastal Maine and Virginia, USA. We then used RF methods to classify plant zonation within a 500-m buffer around coastal marsh delineated in the National Wetland Inventory. We found mean classification accuracies of 94% for high marsh, 76% for low marsh zones, and 90% overall map accuracy. The detailed output is a 3-m resolution continuous map of tidal marsh vegetation communities and cover classes that can be used in habitat modeling of marsh-obligate species or to monitor changes in marsh plant communities over time.

Lavallee, Amanda;Campbell, Daniel

doi: 10.1007/s13157-018-1058-xpmid: N/A

Abstract Boreal and subarctic peatlands may become increasingly used for wastewater tertiary treatment. Colleagues added simulated secondarily-treated wastewater to a subarctic ladder fen over two growing seasons. We examined how carbon storage and nutrient relations changed for key Sphagnum species. We measured the productivity, decomposition, nutrient content, C:N and N:P ratios of Sphagnum species on ridges and pool edges, and the nutrient relations of a third Sphagnum species in pools, compared to a control fen. Closer to the point source, S. fuscum on ridges had a 2-fold increase in productivity, and Sphagnum rubellum along pond edges had a 4 to 12-fold increase in productivity, but areas beyond 50 m downgradient were not affected. The decomposition of S. fuscum did not change, and S. rubellum showed only a slight increase close to the point source. Consequently, net carbon storage increased in Sphagnum within <50 m of the point source. Nutrient effects were apparent in the pools and pool margins, whereas ridges were hardly affected. N:P was the most sensitive nutrient parameter, increasing within 50 m. In the short-term, subarctic peatlands exposed to simulated secondarily-treated wastewater increased their carbon storage. Ridges in string fens were most resilient to nutrient amendments.

Amatya, Devendra M.;Fialkowski, Marcin;Bitner, Agnieszka

doi: 10.1007/s13157-018-1069-7pmid: N/A

Abstract The objective of this paper is to present a relatively simplified model to predict daily water table (WT) by solving ordinary differential equation dWT (t)/dt = F (α1, α2, α3, WT0(t), RF (t), PET (t)), with α1, α2, α3, WT0 as parameters, and RF (rainfall) and PET (potential evapotranspiration), respectively, as inputs. The model was calibrated and validated with WT on four poorly to moderately drained soils (Lenoir, Rains, Lynchburg, and Goldsboro) on a forested wetland. Calibration results were in good agreement with the measured WT for all soils, except the Goldsboro with deeper WT. r2 (coefficient of determination) and NSE (Nash-Sutcliffe Efficiency) statistics both ranged from 0.81 for the Lenoir to 0.89 and 0.87, respectively, for the Lynchburg. Average absolute daily deviation (AADD) varied from 10.8 cm for Lenoir to 16.7 cm for Rains. The performance was somewhat poorer, during relatively dry periods with deeper WT, yielding r2 and NSE as low as 0.55 and 0.29, respectively, for Lenoir, and large AADD for Lynchburg. Discrepancies were associated with WT overprediction for deeper depths. The new model is capable of describing the WT for poorly drained high water table soils, with a potential for assessing effects of land management, wetland hydrology, and climate changes.

Kettenring, Karin M.;Menuz, Diane R.;Mock, Karen E.

doi: 10.1007/s13157-018-1074-xpmid: N/A

Abstract Cryptic invaders are inherently difficult to study due to morphological similarity with native lineages of the same species or genus. Wetland and riparian systems are particularly prone to plant invasions, and have been impacted by a number of widespread cryptic invaders such as Phalaris arundinacea (reed canarygrass). Here we combine molecular genetic analyses with species distribution modeling to assess the nativity of Phalaris and determine potential drivers of non-native Phalaris invasion in riparian areas across a large region of the semiarid northwestern USA. Based on our genetic analyses, we found that throughout our study region Phalaris is largely non-native, and no modern-day samples from our study region were of native North American origin. At least half of the four species distribution models suggested that non-native Phalaris invasion across the region was associated with warmer temperatures, more growing days, wetter summers, drier winters, higher nitrogen levels, shallower stream slopes, and at sites closer to roads and without a history of grazing. These findings can be used to determine the best locations for targeted monitoring. Furthermore, there is the potential for increased Phalaris invasion with climate change-induced temperature increases.

Li, Xiaowei;Hou, Xiyong;Song, Yang;Shan, Kai;Zhu, Shuyu;Yu, Xiubo;Mo, Xunqiang

doi: 10.1007/s13157-018-1075-9pmid: N/A

Abstract The population of shorebirds in the East Asian–Australasian Flyway (EAAF) has severely declined over the past several decades. One reason for this condition is low survival in stopover sites in the Yellow Sea Ecoregion (YSE) due to habitat degradation. Here, we focused on shorebird habitat quality in the Yellow River Delta (YRD), which is a representative shorebird stopover site in the YSE on the EAAF. We used the InVEST model to assess the past and future shorebird habitat quality changes by considering the effects of anthropogenic threats. The entire duration of the study was 1999–2016, and the modeling was done on 2000 and 2015 data. Our results indicate that the abundance of 11 shorebird species had significant downward trends (70–97% reduction) during 1999–2015. Tidal flats in the nature reserve had higher habitat quality than that in the northwestern (NW) and eastern (E) parts of the YRD because major mariculture occurred in NW and E. The mean habitat qualities in NW and E decreased by 27 and 31% during 2000–2015, respectively. The optimal habitat in the YRD declined from 1433 km2 in 2000 to 1154 km2 in 2015. The habitat quality decreased significantly in E and Dongying Port parts during 2015–2020.

Hartsock, Jeremy A.;Wieder, R. Kelman;Vile, Melanie A.

doi: 10.1007/s13157-018-1066-xpmid: N/A

Abstract To evaluate the effects of increasing atmospheric N deposition on net C and N accumulation in Sphagnum-dominated bogs, we conducted a laboratory mesocosm experiment. Following 45 days of watering with N-free rainwater, mesocosms were exposed to simulated atmospheric N deposition values of 0, 4.14, 8.18, and 12.42 mg N m−2 da−1 over a 108 day period. We quantified N retention from leachate N concentrations and from changes in N contents of the Sphagnum/peat mesocosms. As N loading of simulated atmospheric N deposition increased, so did the net retention of simulated atmospherically deposited N. Our hypothesis of a decrease in N retention efficiency with increasing N loading was not observed. Further, for each N loading treatment, rates of retention of simulated atmospherically deposited N remained constant over time. We did not observe a threshold N deposition below which N would be retained in mesocosms and above which N passed through the mesocosms. Substantially more N was retained in mesocosms that was added in simulated atmospheric N deposition, suggesting an unaccounted for N source, most likely biological N2 fixation. In locations where N2 fixation represents a much greater source of new N to Sphagnum-dominated bogs, as in northern Alberta, Canada, increasing atmospheric N deposition may have a minimal effect on overall net N accumulation in peat.

McDaniel, Courtney H.;Batzer, Darold P.

doi: 10.1007/s13157-018-1070-1pmid: N/A

Abstract Effects of river regulation on floodplain ecosystems are understudied, despite the importance of connectivity between these two ecosystems. We investigated the effects of river regulation on a floodplain specialist, Neoporus spp. (Coleoptera: Dytsicidae), regarding its distribution, behavior, and physiology. We used flood pulses (induced in the regulated river system, natural in the unregulated system) to determine if and how 60 years of river regulation has impacted Neoporus populations. We found distinct distributions of Neoporus across the regulated and unregulated floodplains, with the regulated population being limited to permanent oxbow lakes (as compared to Neoporus in the unregulated system accessing temporary and permanent aquatic habitats to an equal degree). Following flood pulses, both the regulated and uregulated river population distributions remained the same. Aerial dispersal percentages did not change in the regulated population pre- vs. post-flood, but dispersal within the unregulated population decreased. Lipid and protein concentrations in Neoporus did not differ between habitat types. Our study provides evidence of long-term effects of river regulation on a floodplain specialist and further emphasizes the significant contribution provided by flood pulses and their importance to the overall functioning of floodplain ecosystems.

Lee, Philip O.;Shoemaker, Cory;Olson, Julie B.

doi: 10.1007/s13157-018-1077-7pmid: N/A

Abstract Soils from four sites distributed along an elevation gradient from marsh to coastal forest in a wetland bordering the Gulf of Mexico were sampled over a 16-months period. In addition to measuring a suite of environmental conditions, terminal restriction fragment length polymorphism analyses of the resident bacterial communities were performed. Wetland soil bacterial communities varied across both space and time, with all measured variables (temperature, pH, percentage of soil organic matter, salinity, and concentrations of sulfide, NH4+, NO3−, and soluble reactive phosphorus) showing significant site by time interactions. Analyses of bacterial communities showed both marsh zones (Spartina and Cladium) supported similar communities, as did the ecotone and coastal forest. Bacterial communities within coastal forest soils were significantly different than those within marsh soils, and the ecotone communities were significantly different from the Spartina marsh soil. Temperature and pH were the most influential environmental factors impacting bacterial community composition but no predictable patterns were identified, suggesting that community changes are likely the result of intrinsic factors that are affected by local-scale processes. The dynamic nature of the physiochemical variables within wetlands suggests that more work is needed to determine potential interactive effects on bacterial community structure.