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Copyright of Canadian Water Resources Journal / Revue Canadienne des Ressources Hydriques is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The U.S. Fish and Wildlife Service (Service) is a primary manager of federal public lands in the northern Great Plains region, with over 400,000 hectares (ha) of mostly grassland and wetland administered under the National Wildlife Refuge System (NWRS). More specifically, the Service manages > 100,000 ha of mixed-grass and tallgrass prairie in northern Great Plains states. Prairies range from small, isolated < 16-ha tracts embedded in agricultural landscapes to > 10,000-ha contiguous tracts embedded within grassland-dominated landscapes. The mission of the NWRS is uniquely wildlife/wildland oriented, with human uses secondary in importance. As such, the expectation is that natural plant communities occur as relatively high-quality habitats. Grant et al. (2009) explored this expectation, concluding that "Despite 40–70 years of protection, the integrity of many prairies held in public trust continues to decline, primarily because of invasion by cool-season, introduced plants and woody vegetation." To address this concern, the Service proposed a program to evaluate restoration of Service-owned prairies following principles of adaptive management, including a decision support function. Our purpose in this paper is to update 14 years of development and implementation of the Native Prairie Adaptive Management (NPAM) program. We confirmed that Service-owned prairies continue to be degraded by invasive plants, especially Bromus inermis (smooth brome) and Poa pratensis (Kentucky bluegrass). However, NPAM has facilitated a significant gain in our understanding of ecological restoration and management of prairies in the region, increasing hope that restoration successes can occur when viewed over the long-term (i.e. many decades). [ABSTRACT FROM AUTHOR]

Climate change is likely to imperil native biodiversity through the increased frequency of extreme events. Here we address the short-term effects of an extreme flooding event on an unplowed prairie reserve, the Faville Prairie Wisconsin State Natural Area. This 25-ha property is a remnant of the formerly extensive Crawfish Prairie that lay on the east bank of the Crawfish River, Jefferson County, Wisconsin USA. The Faville remnant has historically been subject to late winter to spring flooding in its lower portions. In June of 2008, however, an extreme rainfall event caused flooding unprecedented in the 87-year history of streamflow, inundating the entire site. Data were available from 180 permanently marked plots sampled in 1978–79. We assessed the change by resampling these plots in 2010–2015. At the m2 scale, we found significant losses of species richness, a result of most species having fewer occurrences than in the earlier data. There was near extinction of several important prairie species and a relative increase in wetland tolerant species. Lower elevation plots, subject to the encroachment of woody plants and the invasion of Phalaris arundinacea for decades prior to the flood, had the lowest levels of species richness. However, some prairie species survived the flooding with little change, and recent anecdotal observations show that others are rebuilding their populations. Thus, if extreme floods are infrequent, the prairie should be able to recover to its former state. If, however, the hydrological regime shifts toward more frequent, growing-season floods, we predict further decline in those plant species that were the object of the preservation of this remnant. It is critical that fire management continue along with monitoring to track species' recovery or replacement, so that corrective measures can be identified and tested to sustain the native prairie species diversity. [ABSTRACT FROM AUTHOR]

Patterns of resource selection depend upon an animal's behavioral state. Because management strategies are often crafted from an understanding of animal space use, incorporating behavior explicitly into analyses of resource selection has the potential to improve outcomes. In the Prairie Pothole Region of Manitoba, Canada, raccoons (Procyon lotor) are a nest predator of waterfowl, but it is unclear how raccoons use this landscape during the waterfowl nesting season. Our objective was to use high‐resolution global positioning system (GPS) telemetry to differentiate among behaviors by raccoons and evaluate behavior‐specific habitat selection during the waterfowl nesting season. We collected approximately 32,000 locations from 33 animals during the 2018, 2019, and 2021 nesting seasons, amounting to 632 animal‐night's worth of movement data. We used hidden Markov models (HMM) to fit 4‐state models to the movement trajectories, classified observations into discrete behaviors, and fit behavior‐specific random forest resource selection models to evaluate the relative importance of habitat features on selection. Proximity to a wetland was the most important variable contributing to selection for the resting, foraging, and slow travel states. Probability of use was as high as 95% within or immediately adjacent to a wetland for animals engaged in those behaviors, and our best HMM predicted increasing probability of switching from resting or foraging to directed travel with increasing distance from a wetland edge. Human‐use sites were also important to foraging animals, suggesting raccoons subsidize their diet with anthropogenic food resources during spring and summer. These results illuminate the complexity of habitat selection by a waterfowl predator in this patchy landscape, allowing managers to develop effective conservation strategies (e.g., wetland prioritization and conservation, elimination of anthropogenic subsidies) where raccoons are having a disproportionate effect during the waterfowl nesting season. [ABSTRACT FROM AUTHOR]

Wetland permanence, the duration and frequency that surface water is present, affects biological communities and whether wetlands are protected under legislation in some jurisdictions. Wetland drainage in the Prairie Pothole Region (PPR) has changed the distribution of wetlands because smaller and more temporary wetlands are more likely to be drained. This change in distribution affects biodiversity and other wetland ecosystem services. In Manitoba, Canada, wetlands are treated differently under the Water Rights Act based on permanence classification and can either be drained with a simplified registration (temporary and ephemeral wetlands), drained with a permit requiring mitigation (seasonal wetlands), or are protected from drainage (semipermanent and permanent wetlands). To facilitate implementing a conservation program targeting the most vulnerable wetlands, we built a classification model using LiDAR and Sentinel‐2 data (1312 training observations). Our random forest model had 73% accuracy on 563 test observations and is applicable across the agricultural region of southwestern Manitoba. We predicted the wetland permanence class of 365,499 wetlands and built an online tool to help practitioners implement a conservation program that pays producers to conserve temporary and ephemeral wetlands. Our approach is applicable elsewhere in the PPR and other regions with variation in wetland permanence. [ABSTRACT FROM AUTHOR]

Periodic assessments of reference condition wetlands are needed to determine changes over time; however, they are rarely conducted. The vegetation from past assessments, 1998 to 2004, was compared to 2016 assessments of 12 reference wetlands in the Missouri Coteau sub-ecoregion of the Prairie Pothole Region using nonmetric multidimensional scaling and permutational multivariate analysis of variance. Analyses indicated the vegetation in the 2016 assessments trended away from the abundance of native highly conservative species as found during the 1998 to 2004 assessments. Instead, the 2016 plant communities trended towards lower abundance of the same native conservative species and higher abundance of non-native species. Both the average coefficient of conservatism values and floristic quality index values significantly declined, supporting the interpretation that reference wetlands were moving towards plant communities with lower abundance of highly conservative species. The assumption that reference wetlands in the Prairie Pothole Region will change little over time is challenged by these findings. Vegetation in refence wetlands within the Prairie Pothole Region is no longer resembles past monitoring and is trending towards a distinct vegetation composition. Future management will need to consider the potential of reference wetlands' vegetation composition moving away from a historic baseline and how this may impact future wetland assessment, especially when vegetation is compared to reference conditions. [ABSTRACT FROM AUTHOR]

Overwintering in shallow habitats presents a serious obstacle for aquatic invertebrates. Here we investigated the little-known ability of water boatmen (Hemiptera: Corixidae), an aquatic insect, to survive the winter encased in air pockets within the ice of shallow wetlands. We extracted and experimentally thawed large blocks of ice from prairie wetlands in Saskatchewan, Canada, from which we examined the species composition and revival of corixids. While multiple corixid species were present in wetlands prior to freeze-up, a single species, Cymatia americana Hussey, 1920, comprised the vast majority of corixids that were found within the ice later in winter. Only 4%–9% of corixids, all Cymatia americana, revived after ice thawing over both study years. Being encased within an air pocket appeared to be necessary for the survival of corixids in the ice, with up to 300 individuals grouped together. Other invertebrate taxa also revived after thawing, including Haliplidae and Dytiscidae (Coleoptera) encased within air pockets both alongside corixids and on their own, as well as Coenagrionidae (Odonata), Phryganeidae and Leptoceridae (Trichoptera), Chironomidae (Diptera), and Physidae and Planorbidae (Basommatophora), which appeared to be encased in solid ice. The ability to overwinter inside ice represents a little understood survival mechanism of aquatic invertebrates in shallow wetlands, which could confer energetic and reproductive advantages to those that endure until spring. [ABSTRACT FROM AUTHOR]

Wetlands in the Prairie Pothole Region of the North American Northern Great Plains perform multiple ecosystem services and are biodiversity hotspots. However, climatological changes can result in sudden shifts in these important ecosystems. For example, marked increases in precipitation in the last few decades have resulted in a widespread shift in wetlands across the Prairie Pothole Region to a new ecohydrological state. We used multiproxy analyses (diatom community composition and invertebrate stable isotopes) of 210Pb‐dated sediment cores from two adjacent, but morphologically and hydrologically different, prairie‐pothole wetlands to assess the effects of hydroclimatic variability on these wetland ecosystems. Our results provide evidence that the recent ecohydrological shift in the region's wetlands is unprecedented over the past ca. 178 yr. Oxygen stable isotopes in chironomid head capsules provide a record of paleohydrology changes. The most recent sediments (i.e., those deposited after the state shift) from both wetlands revealed novel changes in diatom communities that differed greatly from earlier community compositions. In addition, a depleted signal in deuterium and 13C carbon stable isotopes observed in chironomid head capsules and Daphnia ephippia, respectively, after 1993 is likely related to an increase in methane production in these wetlands. Our study highlights the importance of considering basin morphometry including whether a wetland has an overflow point, and multiple biological indicators to study climate‐change influences on freshwater ecosystems. Research using these techniques can lead to an improved understanding of recent ecosystem shifts, an understanding that will be essential for future climate‐change adaptation and mitigation in this ecologically important region. [ABSTRACT FROM AUTHOR]

Species often exhibit regionally specific habitat associations, so habitat association models developed in one region might not be accurate or even appropriate for other regions. Three programs to survey wetland‐breeding birds covering (respectively) Great Lakes coastal wetlands, inland Great Lakes wetlands, and the Prairie Pothole Region offer an opportunity to test whether regionally specific models of habitat use by wetland‐obligate breeding birds are transferrable across regions. We first developed independent, regional population density models for four species of wetland‐obligate birds: Pied‐billed Grebe (Podilymbus podiceps), Virginia Rail (Rallus limicola), Sora (Porzana carolina), and American Bittern (Botaurus lentiginosus). We then used adjusted pseudo‐R2 values to compare the amount of variation explained by each model when applied to data collected in each of the three regions. Although certain habitat characteristics, such as emergent vegetation and wetland area, were consistently important across regions, models for each species differed by region—both in variables selected for inclusion and often in the directionality of relationships for common variables—indicating that habitat associations for these species are regionally specific. When we applied a model developed in one region to data collected in another region, we found that explanatory power was reduced in most (71%) models. Therefore, we suggest that ecological analyses should emphasize regionally specific habitat association models whenever possible. Nonetheless, models created from inland Great Lakes wetland data had higher median explanatory power when applied to other regions, and the amount of explanatory power lost by other transferred models was relatively small. Thus, while regionally specific habitat association models are preferable, in the absence of reliable regional data, habitat association models developed in one region may be applied to another region, but the results need to be cautiously interpreted. Additionally, we found that median explanatory power was higher when local‐scale habitat characteristics were included in the models, indicating that regionally specific models should ideally be based on a combination of local‐ and landscape‐scale habitat characteristics. Conservation practitioners can leverage such regionally specific models and associated monitoring data to help prioritize areas for management activities that contribute to regional conservation efforts. [ABSTRACT FROM AUTHOR]

Plant communities in North American prairie pothole wetlands vary depending on hydrology, salinity, and anthropogenic disturbance in and around the wetland. We assessed prairie pothole conditions on United States Fish and Wildlife Service fee-title lands in North Dakota and South Dakota to improve our understanding of current conditions and plant community composition. Species-level data were collected at 200 randomly chosen temporary and seasonal wetland sites located on native prairie remnants (n = 48) and previously cultivated lands that were reseeded into perennial grassland (n = 152). The majority of species surveyed appeared infrequently and were low in relative cover. The four most frequently observed species were introduced invasive species common to the Prairie Pothole Region of North America. Our results suggested relative cover of a few invasive species (i.e., Bromus inermis Leyss., Phalaris arundinacea L., and Typha ×glauca Godr. (pro sp.) [angustifolia or domingensis × latifolia]) affect patterns of plant community composition. Wetlands in native and reseeded grasslands possessed distinct plant community composition related to invasive species' relative cover. Invasive species continue to be prevalent throughout the region and pose a major threat to biological diversity, even in protected native prairie remnants. Despite efforts to convert past agricultural land into biologically diverse, productive ecosystems, invasive species continue to dominate these landscapes and are becoming prominent in prairie potholes located in native areas. [ABSTRACT FROM AUTHOR]

The Prairie Pothole Region (PPR) is globally important for breeding waterfowl but has been altered via wetland drainage and grassland conversion to accommodate agricultural land use. Thus, understanding the ecology of waterfowl in these highly modified landscapes is essential for their conservation. Brood occurrence is the cumulative outcome of key life‐history events including pair formation and territory establishment, nest success, and early brood survival. We applied new technological advances in brood surveying methods to understand brood use of wetlands and how land use and wetland‐specific factors influenced brood use of 413 wetlands in crop‐dominated landscapes in the PPR of Iowa, Minnesota, North Dakota, and South Dakota, USA, during summers of 2018–2020. Dynamic occupancy models combining information from 2 visits throughout the year revealed no difference among the 4 states or between private and public lands, resulting in a region‐wide annual wetland occupancy estimate of 0.41 (95% credible interval [CrI] = 0.26, 0.58). We assessed aquatic invertebrate forage availability, wetland and upland vegetation communities, and various water chemistry metrics in a subset (n = 225) of these wetlands to evaluate how landscape and wetland‐specific factors influenced occupancy. The amount of grassland surrounding wetlands was the only variable to influence occupancy at a landscape scale, while wetland size, invertebrates, fish, and vegetation communities influenced occupancy at finer scales. Closer scrutiny of wetland area revealed occupancy was greater in small wetlands after controlling for total wetland area. Our results indicate the greatest constraint on brood occupancy across crop‐dominated landscapes of the PPR in the United States was the occurrence of semipermanent wetlands suitable for brood rearing. Other factors, such as wetland vegetation or surrounding land use, had minor intervening influences on duck brood use and ducks were distributed invariant of wetland ownership or broad spatial processes occurring among states. These results demonstrated wetland conservation and restoration strategies are likely to yield gains in annual duck broods across this vast, altered, and highly modified landscape. [ABSTRACT FROM AUTHOR]

Wetland drainage has been pervasive in the North American Prairie Pothole Region. There is strong evidence that this drainage increases the hydrological connectivity of previously isolated wetlands and, in turn, runoff response to snowmelt and rainfall. It can be hard to disentangle the role of climate from the influence of wetland drainage in observed records. In this study, a basin-classification-based virtual modelling approach is described that can isolate these effects on runoff regimes. The basin class which was examined, entitled Pothole Till, extends throughout much of Canada's portion of the Prairie Pothole Region. Three knowledge gaps were addressed. First, it was determined that the spatial pattern in which wetlands are drained has little influence on how much the runoff regime was altered. Second, no threshold could be identified below which wetland drainage has no effect on the runoff regime, with drainage thresholds as low as 10 % in the area being evaluated. Third, wetter regions were less sensitive to drainage as they tend to be better hydrologically connected, even in the absence of drainage. Low flows were the least affected by drainage. Conversely, during extremely wet years, runoff depths could double as the result of complete wetland removal. Simulated median annual runoff depths were the most responsive, potentially tripling under typical conditions with high degrees of wetland drainage. As storage capacity is removed from the landscape through wetland drainage, the size of the storage deficit of median years begins to decrease and to converge on those of the extreme wet years. Model simulations of flood frequency suggest that, because of these changes in antecedent conditions, precipitation that once could generate a median event with wetland drainage can generate what would have been a maximum event without wetland drainage. The advantage of the basin-classification-based virtual modelling approach employed here is that it simulated a long period that included a wide variety of precipitation and antecedent storage conditions across a diversity of wetland complexes. This has allowed seemingly disparate results of past research to be put into context and finds that conflicting results are often only because of differences in spatial scale and temporal scope of investigation. A conceptual framework is provided that shows, in general, how annual runoff in different climatic and drainage situations will likely respond to wetland drainage in the Prairie Pothole Region. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Water Resources Journal / Revue Canadienne des Ressources Hydriques is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Context: Agricultural land-use conversion has fragmented prairie wetland habitats in the Prairie Pothole Region (PPR), an area with one of the most wetland dense regions in the world. This fragmentation can lead to negative consequences for wetland obligate organisms, heightening risk of local extinction and reducing evolutionary potential for populations to adapt to changing environments. Objectives: This study models biotic connectivity of prairie-pothole wetlands using landscape genetic analyses of the northern leopard frog (Rana pipiens) to (1) identify population structure and (2) determine landscape factors driving genetic differentiation and possibly leading to population fragmentation. Methods: Frogs from 22 sites in the James River and Lake Oahe river basins in North Dakota were genotyped using Best-RAD sequencing at 2868 bi-allelic single nucleotide polymorphisms (SNPs). Population structure was assessed using STRUCTURE, DAPC, and fineSTRUCTURE. Circuitscape was used to model resistance values for ten landscape variables that could affect habitat connectivity. Results: STRUCTURE results suggested a panmictic population, but other more sensitive clustering methods identified six spatially organized clusters. Circuit theory-based landscape resistance analysis suggested land use, including cultivated crop agriculture, and topography were the primary influences on genetic differentiation. Conclusion: While the R. pipiens populations appear to have high gene flow, we found a difference in the patterns of connectivity between the eastern portion of our study area which was dominated by cultivated crop agriculture, versus the western portion where topographic roughness played a greater role. This information can help identify amphibian dispersal corridors and prioritize lands for conservation or restoration. [ABSTRACT FROM AUTHOR]

We investigated variability in δ2H values for two aquatic food webs involving avian consumers (lesser scaup, Aythya affinis Eyton and tree swallow, Tachycineta bicolor Vieillot) foraging from boreal lakes in the Yukon Flats (Alaska, United States) and wetlands in the Prairie Pothole Region (Saskatchewan, Canada), respectively. Generalized linear mixed-effects models were used to decompose sources of variation in water and tissue δ2H. We found inter-annual variation in boreal lakes δ2HW influenced by surface water connectivity (e.g., open vs. closed basins) and distance to the nearest river. Prairie pothole wetland δ2HW displayed intra-annual variability dictated by wetland type (e.g., semipermanent and seasonal) with a range greater than 60‰, which incrementally increased over the summer months. Variance in invertebrate δ2HI was explained by taxonomic category, but factors such as the relative distance to the nearest river (boreal model) and wetland type (prairie model) should be explored in future studies. Lesser scaup duckling feather δ2HF displayed inter-annual and spatial variability with the top model explaining 86% of the overall variation, including the following fixed effects: basin type (open/closed), year, and calendar date of sampling. Similar spatial patterns with known lesser scaup prey items, such as relative site distance to the nearest river, most closely aligned with Amphipoda δ2HI. Variation in tree swallow nestling δ2HF was attributed to sampling date with the top model explaining 38% of overall variation, while sampled prey items (e.g., Chironomidae) did not closely follow this pattern. Our findings quantify the extreme temporal and spatial δ2H variability in food webs fundamentally linked to seasonal evaporative effects in shallow lentic aquatic ecosystems. [ABSTRACT FROM AUTHOR]

The homogenization of freshwater ecosystems and their biological communities has emerged as a prevalent and concerning phenomenon because of the loss of ecosystem multifunctionality. The millions of prairie-pothole wetlands scattered across the Prairie Pothole Region (hereafter PPR) provide critical ecosystem functions at local, regional, and continental scales. However, an estimated loss of 50% of historical wetlands and the widespread conversion of grasslands to cropland make the PPR a heavily modified landscape. Therefore, it is essential to understand the current and potential future stressors affecting prairie-pothole wetland ecosystems in order to conserve and restore their functions. Here, we describe a conceptual model that illustrates how (a) historical wetland losses, (b) anthropogenic landscape modifications, and (c) climate change interact and have altered the variability among remaining depressional wetland ecosystems (i.e., ecosystem homogenization) in the PPR. We reviewed the existing literature to provide examples of wetland ecosystem homogenization, provide implications for wetland management, and identify informational gaps that require further study. We found evidence for spatial, hydrological, chemical, and biological homogenization of prairie-pothole wetlands. Our findings indicate that the maintenance of wetland ecosystem multifunctionality is dependent on the preservation and restoration of heterogenous wetland complexes, especially the restoration of small wetland basins. [ABSTRACT FROM AUTHOR]

Wetlands in the Prairie Pothole Region (PPR) of Canada and the United States represent a unique mapping challenge. They are dynamic both seasonally and year-to-year, are very small, and frequently altered by human activity. Many efforts have been made to estimate the loss of these important habitats but a high-quality inventory of pothole wetlands is needed for data-driven conservation and management of these resources. Typical landcover classifications using one or two image dates from optical or Synthetic Aperture Radar (SAR) Earth Observation (EO) systems often produce reasonable wetland inventories for less dynamic, forested landscapes, but will miss many of the temporary and seasonal wetlands in the PPR. Past studies have attempted to capture PPR wetland dynamics by using dense image stacks of optical or SAR data. We build upon previous work, using 2017–2020 Sentinel-2 imagery processed through the Google Earth Engine (GEE) cloud computing platform to capture seasonal flooding dynamics of wetlands in a prairie pothole wetland landscape in Alberta, Canada. Using 36 different image dates, wetland flood frequency (hydroperiod) was calculated by classifying water/flooding in each image date. This product along with the Global Ecosystem Dynamics Investigation (GEDI) Canopy Height Model (CHM) was then used to generate a seven-class wetland inventory with wetlands classified as areas with seasonal but not permanent water/flooding. Overall accuracies of the resulting inventory were between 95% and 96% based on comparisons with local photo-interpreted inventories at the Canadian Wetland Classification System class level, while wetlands themselves were classified with approximately 70% accuracy. The high overall accuracy is due, in part, to a dominance of uplands in the PPR. This relatively simple method of classifying water through time generates reliable wetland maps but is only applicable to ecosystems with open/non-complex wetland types and may be highly sensitive to the timing of cloud-free optical imagery that captures peak wetland flooding (usually post snow melt). Based on this work, we suggest that expensive field or photo-interpretation training data may not be needed to map wetlands in the PPR as self-labeling of flooded and non-flooded areas in a few Sentinel-2 images is sufficient to classify water through time. Our approach demonstrates a framework for the operational mapping of small, dynamic PPR wetlands that relies on open-access EO data and does not require costly, independent training data. It is an important step towards the effective conservation and management of PPR wetlands, providing an efficient method for baseline and ongoing mapping in these dynamic environments. [ABSTRACT FROM AUTHOR]

We report on the use of a restored prairie/wetland complex, the Granville Schools Land Lab (GSLL), by Thamnophis sirtalis (Eastern garter snake) and small mammals (Peromyscus spp. The loss of grassland and prairie habitats in the agricultural midwestern United States has likely had a negative effect on snake species. Often small mammal communities show a shift in species abundance with shifts from Peromyscus spp. early in restoration to those with B. brevicauda and M. pennsylvanicus as the grassland develops ([17], [16], [15]). Grasslands around the world have greatly decreased due to anthropogenic modifications and activities, including those in North America ([10], [5]). [Extracted from the article]

Evaluating the impact of land-use practices on soil organic carbon (SOC) in the Canadian prairie pothole region (PPR) is of concern due to the potential to sequester carbon and sustain soil health. In a field experiment, SOC content, carbon fractions, and chemical composition were assessed under short-rotation willow (SRW) plantation in the marginal riparian zones of two PPR wetland sites and compared with adjacent annual crop (AC) and pasture (PA). The SOC, water extractable (WEOC), light fraction (LFOC), and particulate organic carbon (POC) were used to evaluate the content and its fractions, whereas Fourier Transform Infrared (FTIR) spectroscopy was used to characterize the chemical composition. The SOC was higher in PA in both sites; however, significant (p < 0.05) only in site B. The SOC, LFOC, and POC followed a similar land-use pattern in both sites, i.e., PA > SRW = AC. The SOC and WEOC were significantly higher (p < 0.05) in 0–15 cm across all land-use practices. The ratios of phenolic and amides to polysaccharides were significantly higher (p < 0.05), while aromatic and carboxylic to polysaccharides were lower under SRW in both sites indicated microbial synthesis of these substances. The abundance of SOC functional groups was higher in the subsoil, accompanied by altered spectral properties with depths showing the potential soil organic matter transformation related to carbon fractions changes. The higher alkyl-C to O-alkyl-C ratio at 15–30 cm under SRW suggested better SOC stability and the potential advantage of C sequestration in the PPR. [ABSTRACT FROM AUTHOR]

The Prairie Pothole Region (PPR) of North America has experienced extreme changes in wetland habitat due to proliferation of invasive plants. Typha × glauca is a highly competitive hybrid between native T. latifolia and non-native T. angustifolia, and it is likely the predominant taxon in PPR wetlands. Genetics-based studies are limited, and distributions are poorly known for the first-generation (F1) hybrid and advanced-generation hybrids from F1 mating. Information pertaining to the distribution of T. × glauca could benefit efforts to understand the mechanisms of its spread and to develop management strategies to limit hybrid expansion and preserve progenitors. We used microsatellite markers of field-collected tissue samples from 131 wetlands spread over approximately 350,000 km2 in the PPR to assess the distribution of hybrid T. × glauca relative to its parental species and to examine the prevalence of F1 hybrids and advanced-generation hybrids. Typha × glauca was found in over 80% of wetlands throughout the PPR, compared to 26 and 18% of wetlands with T. latifolia and T. angustifolia, respectively. Advanced-generation hybrids were more common than F1 hybrids, suggesting that hybridization is not a recent phenomenon. Hybrids were significantly taller than T. latifolia, indicating heterosis. Only 7% of sampled individual genets were pure T. latifolia. These results suggest that T. × glauca is pervasive throughout the PPR and may spread independently of both parents. In addition, limited prevalence of native T. latifolia indicates the need for active management to preserve the species. [ABSTRACT FROM AUTHOR]

The societal benefits of wetland conservation can outweigh the costs, and yet the financial incentive for individual landowners to conserve wetlands is often insufficient due to a mismatch between who bears the costs of wetland conservation (eg the farmer) and who benefits (eg the public) (Dias and Belcher [29]). Summary: Prairie wetland drainage impacts are numerous and widespread The current western scientific knowledge about the effects of wetland drainage in the Canadian Prairies presents a compelling case that past and future wetland drainage will have profound impacts (Table 1). Hence, drainage of one small wetland has less impact on discharge than drainage of one large wetland because there is less storage capacity in a small wetland (Shaw, van der Kamp, et al. [82]). In the typical dry climate of the Canadian Prairie, where wetlands often provide storage capacity, drainage of wetlands closer to the stream outlet results in a more rapid expansion of area contributing to the outlet than does drainage of wetlands in upper reaches. Keywords: Wetland; Canadian Prairies; drainage; ecosystem service; water; agriculture EN Wetland Canadian Prairies drainage ecosystem service water agriculture 229 241 13 11/30/21 20211201 NES 211201 Background, and goals of this synthesis Extensive wetland drainage has occurred across the Canadian Prairies, and drainage activities are ongoing in many areas (Dahl [26]; Watmough and Schmoll [103]; Bartzen et al. [11]; Dahl [25]; Prairie Habitat Joint Venture [78]; Dumanski, Pomeroy, and Westbrook [31]; Waz and Creed [104]). [Extracted from the article]

There is increasing recognition of the importance of wetlands in the prairie pothole region (PPR) of the northern United States for stopover habitat for spring‐migrating waterfowl. The quality and quantity of stopover habitat found near breeding areas can affect speed and success of migration and subsequent breeding events. Conservation and management of wetlands in the region has traditionally focused narrowly on reproductive phases of the life cycle, and little to no research has examined how ducks use a diversity of available wetlands in the region during migration. We conducted weekly surveys on 1,061 wetlands during spring 2018 and 2019 to examine factors affecting duck use of wetlands in the intensively modified southern PPR landscape of Iowa, USA, for wetland restoration and conservation strategies. We compared wetland types, which included farmed, seasonal, and semi‐permanent wetlands, and lakes. The highest duck use per unit area occurred on semi‐permanent wetlands, followed by seasonal, and then farmed wetlands, and lakes. Ducks were highly clustered in our study, with 75% of all use‐days occurring on only 37 wetlands comprising 41% of all wetland area surveyed. We used hurdle models to examine how local and landscape factors measured within and around wetlands influenced duck use during spring migration. Multiple factors related to duck use at local and landscape scales, such as wetland area, vegetation abundance, and number of wetlands in the surrounding landscape. Among semi‐permanent wetlands, local factors within wetlands were more important than landscape factors in determining duck use. Collectively, our findings suggest semi‐permanent wetlands within the PPR play a key role in transitioning birds from wintering areas to breeding areas and that management of semi‐permanent wetlands should promote interspersion of emergent vegetation and open water and growth of submersed aquatic plants to improve their function for migrants. © 2021 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society. : We examined spring migrating duck use of a diversity of wetland types in the southern Prairie Pothole Region in Iowa, USA, and a highly clustered distribution of migrants, focused on a few large semi‐permanent wetlands. Furthermore, local wetland factors, such as wetland area and vegetation characteristics, were more important than landscape factors for predicting duck use on different wetland types. [ABSTRACT FROM AUTHOR]

Contaminants alter the quantity and quality of insect prey available to terrestrial insectivores. In agricultural regions, the quantity of aquatic insects emerging from freshwaters can be impacted by insecticides originating from surrounding croplands. We hypothesized that, in such regions, adult aquatic insects could also act as vectors of pesticide transfer to terrestrial food webs. To estimate insect‐mediated pesticide flux from wetlands embedded in an important agricultural landscape, semipermanetly and temporarily ponded wetlands were surveyed in cropland and grassland landscapes across a natural salinity gradient in the Prairie Pothole Region of North Dakota (USA) during the bird breeding season in 2015 and 2016 (n = 14 and 15 wetlands, respectively). Current‐use pesticides, including the herbicide atrazine and the insecticides bifenthrin and imidacloprid, were detected in newly emerged insects. Pesticide detections were similar in insects emerging from agricultural and grassland wetlands. Biomass of emerging aquatic insects decreased 43%, and insect‐mediated pesticide flux increased 50% along the observed gradient in concentrations of insecticides in emerging aquatic insects (from 3 to 577 ng total insecticide g–1 insect). Overall, adult aquatic insects were estimated to transfer between 2 and 180 µg total pesticide wetland–1 d–1 to the terrestrial ecosystem. In one of the 2 study years, biomass of emerging adult aquatic insects was also 73% lower from agricultural than grassland wetlands and was dependent on salinity. Our results suggest that accumulated insecticides reduce the availability of adult aquatic insect prey for insectivores and potentially increase insectivore exposure to insect‐borne pesticides. Adult aquatic insects retain pesticides across metamorphosis and may expose insectivores living near both agricultural and grassland wetlands to dietary sources of toxic chemicals. Environ Toxicol Chem 2021;40:2282–2296. Published 2021. This article is a U.S. Government work and is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

Numerous wetlands in the prairies of Canada provide important ecosystem services, yet are threatened by climate and land‐use changes. Understanding the impacts of climate change on prairie wetlands is critical to effective conservation planning. In this study, we construct a wetland model with surface water balance and ecoregions to project future distribution of wetlands. The climatic conditions downscaled from the Weather Research and Forecasting model were used to drive the Noah‐MP land surface model to obtain surface water balance. The climate change perturbation is derived from an ensemble of general circulation models using the pseudo global warming method, under the RCP8.5 emission scenario by the end of 21st century. The results show that climate change impacts on wetland extent are spatiotemporally heterogenous. Future wetter climate in the western Prairies will favor increased wetland abundance in both spring and summer. In the eastern Prairies, particularly in the mixed grassland and mid‐boreal upland, wetland areas will increase in spring but experience enhanced declines in summer due to strong evapotranspiration. When these effects of climate change are considered in light of historical drainage, they suggest a need for diverse conservation and restoration strategies. For the mixed grassland in the western Canadian Prairies, wetland restoration will be favorable, while the highly drained eastern Prairies will be challenged by the intensified hydrological cycle. The outcomes of this study will be useful to conservation agencies to ensure that current investments will continue to provide good conservation returns in the future. Key Points: A wetland model in the Canadian prairies, based on surface water balance and ecoregion, shows reliable prediction of wetland extentsFuture projected wetland distribution under climate change exhibits strong spatial heterogeneity and seasonal variabilityEastern Canadian prairies face complex challenges due to wetland drying whereas wetlands become more abundant in western in future climate [ABSTRACT FROM AUTHOR]

Phosphorus (P) release to surface and groundwater often occurs in wetlands that were restored on former agricultural fields. We identified pore water, shallow groundwater, and plant biomass decomposition as sources of soluble reactive (SRP) and total phosphorus (TP) export to the Chicago River between 1998 and 2014 from Prairie Wolf Slough Wetland Demonstration Project (PWS), a wetland restored on a former farmed field in suburban Chicago, Illinois. We estimated the relative annual contributions of SRP from these sources to yearly discharge to the river and conducted an SRP mass balance. SRP and TP concentrations and loadings were consistently greater at the outlet compared to the inlet, suggesting PWS was a source of P. Twenty‐three grams of SRP was exported during the mass balance study. SRP concentration at the inlet accounted for less than 3% of the SRP exported annually at the outlet to the Chicago River. Plant biomass decomposition, pore water diffusion, and groundwater seepage together accounted for 85% of annual export. Twelve percent of annual SRP export remains unknown. PWS was ineffective in reducing P export, indicating an ecosystem disservice. Our study highlights the need to identify the sources of P exported from wetlands restored on farm fields to better understand the biogeochemical processes that determine whether a wetland will serve as a source or sink of P. Pre‐restoration measurement, followed by decadal‐scale post‐restoration monitoring, of source‐water and soil P are needed to evaluate the success of wetland restorations designed to sequester P from runoff. [ABSTRACT FROM AUTHOR]

The lack of information on the value of ecosystems contributing to human well-being in urban and peri-urban setting is known to contribute to the degradation of natural capital and ecosystem services (ES). The purpose of this study was to determine the economic value of ES in Canada's Capital Region (Ottawa-Gatineau region), so that these values can be integrated in future planning decisions. Using the valuation methods of market pricing, cost replacement, and two benefit transfer approaches (with adjustment and with meta-analysis), the value of 13 ES from five ecosystems (forests, wetlands, croplands, prairies and grasslands, and freshwater systems) was measured. The annual economic value of these 13 ES amounts to an average of 332 million dollars, and to a total economic value of over 5 billion dollars, annualized over 20 years. The largest part of this value is generated by nonmarket ES, indicating that much more emphasis should be put on the management, preservation, and understanding of processes that make up these types of ES. The work generated as part of this study is a first step towards operationalizing the concept of ES in planning. More specifically, these results can be used to raise awareness, but also as a stepping stone to improve ecosystem-wide planning in the Canada's Capital Region. [ABSTRACT FROM AUTHOR]

Inland sand areas scattered across the North American eastern deciduous forest and western tallgrass prairie ecotone are known for supporting pyrogenic early-successional vegetation and specially adapted terrestrial faunas. Many of these globally and regionally rare systems contain functionally connected wetland networks ("wetscapes") potentially important for aquatic insects. Sampling adults, nymphs, and exuviae in a remnant sand prairie-savanna wetscape in Illinois, USA, I assessed odonate species diversity (alpha, gamma, beta), distributions (spatial, temporal, abundance), and rarity status. In one field season (12 sites, 12 visits) I found more than a third of Illinois odonate species and close to half of the state's lentic breeding odonates, including a new state record (Erythemis vesiculosa). Richness averaged 25.8 species per site, reducing to 12.4 species with removal of nonbreeding occurrences. Three sites including a shrub swamp, beaver pond, and forested vernal depressions complex made significant contributions to beta diversity, dependent on general versus breeding occurrences. Majorities of Anisoptera species (70%) and Zygoptera species (53%) bred at three or fewer sites. Eight species flew during all or most of the study period (late May to early Oc-tober) whereas 14 species were detected on a single survey. Status classification derived from the observed spatial, temporal, and abundance distributions resulted in 24 common or very common species, 20 uncommon or rare species, and 10 vagrants across the wetscape. These context-specific classifications may be combined with diversity and breeding patterns and other information in wetscape prioritization schemes. [ABSTRACT FROM AUTHOR]

Millions of wetland basins, embedded in croplands and grasslands, are biodiversity hotspots in North America's Prairie Pothole Region, but prairie wetlands continue to be degraded and drained, primarily for agricultural activities. Aerial insectivorous swallows are known to forage over water, but it is unclear whether swallows exhibit greater selection for wetlands relative to other habitats in croplands and grasslands. Central-place foraging theory suggests that habitat selectivity should increase with traveling distance from a central place, such that foragers compensate for traveling costs by selecting more profitable foraging habitat. Using global positioning system (GPS) tags, we evaluated habitat selection by female Tree Swallows (Tachycineta bicolor) at 4 sites containing wetlands and where terrestrial land cover was dominated by grasslands (grass, herbaceous cover) and/or cultivated cropland. We also used sweep-net transects to assess the abundance and biomass of flying insects in different habitats available to swallows (wetland pond margins, grassy field margins, and representative uplands). As expected for a central-place forager, GPS-tagged swallows selected more for wetland ponds (disproportionate to availability), and appeared to increasingly select for wetlands with increasing distance from their nests. On cropland-dominated sites, insect abundance and biomass tended to be higher in pond margins or grassy field margins compared to cropped uplands, while abundance and biomass were more uniform among sampled habitats at sites dominated by grass and herbaceous cover. Swallow habitat selection was not clearly explained by the distribution of sampled insects among habitats; however, traditional terrestrial sampling methods may not adequately reflect prey distribution and availability to aerially foraging swallows. Overall, our results underscore the importance of protecting and enhancing prairie wetlands and other non-crop habitats in agricultural landscapes, given their disproportionate use and capacity to support breeding swallow and insect populations. LAY SUMMARY Miniature GPS tags were used to track breeding female Tree Swallows at agricultural sites. Across agroecosystems, Tree Swallows selected more for wetland ponds than available in the landscape. Swallows increasingly selected for wetland ponds with increasing distance from nests, consistent with central-place foraging theory. Insect abundance and biomass tended to be greater in pond margins and non-crop vegetation (field margins or grasslands) than in croplands, but insect distribution patterns did not fully explain swallow habitat selection. [ABSTRACT FROM AUTHOR]

Wetland decline under post-European settlement and land use change across western Canada has led to mitigation strategies, including wetland creation. Created wetlands can trigger environmental change, including woody species encroachment, in turn altering vegetation and soil. We quantify changes in shrub abundance from prior to wetland creation (1949) until 60 years later (2012) within a Mixedgrass ecosystem of the Verger watershed in Alberta, Canada. In addition, we compare remaining grassland with areas colonized by shrubland on similar ecosites for differences in (1) plant composition, including native and introduced flora, (2) herbage yield and forage accessibility for livestock, and (3) soil properties (surface organic depth, bulk density, mineral nitrogen (N), and carbon (C) concentration). Repeat photos show Shepherdia argentea shrublands increased from 0 to 88 ha (to 1.15% of study area) following wetland creation, with the greatest increase in the last 20 years. Relative to grasslands, shrublands had lower total plant diversity but greater presence of introduced plant species. Shrub patches were 94% lower in herbaceous production, with 77% of shrublands non-utilized by cattle, collectively leading to reduced grazing capacity. Relative to grasslands, shrublands had a thicker soil surface mulch layer, and where cattle were present, had increased mineral soil N and C. Overall, shrub encroachment following wetland creation has markedly altered vegetation and soils in this once grassland landscape, with negative impacts on native plant diversity, herbage production and forage accessibility, and has implications for the management of shrub encroachment. [ABSTRACT FROM AUTHOR]

Simplification of communities is a common consequence of anthropogenic modification. However, the prevalence and mechanisms of biotic homogenization among wetland systems require further examination. Biota of wetlands in the North American Prairie Pothole Region are adapted to high spatial and temporal variability in ponded-water duration and salinity. Recent climate change, however, has resulted in decreased hydrologic variability. Land-use changes have exacerbated this loss of variability. We used aquatic-macroinvertebrate data from 16 prairie-pothole wetlands sampled between 1992 and 2015 to explore homogenization of wetland communities. Macroinvertebrate communities of small wetlands that continued to cycle between wet and dry phases experienced greater turnover and supported unique taxa compared to larger wetlands that shifted towards less dynamic permanently ponded, lake-like regimes. Temporal turnover in beta-diversity was lowest in these permanently ponded wetlands. Additionally, wetlands that shifted to permanently ponded regimes also experienced a shift from palustrine to lacustrine communities. While increased pond permanence can increase species and overall beta-diversity in local areas previously lacking lake communities, homogenization of wetland communities at a larger, landscape scale can result in an overall loss of biodiversity as the diverse communities of many wetland systems become increasingly similar to those of lakes. [ABSTRACT FROM AUTHOR]

Recent work has suggested that a tradeoff exists between habitat area and habitat heterogeneity, with a moderate amount of heterogeneity supporting greatest species richness. Support for this unimodal relationship has been mixed and has differed among habitats and taxa. We examined the relationship between habitat heterogeneity and species richness after accounting for habitat area in glacially formed wetlands in the Prairie Pothole Region in the United States at both local and landscape scales. We tested for area–habitat heterogeneity tradeoffs in wetland bird species richness, the richness of groups of similar species, and in species' abundances. We then identified the habitat relationships for individual species and the relative importance of wetland area vs. habitat heterogeneity and other wetland characteristics. We found that habitat area was the primary driver of species richness and abundance. Additional variation in richness and abundance could be explained by habitat heterogeneity or other wetland and landscape characteristics. Overall avian species richness responded unimodally to habitat heterogeneity, suggesting an area–heterogeneity tradeoff. Group richness and abundance metrics showed either unimodal or linear relationships with habitat heterogeneity. Habitat heterogeneity indices at local and landscape scales were important for some, but not all, species and avian groups. Both abundance of individual species and species richness of most avian groups were higher on publicly owned wetlands than on privately owned wetlands, on restored wetlands than natural wetlands, and on permanent wetlands than on wetlands of other classes. However, we found that all wetlands examined, regardless of ownership, restoration status, and wetland class, supported wetland-obligate birds. Thus, protection of all wetland types contributes to species conservation. Our results support conventional wisdom that protection of large wetlands is a priority but also indicate that maintaining habitat heterogeneity will enhance biodiversity and support higher populations of individual species. [ABSTRACT FROM AUTHOR]

Alternative stable states are nontransitory states within which communities can exist. However, even highly dynamic communities can be viewed within the framework of stable‐state theory if an appropriate "ecologically relevant" time scale is identified. The ecologically relevant time scale for dynamic systems needs to conform to the amount of time needed for a system's community to complete an entire cycle through its normal range of variation. For some systems, the ecologically relevant period can be relatively short (eg, tidal systems), for others it can be decadal (eg, prairie wetlands). We explore the concept of alternative stable states in unstable systems using the highly dynamic wetland ecosystems of North America's Prairie Pothole Region. The communities in these wetland ecosystems transition through multiple states in response to decadal‐long climate oscillations that cyclically influence ponded‐water depth, permanence, and chemistry. The perspective gained by considering dynamic systems in the context of stable‐state theory allows for an increased understanding of how these systems respond to changing drivers that can push them past tipping points into alternative states. Incorporation of concepts inherent to stable‐state theory has been suggested as a key scientific element upon which to base sustainable environmental management. [ABSTRACT FROM AUTHOR]

Antimicrobials used in livestock production can be present in manure via excretion in the feces and/or urine. Application of raw or processed (composted or stockpiled) manure to crop and pasture land as a plant nutrient source can result in antimicrobial transport to surface waters via rainfall or snowmelt runoff. Little is known regarding antimicrobial persistence in aquatic ecosystems. Consequently, dissipation of environmentally relevant concentrations of three veterinary antimicrobials (lincomycin, chlortetracycline, and sulfamethazine) was studied in three wetlands on the Canadian Prairies. Study wetlands were fortified in the fall to simulate antimicrobial transport via rainfall runoff from fall manure applications to the wetland catchments. After fortification, water column concentrations of all three antimicrobials decreased through September and October. Plotting natural logarithm values of antimicrobial concentration against time resulted in linear relationships for all three antimicrobials, indicating that the summation of all dissipation processes for each antimicrobial could be described by first‐order kinetics. The slopes of the three plots were significantly different, indicating that the order of dissipation was lincomycin < sulfamethazine < chlortetracycline. Consequently, the dissipation DT50 (time required for 50% antimicrobial dissipation) values for lincomycin (14.0 d), sulfamethazine (7.0 d), and chlortetracycline (3.3 d) were significantly different. The longer DT50 values of lincomycin and sulfamethazine suggest that environmentally relevant concentrations of these antimicrobials may affect bacterial production in prairie wetlands. [ABSTRACT FROM AUTHOR]

Aim: Wetland loss and degradation threaten biodiversity to an extent greater than most ecosystems. Science‐supported responses require understanding of interacting effects of land use and climate change on wetland biodiversity. Location: Alberta, Canada. Methods: We evaluated how current climate, climate change (as a ghost of the past), land use and wetland water quality relate to aquatic macroinvertebrates and birds. Results: Climatic relationships and climate–land use interactions were observed on chironomid abundance, but not macroinvertebrate taxa richness (MTR) or odonate abundance, which responded to land use and water chemistry. Chironomid abundance was positively associated with cropland and negatively associated with total precipitation. Higher cropland cover and dissolved organic carbon synergistically interacted with total precipitation to affect chironomids. MTR was negatively related to salinity, yet greater area of non‐woody riparian vegetation attenuated salinity effects on MTR. Odonate abundance was negatively related to total phosphorus. Higher grassland cover also increased the negative relationship of total phosphorous to odonate abundance. Climatic relationships and climate–land use interactions were observed on bird species richness (BSR) and abundance of several bird functional groups. Higher BSR and abundances of several bird groups were positively related to average rainfall and greater warming temperatures over time. Area of non‐crop cover and wetlands was positively associated with most bird groups and BSR. Warming temperatures over time ameliorated the negative relationship of higher cropland or less shrubland on aerial insectivores and other bird groups. Main conclusions: Climate patterns and climate change are as important as land use pressures with stronger impacts on birds. Climate change was more influential than current climate and provided novel empirical evidence that progressively warmer, wetter conditions is benefiting some bird groups, including aerial insectivores, a group of conservation concern. Riparian vegetation ameliorated the negative impacts of climate and water quality gradients on MTR and could mitigate global change impacts in agricultural systems. [ABSTRACT FROM AUTHOR]

Elucidating drivers of aquatic ecosystem metabolism is key to forecasting how inland waters will respond to anthropogenic changes. We quantified gross primary production (GPP), respiration (ER), and net ecosystem production (NEP) in a natural and two restored prairie wetlands (one "older" and one "recently" restored) and identified drivers of temporal variation. GPP and ER were highest in the older restored wetland, followed by the natural and recently restored sites. The natural wetland was the only net autotrophic site. Metabolic differences could not be definitively tied to restoration history, but were consistent with previous studies of restored wetlands. Wetlands showed similar metabolic responses to abiotic variables (photosynthetically active radiation, wind speed, temperature), but differed in the direct and interactive influences of biotic factors (submersed aquatic vegetation, phytoplankton). Drivers and patterns of metabolism suggested the importance of light over nutrient limitation and the dominance of autochthonous production. Such similarity in ecosystem metabolism between prairie wetlands and shallow lakes highlights the need for a unifying metabolic theory for small and productive aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Wetlands conservation within agricultural working lands is currently incentivized by land retirement programs and farm program eligibility criteria. Private ownership of the majority of agricultural lands within which these wetlands reside and growing opportunity costs facing landowners put wetlands at risk and motivate consideration of alternative policy options. A choice experiment was used to estimate likelihood of enrollment in a hypothetical working wetlands program. Landowners preferred shorter contract lengths, higher rental rates, midterm adjustment rather than a fixed‐rate contract, the right to conduct managed burning on their lands‐containing program wetlands, and no conservation practice requirement. Landowners with higher expressed valuation of conservation and who favor protecting wetlands, believe that small wetlands are important for their farms, who would not drain any of their wetlands, and raise ruminant animals are more inclined to participate in the program. Recommendations include consideration of program targeting during program design, practicing creative thought regarding program promotion, and exploration of no‐loss wetlands solutions, especially those market based. [ABSTRACT FROM AUTHOR]

Tallgrass prairies are some of the most imperiled ecosystems in North America, yet the herpetofauna found within these habitats are not well known. We studied the herpetofaunal assemblage of the Chichaqua Bottoms Greenbelt and Chichaqua Wildlife Management Area complex (CBG) in Iowa as well as the natural history of Thamnophis species. We found that the CBG housed substantial diversity with seven species of anurans, one species of salamander, three species of turtles, and nine species of snakes. Three Thamnophis species in the CBG differed in body size, diet, and both ambient temperature and time of day at capture. This research contributes to our knowledge of the diversity and natural history of herpetofauna in northern prairies. [ABSTRACT FROM AUTHOR]

Restoration efforts are being implemented globally to mitigate the degradation and loss of wetland habitat; however, the rate and success of wetland vegetation recovery post‐restoration is highly variable across wetland classes and geographies. Here, we measured the recovery of plant diversity along a chronosequence of restored temporary and seasonal prairie wetlands ranging from 0 to 23 years since restoration, including drained and natural wetlands embedded in agricultural and natural reserve landscapes in central Alberta, Canada. We assessed plant diversity using the following structural indicators: percent cover of hydrophytes, native and non‐native species, species richness, and community composition. Our findings indicate that plant diversity recovered to resemble reference wetlands in agricultural landscapes within 3–5 years of restoration; however, restored wetlands maintained significantly lower species richness and a distinct community composition compared to reference wetlands located within natural reserves. Early establishment of non‐native species during recovery, dispersal limitation, and depauperated native seed bank were probable barriers to complete recovery. Determining the success of vegetation recovery provides important knowledge that can be used to improve restoration strategies, especially considering projected future changes in land use and climate. [ABSTRACT FROM AUTHOR]

Context: Agricultural expansion is the greatest source of wetland loss in the Prairie Pothole Region (PPR) of North and South Dakota, a critical waterfowl production area in North America. It is unknown how wetland losses from grassland conversion may alter structural connectivity in the prairie pothole network, however. Objectives: We examined how agricultural expansion over the period 2001–2011 altered the number, size, shape, and structural connectivity of PPR wetlands. We hypothesized that the loss of wetlands or wetland area would decrease structural connectivity on the landscape. Methods: We analyzed a published raster database that quantified 2001–2011 agricultural conversion of wetlands in the Dakotas. A suite of structural connectivity metrics was computed using the igraph R package. Results: Wetland area decreased by 25% within the study area, density decreased by 16%, and average size decreased from 2.41 to 2.16 ha with no increase in perimeter:area ratios, thus indicating changes more from the splitting of larger wetlands (accounting for 23% of area lost) and "nibbling" at patch area (38%) than from complete wetland elimination (39%). Despite loss of wetlands and wetland area to cropland, however, the network did not display constrained structural connectivity. Conclusions: Structural connectivity has not been significantly affected by wetland losses because of the large number of remaining wetlands, but wetlands will continue to be lost with ongoing grassland conversion and climate shifts. It is unknown where the tipping point of wetland losses lies in the PPR that will incur ecological costs. [ABSTRACT FROM AUTHOR]

Farmed pothole depressions, common in the Prairie Pothole Region, frequently hold water during wet periods and play an important role in ecosystem dynamics such as flood retention and hosting migratory waterfowl. In this study, we developed a spreadsheet-based daily water budget model of a drained and farmed pothole in Hamilton County, Iowa, to evaluate how site-specific characteristics affect the frequency, depth, and duration of surface ponding. For a 3-year period characterized by a range of precipitation, the model predicted that on an annual basis ponded water would be present in the pothole approximately 14 to 47% of the time. Total ponding days ranged from 51 to 173 days year−1 and maximum ponding depth ranged from 112 to 334 mm. Infiltration rate, catchment-to-pothole ratio, and the presence of a surface intake had the largest impact on ponding depth and duration. Results of this study have implications for management of farmed and drained potholes and we can envision using the PPWB model to test potential strategies for pothole management from both agricultural profitability and ecological perspectives. [ABSTRACT FROM AUTHOR]

This study investigates changes in run-off production behaviour which may have occurred due to climate change/variability and/or as a result of draining of wetlands over Canadian portion of North American Prairies. The study uses statistical methods to quantify changes in precipitation/run-off over various spatial and temporal scales. The major results indicate dominated upward trends in some run-off metrics over some Prairie watersheds, whereas there is no concrete evidence of statistically significant precipitation trends during the observation period. The observed changes in run-off response, therefore, are interpreted to represent the possible effects of intensive wetland drainage. The remaining unchanged metrics over the majority of tested watersheds are interpreted to be due to varying progressive land use/cover disturbances which may have conflicting impacts on watershed response in the Prairies. The absence of significant changes in precipitation and observed changes in hydrology of some parts of the study area may support the narrative that loss of wetlands has led to increased flood risks in this area. However, information on major land cover indices like intact forests, agricultural land, urban areas within the study area, and landscape best management practices would be necessary to fully comprehend land use change and its impact on the Prairie's hydrology. [ABSTRACT FROM AUTHOR]

The change from deep-rooted grass and shrub vegetation to annual-cropping dryland farming has contributed to serious soil salinization challenges on the semi-arid North American Great Plains. In some cases, cultivation of the Great Plains has increased the availability of water, causing dominant sulfate salts to travel from the uphill areas to depressions where it will surface when water evaporates at the soil surface. A potential solution could include the replanting of the native deep-rooted vegetation, which requires knowledge of the spatial distribution of soil salinity. This study tested the soil factors influencing electromagnetic-induction meter (EM38) readings of soil salinity distribution around wetlands. The objectives were to: (1) predict growth and survival of Salix dasyclados Wimm. (cv. ‘India’) along a salinity gradient in a small wetland, and (2) investigate whether newly established willows affected water-table fluctuations, which would indicate their phreatophytic nature or their ability to obtain their water supply from the zone of saturation. Results indicated significantly lower salinity values for sampling points with EM38 readings above 175 and 250 mS m−1 for height and survival, respectively. In addition, diurnal fluxes of the water table in areas of good willow growth and lower salinity indicated that cultivar ‘India’ was phreatophytic in these areas and therefore has great potential for being used to combat saline seeps. [ABSTRACT FROM AUTHOR]

Abstract: Wetlands represent one of the world's most biodiverse and threatened ecosystem types and were diminished globally by about two‐thirds in the 20th century. There is continuing decline in wetland quantity and function due to infilling and other human activities. In addition, with climate change, warmer temperatures and changes in precipitation and evapotranspiration are reducing wetland surface and groundwater supplies, further altering wetland hydrology and vegetation. There is a need to automate inventory and monitoring of wetlands, and as a study system, we investigated the Shepard Slough wetlands complex, which includes numerous wetlands in urban, suburban, and agricultural zones in the prairie pothole region of southern Alberta, Canada. Here, wetlands are generally confined to depressions in the undulating terrain, challenging wetlands inventory and monitoring. This study applied threshold and frequency analysis routines for high‐resolution, single‐polarization (HH) RADARSAT‐2, synthetic aperture radar mapping. This enabled a growing season surface water extent hyroperiod‐based wetland classification, which can support water and wetland resource monitoring. This 3‐year study demonstrated synthetic aperture radar‐derived multitemporal open‐water masks provided an effective index of wetland permanence class, with overall accuracies of 89% to 95% compared with optical validation data, and RMSE between 0.2 and 0.7 m between model and field validation data. This allowed for characterizing the distribution and dynamics of 4 marsh wetlands hydroperiod classes, temporary, seasonal, semipermanent, and permanent, and mapping of the sequential vegetation bands that included emergent, obligate wetland, facultative wetland, and upland plant communities. Hydroperiod variation and surface water extent were found to be influenced by short‐term rainfall events in both wet and dry years. Seasonal hydroperiods in wetlands were particularly variable if there was a decrease in the temporary or semipermanent hydroperiod classes. In years with extreme rain events, the temporary wetlands especially increased relative to longer lasting wetlands (84% in 2015 with significant rainfall events, compared with 42% otherwise). [ABSTRACT FROM AUTHOR]

Subsurface storage of sulfate salts allows closed-basin wetlands in the semiarid Prairie Pothole Region (PPR) of North America to maintain moderate surface water salinity (total dissolved solids [TDS] from 1 to 10 g L −1 ), which provides critical habitat for communities of aquatic biota. However, it is unclear how the salinity of wetland ponds will respond to a recent shift in mid-continental climate to wetter conditions. To understand better the mechanisms that control surface-subsurface salinity exchanges during regional dry-wet climate cycles, we made a detailed geoelectrical study of a closed-basin prairie wetland (P1 in the Cottonwood Lake Study Area, North Dakota) that is currently experiencing record wet conditions. We found saline lenses of sulfate-rich porewater (TDS > 10 g L −1 ) contained in fine-grained wetland sediments 2–4 m beneath the bathymetric low of the wetland and within the currently ponded area along the shoreline of a prior pond stand ( c . 1983). During the most recent drought (1988–1993), the wetland switched from a groundwater discharge to recharge function, allowing salts dissolved in surface runoff to move into wetland sediments beneath the bathymetric low of the basin. However, groundwater levels during this time did not decline to the elevation of the saline lenses, suggesting these features formed during more extended paleo-droughts and are stable in the subsurface on at least centennial timescales. We hypothesize a “drought-induced recharge” mechanism that allows wetland ponds to maintain moderate salinity under semiarid climate. Discharge of drought-derived saline groundwater has the potential to increase the salinity of wetland ponds during wet climate. [ABSTRACT FROM AUTHOR]

Understanding the catchment areas of key stopover sites for migratory birds is important for their management and conservation. The Saskatchewan River Delta (SRD) in central Canada is North America's largest inland delta and an important spring and fall stopover site for migratory waterfowl, but there is little information on the origins of waterfowl that use the SRD. We used stable isotope analyses of hydrogen (δ²H) and sulfur (δ34S) in feathers of hunter-killed waterfowl on the SRD to infer natal or molt origins of 5 duck species, using spatially explicit assignment to a δ²H feather isoscape developed for waterfowl in North America. Initial classification with δ²H estimated that 50% were migrants from the north and 10% were assigned to regions south of the SRD, leaving only 39% of the sample with origins in the SRD. Using thresholds in feather δ34S values associated with prairie and forest biomes, we further reassigned 64% of SRD birds as having originated from nearby agricultural and forested areas that have similar δ²H values as the delta. Together, these results suggest that >80% of all waterfowl sampled were recent arrivals that were using the SRD as a stopover site. This demonstrates that stable isotope analyses of hunter-killed birds can be used to monitor changes in origins and recruitment into the fall waterfowl population of key stopover sites. [ABSTRACT FROM AUTHOR]