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Temporary wetlands: challenges and solutions to conserving a ‘disappearing’ ecosystem

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... Temporary wetlands are generally small and shallow aquatic ecosystems, characterised by frequent drying (Boix et al., 2020) and can be found in a variety of landscape settings worldwide (Calhoun et al., 2017). Their intermittent character makes these ecosystems an ecotone between terrestrial and aquatic environments. ...
... Results demonstrated that long term changes in the area associated with land use caused significant impacts on the ecosystem, landscape structure and the provided services. Even though scientific attention to the ecology and function of temporary wetlands has been historically limited (Williams, 2006;Boix et al., 2020), it is well documented that they are threatened by human-made habitat degradation and loss mainly due to land-use changes and urbanisation (Calhoun et al., 2017). However, to the best of our knowledge, studies that investigate the effects of land-use changes and habitat loss on ecosystem function and services are still limited. ...
... To date, there have been limited attempts to link landscape structure with ES provision (Zorrilla-Miras et al., 2014;Varin et al., 2019) and even fewer attempts trying to identify the relative influence of composition and configuration in the provision of these ES (Lamy et al., 2016). Although this study did not link explicitly landscape structure to ES, it is expected that this is certainly the case at least for avifauna richness and landscape aesthetics given that temporary wetlands is an ecotone between land and water, providing foraging and resting sites for migrating species (Calhoun et al., 2017). ...
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Changes in land use/land cover (LULC) are the key factors driving biodiversity and ecosystem services decline globally. This study examines spatiotemporal LULC changes in a Ramsar coastal temporary wetland (Larnaca Salt Lake) on the island of Cyprus between 1963 and 2015. LULC changes in the area are related to variations in the provision of ecosystem services (ES) namely food provision, climate regulation, avifauna support and landscape aesthetics. LULC mapping was performed based on the interpretation of aerial photos taken in 1963, while 2015 mapping was based on CORINE classification validated by satellite image analysis and fieldwork. We used the following indicators for the ES examined: (1) crops’ yield for the estimation of food supply, (2) carbon storage potential for climate regulation, (3) land cover potential to support avifauna richness and (4) naturalness as a proxy for landscape aesthetics. Quantifications were based on a mixed-methods approach with the use of statistical data, expert opinion and bibliography. Estimates for every service were assigned to CORINE land use classes (CLC) present in the area. Landscape structure was measured using a suite of commonly employed landscape metrics. The results showed that between 1963 and 2015 there has been a significant reduction in food provisioning service by 75%, a 37% reduction in carbon storage capacity, an 11% reduction in the capacity to support avifauna, and a 13% reduction in landscape aesthetics. Increased soil surface sealing, mainly with the construction of the international airport, which resulted in the conversion of natural or semi-natural to artificial surfaces, has been the main reason for the decrease in ES supply over the last fifty years in the study area. The character of the area in terms of land use types richness and diversity remains fairly stable but the dominant land use types have experienced fragmentation. The study sets the basis for a monitoring scheme to evaluate the state of the temporary wetlands with emphasis placed on spatial processes as a link to ES provision.
... Although "NFW" has gradually gained acceptance in academia for emphasizing the geographical location rather than falsely generalizing the hydrological isolation of these waters (Mushet et al., 2015;Calhoun et al., 2017a;Lane et al., 2018), it is used inconsistently and often accompanied by "GIWs", even in the recent research literature and government documents (e.g., U.S. Environmental Protection Agency, 2015). Other terms including but not limited to "small water bodies" (Biggs et al., 2017), "neglected freshwater habitats" (Hunter et al., 2017), "temporary wetlands" (Calhoun et al., 2017b), "vulnerable waters" , and "wetlandscapes" (Thorslund et al., 2017;Ghajarnia et al., 2020) are used or partially used in studying similar small wetlands, but often with a specific focus on wetland attributes (e.g., size, perimeter-area-volume relationship, and hydroperiod), functions (e.g., flood attenuation, nutrient retention, and biodiversity support), and study scales (e.g., individual wetlands, wetlands across landscapes, and wetlands at watershed and regional scales), respectively. Such marked heterogeneity has been crossvalidated by several reviews and calls for improved research and collaborative utilization of these wetland systems (Hunter et al., 2017;Chen et al., 2019;Golden et al., 2019;Sayer et al., 2020), which indicate the prevailing perspectives at local and regional scales --NFWs are studied with different emphases under different motivations, depending upon where they are located and what we are interested in. ...
... We present here a vision for global collaboration, and outline four pathways that will enhance our understanding and sustainable use of these wetland systems across regions --from classification and simulation as theoretical and technical bases, to improved legislative/regulative support via mutual learning of governments, and bidirectionally reinforced education and science ( Figure 3). These recommendations, particularly for countries with similar geo-climatic settings and socioeconomic development levels (due to better opportunities to learn from each other), can complement existing frameworks of NFW utilization and protection for governments and agencies (Calhoun et al., 2017b;Golden et al., 2017;Hunter et al., 2017;Chen et al., 2019;Swartz and Miller, 2021), and have potential to galvanize broader international collaborations on sustainable wetland use. ...
... Schematic diagram of four activity areas to further the NFW typology framework and to promote collaboration and sustainable NFW use at global scales.Classification.NFWs have heterogeneous naming criteria in different geographical settings, e.g., relating to hydroperiod for temporary ponds(Calhoun et al., 2017b), landforms for karst ponds(Hill et al., 2018), structures for chainof-ponds (Williams et al., 2020), and purpose for farm ponds(Takeuchi et al., 2016) (Figure 1a). Previous studies have attempted semantic mediation among the terms used(Mushet et al., 2015; Leibowitz, 2015; ...
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Non-floodplain wetlands (NFWs) are important but vulnerable inland freshwater systems that are receiving increased attention and protection worldwide. However, a lack of consistent terminology, incohesive research objectives, and inherent heterogeneity in existing knowledge hinder cross-regional information sharing and global collaboration. To address this challenge and facilitate future management decisions, we synthesized recent work to understand the state of NFW science and explore new opportunities for research and sustainable NFW use globally. Results from our synthesis show that although NFWs have been widely studied across all continents, regional biases exist in the literature. We hypothesize these biases in the literature stem from terminology rather than real geographical bias around existence and functionality. To confirm this observation, we explored a set of geographically representative NFW regions around the world and characteristics of research focal areas. We conclude that there is more that unites NFW research and management efforts than we might otherwise appreciate. Furthermore, opportunities for cross-regional information sharing and global collaboration exist, but a unified terminology will be needed, as will a focus on wetland functionality. Based on these findings, we discuss four pathways that aid in better collaboration, including improved cohesion in classification and terminology, and unified approaches to modeling and simulation. In turn, legislative objectives must be informed by science to drive conservation and management priorities. Finally, an educational pathway serves to integrate the measures and to promote new technologies that aid in our collective understanding of NFWs. Our resulting framework from NFW synthesis serves to encourage interdisciplinary collaboration and sustainable use and conservation of wetland systems globally.
... Given these shifting federal protections, state definitions of jurisdictional wetlands are increasingly relevant seasonal pond conservation and management (Calhoun et al. 2017). In some states seasonal ponds are classified as jurisdictional wetlands based on hydrology, soils, and vegetation [i.e., Connecticut, Minnesota, Rhode Island, Wisconsin;MN BWSR 2019;CT DEEP 2021;RIDEM 2021;WDNR 2021a,b] or proximity from other surface water bodies (i.e., Michigan; MI EGLE 2021). ...
... There are also some states (i.e., New York) without statewide protections for seasonal ponds and only ponds considered to be of "unusual local importance" receive protections (NYDEC 2021). Ultimately, while seasonal pond definitions used by regulators and resource managers can differ from those used by scientists, there are examples of successful case-by-case seasonal pond conservation efforts involving a variety of stakeholders and their collective recognition that seasonal ponds are important landscape features even if they are not included in Federal or State jurisdictional definitions (Cohen et al. 2016;Calhoun et al. 2017;Golden et al. 2017;Levesque et al. 2019). ...
... While most seasonal ponds are individually quite small, they are common features across much of the western Great Lakes states and Northeast and conserving them contributes to maintaining forest ecosystem services more broadly (Calhoun et al. 2017). The principal factors that challenge seasonal pond conservation include inconsistent definitions, lack of thorough inventories, limited regulatory protections, and landowner attitudes towards pond conservation (Semlitsch and Bodie 2003;Zedler 2003;Jansujwicz et al. 2013;Calhoun et al. 2017;Levesque et al. 2019). ...
Article
Seasonal ponds are small, isolated wetlands with variable hydrology, often occurring embedded in upland forests, which provide habitat for amphibians and invertebrates uniquely adapted to fishless waters. Seasonal ponds are challenging to identify due to their small size, ephemeral hydrology, diverse vegetation, and occurrence across a range of settings, yet in order to inform their conservation and management, it is essential to understand their distribution and how management impacts them. We conducted a systematic review to define and quantify attributes of seasonal ponds, summarize mapping and inventory methods, and synthesize forest harvesting impacts on ponds in the western Great Lakes and northeastern United States. Definitions of seasonal ponds differ regionally and for scientific vs. regulatory purposes; the necessity of documenting pond-dependent indicator species (e.g., fairy shrimp) is one of the most vexing inconsistencies. Seasonal ponds are most effectively mapped in the spring, using a combination of aerial photographs or radar imagery and topographic information, especially in settings with small ponds or heavy canopies. Combining these mapping efforts with carefully stratified field validation is essential for developing a regional inventory of seasonal ponds. Most guidelines intended to reduce impacts of forest harvesting on pond ecosystems rely on buffers, which most effectively minimize physical or biological impacts when most lightly treated, although some impacts (particularly water levels) appear unavoidable when any harvesting occurs adjacent to seasonal ponds. Overall, distinct physical and biological impacts of harvesting differ in magnitude and direction, though most appear to subside over multi-decadal timescales.
... Intermittently inundated wetlands, known as temporary wetlands, are generally shallow, relatively small aquatic features found in a variety of landscape settings throughout all continents (Calhoun et al., 2017). ...
... Temporary wetlands therefore contain specialist species that do not normally occur in permanent waters, many of which are rare or threatened (Médail, 2004;Rhazi et al., 2006). Their role within the landscapes as a whole is thus recognized as disproportionate with regard to what might be expected in view of the limited area they cover (Calhoun et al., 2017;Rains et al., 2016). ...
... These ponds play a major role within the hydrological networks in any given watershed to the point that they have been described as 'nodes in hydrologic networks connecting landscapes in four dimensions-longitudinal, lateral, vertical, and through time' by Rains et al. (2016). Found in a variety of landscape, geomorphic and climatic settings in all continents (Deil, 2005), temporary ponds vary greatly in their predominant water sources and outflows (Calhoun et al., 2017). These may be from readily observable surface water or along flow paths that are difficult to observe, such as shallow subsurface or groundwater flows. ...
Article
The lack of hydrological considerations in the existing protection statutes for small temporary wetlands has recently been pointed out as the main cause of their rapidly increasing disappearance. In the present study, we aim to demonstrate the interest of using the tools of isotope hydrology to obtain a rapid and cost effective understanding of the hydrological connectivity of Mediterranean temporary wetlands in order to define the optimal environmental conditions needed to ensure their sustainability. By combining physical and isotope measurements, we have investigated the fragile balance of direct precipitation, subsurface water and groundwater influencing the hydroperiod of a typical Mediterranean temporary pond. The use of the water stable isotopes enabled us to demonstrate (i) the major role played by groundwater and subsurface water in the flooding phase of the temporary pond; (ii) the involvement of different water reservoirs in varying proportions over time to maintain the pond filled with water: precipitation, subsurface and groundwater by using d‐excess; (iii) the main role played by evaporation in starting the drying up phase; and (iv) the connection existing between a geographically isolated wetland and the regional groundwater body. These results highlight the urgent need to consider both surface and groundwater fluxes in specific protection statutes for wetlands. To this end, we recommend the use of the water stable isotopes to provide insights into the hydrological behaviour of the wetlands in order to dispose of additional cost‐effective arbitration arguments to help ensure their sustainability.
... Numerous unlisted but declining species and common species also depend on the global conservation of geographically isolated wetland habitats. However, like other small aquatic habitats, geographically isolated wetlands have few legal protections [8]. Historical and current wetland loss and degradation have made the restoration of geographically isolated wetlands a high priority for the conservation of pond-breeding amphibians [9,10]. ...
... Pond-breeding amphibians are resilient to these stochastic disturbances, provided that abundant wetlands are available across the landscape, in relative proximity to one another, and represent a range of hydroperiods [6,10,[20][21][22]. Historical and current destruction of wetlands disproportionately affects geographically isolated wetlands [3,8,[23][24][25]. Some land management and agricultural practices, including ditching and (or) draining, intensive site preparation, intensive livestock grazing, as well as fire exclusion, among others, have also contributed to past and current degradation of wetland conditions [3,8]. ...
... Historical and current destruction of wetlands disproportionately affects geographically isolated wetlands [3,8,[23][24][25]. Some land management and agricultural practices, including ditching and (or) draining, intensive site preparation, intensive livestock grazing, as well as fire exclusion, among others, have also contributed to past and current degradation of wetland conditions [3,8]. Given these pervasive threats and the historical destruction of many geographically isolated wetlands, restoring remaining habitat is essential for the conservation of pond-breeding amphibians [6,8,9]. ...
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Geographically isolated wetlands provide a critical habitat for pond-breeding amphibians, a taxa of broad conservation concern. Global wetland loss and degradation has made restoration essential for amphibian conservation. Restoration goals typically include recovering the wetlands’ physiochemical, hydrological, and ecological functions. However, for pond-breeding amphibians, successful restoration should also result in sustained populations, which is difficult to assess and infrequently reported. In this paper, we review the available evidence that restoration of geographically isolated wetlands promotes pond-breeding amphibian occupancy and population persistence. We provide an overview of restoration practices addressing hydrology, vegetation, and ecological processes within these unique environments and across spatial scales. We then summarize the evidence, and discuss the limitations, for evaluating successful restoration within the context of amphibian conservation across these categories. Finally, we provide recommendations for researchers and practitioners to leverage prior successes and establish systematic data collection and dissemination. Moving restoration of wetlands for amphibian conservation forward will require more robust data collection and reporting.
... The smaller, temporarily ponded wetlands that were once much more common in the PPR landscape provide many important ecosystem services due to their unique properties [60]. For example, these smaller wetlands are the primary contributors to groundwater recharge to an aquifer [24,140] because they store and quickly lose water to groundwater. ...
... This is especially important under current climate conditions when many larger wetlands have remained at or near their spill point which limits their water-storage capacity. In addition to water storage, smaller wetlands are disproportionately important for their geochemical functions as well [60]. For example, smaller wetland basins have proportionally larger reactive zones, which make them more efficient in biogeochemical cycling [15]. ...
... However, in the future, climate warming will likely shift wetlands towards a dry state, which will disproportionately influence smaller wetlands. Currently, the smaller temporarily ponded wetlands continue to be the most vulnerable to future losses and are perhaps the most valuable for maintaining wetland landscape multifunctionality [13,15,24,60]. While it is hard to predict all of the potential climate and land-use scenarios and how they might alter prairie-pothole wetland ecosystems in the future, understanding the vulnerabilities of these systems to potential changes is an important consideration for proactive conservation planning strategies. ...
Article
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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.
... The diversity of Mediterranean temporary ponds provides a continuum of functions and ecosystem services from local to much larger spatial scales (Calhoun et al., 2017). In spite of this, they are strongly threatened (Gigante et al., 2016(Gigante et al., , 2018. ...
... Their small size (high watershed to surface area or volume ratio) and short-term hydroperiod make them very responsive to changes in temperature and precipitation. They are more threatened, for example, by reduced rainfall, increased salinity, and extended droughts than temperate or boreal temporary wetlands (Calhoun et al., 2017). ...
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Questions Which are the effects of inter-annual meteorological fluctuations on plant species richness and vegetation dynamics in Mediterranean temporary ponds, shallow wetlands characterized by alternating phases of drought and flooding? Which are the effects of wild boar disturbance? How do the responses of specialist or non-specialist species of the habitat differ? Location NW Sardinia Island (Italy). Methods We assessed plant cover during six years within one 60 cm x 60 cm quadrats in five areas. To measure the effect of interannual meteorological fluctuations on vegetation, we used two indices: the evapotranspiration and the synthetic agrometeorological indicator. To quantify the effect of the boar disturbance, we compared two treatments: disturbed and non-disturbed (located outside and inside 1.5 m x 1.5 m exclosures, respectively). As a whole, we monitored 60 plots (6 years x 2 treatments x 5 replications). We analysed data using ANOVA, PERMANOVA and BIO-ENV. Results Plant species richness and composition showed significant differences between years and treatments. Species composition was correlated with the evapotranspiration during the last period before the vegetative peak and with the agrometeorological indicator during the whole vegetative period. Specialist species showed much weaker growth, quantified as cover, in the drier years. Starting from the third survey year, plant richness and cover of specialist species were significantly higher in disturbed than in not-disturbed plots. The extent of bare soil generally was not affected by the treatment. Conclusions Meteorological fluctuations affect plant species composition and vegetation dynamics in Mediterranean temporary ponds. The sensitivity of specialist species could make them particularly vulnerable to climate change. Nevertheless, they are resilient to unpredictable disturbances such as wild boar burrowing. However, our results concerning the positive impact of wild boar disturbance on the vegetation cannot be generalized. Elsewhere, the lack of hunting activity could also be a problem for these habitats.
... Precipitation and temperature driven changes in these wetlands determine the availability of suitable habitat for waterbirds (Haig et al. 2019, Mushet et al. 2020. However, the wetland ecosystems of the PPR are disappearing (Calhoun et al. 2017) due to agricultural intensification (Anteau et al. 2016, McKenna et al. 2019) and high regional climatic variability (Winter and Rosenberry 1998). ...
... Sustained wet periods under increased-precipitation climate scenarios can result in a change in the hydroperiods of small wetlands resulting in these wetlands remaining wetter longer and drying less frequently. Small wetlands are known to provide disproportionate contributions to hydrologic, biogeochemical, and ecological functions than would be predicted by their proportional area in any given watershed (Calhoun et al. 2017). Thus, a loss of smaller wetlands and convergence towards more homogeneous wet/ dry cycling can limit the diversity of species that use wetlands of the PPR (McLean et al. 2019). ...
Article
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Grasslands, and the depressional wetlands that exist throughout them, are endangered ecosystems that face both climate and land‐use change pressures. Tens of millions of dollars are invested annually to manage the existing fragments of these ecosystems to serve as critical breeding habitat for migratory birds. The North American Prairie Pothole Region (PPR) is a region that contains millions of depressional wetlands that produce between 50 and 80% of the continent’s waterfowl population. Previous modeling efforts suggested that climate change would result in a shift of suitable waterfowl breeding habitat from the central to the southeast portion of the PPR, an area where over half of the wetlands have been drained. The implications of these projections suggest a massive investment in wetland restoration in the southeastern PPR would be needed to sustain waterfowl populations at harvestable levels. We revisited these modeled results indicating how future climate may impact the distribution of waterfowl‐breeding habitat using up‐to‐date climate model projections and a newly developed model for simulating prairie‐pothole wetland hydrology. We also presented changes to the number of “May ponds,” a metric used by the U.S. Fish and Wildlife Service to estimate waterfowl breeding populations and establish harvest regulations. Based on the output of 32 climate models and 2 emission scenarios, we found no evidence that the distribution of May ponds would shift in the future. However, our results projected a 17% decrease to 5% increase in May‐pond numbers when comparing the most recent climate period (1989–2018) to the end of the 21st century (2070–2099). When combined, our results suggest areas in the PPR that currently support the highest densities of intact wetland basins, and thus support the largest numbers of breeding‐duck pairs, will likely also be the places most critical to maintaining continental waterfowl populations in an uncertain future.
... Freshwaters encompass a wide diversity of other habitats, including small and temporary wetlands, which are not defined in regulations globally. There are many different temporary wetland types (e.g., alpine pool, prairie pothole, vernal pool); but they are all small, shallow, and they often dry annually (Calhoun et al., 2017). The unique features of these wetlands make them biodiversity hotspots for many species, such as aquatic invertebrates (Colburn et al., 2007), semi-aquatic amphibians (Snodgrass et al., 2000;Gibbons et al., 2006) or waterbirds , and terrestrial moose (Alces alces) or hares (Lepus sp.) (Dixneuf et al., 2021). ...
... Additionally, several papers investigated the DOC/DOM characteristics of temporary wetlands (e.g., Yu et al., 2015;Chow et al., 2016). The importance of small and temporary wetlands is now recognized (Zedler, 2003;Calhoun et al., 2017;Ramsar Convention on Wetlands, 2018). Research on such habitats should thus now investigate how browning may modify them and their communities; it would improve knowledge on the processes of browning and help targeting good integrated watershed management strategies, including networks of all wetland types. ...
Article
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Water browning or brownification refers to increasing water color, often related to increasing dissolved organic matter (DOM) and carbon (DOC) content in freshwaters. Browning has been recognized as a significant physicochemical phenomenon altering boreal lakes, but our understanding of its ecological consequences in different freshwater habitats and regions is limited. Here, we review the consequences of browning on different freshwater habitats, food webs and aquatic-terrestrial habitat coupling. We examine global trends of browning and DOM/DOC, and the use of remote sensing as a tool to investigate browning from local to global scales. Studies have focused on lakes and rivers while seldom addressing effects at the catchment scale. Other freshwater habitats such as small and temporary waterbodies have been overlooked, making the study of the entire network of the catchment incomplete. While past research investigated the response of primary producers, aquatic invertebrates and fishes, the effects of browning on macrophytes, invasive species, and food webs have been understudied. Research has focused on freshwater habitats without considering the fluxes between aquatic and terrestrial habitats. We highlight the importance of understanding how the changes in one habitat may cascade to another. Browning is a broader phenomenon than the heretofore concentration on the boreal region. Overall, we propose that future studies improve the ecological understanding of browning through the following research actions: 1) increasing our knowledge of ecological processes of browning in other wetland types than lakes and rivers, 2) assessing the impact of browning on aquatic food webs at multiple scales, 3) examining the effects of browning on aquatic-terrestrial habitat coupling, 4) expanding our knowledge of browning from the local to global scale, and 5) using remote sensing to examine browning and its ecological consequences.
... Research to date has generally focused on soil organic C (SOC) of permanently saturated wetlands, where anoxia and subsequently slow decomposition are strong environmental drivers of SOC storage. However, a considerable yet frequently overlooked subset of wetlands are seasonally saturated and therefore experience dry, oxic conditions annually (e.g., vernal pools, Delmarva bays, prairie potholes) (Zedler 2003;Brooks 2005;Calhoun et al. 2017). Under the existing understanding of wetland SOC storage, periodic drying of seasonally saturated wetlands might be expected to stimulate C emissions and SOC loss (Miao et al. 2017). ...
... The role of global wetlands as a future C sink or source is uncertain, as climate and land use change alter wetland area and biogeochemical processing (e.g., Dahl 2011;Kolka et al. 2018;Moomaw et al. 2018). While the wetlands in this study are relatively small in area, up to one-fifth of wetland area in this region experiences seasonally dynamic hydrology (MD iMAP 2016), and seasonally saturated wetlands are globally ubiquitous (Calhoun et al. 2017). Therefore, the seasonally saturated areas of many small wetlands are likely to have a large cumulative impact on SOC stocks at the landscape scale. ...
Article
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Wetlands store significant soil organic carbon (SOC) globally due to anoxic conditions that suppress SOC loss. However, stored SOC may become vulnerable to decomposition where climate and land use change alter wetland hydrology. Seasonally saturated wetlands experience fluctuating hydrologic conditions that could promote physicochemical mechanisms known to stabilize terrestrial SOC. These wetlands are therefore likely to be important for SOC storage at the landscape-scale. This study examined physicochemical stabilization of SOC within five seasonally saturated wetlands across a hydrologic gradient from the frequently saturated basin edge to the rarely saturated upland. At each wetland, we monitored water level and collected soil samples from the top two mineral horizons across five transect points to quantify physical protection of SOC in aggregates and organo-mineral associations between SOC and iron (Fe). As expected, both SOC concentrations and SOC stocks from 10–50 cm decreased across the transect from frequently saturated soils to rarely saturated soils. However, SOC stocks from 0–10 cm increased along this gradient, indicating diverging SOC dynamics throughout the soil profile. The majority of SOC was associated with macroaggregates across the transect, suggesting that macroaggregates are likely to physically protect wetland SOC during seasonal drying. By contrast, Fe-associated SOC was low across the transect, though modest accumulations of Fe (5 mg Fe g−1 soil) were observed in the transition zone where saturation was most dynamic throughout the year. Our results suggest that SOC stabilization occurs via physical protection within macroaggregates and, to a lesser extent, organo-mineral associations during dry periods in and around seasonally saturated wetlands. As climate scenarios predict intensified wet and dry cycles in many wetlands, understanding SOC stabilization is critical to predicting vulnerability to future change.
... This could exacerbate the existing stress on threatened species (Amano et al., 2020), as well as wetland economic and ecosystem services, such as nutrient cycling, water storage and purification, food production, and recreation (Zedler and Kercher, 2005). Concerns about climate change tend to focus on temperature increases, but precipitation changes can dramatically alter hydrologic regimes and invertebrate communities of wetlands as well (Calhoun et al., 2017). For example, studies in California vernal pools, Andean ponds and Mediterranean wetlands, areas with seasonally dry periods, have detected relationships between temporal shifts in precipitation regimes and regional diversity (Boix et al., 2001;Kneitel, 2014;Montemayor et al., 2017). ...
Article
Climate change is rapidly driving global biodiversity declines. How wetland macroinvertebrate assemblages are responding is unclear, a concern given their vital function in these ecosystems. Using a data set from 769 minimally impacted depressional wetlands across the globe (467 temporary and 302 permanent), we evaluated how temperature and precipitation (average, range, variability) affects the richness and beta diversity of 144 macroinvertebrate families. To test the effects of climatic predictors on macroinvertebrate diversity, we fitted generalized additive mixed-effects models (GAMM) for family richness, and generalized dissimilarity models (GDMs) for total beta diversity. We found non-linear relationships between family richness, beta diversity and climate. Maximum temperature was the main climatic driver of wetland macroinvertebrate richness and beta diversity, but precipitation seasonality was also important. Assemblage responses to climatic variables also depended on wetland water permanency. Permanent wetlands from warmer regions had higher family richness than temporary wetlands. Interestingly, wetlands in cooler and dry-warm regions had the lowest taxonomic richness, but both kinds of wetlands supported unique assemblages. Our study suggests that climate change will have multiple effects on wetlands and their macroinvertebrate diversity, mostly via increases in maximum temperature, but also through changes in patterns of precipitation. The most vulnerable wetlands to climate change are likely those located in warm-dry regions, where entire macroinvertebrate assemblages would be extirpated. Montane and high-latitude wetlands (i.e., cooler regions) are also vulnerable to climate change, but we do not expect entire extirpations at the family level.
... Over the almost flat region of La Mancha, north and south of the Guadiana river, exist numerous intermittently inundated wetlands, temporary wetlands, known under the Spanish names of hoya, lagunajo, lavajo, and even laguna (Cirujano & Medina 2002). Temporary wetlands enhance biodiversity and provide aesthetic, biogeochemical and hydrological functions (Calhoun & al. 2017), and resources suitable for basketry (Cirujano & Medina 2002). ...
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Ecosystem services from wetlands include products such as food, water, fibers, timber, medicinal plants, and genetic resources for agriculture. One of the most abundant supplies is the raw material for basketry. In this study we aim to document the role of wetland plants as resources for basketry and broom-making in the Guadiana river basin and to analyze the local traditional knowledge of the species used in the area. We describe different types of baskets and other artifacts, and document basketry techniques. We found 30 species belonging to 12 families, 18 of them occurring in wetlands, four in irrigated fields, and seven in the adjacent dry territories. Twenty species are used in the manufacture of brooms. Twenty two types of basketry artifacts are described with their uses. The area shows a relevant cultural heritage, not merely as it was in the past, but also adapted to the new cultural and social contexts. The degradation and loss of wetlands in central Spain threatens these ecosystems and their associated cultural heritage. We suggest the declaration of this intangible human heritage as the “Culture of the Mediterranean Wetlands” before it disappears.
... Such regional importance is a key asset to maintain their high diversity levels (Horváth et al. 2019). However, because of this importance, an alteration in the landscape structure generated by a disturbance such as a wildfire may produce a strong change in the diversity of these already endangered systems (EPCN 2008, Bagella et al. 2016, Calhoun et al. 2017. Finally, apart from this strong spatial relevance, these temporary systems are also strongly impacted by seasonal changes related to water level and hydroperiod length and timing (Kneitel 2014, Shin andKneitel 2019). ...
Article
Wildfires are a global disturbance being enhanced by human-induced pressures. Their frequency and intensity are expected to increase in the near future in regions such as the Mediterranean Basin. While responses of terrestrial systems to wildfire have been thoroughly studied, aquatic systems such as temporary ponds have received less attention. Furthermore, previous works have focused on wildfire impacts in aquatic systems from a functional and trait-based approach, but such disturbances can also impact the diversity of these systems at the local and regional level. In this work, we assessed wildfire impacts on alpha and beta diversity of Mediterranean temporary ponds by analysing samples of pond macrofauna after a wildfire burned part of a cluster of these habitats. The wildfire did not change alpha diversity patterns, but differences in beta diversity were observed when considering species abundance. Species with greater contribution to beta diversity were more strongly represented in unburned ponds after the wildfire. These changes occurred mostly during the beginning of the hydroperiod, which increased regional differences in burned ponds, but decreased toward the middle and the end of the hydroperiod. Overall, we report a fast recovery of communities after the wildfire, tightly linked to a rapid recolonization that increased similarity. Landscape structure and seasonal succession are key to the recovery of these systems. However, this recovery capacity might be compromised in the future by increasing occurrence of wildfire and the potential for substantial habitat loss.
... Topographic and geomorphological factors (altitude, slope) affect the spatial redistribution of solar radiation, surface water distribution [27], and in uence the growth and distribution of wet plants. Therefore, compared with other environmental factors, soil physical and chemical conditions (soil type, soil nutrient, soil moisture, pH, salinity, etc.) directly affect the distribution of wet plants [28][29][30]. To protect and restore the lake-terrestrial ecotone, research the wet plant biodiversity, distribution characteristics, and in uencing factors will help clarify the relationship between wetland plant distribution range and lake-terrestrial ecotone habitat factors. ...
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Background: Lake is a critical part of Tibet's hydrological cycle, the lake-terrestrial ecotone is the most sensitive area in the water and terrestrial ecosystem. For the ecological protection and maintenance of the lakeside zone, defining the upper boundary of the lake-terrestrial ecotone is a key issue that needs to be solved urgently. However, the ecological characteristics of lake-terrestrial ecotone made it diffcult to delimit. Wetland herbs are characteristic plants of the radiant belt toward the land of the lake-terrestrial ecotone, and their distribution range can be used to reflect the upper boundary of the lake-terrestrial ecotone. We took Baksum Lake, Yambdroktso, Namtso, Siling Co as examples, based on the spatial structure of the lake-terrestrial ecotone, used the moving split-window technology (MSWT) delimited the range of wetland herbs. Results:The results of MSWT showed the distribution range of wetland herbs in each lake-terrestrial ecotone with the natural-wetland type sampling line of Baksum Lake, Yambdroktso, Namtso, Siling Co was 51m, 56m, 33~53m, 19~31m. DCA showed number of wetland herbs species,BK1>YT1=NT1>NT2>SC1=SC2. PCA, RDA showed SMO, pH, SSC, and soil nutrient content had obvious correlation with distribution range. Conclusion:MSWT was a feasible method to delimit the distribution range of wetland herbs. SMO, pH, SSC, and soil nutrient content were all-important environmental factors affect the wetland herbs distribution range of the four lakes, however, the SMO was the most important factor. Besides, compare with the lakes in the lower Yangtze Plain,the high-density population distribution,high-intensitive human activity invaded the plants' growth area, resulting in a smaller distribution range.
... For example, Mikkonen (1985) found that Chaffinch males (Fringilla coelebs) arrive in early spring to secure a territory with abundant future food resources and to attract females. Ephemeral wetlands can be found in many climate zones (Deil, 2005), such as in temperate forest (France; Calhoun et al., 2016). Most vernal pool studies have been done in North America in temperate and boreal forests. ...
Article
Biodiversity and habitats are under threat from many factors such as human population increase, habitat loss, fragmentation, and climate change. In freshwater habitats, including wetlands, biodiversity is expected to decline on a greater scale than in terrestrial ecosystems. Ephemeral wetlands are little studied habitats compared to other wetlands, such as permanent lakes and rivers. The purpose of this study was to investigate the vertebrate fauna present by ephemeral vernal pools and to see whether vernal pools increase the activity and diversity of vertebrates in a boreal forest ecosystem in northern Europe. We studied the activity and species richness of birds and mammals with direct observations, camera traps, faeces tracking, and snap-trapping by ten vernal pools and ten permanent wetlands. Bird activity was higher in the spring period in vernal pools than in permanent wetlands. For large mammals, both activity and species richness were greater around vernal pools than by permanent wetlands. Of individuals species, the moose (Alces alces), roe deer (Capreolus capreolus), and hares (Lepus europaeus and Lepus timidus) used vernal pools significantly more between seasons compared to permanent wetlands. Small mammal activity was higher by vernal pools in April, while in May and June the pattern reversed. In the light of these results, vernal pools seem to have different importance and use depending on the vertebrate group, e.g., for sheltering, foraging, resting, nesting, or thermoregulation.
... Temporary ponds are unique freshwater wetland habitats exposed to extreme environmental conditions where flooding occurrences are often ephemeral and alternate with periods of severe drought (Calhoun et al., 2017). Due to its transient nature, these habitats host vulnerable biotic assemblages that developed specific adaptations to cope with these conditions (Brendonck, 1996). ...
Article
• Temporary lentic water bodies host biotic assemblages adapted to the transient nature of these freshwater habitats. Fairy shrimps (Crustacea, Branchiopoda, Anostraca) are one of the most important biological components of these unique environments and have a fossil record dating back to the Middle Jurassic (>150 million years). • Some anostracan species show a geographically restricted distribution, whereas others are widely dispersed. We aimed to investigate the relationship between different geographic extents and patterns of genetic structure in species of Anostraca. Following this objective, we selected two species with contrasting ranges but overlapping geographic distributions and similar life-history traits in the study area. We analysed additional information that, from an ecological (e.g. egg-bank, niche breadth, and pond connectivity) and evolutionary (e.g. crown-group age of each species) perspective, may explain the obtained phylogeographic patterns. • Between 2005 and 2018, we sampled two species of fairy shrimps (309 specimens of Branchipus cortesi and 264 specimens of Tanymastix stagnalis) from 53 temporary ponds of Portugal. We added five other locations from Spain and France to include other European locations for T. stagnalis. Additionally, we also sampled Branchipus schaefferi from two temporary water bodies (Spain and Morocco) to include in the dating analysis. • Reconstructed phylogenies based on mitochondrial sequence data indicate the existence of deeply divergent clades with an unequivocal phylogeographic structure in T. stagnalis and shallower divergences in B. cortesi with a less clear geographic correspondence. We found evidence of frequent local and rare long-distance dispersal events in both species and limited intermediate dispersal, which was more common in B. cortesi. A Bayesian dating analysis using the Branchiopoda fossil record estimated the age of the most recent common ancestors of T. stagnalis and B. cortesi at 32.4 and 12.8 million years, respectively. • Haplotype accumulation curves indicated that only a portion of the genetic composition of the species was sampled on each hydroperiod and showed the existence of large, genetically diverse egg banks that remain in the soil. These egg banks represent a genetic reservoir that guarantees the survival of the species because active populations from different hydroperiods may be genetically different and adapt to a changing environment. • We hypothesise that the contrasting phylogeographic patterns displayed by the two fairy shrimp species may result from: (1) the earlier age of the most recent common ancestor of T. stagnalis, as older species have more time to accumulate mutations and, thus, are expected to exhibit higher genetic differentiation among populations; (2) slight differences in adult behaviour, life-history traits and cyst morphologies of T. stagnalis and B. cortesi favouring different animal dispersal vectors with distinct dispersal abilities. Therefore, phylogeographic patterns may be explained by both evolutionary and ecological processes, which operate in different time scales.
... Temporary lagoons are very dynamic ecosystems, with a considerable water level fluctuation completely dependent on the local rainfall regime and frequently drying partially or completely over the year (Calhoun et al., 2017). In these ecosystems, the flora and fauna are influenced by the water regime (Sandi et al., 2020) and hydroperiod length (Vanschoenwinkel et al., 2009). ...
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Cite as: Silva, K.R.P. et al. Phytoplankton functional groups in shallow aquatic ecosystems from the semiarid region of Brazil. Acta Limnologica Brasiliensia, 2021, vol. 33, e24. Abstract: Aim: The study analyzed the potential use of the phytoplankton functional groups as an environmental bioindicator in aquatic ecosystems of Brazilian semiarid region. Methods: Using data collected over five years of a natural lagoon and two reservoirs, we evaluate the relationship between functional groups and environmental conditions through the multivariate approach. The Q index was applied to assess ecological status in these ecosystems. Results: In Panati, the temporary and natural lagoon, the partial habitat desiccation and presence of macrophytes reflected in the less nutrients concentrations and phytoplankton composition, with high biomass of coccoids Chlorophyceae, diatoms and desmids (functional groups J, MP and N, respectively). Taperoá and Soledade reservoirs presented high cyanobacteria contribution, however the biomass and contribution of cyanobacteria in Taperoá (S N , S 1) were lower than in Soledade. In this reservoir, cyanobacteria were more abundant, alternating in dominance (L O , M, L M , S N , S 1). According to tendencies revealed by Redundancy Analysis (RDA), the main driving abiotic factors on the phytoplankton functional groups were pH, nutrients and light availability. As expected, phytoplankton composition directly influenced the Q index result, showing mostly bad to tolerable conditions in Soledade, medium to good in Taperoá and good to excellent in Panati. Conclusions: The Q index was a good tool to assess the water quality and ecological status in aquatic ecosystems from the Brazilian semiarid region, reflecting the influence of natural control mechanisms on the harmful cyanobacteria blooms in temporary ecosystems.
... In arid environments, the phytotelmaassociated micro-ecosystem is defined by the seasonality of water availability. Once water accumulates following the rains, growth occurs in the aquatic biota that is well adapted to temporary environments, significantly increasing the diversity of aquatic organisms in the area (Calhoun et al., 2017). ...
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Pseudalcantarea grandis (Schltdl.) Pinzón & Barfuss is a tank bromeliad that grows on cliffs in the southernmost portion of the Chihuahuan desert. Phytotelmata are water bodies formed by plants that function as micro-ecosystems where bacteria, algae, protists, insects, fungi, and some vertebrates can develop. We hypothesized that the bacterial diversity contained in the phytotelma formed in a bromeliad from an arid zone would differ in sites with and without surrounding vegetation. Our study aimed to characterize the bacterial composition and putative metabolic functions in P. grandis phytotelmata collected in vegetated and non-vegetated sites.
... Although many questions remain concerning the potential function of hydrologic refugia in supporting amphibian species persistence under climate change, existing knowledge can help identify hypotheses and research needs. Even without identifying specific refugia from a known set of surveyed sites (as we do here), a landscape with a diversity of pool sizes and hydroperiods is expected to maximize the probability that some pools within a protected area could serve as refugia during droughts or other adverse climatic conditions (Dodd, 1994;Shoo et al., 2011), lending support to calls to conserve diverse types and sizes of wetlands (Babbitt et al., 2003;Calhoun et al., 2017;Snodgrass et al., 2000). Our findings support the notion that larger pools and/or those with generally longer hydroperiods may be more likely to function as hydrologic refugia under droughts or climate change (Baldwin et al., 2006;Brooks, 2009). ...
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Vernal pools of the northeastern United States provide important breeding habitat for amphibians but may be sensitive to droughts and climate change. These seasonal wetlands typically fill by early spring and dry by mid‐to‐late summer. Because climate change may produce earlier and stronger growing‐season evapotranspiration combined with increasing droughts and shifts in precipitation timing, management concerns include the possibility that some pools will increasingly become dry earlier in the year, potentially interfering with amphibian life‐cycle completion. In this context, a subset of pools that continue to provide wetland habitat later into the year under relatively dry conditions might function as ecohydrologic refugia, potentially supporting species persistence even as summer conditions become warmer and droughts more frequent. We used approximately 3,000 field observations of inundation from 449 pools to train machine‐learning models that predict the likelihood of pool inundation based on pool size, day of the year, climate conditions, short‐term weather patterns, and soil, geologic, and landcover attributes. Models were then used to generate predictions of pool wetness across five seasonal time points, three short‐term weather scenarios, and four sets of downscaled climate projections. Model outputs are available through a website allowing users to choose the inundation thresholds, time points, weather scenarios, and future climate projections most relevant to their management needs. Together with long‐term monitoring of individual pools at the site scale, this regional‐scale study can support amphibian conservation by helping to identify which pools may be most likely to function as ecohydrologic refugia from droughts and climate change.
... Our results also point to the need to reassess instruments related to wetland management. For instance, although we have shown that ponds make unique contributions to wetland plant diversity, such ecosystems are neglected in various regions of the globe (e.g., see Williams et al. 2004;Calhoun et al. 2017;Grasel et al. 2018;Hill et al. 2018). A critical example comes from Brazil, where ponds have practically lost their legal protection on private properties after the revision of the "Forest Code" (Federal Law nº 4,771/1965; renamed as the Native Vegetation Protection Law: Federal Law nº 12,651/2012), which also reduced or removed the protection of several other wetland habitats (Brancalion et al. 2016;Grasel et al. 2018Grasel et al. , 2019a)ponds and other wetlands are also mostly neglected in protected areas of the country (see Azevedo-Santos et al. 2019). ...
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Understanding how wetland plant communities are organized in different ecosystems and spatial scales is essential to support conservation. Studies that have addressed this primary need, however, are exceptionally scarce. Here, we compared the diversity (alpha, beta and gamma) and composition of herbaceous and woody communities (treated separately and jointly) in ponds, streambanks and riverbanks in the upper Uruguay River Basin, southern Brazil. Results showed that each wetland ecosystem exhibited unique community patterns, depending on the plant group, data property (e.g., presence-absence or abundance), and community parameter. All ecosystem types had exclusive species, beta diversity explained by high rates of species turnover and balanced variation in abundance components, and particular floristic composition, revealing that each wetland type and site contributes fundamentally to the overall wetland plant diversity. These findings indicate that safeguarding wetland plant diversity depends on the adoption of holistic conservation measures.
... Detailed group discussions followed, which reduced individual lists (over >30 research priorities in total) to nine research themes: (1) definition of pond habitats; (2) global and long-term data; (3) anthropogenic stressors; (4); aquaticterrestrial interactions; (5) succession and disturbance; (6) freshwater connectivity; (7) pond monitoring and technological advances (8) socioeconomic factors; and (9) conservation, management and policy ( Fig. 2; Table 1). Subsequently, workshop organizers collated research questions from attendees, based on the research themes, and refined them into 30 questions for future pond research, building upon previous studies by Calhoun et al. (2017) and Biggs et al. (2017). The research themes and questions are outlined below by theme and are not ordered by importance or relevance. ...
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Ponds are among the most biodiverse and ecologically important freshwater habitats globally and may provide a significant opportunity to mitigate anthropogenic pressures and reverse the decline of aquatic biodiversity. Ponds also provide important contributions to society through the provision of ecosystem services. Despite the ecological and societal importance of ponds, freshwater research, policy, and conservation have historically focused on larger water bodies, with significant gaps remaining in our understanding and conservation of pond ecosystems. In May 2019, pond researchers and practitioners participated in a workshop to tackle several pond ecology, conservation, and management issues. Nine research themes and 30 research questions were identified during and following the workshop to address knowledge gaps around: (1) pond habitat definition; (2) global and long‐term data availability; (3) anthropogenic stressors; (4) aquatic–terrestrial interactions; (5) succession and disturbance; (6) freshwater connectivity; (7) pond monitoring and technological advances; (8) socio‐economic factors; and (9) conservation, management, and policy. Key areas for the future inclusion of ponds in environmental and conservation policy were also discussed. Addressing gaps in our fundamental understanding of pond ecosystems will facilitate more effective research‐led conservation and management of pondscapes, their inclusion in environmental policy, support the sustainability of ecosystem services, and help address many of the global threats driving the decline in freshwater biodiversity.
... However, such depression wetlands may be increasingly vulnerable to anthropogenic climate and landcover change and to human demands on water resources (Tiner 2003;Wolfe et al. 2004;Gómez-Rodríguez et al. 2010;Bird and Day 2014;Bolpagni et al. 2019;Cartwright 2019). Many small depression wetlands are seasonally inundated-holding water for only part of each year-with inundation patterns driven by wetland and drainage-basin characteristics (e.g., size, geomorphology, substrate) and climate variability (Brooks 2004;Calhoun et al. 2017;Bertassello et al. 2019;Davis et al. 2019). Primary impacts of climate change and human water use in these depression wetland ecosystems can arise through hydrologic changes such as shifts in seasonal timing of inundation and changes in hydroperiod (i.e., the number of days per year that a wetland is inundated ;Brooks 2009;Gómez-Rodríguez et al. 2010;Russell et al. 2020). ...
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The hydrology of seasonally inundated depression wetlands can be highly sensitive to climatic fluctuations. Hydroperiod—the number of days per year that a wetland is inundated—is often of primary ecological importance in these systems and can vary interannually depending on climate conditions. In this study we re-examined an existing hydrologic model to simulate daily water levels in Sinking Pond, a 35-hectare seasonally inundated karst-depression wetland in Tennessee, USA. We recalibrated the model using 22 years of climate and water-level observations and used the recalibrated model to reconstruct (hindcast) daily water levels over a 165-year period from 1855 to 2019. A trend analysis of the climatic data and reconstructed water levels over the hindcasting period indicated substantial increases in pond hydroperiod over time, apparently related to increasing regional precipitation. Wetland hydroperiod increased on average by 5.9 days per decade between 1920 and 2019, with a breakpoint around the year 1970. Hydroperiod changes of this magnitude may have profound consequences for wetland ecology, such as a transition from a forested wetland to a mostly open-water pond at the Sinking Pond site. More broadly, this study illustrates the needs for robust hydrologic models of depression wetlands and for consideration of model transferability in time (i.e., hindcasting and forecasting) under non-stationary hydroclimatic conditions. As climate change is expected to influence water cycles, hydrologic processes, and wetland ecohydrology in the coming decades, hydrologic model projections may become increasingly important to detect, anticipate, and potentially mitigate ecological impacts in depression wetland ecosystems.
... Les mares temporaires du littoral méditerranéen (MTL) sont menacées, des centaines d'entre elles ayant disparu ces dernières décennies, détruites ou perturbées entre autres par les effets du changement climatique (Bagella et al. 2016 ;Calhoun et al. 2017 ;Grillas et al. 2004). Les mares littorales sont aussi exposées à des phénomènes de salinisation étant donné leur proximité avec la mer et une plus forte exposition au risque de submersion marine (Bawedin 2004). ...
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The salinization of coastal wetlands resulting from sea level rise is one of the many effects expected from global warming. In the coastal plains of the Mediterranean Basin, this phenomenon particularly concerns oligo- and mesohaline temporary ponds and marshes, as well as the fauna and flora associated with these environments. We have studied this vulnerability on the Camargue’s former saltworks site (Bouches-du-Rhône, France), formerly used for salt production and subject to major changes since its transfer to the Conservatoire du littoral between 2008 and 2012. The formation of breaches along the former protection dikes and, more generally, the process of renaturalization of the coastline, are causing the lagoons of these former saltworks to be reconnected to the sea. The Natterjack toad (Epidalea calamita) is potentially one of the species most vulnerable to these modifications, as it breeds in temporary coastal pools, most of which are located on the periphery of the lagoons and may be subject to the risk of salinization. Data on the physical characteristics of the coastal ponds as well as on the reproduction of the Natterjack toad were collected over a four-year period on 47 one hectare plots visited three times each spring. Using the site occupancy model, we estimated that 60% (range 43-75%) of pools located at this site were used as breeding habitat by adults of E. calamita in 2015. Over the next two years, this occupancy rate decreases to below 40%, and finally to almost zero in 2018. Our observations show that the reproductive success of Epidalea calamita is low and that only a few ponds presented conditions that allowed the species to complete its reproductive cycle. The number of ponds presenting favourable conditions for reproduction decreased throughout the four years of the study, because of the short periods of impoundment, excessive salinity or the conjunction of these two factors. Our results show that Epidalea calamita tadpoles are absent in waters with a conductivity above 10,2 PSU. The study period was marked by several years with very low annual rainfall, as well as significant episodes of marine submersion, which seem to be the cause of an increase in the salinity of the ponds. The occurrence of these phenomena and their aggravation, in a context of climate change and rising sea levels, make the future of the population on this coastal area uncertain. In order to assess more globally the issue related to the salinization of ponds on the Mediterranean coast, a survey was carried out among a sample of people in charge of the management or monitoring of 20 coastal sites or groups of sites benefiting of regulatory or land protection in the Occitanie and Sud Provence-Alpes-Côte-d'Azur regions. A total of 12 amphibian taxa are present on all the sites surveyed. One or more amphibian species are monitored in nearly half of the sites and groups of sites surveyed, with a wide variety of protocols implemented. 7 sites or groups of sites are concerned by recent phenomena of local extinction, either confirmed or suspected. Pelobates cultripes is the most frequently mentioned locally extinct species, however its disappearance is formally attributed to the phenomenon of salinization at only one site. More generally, for the communities of amphibians and in the long term, salinization is a recognized issue at half of the sites or groups of sites surveyed. We recommend that the monitoring of amphibians, where it is already in place, be supplemented by monitoring of water levels, salinities and possibly hydroperiods, when these variables are not yet measured. The implementation of monitoring at new sites can also be encouraged.
... Fishless, ephemeral wetlands are the preferred breeding habitat for many amphibian species including northern leopard frogs (Kendell, 2002). However, over recent decades, the abundance and quality of ephemeral wetlands across the landscape have declined due to anthropogenic impacts including climate change, draining for agricultural purposes, and introduction of exotic species (Calhoun et al., 2017). These changes may force amphibians to breed in suboptimal habitat, thereby altering their in- ...
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The role of parasites can change depending on the food web community. Predators, for instance, can amplify or dilute parasite effects on their hosts. Likewise, exposure to parasites or predators at one life stage can have long‐term consequences on individual performance and survival, which can influence population and disease dynamics. To understand how predators affect amphibian parasite infections across life stages, we manipulated exposure of northern leopard frog (Rana pipiens) tadpoles to three predators (crayfish [Orconectes rusticus], bluegill [Lepomis macrochirus], or mosquitofish [Gambusia affinis]) and to trematode parasites (Echinostoma spp.) in mesocosms and followed juveniles in outdoor terrestrial enclosures through overwintering. Parasites and predators both had strong impacts on metamorphosis with bluegill and parasites individually reducing metamorph survival. However, when fish were present, the negative effects of parasites on survival was not apparent, likely because fish altered community composition via increased algal food resources. Bluegill also reduced snail abundance, which could explain reduced abundance of parasites in surviving metamorphs. Bluegill and parasite exposure increased mass at metamorphosis, which increased metamorph jumping, swimming, and feeding performance, suggesting that larger frogs would experience better terrestrial survival. Effects on size at metamorphosis persisted in the terrestrial environment but did not influence overwintering survival. Based on our results, we constructed stage‐structured population models to evaluate the lethal and sublethal effects of bluegill and parasites on population dynamics. Our models suggested that positive effects of bluegill and parasites on body size may have greater effects on population growth than the direct effects of mortality. This study illustrates how predators can alter the outcome of parasitic infections and highlights the need for long‐term experiments that investigate how changes in host–parasite systems alter population dynamics. We show that some predators reduce parasite effects and have indirect positive effects on surviving individuals potentially increasing host population persistence. Using an amphibian‐trematode model system, our study demonstrates that predators can alter the outcome of parasitic infections and highlights the need for long‐term experiments that investigate how changes in host‐parasite systems alter population dynamics. Predator identity matters; some predators reduce parasite effects and have indirect positive effects on surviving individuals increasing host population persistence.
... Topographic and Fig. 1 Spatial structure of lake-terrestrial ecotone with natural-wetland type geomorphological factors (altitude and slope) affect spatial redistribution of solar radiation and surface water distribution [28], thus influencing the growth and distribution of wetland herbs. In contrast with other environmental factors, soil physical and chemical conditions (soil type, soil nutrient, soil moisture, soil pH, soil salinity, etc.) directly affect the distribution of wetland herbs [29][30][31]. Examining wetland herbs biodiversity, distribution characteristics, and influencing factors will help understand the relationship between the wetland herbs distribution width and the lake-terrestrial ecotone habitat factors. Moreover, prediction of the dynamic changes in the spatial range of the lake-terrestrial ecotone will reveal the formation mechanism of the distribution pattern of wetland herbs as well as the ecological process of community succession and its internal mechanisms. ...
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Background Lake is a critical part of Tibet's hydrological cycle, the lake–terrestrial ecotone is the most sensitive area in the water and terrestrial ecosystem. For the ecological protection and maintenance of the lakeside zone, defining the upper boundary of the lake–terrestrial ecotone is a key issue that needs to be solved urgently. However, the ecological characteristics of lake–terrestrial ecotone made it difficult to delimit. Wetland herbs are characteristic plants of the lake–terrestrial ecotone, and their distribution width can be used to reflect the upper boundary of the lake–terrestrial ecotone. We took Baksum Lake, Yamdroktso, Namtso, Siling Co as examples, based on the spatial structure of the lake–terrestrial ecotone, used the moving split-window technology (MSWT) delimited the width of wetland herbs. Results The results of the MSWT showed the distribution width of wetland herbs in each lake–terrestrial ecotone with the natural-wetland type sampling line of Baksum Lake, Yamdroktso, Namtso, Siling Co was 51 m, 56 m, 33 ~ 53 m, 19 ~ 31 m. The detrended correspondence analysis (DCA) showed quantity of wetland herbs species, BK1 > YT1 = NT1 > NT2 > SC1 = SC2. The principal component analysis (PCA) and the (redundancy analysis) RDA showed soil moisture content (SMO), pH, soil moisture content (SSC), and soil nutrient content had obvious correlation with distribution width. Conclusion The MSWT was a feasible method to determine the width of lake – terrestrial ecotone. SMO, pH, SSC, and soil nutrient content were all important environmental factors affecting the wetland herbs distribution width of the four lakes; and the SMO was the most important factor. Besides, compared with the lakes in the Middle-Lower Yangtze Plain, the high-density population distribution, high-intensive human activity invaded the plants' growth area, resulting in a smaller distribution width. The distribution edge of wetland herbs is equivalent to the upper boundary of lake–terrestrial ecotone. It determines the management boundary of the lake–terrestrial ecotone, provides a theoretical basis for the construction of environmental protection projects, and is of great significance to the lake ecological restoration and management in watershed control planning.
... Due to their natural heterogeneity, SWEs play a pivotal ecological role. First, they participate in hydrological and biogeochemical processes [2,7]. Second, they are considered a biodiversity hotspot, being an incredibly wide habitat with high species diversity [6,8]. ...
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Small standing-Water Ecosystems (SWEs), despite their pivotal ecological role due to their participation in hydrogeological processes and their richness in biodiversity, seem to be often overlooked by the scientific community. In this study, the vascular plant diversity in some representative SWEs, that host a peculiar assemblage of plant and animal species, was investigated in relation to the disturbance effects of a wild horse population. A total of 50 plots, equally distributed in small and large SWEs, were surveyed and a level of disturbance was attributed to each plot. We found greater species richness in small and undisturbed SWEs, which suggests the negative impact of horse grazing on the richness of plant species in this type of habitat. Significant differences in plant assemblage were found according to the disturbance level, whereas, contrary to what was observed for species richness, no differences were detected based on their size. The diversity indices, used to evaluate the richness and diversity in these areas, recorded the highest values for small and undisturbed areas. This result highlights that the disturbance of the horse grazing plays a pivotal role in affecting the diversity and richness of species in the SWEs. These findings suggest that SWE systems should be analyzed considering these areas as unique in order to allow the conservation of the plant richness and biodiversity of the SWE systems in conjunction with the protection of horses.
... One of the main problems encountered affects the reduction and disappearance of biological diversity, a consequence of habitat modification, usually due to the conversion and degradation of wetlands [17]. The objectives in these cases are to promote the reduction of ecosystem stress through the identification of environmental problems in a diagnostic analysis, then Eng 2022, 3 388 establishing strategic action programs [18]. Normally, among the programmed strategies, public awareness campaigns are carried out to increase environmental awareness directed at different levels of society [19][20][21], including parliamentary workshops for politicians, training events for local government officials, scientific conferences, and the participation of scientists in research and reporting to university and high school students, sometimes conducting environmental camps [22]. ...
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The LIFE SALINAS project, co-financed by the European Union, aims for the conservation and improvement of the protected area named the Regional Park of Las Salinas and Arenales de San Pedro del Pinatar (Region of Murcia, Spain). The main objectives are, among others, to stop the erosion of the dunes in front of a 500 m long beach and to expand the breeding habitat of aquatic birds. Between the dune and the beach, a barrier was placed to protect the dune from the effects of storms. The dunes were fenced, placed with sand traps and revegetation was carried out with native species in the most degraded areas. Within the salt pans, 1800 m of new sandy dikes were built to separate the salt ponds. The results have been the recovery of the dune ecosystem and the increase in the population of nesting aquatic birds and other species, as well as an increase in the quality and production of salt.
... Numerous studies have revealed the need to conserve and restore the spatial connectivity of wetlands in addition to simply maintaining wetlands in the landscape (e.g., Gibbs, 2000;Calhoun et al., 2017;Verheijen et al., 2018Verheijen et al., , 2020. This reflects an understanding of the importance of processes external to wetland habitat characteristics (e.g., hydrology, vegetative structure) that link wetland communities on the landscape, in addition to the unique characteristics internal to individual wetlands. ...
Article
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Wetland ecosystems are diverse, productive habitats that are essential reservoirs of biodiversity. Not only are they home to numerous wetland-specialist species, but they also provide food, water, and shelter that support terrestrial wildlife populations. However, like observed patterns of biodiversity loss, wetland habitats have experienced widespread loss and degradation. In order to conserve and restore wetlands, and thereby the biodiversity they support, it is important to understand how biodiversity in wetland habitats is maintained. Habitat heterogeneity and connectivity are thought to be predominate drivers of wetland biodiversity. We quantified temporal coherence (i.e., spatial synchrony) of wetland invertebrate communities using intra-class correlations among 16 wetlands sampled continuously over 24 years to better understand the relative influences wetland heterogeneity (i.e., internal processes specific to individual wetlands and spatial connectivity and external processes occurring on the landscape) on wetland biodiversity. We found that while wetlands with different ponded-water regimes (temporarily ponded or permanently ponded) often hosted different invertebrate communities, temporal shifts in invertebrate composition were synchronous. We also found the relative importance of internal versus external forces in determining community assembly vary depending on a wetland’s hydrologic function and climate influences. Our results confirm that heterogeneity and spatial connectivity of wetland landscapes are important drivers of wetland biodiversity.
... As such, a habitat structure of high vertical complexity qualifies as a 'keystone structure' for bird conservation in the eastern QTP (Tews et al., 2004;Manning et al., 2006). Keystone structures have been related to bird abundance and diversity in several habitat types, such as forests (Basile et al., 2021) or wetlands (Calhoun et al., 2017). Agricultural landscapes are known to host artificial keystone structures that positively contribute to biodiversity (Poschlod and Braun-Reichert, 2017), but their relevance in pastoral landscapes has been so far overlooked. ...
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The post-2020 global biodiversity framework calls for a transformative change in food systems. Promoting agricultural multifunctionality is a viable approach to this sustainability transformation. The eastern Qinghai–Tibetan Plateau (QTP) is both one of the world’s largest livestock grazing systems and a hotspot of endemic birds in Asia. In this research, we aim to investigate the impact of livestock grazing on alpine bird assemblages at the local scale (alpha diversity) and their variation across the pastoral landscape (beta diversity). In the study area Nyanpo Yutse, we conducted surveys of 126 bird sample plots during two breeding seasons to acquire bird assemblage data. Meanwhile, we employed unmanned aerial vehicles to measure 2D and 3D habitat features within the 150-m radius. We investigated the key habitat variables driving the spatial distributions of both alpha and beta diversities of birds. Particularly, we partitioned beta diversity into its turnover and nestedness components and tested their patterns across sites of four levels of livestock grazing intensities (LGIs). Our results found no significant correlation between LGIs with species richness of birds, while 2D and 3D habitat complexity and built structure were positively correlated with alpha diversity (p < 0.05). At the landscape scale, pairwise LGI differences had no significant correlation (p > 0.05) with any pairwise beta diversity. The ordination plotting detected distinguished habitat preferences among 12 common birds and eight endemic birds. The multiple-site beta diversity of the 126 plots showed high species turnover (>0.871) where LGI was lower than 1.065 sheep units/ha, indicating the importance of moderate grazing for the conservation of diverse avian assemblages at the landscape scale. Our study demonstrated that extensive pastoralism is important for both maintaining the mosaic landscape and conserving avian biodiversity on the eastern QTP. We unveiled one of the ecological mechanisms through which synergies can be realized to support both agricultural production and biodiversity conservation in the Tibetan grazing system.
... This study further highlights the fact that the ecological footprint of an ephemeral breeding pool on the landscape is far greater than its size and hydroperiod would suggest. Ephemeral wetlands support distinct suites of plant and animal species, including vertebrate and invertebrate animals, many of which are declining or vulnerable and under threat from accelerating land development (Calhoun et al., 2017). The uncertainty and inconsistency surrounding regulatory protections of wetlands in the United States are only heightened for ephemeral wetlands (Waters et al., 2019). ...
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... In their natural condition, wetlands support many environmental and socio-economic services to the neighbouring communities, which are, to some extent, largely controlled by the variations in inundation and soil saturation patterns (Dubeau et al. 2017;Thamaga et al. 2021). These ecosystems play a critical role by controlling floods, moderating micro-climates, maintaining and improving the water quality and protecting against erosion (Calhoun et al. 2017;Chandler et al. 2017;Materu et al. 2018). In sub-Saharan Africa, wetlands provide a basis for human livelihoods of many communities living around these ecosystems (Horwitz and Finlayson 2011;Rebelo et al. 2010). ...
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The study explored the impact of Land Use and Land Cover (LULC) change dynamics in relation to the condition and status of an unprotected wetland located in the arid-tropical parts of the Limpopo Province, South Africa. The long-term Landsat archival data series was used to map and quantify the impacts of LULC change on the wetland over a period of 36 years (1983-2019). A multi-source satellite image analysis was performed, using the Support Vector Machine (SVM) algorithm and advanced spatially- explicit geographic information system tools. Landsat data series covering the entire study area was used to assess, map and monitor LULC change that occurred over-time. Post-classification maps for the Maungani wetland area were analysed to provide a quantitative assessment and a detailed overview of the rate of change. The generated wetland detection maps for four temporal phases (i.e. 1983-1992, 1992-2001, 2002-2010) were analysed. This study found that the spatial extent of the wetland area declined severely during the period under study with 728 300 ha. The findings of this work provide critical insights and baseline information about the state of unprotected wetlands in the rural parts. This information is useful for the development of tailor-made wetland management strategies and a possible rehabilitation framework for unprotected wetland ecosystems.
... An increase in Multi-Ecosystem banks and associated credits would be supported by an increased call for matching spatial, ecological and administrative aspects better as well as incorporating feedback loops across systems and landscapes to allow for synergetic benefits (e.g., Henle et al. 2010;Moilanen et al. 2005). Multi-Ecosystem approaches have become more and more important especially in the context of urbanized landscapes and temporary ecosystems (e.g., temporary streams; temporary wetlands; Calhoun et al. 2017;Qui & Turner 2013). ...
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... The greater taxonomic and functional diversity of the dormant community in temporary ponds when compared to that of perennial lagoons confirms our initial hypothesis that, due to historical factors, ponds present more species originating from a diversified and wellestablished egg bank (Declerck et al., 2011;Vanschoenwinkel et al., 2009). A large number of studies have emphasized the importance of temporary environments on a regional scale (Bozelli et al., 2018;Calhoun et al., 2017;de Meester et al., 2005;Hunter et al., 2017;Mullins and Doyle, 2019;Setubal and Bozelli, 2021) and our results showed that temporary ponds are complementary to each other and to perennial lagoons. Moreover, our results illustrate that temporary ponds are important refuges for species and functional traits supporting greater variability. ...
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We characterized the functional and taxonomic composition of the active and dormant communities from perennial lagoons and temporary ponds in a coastal plain. We sought to determine the degree of coherence between the egg bank and the active community within the same type of environment (temporary or perennial) and between environments subject to different hydrological cycles. We sampled the zooplankton community and environmental variables in six temporary ponds and five perennial lagoons in the dry and the wet periods of the hydrological cycle. Temporary ponds and perennial lagoons differed in abiotic conditions, with higher values of dissolved carbon in temporary ponds and higher values of salinity in perennial lagoons. The taxonomic coherence between active and dormant communities in temporary environments was greater than in perennial environments. In functional terms, we observed a high coherence between active and dormant communities for both types of environments. Our results highlight the need to conserve both temporary and perennial environments to assure the maintenance of zooplankton diversity. Although these environments are subject to the same set of climatic variables and pool of species, their idiosyncrasies are important forces promoting and sustaining biological diversity.
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Accurate, un-biased wetland inventories are critical to monitor and protect wetlands from future harm or land conversion. However, most wetland inventories are constructed through manual image interpretation or automated classification of multi-band imagery and are biased towards wetlands that are easy to detect directly in aerial and satellite imagery. Wetlands that are obscured by forest canopy, occur ephemerally, and those without visible standing water are, therefore, often missing from wetland maps. To aid in detection of these cryptic wetlands, we developed the Wetland Intrinsic Potential tool, based on a wetland indicator framework commonly used on the ground to detect wetlands through the presence of hydrophytic vegetation, hydrology, and hydric soils. Our tool uses a random forest model with spatially explicit input variables that represent all three wetland indicators, including novel multi-scale topographic indicators that represent the processes that drive wetland formation, to derive a map of wetland probability. With the ability to include multi-scale topographic indicators, the WIP tool can identify areas conducive to wetland formation and provides a flexible approach that can be adapted to diverse landscapes. For a study area in the Hoh River Basin in Western Washington, USA, classification of the output probability with a threshold of 0.5 provided an overall accuracy of 91.97 %. Compared to the National Wetland Inventory, the classified WIP-tool output increased areas classified as wetland by 160 % and reduced errors of omission from 47.5 % to 14.1 %, but increased errors of commission from 1.9 % to 10.5 %. The WIP tool is implemented using a combination of R and python scripts in ArcGIS.
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Small wetlands have a high conservation value due to their importance as biodiversity hot spots. Despite this, they are nowadays at risk due to global change variables. We surveyed a set of seasonal wetlands located in Andean Patagonian forests which are the less studied aquatic systems. The wetlands selected presented different degrees of human impact, and some of them were geographically close and others were faraway and insulated. We registered environmental variables and the diversity and abundance of common pond animals in each wetland. Wetlands were described performing a principal component analysis considering the environmental variables. The main explanatory variables were dissolved organic carbon, water color, total nitrogen, and depth of the wetlands. The diversity of the aquatic organisms was studied using the Shannon index, and the relationship between environmental variables and aquatic organism was analyzed using canonical correspondence analysis (CCA). The rotifers showed the greatest diversity in the zooplankton assemblage, and the trichopterans were the most diverse of the benthic groups studied. The CCA showed that different variables explained the distribution of zooplankton and caddisfly/amphibian larvae assemblages. Each wetland presented a particular assemblage of species, and shared few species among them. Despite the differences in human impact and geographical distance, none of these factors appears to influence the diversity of these wetlands. We postulate that the high environmental heterogeneity found in these wetlands drives the diversity and abundance pattern of the aquatic biota observed.
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Wetlands store significant soil organic carbon (SOC) globally due to anoxic conditions that suppress SOC loss, yet this SOC is sensitive to climate and land use change. Seasonally saturated wetlands experience fluctuating hydrologic conditions that may also promote mechanisms known to control SOC stabilization in upland soils; these wetlands are therefore likely to be important for SOC storage at the landscape-scale. We investigated the role of physicochemical mechanisms of SOC stabilization in five seasonally saturated wetlands to test the hypothesis that these mechanisms are present, particularly in the transition between wetland and upland where soil saturation is most variable. At each wetland, we monitored water level and collected soil samples at five points along a transect from frequently saturated basin edge to rarely saturated upland. We quantified physical protection of SOC in aggregates and organo-mineral associations in mineral horizons to 0.5 m depth. As expected, SOC decreased from basin edge to upland. In the basin edge and transition zone, the majority of SOC was physically protected in macroaggregates. By contrast, overall organo-mineral associations were low, with the highest Fe concentrations (5 mg Fe g -1 soil) in the transition zone. While both stabilization mechanisms were present in the transition zone, physical protection is more likely to influence SOC stabilization during dry periods in seasonally saturated wetlands. As future climate scenarios predict changes in wetland wet and dry cycles, understanding the mechanisms by which SOC is stabilized in wetland soils is critical for predicting the vulnerability of SOC to future change.
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Annual killifish are among the most remarkable extremophile species with the shortest vertebrate life span. Few studies have reported on the oxidative balance throughout their life cycle and its association to the natural aging process of these neotropical animals in a natural environment. We standardized and analyzed physiological markers related to the redox balance of the annual killifish (Cynopoecilus fulgens) throughout the post-embryonic life cycle (enzyme activity of Superoxide Dismutase, Catalase, Glutathione Peroxidase, and Glutathione S-transferase, as well as the determination of the levels of Lipoperoxidation, Carbonylated Proteins, and Total Proteins). We tested the influence of environmental variables on these biomarkers. Individuals were collected, including juveniles, adults, and seniles, in three sampling units around the Parque Nacional da Lagoa do Peixe, located in the Coastal Plain of Rio Grande do Sul. We observed that males and females used different physiological strategies of their redox balance during their life cycle, and their oxidative balance was influenced by their reproductive period and environmental variables (water temperature, abundance of predators, abundance of another sympatric annual killifish species, and abundance of C. fulgens). The population of each temporary pond presented different physiological responses to the adaptation of their life cycle, and there was an influence of environmental component as a modulator of this cycle. Our study offers reference values that will be useful for comparison in future research with short-lived organisms.
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Leptopanchax opalescens is a critically endangered small annual fish. Reproductive traits of this species were studied to improve our understanding of the strategies that facilitate the occupation of temporary wetlands. We compiled egg diameter and maximum total length (TLmax) data from 132 neotropical freshwater fish (83 genera, 43 families) to establish comparisons with this species. We used the egg diameter / TLmax ratio to test the hypothesis that annual fish in temporary wetlands have relatively larger eggs than non-annual species from perennial habitats (lakes, rivers). Fish were collected from Guandu River drainages (Brazil). DNA barcoding was employed to confirm the species identity. The phases of gonadal development and spawn type were described using histological techniques. Egg size and fecundity were determined with microscopic analysis. Females with batch spawning and males with continuous spawning were detected. The bath fecundity ranged from 22–32 vitellogenic oocytes (mean 27 ± 7 SD). Annual species presented greater relative egg size than perennial species (p < 0.001), which is an indication of greater reproductive investment at the expense of somatic growth in temporary wetlands. Larger eggs are advantageous for annual fish as their lifespan is limited, and they can allocate a greater amount of yolk reserves for long periods buried in the substrate under embryonic diapause. Large relative oocytes, spawning in batches, synchronous modal development of oocytes, continued production of sperm in males, and a complex process of embryonic diapause are reproductive traits that favor resilience of L. opalescens and other annual fish in temporary wetlands.
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Ponds are aquatic habitats defined by their small size. Although small they are found on every continent, they are disproportionately rich in aquatic biodiversity, benefit terrestrial wildlife and have important ecosystem function benefits. One of these benefits might be carbon sequestration, a possibility suggested by (1) their abundance, (2) the intensity of their biogeochemical activity. Whilst greenhouse gas fluxes from ponds have been monitored widely, quantifying the stocks of organic carbon buried in sediment is a gap in our knowledge. Here we summarise measures of organic carbon in pond sediments cores from a diverse range of lowland ponds in England. We estimate a general measure of 9.38 kg OC in a 1 m² × 20 cm block of pond sediment and scale this up to an overall estimate for Great Britain of 2.63 million tons of OC in pond sediment, with 95% CI of 1.41 to 3.84 million tons. The relationship between sediment carbon and gas fluxes remains a significant unknown.
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Botswana constitutes a major gap in our knowledge of the distribution of Ostracoda in the region of Southern Africa, restraining thorough biogeographic interpretations. We combine records from previously published surveys along with our own field collections to provide a collation of living and fossil (Late Pleistocene to Holocene) Ostracoda recorded in Botswana. Our survey yielded 17 species, of which nine species have not been recorded before in the country. Including the present update, 54 species (45 living and nine fossil or subfossil) belonging to 22 genera of five families (with 76% species belonging to the family Cyprididae) are currently reported from Botswana. Yet, 23 taxa are left in open nomenclature, indicating the urgent need for sound systematic studies on harmonizing taxonomy of Southern African ostracods, especially of those inhabiting small temporary waterbodies, considered as threatened with extinction before being properly described or discovered. This updated checklist provides detailed information about the distribution and habitat of each recorded species. Species richness, distribution patterns, and diversity of ostracod species regionally and in different freshwater ecoregions are also discussed. We found low alpha (site) diversity (mean 3.3 species per site) and a significant difference in species composition and beta diversity of the Okavango ecoregion versus the Kalahari and Zambezian Lowveld ecoregions.
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The Italian rice agroecosystem plays a key role in the European production and provides a unique range of rice varieties. As productive man-made wetlands, rice paddies are strategic and economic components in the habitat provision for migratory wildlife at the European scale. However, the characteristic of being a “temporary wetland” causes the creation of an ecological trap for a number of living organisms. For this reason, agricultural practices adopted for the management of rice paddies are essential to move towards more sustainable cultivations capable of promoting biodiversity and to minimising negative environmental impacts. This study proposes an ecologically-oriented strategy to implement a circular and self-regulating farming system designed considering the role of constructed wetlands in providing ecosystem services in rice agroecosystems. It demonstrates the economic feasibility and benefits provided by a self-regulating biosystem based on an integrated wetland for a small-size rice farm of the Vercelli province (Piedmont Region, Italy). The study was conducted in collaboration with the rice farm, which already experiments with organic farming techniques. The investigation focuses on the current management structure of the farm and develops an ecologically-oriented business strategy to sustain local biodiversity. This strategy rediscovers and improves the traditional co-culture technique through the development of a permanent pond. It explores the potential benefits generated by the approach, in terms of biodiversity conservation, biological control of pests and weeds and habitat provision for wildlife. The study presents a real case study of economic sustainability of the business strategy through financial analysis. The findings highlight promising economic outcomes compared to the conventional rice cultivation systems. The diversification of marketing strategy and the reduction of operating costs are key factors in the success of the strategy. The ecologically-oriented design methodology presented in this article can easily be applied to other small-scale farms in the agrifood sector.
Chapter
Mediterranean regions are biodiversity hotspots whose landscapes are characterized by evergreen sclerophyllous vegetation, mild-wet winters, and hot-dry summers. In the Northern Hemisphere, they occur in the Mediterranean Basin and California regions. In these areas, whose habitats are heavily shaped by centuries of anthropic activities, the main effects of climate change include a decrease in precipitation and change in its regime, a pronounced warming, an increase in frequency of extreme temperature events, and altered and intensified fire regimes. Climate change poses a double challenge to the regeneration from seeds of Mediterranean plants. Warmer winters mainly affect the seed germination phase by limiting “typical” Mediterranean cold-cued germination in autumn/winter and reducing overwinter dormancy release for those species whose seeds germinate in spring. Harsher summers are detrimental for the establishment phase, compromising seedling survival. However, evidence of phenotypic plasticity in some Mediterranean plants suggests potential adaptation to a changing climate in the short- to medium-term for species of these regions.
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A cost-efficient approach to long-term monitoring is to focus on one species or group of organisms as indicators of ecological condition. Through the use of autonomous monitoring technologies, monitoring programs can efficiently expand the biological community surveyed and inferences made. Amphibians have been monitored in Yellowstone and Grand Teton national parks by the Greater Yellowstone Inventory and Monitoring Network (GRYN) since 2006, yet other taxa dependent on wetlands have not been systematically studied. Our main aim was to explore what additional insights we could gain about wetland biodiversity by combining GRYN’s amphibian surveys with multiple autonomous technologies. We deployed wildlife cameras and acoustic recorders (for audible and ultrasonic sounds) at 4 permanent wetlands in Grand Teton National Park, WY during early and late summer 2017 and used descriptive metrics to summarize our findings. During GRYN’s surveys, 3 of 4 native amphibians were detected. With autonomous monitoring tools, we also documented avian and mammalian communities and detected changes in the degree of activity over the summer. Combining multiple, complementary technologies with field-based surveys provides a more comprehensive picture of wetland biodiversity and enhances insights about ecological condition and change.
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Wetlands are essential for life on Earth, but at the same time the most threatened environments due to the gradual alterations associated with climate change and human action. The botanical studies on wetland higher plants carried out in Italy from 1950 until today are analysed in this survey. The 1,265 contributions resulting from this study are analysed from a historical, geographical, and content point of view. Most of the scientific contributions were published in the 1980s and 1990s, often by the same research groups and on a local scale. The predominant research theme is the inventory. Most papers are mainly focused on lakes and rivers. The results of this literature survey point to the need to continue and intensify these studies, especially in southern Italy and in temporary wetlands. It is essential to make the huge amount of data resting in drawers or included in scientific reports but not published in scientific journals readily accessible. This could also be achieved through online geographical databases.
Thesis
Les friches industrielles représentent de réelles opportunités pour la création d’espaces naturels mais les méthodes de restauration et d’évaluation des bénéfices environnementaux de ces opérations sont très lacunaires. L’objectif de cette thèse a été, au travers d’un cas d’étude, de palier à ce manque. Les résultats obtenus mettent en évidence que la restauration des technosols de friches industrielles nécessite une approche pluri-compartimentale (végétation et sol) et que les méthodes utilisées actuellement en restauration des sols sont moins efficaces dans des milieux aussi dégradés. Une approche pluridisciplinaire alliant outils d’évaluation économique et indicateurs écologiques a été ajustée permettant l’évaluation des bénéfices environnementaux de tels projets. Des adaptations sont cependant encore nécessaires dans la récolte de données, la sélection des indicateurs et la conception de la méthode pour garantir une meilleure prise en compte du compartiment sol, optimiser l’intégration des objectifs du projet de restauration et des potentiels impacts de la restauration sur les populations locales.
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Beyond the importance of ponds for aquatic and terrestrial life, pond networks seem to be crucial to providing a vital spatial resource in response to global climate change for all migrating and spreading taxa. Additionally, ponds offer sustainable solutions to issues of concern in water management, such as nutrient retention, rainfall interception, or carbon sequestration. Although the ecological role of shallow waters seems clear, significant work must be performed to set future guidelines and actions towards their conservation. The main aims of the present study are to (i) georeference all small temporary wetlands within the Tyrrhenian central Italy coastal area, (ii) evaluate their hydroperiod, and (iii) calculate their surface size variability. We found 137 wetlands, 53 of which were temporary and contained listed habitats. Each wetland’s status was assessed in relation to land use and proximity to stressors (e.g., urban centres, railways, roads) while observing the relationship between pond occurrence, lithology, and permeability. Amongst the detected wetlands, we selected and monitored 21 temporary ponds (homogeneously distributed within the study area) for 12 months using images collected by the non-professional drone Parrot Bebop 2. All images were then acquired in ArcGIS to georeference all temporary ponds. The analysis confirmed that the majority of the surveyed ponds are in close proximity to roads and tracks, which might have significant impacts on the preservation of such fragile habitats. Moreover, despite the wide variability of hydroperiod duration, the greater part of the pools fill with water in autumn and dry in summer, in alignment with the Mediterranean climate. This preliminary study allowed for the creation of the first temporary ponds’ database, which is useful for monitoring their status in central Italy and planning further studies to assess eventual detrimental effects caused by human-mediated activities.
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Inundation area is a major control on the ecosystem services provisioned by geographically isolated wetlands. Despite its importance, there has not been any comprehensive study to map out the seasonal inundation characteristics of geographically isolated wetlands over the continental United States (CONUS). This study fills the aforementioned gap by evaluating the seasonality or the long-term intra-annual variations of wetland inundation in ten wetlandscapes across the CONUS. We also assess the consistency of these intra-annual variations. Finally, we evaluate the extent to which the seasonality can be explained based on widely available hydrologic fluxes. Our findings highlight significant intra-annual variations of inundation within most wetlandscapes, with a standard deviation of the long-term averaged monthly inundation area ranging from 15 % to 151 % of its mean across the wetlandscapes. Stark differences in inundation seasonality are observed between snow-affected vs. rain-fed wetlandscapes. The former usually shows the maximum monthly inundation in April following spring snowmelt, while the latter experiences the maximum in February. Although the magnitude of inundation fraction has changed over time in several wetlandscapes, the seasonality of these wetlands shows remarkable constancy. Overall, commonly available regional hydrologic fluxes (e.g., rainfall, snowmelt, and evapotranspiration) are found to be able to explain the inundation seasonality at wetlandscape scale with determination coefficients greater than 0.57 in 7 out of 10 wetlandscapes. Our methodology and presented results may be used to map inundation seasonality and consequently account for its impact on wetland functions.
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Wetlands are an important habitat for many species but over the past few decades ecosystem biodiversity and function have been threatened. Due to their shallow and fluctuating water levels, wetlands are particularly vulnerable to climate variability. This is especially a risk for ephemeral and intermittent wetlands with limited hydrologic connections to deep aquifers, designated herein as Climate-induced Intermittent Wetlands (CiIWs). However, the response of CiIW systems to long-term climate variability has received limited research attention, partly because continuous ground surface monitoring data is rarely available over inter-decadal periods. An alternative to ground surface data is the use of satellite imagery to estimate the temporal water extent variability. An integrated remote sensing and modeling approach is presented here to provide a novel method for investigating historical water storage variations in a CiIW system. The new method estimates water levels in a shallow wetland using Landsat data and was successfully validated against field water level data. The new method performed better than five existing algorithms. A water balance model was calibrated using the combined remotely sensed and local field data to derive daily water level time series since 1900. The validated water balance model results indicated that most of the water level fluctuations in the intermittent wetland can be explained by climatic drivers and subsurface flow interactions. Overall, this study demonstrates the importance of an integrated remote sensing and water balance modeling approach for hydroclimatic analysis of intermittent wetlands.
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Effective natural resource policy depends on knowing what is needed to sustain a resource and building the capacity to identify, develop, and implement flexible policies. This retrospective case study applies resilience concepts to a 16-year citizen science program and vernal pool regulatory development process in Maine, USA. We describe how citizen science improved adaptive capacities for innovative and effective policies to regulate vernal pools. We identified two core program elements that allowed people to act within narrow windows of opportunity for policy transformation, including (1) the simultaneous generation of useful, credible scientific knowledge and construction of networks among diverse institutions, and (2) the formation of diverse leadership that promoted individual and collective abilities to identify problems and propose policy solutions. If citizen science program leaders want to promote social-ecological systems resilience and natural resource policies as outcomes, we recommend they create a system for internal project evaluation, publish scientific studies using citizen science data, pursue resources for program sustainability, and plan for leadership diversity and informal networks to foster adaptive governance.
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Given the complexity and multiplicity of goals in natural resource governance, it is not surprising that policy debates are often characterized by contention and competition. Yet at times adversaries join together to collaborate to find creative solutions not easily achieved in polarizing forums. We employed qualitative interviews and a quantitative network analysis to investigate a collaborative network that formed to develop a resolution to a challenging natural resource management problem, the conservation of vernal pools. We found that power had become distributed among members, trust had formed across core interests, and social learning had resulted in shared understanding and joint solutions. Furthermore, institutions such as who and when new members joined, norms of inclusion and openness, and the use of small working groups helped create the observed patterns of power, trust, and learning.
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Geographically isolated wetlands (GIWs), those surrounded by uplands, exchange materials, energy, and organisms with other elements in hydrological and habitat networks, contributing to landscape functions, such as flow generation, nutrient and sediment retention, and biodiversity support. GIWs constitute most of the wetlands in many North American landscapes, provide a disproportionately large fraction of wetland edges where many functions are enhanced, and form complexes with other water bodies to create spatial and temporal heterogeneity in the timing, flow paths, and magnitude of network connectivity. These attributes signal a critical role for GIWs in sustaining a portfolio of landscape functions, but legal protections remain weak despite preferential loss from many landscapes. GIWs lack persistent surface water connections, but this condition does not imply the absence of hydrological, biogeochemical, and biological exchanges with nearby and downstream waters. Although hydrological and biogeochemical connectivity is often episodic or slow (e.g., via groundwater), hydrologic continuity and limited evaporative solute enrichment suggest both flow generation and solute and sediment retention. Similarly, whereas biological connectivity usually requires overland dispersal, numerous organisms, including many rare or threatened species, use both GIWs and downstream waters at different times or life stages, suggesting that GIWs are critical elements of landscape habitat mosaics. Indeed, weaker hydrologic connectivity with downstream waters and constrained biological connectivity with other landscape elements are precisely what enhances some GIW functions and enables others. Based on analysis of wetland geography and synthesis of wetland functions, we argue that sustaining landscape functions requires conserving the entire continuum of wetland connectivity, including GIWs.
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In this chapter, we perform a comparison of the invertebrate assemblages of the 15 wetland types included in the book using nine faunal groups (mollusks, leeches, large branchiopods, malacostracans, odonates, the so-called EPT taxa (Ephemeroptera, Plecoptera, Trichoptera), hemipterans, coleopterans, and dipterans). Family level was used in order to avoid some biogeographic biases and because it is the lowest taxon that was reliably reported by authors across all habitats. Tables comparing assemblage composition of each wetland type were provided for each fauna group. Richness patterns of the nine analyzed taxonomic groups clearly distinguished between high- and low-richness wetland types. Additionally, we proposed some conceptual models in order to explain how the Pool of Taxa available to colonize specific wetland types are determined by biogeography, climate, and habitat history, and how environmental factors operate filter the taxa present in a wetland type (i.e., hydroregime, wetland size, predation, etc.).