Are pools created when restoring extracted peatlands biogeochemically similar to natural peatland pools?

In the last 25 years, several degraded peatlands in eastern Canada have been restored toward their natural structure. Pools are common in natural peatlands and are important habitats for unique flora and fauna. Because of their ecological value, pools have been created in some restored peatland sites. Nevertheless, the biogeochemistry of created pools in a restoration context has seldom been studied. The objective of our study is to characterize the biogeochemistry of created pools from restored peatlands and compare them with natural pools along a chronosequence since their creation. We measured different biogeochemical variables (pH, concentrations of nitrogen (N), phosphorus (P), dissolved organic carbon (DOC), dissolved organic matter (DOM), base cations-calcium (Ca), sodium (Na), magnesium (Mg), and potassium (K)-and dissolved gases-methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O)-) in 61 pools distributed over seven peatlands in eastern Canada. The sites represent a range of conditions, from natural to restored peatlands with pools ranging from 3 to 22 years old. Created and natural pools had distinctive biogeochemistry, with created pools being generally less acidic (pH >5) and 2.5 times more concentrated in nutrients (N and P) than in natural pools. DOC, N, P, dissolved gases, and base cations concentrations were lower in natural pools than in created pools, and varied between created sites. The oldest created pools (age >17 years) tend to approach the biogeochemical characteristics of natural pools, indicating that created pools may, over time, provide habitats with similar conditions to natural pools. A return of created pools to a natural pool-like biogeochemistry could thus inform on the success of peatland restoration.

Water quality and microbial interaction network topological parameters were the key factors affecting litter decomposition under wetland restoration.

Wetland restoration has a significantly impacts biogeochemical cycles. However, the specific mechanisms and potential microbial processes by which wetland restoration influences litter decomposition remain unclear. This knowledge gap hinders our ability to accurately predict ecological processes within wetland ecosystems across various restoration timeframes. Therefore, we conducted an in situ experiment was conducted in wetlands in Northeast China using the litterbag method, involving a restoration time gradient. Natural wetlands served as controls, with wetlands restored for 17 years (R17), 3 years (R3), 2 years (R2), and 1 year (R1). The study focused on two typical wetland plants: reed (Phragmites australis) and sedge (Cyperus rotundus), to investigate the effects of wetland restoration on microbial community, as well as the decomposition of litter. During the experiment, the decomposition rates (k-values) of both types of litter were lower in restored wetlands than natural wetlands. Fungal diversity varied significantly between restored and natural wetlands. In the short term (R3), the community structures of bacteria and fungi in restored wetlands resembled those of natural wetlands. However, significant differences persisted in long-term restored wetlands (R17). Partial Least Squares Path Modeling (PLS-PM) revealed that bacterial network cohesion (network average density, network transitivity) and wetland restoration time are the primary drivers of Reed and Sedge litter decomposition. Overall, wetland restoration enhances litter decomposition by altering the physicochemical properties of water and the characteristics of the microbial interaction network, suggesting that wetland restoration can accelerate the material cycling processes within wetland ecosystems.

Targeted grazing reduces a widespread wetland plant invader with minimal nutrient impacts, yet native community recovery is limited.

Targeted grazing to control undesirable plant species is increasingly of interest across a diversity of ecosystems, particularly as an alternative or complement to widely used herbicides. However, there are limited comprehensive evaluations of targeted grazing that evaluate both invasive species management effectiveness and potential negative effects on the ecosystem. Phragmites australis, a tall-statured, dense perennial invasive grass from Eurasia, is a pervasive problem in wetlands across the North American continent. As with many invasive species where management has historically relied on herbicides and resistance is a growing concern, land managers seek viable alternatives that have minimal negative ecosystem impacts. Grazing has been used for millennia to manage native Phragmites in Europe. Similarly, in its invasive range within North America, small-scale studies suggest Phragmites may be suppressed by grazers. Yet, the effectiveness of grazing at large scales and its effects on broader ecosystem properties remain largely unknown. We evaluated the influence of targeted grazing on vegetation, soil nutrients, and water nutrients over two years in large plots (∼300x the size of previous studies). We also tested the effects of mowing, a treatment that can be used to facilitate grazer access to large, dense Phragmites stands. In line with our predictions, we found that cattle grazing effectively suppressed invasive Phragmites over two years. Mowing reduced litter, and moderately reduced standing dead Phragmites, both of which suppress native plant germination in this system. However, these reductions in Phragmites were not accompanied by indications of native plant community recovery, as we had optimistically predicted. Despite the potential for grazing to reduce nutrient sequestration by plants and fertilize soils, we were surprised to find no clear negative effects of grazing on nutrient mobilization to groundwater or floodwater. Taken together, our findings indicate that targeted grazing, when implemented at broad scales over short time frames, is effective at achieving invasive plant management goals without sizable nutrient impacts. However, additional steps will be needed to achieve the restoration of diverse, robust native plant communities.

Re-watering solution facilitates seed germination and seedling growth of Carex schmidtii: Implication for species re-introduction in degraded semi-arid wetlands.

Water deficiency threatens the health and function of wetlands in semi-arid areas. Optimum re-watering is an effective method for close-to-natural restoration to mitigate wetland degradation. Although the ecological importance of optimal re-watering as a nature-based solution for promoting wetland plant growth has been widely recognized, the response mechanisms of seed germination and seedling growth to re-watering are still poorly understood despite their decisive impact on plant life history. To fill this gap, this study compared the characteristics of seed germination and seedling growth in Carex schmidtii under initial water content with three levels (30%, 50%, and 70%) and five re-watering treatments (maintained at constant water content and re-watering to 100% on 7th, 14th, 21st, and 28th day). Moreover, the degree of reserve mobilization during four germination stages (seed suckering, sprouting, 20% germination, and seedling growth) was investigated. The results showed that water deficiency and re-watering treatments significantly affected C. schmidtii seed germination, seedling growth, and reserve mobilization. Compared with the other treatments, 50% moisture content and re-watering to 100% on the 14th day (50%-RT3) treatment significantly improved germination traits (germination rate, daily germination rate, germination index, and vigor index) and seedling growth characteristics (shoot length, root length, shoot biomass, root biomass, and total biomass). Furthermore, the degree of mobilization of starch, soluble protein, fat, and soluble sugar accumulation in C. schmidtii seeds under 50%-RT3 was higher than that in the other treatments. The structural equation model showed that the characteristics of seed germination and seedling growth of C. schmidtii were directly related to water deficiency and re-watering treatments, whereas reserve mobilization indirectly affected seed germination and seedling growth. These findings demonstrated that water deficiency and re-watering treatments have a crucial regulatory effect on seed germination and seedling growth of wetland plant species through a dual mechanism. This study provides information for the formulation of an optimum re-watering strategy for wetland vegetation restoration in semi-arid areas of the world.

Our national nutrient reduction needs: Applying a conservation prioritization framework to US agricultural lands.

Targeted conservation approaches seek to focus resources on areas where they can deliver the greatest benefits and are recognized as key to reducing nonpoint source nutrients from agricultural landscapes into sensitive receiving waters. Moreover, there is growing recognition of the importance and complementarity of in-field and edge-of-field conservation for reaching nutrient reduction goals. Here we provide a generic prioritization that can help with spatial targeting and applied it across the conterminous US (CONUS). The prioritization begins with identifying areas with high agricultural nutrient surplus, i.e., where the most nitrogen (N) and/or phosphorus (P) inputs are left on the landscape after crop harvest. Subwatersheds with high surplus included 52% and 50% of CONUS subwatersheds for N and P, respectively, and were located predominantly in the Midwest for N, in the South for P, and in California for both N and P. Then we identified the most suitable conservation strategies using a hierarchy of metrics including nutrient use efficiency (proportion of new nutrient inputs removed by crop harvest), tile drainage, existing buffers for agricultural run-off, and wetland restoration potential. In-field nutrient input reduction emerged as a priority because nutrient use efficiency fell below a high but achievable goal of 0.7 (30% of nutrients applied are not utilized) in 45% and 44% of CONUS subwatersheds for N and P, respectively. In many parts of the southern and western US, in-field conservation (i.e., reducing inputs + preventing nutrients from leaving fields) alone was likely the optimal strategy as agriculture was already well-buffered. However, stacking in-field conservation with additional edge-of-field buffering would be important to conservation strategies in 35% and 29% of CONUS subwatersheds for N and P, respectively. Nutrient use efficiencies were often high enough in the Midwest that proposed strategies focused more on preventing nutrients from leaving fields, managing tile effluent, and buffering agricultural fields. Almost all major river basins would benefit from a variety of nutrient reduction conservation strategies, underscoring the potential of targeted approaches to help limit excess nutrients in surface and ground waters.

Knowledge coproduction on the impact of decisions for waterbird habitat in a changing climate.

Scientists, resource managers, and decision makers increasingly use knowledge coproduction to guide the stewardship of future landscapes under climate change. This process was applied in the California Central Valley (USA) to solve complex conservation problems, where managed wetlands and croplands are flooded between fall and spring to support some of the largest concentrations of shorebirds and waterfowl in the world. We coproduced scenario narratives, spatially explicit flooded waterbird habitat models, data products, and new knowledge about climate adaptation potential. We documented our coproduction process, and using the coproduced models, we determined when and where management actions make a difference and when climate overrides these actions. The outcomes of this process provide lessons learned on how to cocreate usable information and how to increase climate adaptive capacity in a highly managed landscape. Actions to restore wetlands and prioritize their water supply created habitat outcomes resilient to climate change impacts particularly in March, when habitat was most limited; land protection combined with management can increase the ecosystem's resilience to climate change; and uptake and use of this information was influenced by the roles of different stakeholders, rapidly changing water policies, discrepancies in decision-making time frames, and immediate crises of extreme drought. Although a broad stakeholder group contributed knowledge to scenario narratives and model development, to coproduce usable information, data products were tailored to a small set of decision contexts, leading to fewer stakeholder participants over time. A boundary organization convened stakeholders across a large landscape, and early adopters helped build legitimacy. Yet, broadscale use of climate adaptation knowledge depends on state and local policies, engagement with decision makers that have legislative and budgetary authority, and the capacity to fit data products to specific decision needs.

Coproducción de información sobre el impacto de las decisiones para el hábitat de las aves acuáticas en un clima cambiante Resumen Hay un incremento del uso que dan los científicos, gestores de recursos y los órganos decisorios a la coproducción de información para guiar la administración de los futuros paisajes bajo el cambio climático. Se aplicó este proceso para resolver problemas complejos de conservación en el Valle Central de California (EE. UU.), en donde los humedales y campos de cultivos manejados se inundan entre el otoño y la primavera para mantener una de las mayores concentraciones de aves playeras y acuáticas del mundo. Coproducimos narrativas de escenarios, modelos espacialmente explícitos de hábitats inundados de las aves acuáticas, productos de datos y conocimiento nuevo sobre el potencial de adaptación climática. Documentamos nuestro proceso de coproducción y usamos los modelos resultantes para determinar cuándo y en dónde marcan una diferencia las acciones de manejo y cuándo el clima anula estas acciones. Los resultados de este proceso proporcionan aprendizaje sobre cómo cocrear información útil y cómo incrementar la capacidad adaptativa al clima en un paisaje con mucha gestión. Las acciones de restauración de los humedales y la priorización del suministro de agua originaron un hábitat resiliente al impacto del cambio climático, particularmente en marzo, cuando el hábitat estaba más limitado; la protección del suelo combinado con el manejo puede incrementar la resiliencia del ecosistema al cambio climático; y la captación y uso de esta información estuvo influenciada por el papel de los diferentes actores, el cambio rápido de las políticas del agua, discrepancias en los marcos temporales de la toma de decisiones y las crisis inmediatas de la sequía extrema. Mientras que un grupo amplio de accionistas contribuyó conocimiento para las narrativas de escenarios y el desarrollo del modelo, para coproducir información útil, los productos de datos fueron adaptados para un conjunto pequeño de contextos decisivos, lo que con el tiempo llevó a una reducción en la participación de los actores. Una organización fronteriza convocó a los actores de todo un paisaje y los primeros adoptantes ayudaron a construir la legitimidad. A pesar de esto, el uso a gran escala de la información sobre la adaptación climática depende de las políticas locales y estatales, la participación de los órganos decisorios que tienen autoridad legislativa y presupuestaria y de la capacidad para ajustar los productos de datos a las necesidades específicas de las decisiones.

River Basin Simulations Reveal Wide-Ranging Wetland-Mediated Nitrate Reductions.

River basin-scale wetland restoration and creation is a primary management option for mitigating nitrogen-based water quality challenges. However, the magnitude of nitrogen reduction that will result from adding wetlands across large river basins is uncertain, partly because the areal extent, location, and physical and functional characteristics of the wetlands are unknown. We simulated over 3600 wetland restoration scenarios across the ∼450,000 km2 Upper Mississippi River Basin (UMRB) depicting varied assumptions for wetland areal extent, physical and functional characteristics, and placement strategy. These simulations indicated that restoring wetlands will reduce local nitrate yields and nitrate loads at the UMRB outlet. However, the projected magnitude of nitrate reduction varied widely across disparate scenario assumptions─e.g., restoring 4500 km2 of wetlands (i.e., 1% of UMRB area) decreased mean annual nitrate loads at the UMRB outlet between 3 and 42%. Higher magnitude nitrate reductions correlated with best-case assumptions, particularly for characteristics controlling nitrate loading rates to the wetlands. These results show that simplified claims about basin-scale wetland-mediated water quality improvements discount the breadth of possible wetland impacts across disparate wetland physical and functional conditions and highlight a need for greater clarity regarding the likelihood of these conditions at river basin scales.

Soil Carbon, Nitrogen, and Phosphorus Stoichiometry and Fractions in Blue Carbon Ecosystems: Implications for Carbon Accumulation in Allochthonous-Dominated Habitats.

Blue carbon ecosystems (BCEs) including mangroves, saltmarshes, and seagrasses are highly efficient for organic carbon (OC) accumulation due to their unique ability to trap high rates of allochthonous substrates. It has been suggested that the magnitude of OC preservation is constrained by nitrogen (N) and phosphorus (P) limitation in response to climate and anthropogenic changes. However, little is known about the connection of soil OC with N-P and their forms in response to allochthonous inputs in BCEs. By analyzing soil OC, N, and P densities of BCEs from 797 sites globally, we find that, in China, where allochthonous OC provides 50-75% of total OC, soil C/P and N/P ratios are 4- to 8-fold lower than their global means, and 23%, 29%, and 20% of buried OC, N, and P are oxidation-resistant fractions that linked with minerals. We estimate that the OC stocks in China should double over the next 40 years under high allochthonous inputs and elevated N/P ratio scenarios during BCE restoration. Allochthonous-dominated BCEs thus have the capacity to enhance refractory and mineral bound organic matter accumulation. Protection and restoration of such BCEs will provide long-term mitigating benefits against sea level rise and greenhouse gas emissions.

Process-based modeling for ecosystem service provisioning: Non-linear responses to restoration efforts in a quarry lake under climate change.

Healthy freshwater ecosystems can provide vital ecosystem services (ESs), and this capacity may be hampered due to water quality deterioration and climate change. In the currently available ES modeling tools, ecosystem processes are either absent or oversimplified, hindering the evaluation of impacts of restoration measures on ES provisioning. In this study, we propose an ES modeling tool that integrates lake physics, ecology and service provisioning into a holistic modeling framework. We applied this model to a Dutch quarry lake, to evaluate how nine ESs respond to technological-based (phosphorus (P) reduction) and nature-based measures (wetland restoration). As climate change might be affecting the future effectiveness of restoration efforts, we also studied the climate change impacts on the outcome of restoration measures and provisioning of ESs, using climate scenarios for the Netherlands in 2050. Our results indicate that both phosphorus reduction and wetland restoration mitigated eutrophication symptoms, resulting in increased oxygen concentrations and water transparency, and decreased phytoplankton biomass. Delivery of most ESs was improved, including swimming, P retention, and macrophyte habitat, whereas the ES provisioning that required a more productive system was impaired (sport fishing and bird watching). However, our modeling results suggested hampered effectiveness of restoration measures upon exposure to future climate conditions, which may require intensification of restoration efforts in the future to meet restoration targets. Importantly, ESs provisioning showed non-linear responses to increasing intensity of restoration measures, indicating that effectiveness of restoration measures does not necessarily increase proportionally. In conclusion, the ecosystem service modeling framework proposed in this study, provides a holistic evaluation of lake restoration measures on ecosystem services provisioning, and can contribute to development of climate-robust management strategies.

Quantifying the Impact of Hydrological Connectivity on Salt Marsh Vegetation in the Liao River Delta Wetland.

Salt marshes play a critical role in ecological functioning and have significant economic value. Hydrological elements are considered to be one of the major contributors to salt marsh degradation. However, how hydrological connectivity affects salt marshes remains poorly investigated at fine scales. This paper used spatial analysis and statistical methods to investigate the impact of hydrological connectivity on the spatial and temporal distribution characteristics of salt marsh vegetation in two natural succession areas of the Liao River Delta wetland in 2020 and 2021 by selecting vegetation area, NDVI, tidal creeks area, distance to tidal creeks, and the Index of Connectivity, using 1 m Gaofen-2 data and 0.2 m aerial topographic data. The study found that the area and growth status of vegetation and the overall connectivity in 2021 were better than that in 2020, while the west bank of the Liao River was better than that on the east bank. Phragmites australis showed a round island distribution pattern primarily at the end of tidal creeks. The differences between different hydrological connectivity and vegetation area were significant in 2021. The vegetation area was the largest under poor and moderate connectivity. We also found that within a distance range of 0-6 m from tidal creeks, the vegetation area increased with increasing distance, but beyond 6 m, the vegetation area decreased with increasing distance. Our results showed that poor and moderate connectivity conditions were more suitable for vegetation growth. The threshold value of 6 m can provide an important reference for wetland vegetation restoration in the Liao River Delta wetland. Supplementary Information: The online version contains supplementary material available at 10.1007/s13157-023-01693-4.

Tipping the balance: The role of seed density, abiotic filters, and priority effects in seed-based wetland restoration.

Sowing native seeds is a common approach to reintroduce native plants to degraded systems. However, this method is often overlooked in wetland restoration despite the immense global loss of diverse native wetland vegetation. Developing guiding principles for seed-based wetland restoration is critical to maximize native plant recovery, particularly in previously invaded wetlands. Doing so requires a comprehensive understanding of how restoration manipulations, and their interactions, influence wetland plant community assembly. With a focus on the invader Phragmites australis, we established a series of mesocosm experiments to assess how native sowing density, invader propagule pressure, abiotic filters (water and nutrients), and native sowing timing (i.e., priority effects) interact to influence plant community cover and biomass in wetland habitats. Increasing the density of native seeds yielded higher native cover and biomass, but P. australis suppression with increasing sowing densities was minimal. Rather, community outcomes were largely driven by invader propagule pressure: P. australis densities of ≤500 seeds/m2 maintained high native cover and biomass. Low-water conditions increased the susceptibility of P. australis to dominance by native competitors. Early sowing of native seeds showed a large and significant benefit to native cover and biomass, regardless of native sowing density, suggesting that priority effects can be an effective restoration manipulation to enhance native plant establishment. Given the urgent wetland restoration need combined with the limited studies on seed-based wetland restoration, these findings provide guidance on restoration manipulations that are grounded in ecological theory to improve seed-based wetland restoration outcomes.

Methane Emissions from Wetlands in China and Their Climate Feedbacks in the 21st Century.

Wetlands are large sinks of carbon dioxide (CO2) and sources of methane (CH4). Both fluxes can be altered by wetland management (e.g., restoration), leading to changes in the climate system. Here, we use multiple models to assess CH4 emissions and CO2 sequestration from the wetlands in China and the impacts on climate under three climate scenarios and four wetland management scenarios with various levels of wetland restoration in the 21st century. We find that wetland restoration leads to increased CH4 emissions with a national total of 0.32-11.31 Tg yr-1. These emissions induce an additional radiative forcing of 0.0005-0.0075 W m-2 yr-1 and global annual mean air temperature rise of 0.0003-0.0053 °C yr-1, across all future climate and management scenarios. However, wetland restoration also resulted in net CO2 sequestration, leading to a combined net greenhouse gas sink in all climate management scenarios, except in the highest restoration level combined with the hottest climate scenario. The highest climate cooling was achieved under medium restoration, with the climate scenario consistent with the Paris agreement target of below 2 °C, with a cumulative global warming potential of -3.2 Pg CO2-eq (2020-2100). Wetland restoration in the Qinghai-Tibet Plateau offers the greatest cooling effect.

Image-driven hydrological parameter coupled identification of flood plain wetland conservation and restoration sites.

A good many works focus on wetland vulnerability; some works also explore restoration sites at a very limited spatial extent. But the satellite image-driven hydrological data-based approach adopted in this work is absolutely new. Moreover, existing work only focused on identifying restoration sites in the present context, but for devising long-term sustainable planning, predicted hydrological parameters based on possible restoration sites may be an effective tool. Considering this, the present work focused on exploring hydrological data (water presence frequency (WPF), hydro-period (HP) and water depth (WD)) from time-series satellite images. This exploration may resolve the hydrological data scarcity of wetland over the wider geographical areas. Using these parameters, we developed wetland restoration and conservation sites for different historical years (2008, 2018) and predicted years (2028) using ensemble machine learning (EML) models. From the analysis, it was found that water depth, hydro-period and WPF became poorer over the period, and the trend may seem to continue in predicted years. Among the applied EML models, Random Subspace (RS) predicted wetland restoration and conservation sites precisely over others. The predicted area under high-priority restoration sites is 34% in 2018, which was 14% in 2008. In 2028, 12% more areas may fall in this priority level. Wetland away from main streams (mainly ortho-fluvial wetland) and fringe wetland parts should be given more priority for restoration. These present and predicted information will effectively help to frame sustainable wetland restoration planning.

Effects of land use change, wetland fragmentation, and best management practices on total suspended sediment concentrations in an urbanizing Oregon watershed, USA.

While many different watershed management strategies have been implemented to improve water quality, relatively few studies empirically tested the combined effects of different strategies on water quality in relation to land cover changes using long-term empirical data at the sub-basin scale. Using 10 years of total suspended solids (TSS) data, we examined how the conversion of wetland, wetland fragmentation, beaver dams, and Best Management Practices (BMPs) affect wet season TSS concentrations for the 25 monitoring stations in the Tualatin River basin, USA. Geographic information systems, FRAGSTATS, and correlation analysis were used to identify the direction of land cover change, degree of wetland fragmentation, and the strength of the relationship between TSS change and explanatory variables. Improvement in TSS concentrations was tightly coupled with the aggregation of wetlands, presence of beaver dams, particularly during the mid-wet season when flows were highest. Other BMPs effectively reduced TSS concentrations for the early and late-wet seasons when flows were not as high as in the middle wet-season. Aggregated wetlands were more effective for improving water quality than smaller disaggregated wetlands of similar total area when combined with the presence of beaver dams and BMPs. These findings offer important scientific and practical implications for management of urbanizing watersheds that seek to achieve the dual goals of improving environmental quality and land development.

A Framework for Identifying Reference Wetland Conditions in Highly Altered Landscapes.

This paper arose from collaboration and discussions over the past years between the authors about what wetlands should be restored to in landscapes that have been intensively altered due to human activities over many centuries and where reference conditions are lacking. It is not intended as an in-depth review of the thinking about reference conditions, but as an opinion paper, with the goal of stimulating discussions about wetland restoration approaches, particularly in regions around the world with highly altered landscapes where restoration of wetlands has been gaining traction only relatively recently. We first explain why the thinking on reference wetlands is biased towards North America, where large areas exist with wetlands that are relatively unimpacted by anthropogenic activities. We then argue that in regions with few unimpaired wetlands those of fair condition may still be good enough to be used as reference wetlands, and that restored and created wetlands should be considered as well.

Large-Scale Marsh Loss Reconstructed from Satellite Data in the Small Sanjiang Plain since 1965: Process, Pattern and Driving Force.

Monitoring wetland dynamics and related land-use changes over long-time periods is essential to understanding wetland evolution and supporting knowledge-based conservation policies. Combining multi-source remote sensing images, this study identifies the dynamics of marshes, a core part of wetlands, in the Small Sanjiang Plain (SSP), from 1965 to 2015. The influence of human activities on marsh patterns is estimated quantitatively by the trajectory analysis method. The results indicate that the marsh area decreased drastically by 53.17% of the total SSP area during the study period, which covered the last five decades. The marsh mostly transformed to paddy field and dry farmland in the SSP from 1965 to 2015, indicating that agricultural encroachment was the dominant contributor to marsh degradation in the area. Analysis of the landscape indexes indicates that marsh fragmentation was aggravated during the past five decades in the SSP. Trajectory analysis also indicated that human activities have acted as the primary driving force of marsh changes in the SSP since 1965. This study provides scientific information to better understand the evolution of the wetland and to implement ecological conservation and sustainable management of the wetlands in the future.

Impact of different restoration methods on coastal wetland loss in Louisiana: Bayesian analysis.

Extensive efforts have been undertaken in the northern Gulf of Mexico to restore coastal wetlands that have been lost rapidly. The evaluation of these restorations mostly focused on individual-project scales. A modeling framework that can coherently synthesize multi-scale monitoring data and account for various uncertainties would improve quantitative evaluations at broader spatial scales needed for regional decision-making. We aim to develop such a framework to investigate the impact of different restoration methods (hydrological alteration, breakwater infrastructure, vegetative planting, or marsh creation using dredged materials) on wetland loss on the outermost mainland coastlines in Louisiana. We did this by implementing multi-level Bayesian models to predict areal wetland loss (1996-2005 before Hurricane Katrina) as a function of local geophysical variables (relative sea-level rise, wave height, tidal range) and a dummy variable indicating presence/absence of restoration. We assumed the effects of these variables varied by broader watershed scales. The restoration's effect also depended on temporal scales of implementation. The results indicate the sites with hydrological alteration, when implemented for longer than 7 years, had significantly smaller areal wetland loss, compared to the reference sites controlled for the local geophysical variables, in the Chenier Plain watershed, but not in the lower Mississippi River watershed. The effects of the other restoration methods on wetland loss were not significant based on limited numbers of sites. The Bayesian modeling framework we developed can integrate monitoring data/key drivers across projects with uncertainties accounted for, it is adaptable, and presents a useful tool in restoration evaluations spatially and temporally.

Facilitation shifts paradigms and can amplify coastal restoration efforts.

Restoration has been elevated as an important strategy to reverse the decline of coastal wetlands worldwide. Current practice in restoration science emphasizes minimizing competition between out-planted propagules to maximize planting success. This paradigm persists despite the fact that foundational theory in ecology demonstrates that positive species interactions are key to organism success under high physical stress, such as recolonization of bare substrate. As evidence of how entrenched this restoration paradigm is, our survey of 25 restoration organizations in 14 states in the United States revealed that >95% of these agencies assume minimizing negative interactions (i.e., competition) between outplants will maximize propagule growth. Restoration experiments in both Western and Eastern Atlantic salt marshes demonstrate, however, that a simple change in planting configuration (placing propagules next to, rather than at a distance from, each other) results in harnessing facilitation and increased yields by 107% on average. Thus, small adjustments in restoration design may catalyze untapped positive species interactions, resulting in significantly higher restoration success with no added cost. As positive interactions between organisms commonly occur in coastal ecosystems (especially in more physically stressful areas like uncolonized substrate) and conservation resources are limited, transformation of the coastal restoration paradigm to incorporate facilitation theory may enhance conservation efforts, shoreline defense, and provisioning of ecosystem services such as fisheries production.

Surveying managers to inform a regionally relevant invasive Phragmites australis control research program.

Managers of invasive species consider the peer-reviewed literature only moderately helpful for guiding their management programs. Though this "knowing-doing gap" has been well-described, there have been few efforts to guide scientists in how to develop useful and usable science. Here we demonstrate how a comprehensive survey of managers (representing 42 wetland management units across the Great Salt Lake watershed) can highlight management practices and challenges (here for the widespread invasive plant, Phragmites australis, a recent and aggressive invader in this region) to ultimately inform a research program. The diversity of surveyed organizations had wide-ranging amounts of Phragmites which led to different goals and approaches including more aggressive control targets and a wider array of control tools for smaller, private organizations compared to larger government-run properties. We found that nearly all managers (97%) used herbicide as their primary Phragmites control tool, while burning (65%), livestock grazing (49%), and mowing (43%) were also frequently used. Managers expressed uncertainties regarding the timing of herbicide application and type of herbicide for effective control. Trade-offs between different Phragmites treatments were driven by budgetary concerns, as well as environmental conditions like water levels and social constraints like permitting issues. Managers had specific ideas about the plant communities they desired following Phragmites control, yet revegetation of native species was rarely attempted. The results of this survey informed the development of large-scale, multi-year Phragmites control and native plant revegetation experiments to address management uncertainties regarding herbicide type and timing. The survey also facilitated initial scientist-manager communication, which led to collaborations and knowledge co-production between managers and researchers. An important outcome of the survey was that experimental results were more pertinent to manager needs and trusted by managers. Such an approach that integrates manager surveys to inform management experiments could be adapted to any developing research program seeking to be relevant to management audiences.

Multispecies benefits of wetland conservation for marsh birds, frogs, and species at risk.

Wetlands conserved using water level manipulation, cattle exclusion, naturalization of uplands, and other techniques under the North American Waterfowl Management Plan ("conservation project wetlands") are important for ducks, geese, and swans ("waterfowl"). However, the assumption that conservation actions for waterfowl also benefit other wildlife is rarely quantified. We modeled detection and occupancy of species at sites within 42 conservation project wetlands compared to sites within 52 similar nearby unmanaged wetlands throughout southern Ontario, Canada, and small portions of the adjacent U.S., using citizen science data collected by Bird Studies Canada's Great Lakes Marsh Monitoring Program, including 2 waterfowl and 13 non-waterfowl marsh-breeding bird species (n = 413 sites) and 7 marsh-breeding frog species (n = 191 sites). Occupancy was significantly greater at conservation project sites compared to unmanaged sites in 7 of 15 (47%) bird species and 3 of 7 (43%) frog species, with occupancy being higher by a difference of 0.12-0.38 across species. Notably, occupancy of priority conservation concern or at-risk Black Tern (Chlidonias niger), Common Gallinule (Gallinula galeata), Least Bittern (Ixobrychus exilis), Sora (Porzana carolina), and Western Chorus Frog (Pseudacris triseriata) was significantly higher at conservation project sites compared to unmanaged sites. The results demonstrate the utility of citizen science to inform wetland conservation, and suggest that actions under the North American Waterfowl Management Plan are effective for conserving non-waterfowl species.