Wetlands Reserve Program Research Articles

Evaluating wetland hydrological performance under three different conservation programs in Nebraska, United States, during 2018–2021

AbstractAssessing hydrological dynamics of wetlands is essential for understanding ecological services. This study utilized open‐access Sentinel‐2 satellite data to enhance conservation management by enabling near‐real‐time monitoring and assessment of hydrological dynamics in conserved lands across Nebraska, United States. Using machine learning and Google Earth Engine, this research classifies surface water cover rate for different conserved land sites in Nebraska in 2018–2021. The results of the study confirmed successful inundation performance in conserved wetland sites under Wildlife Management Areas (WMA), Wetlands Reserve Program (WRP), and Waterfowl Production Areas (WPA). The WMA sites had the highest inundated area rate of 16.41%, indicating active hydrological inundation of the core conserved land areas. The WRP and WPA sites reached a mean annual surface water cover rate of 8.07% and 7.51%, respectively, demonstrating occasional flooding or periodic inundation of core wetland areas but limited inundation coverages of the surrounding areas. The findings confirmed that wetland conservation practices are functioning very well on the sites with higher inundation rates, but hydrological restoration at the watershed scale could boost conservation performance for the entire conserved land areas. The findings of this research provide robust evidence for obtaining surface water inundation data, which is crucial for sustainable conservation assessment and achieving long‐term goals in wetland monitoring, protection, and management.

Using Sentinel-2 Imagery and Machine Learning Algorithms to Assess the Inundation Status of Nebraska Conservation Easements during 2018–2021

Conservation easements (CEs) play an important role in the provision of ecological services. This paper aims to use the open-access Sentinel-2 satellites to advance existing conservation management capacity to a new level of near-real-time monitoring and assessment for the conservation easements in Nebraska. This research uses machine learning and Google Earth Engine to classify inundation status using Sentinel-2 imagery during 2018–2021 for all CE sites in Nebraska, USA. The proposed machine learning approach helps monitor the CE sites at the landscape scale in an efficient and low-cost manner. The results confirmed effective inundation performance in these floodplain or wetland-related CE sites. The CE sites under the Emergency Watershed Protection-Floodplain Easement (EWPP-FPE) had the highest inundated area rate of 18.72%, indicating active hydrological inundation in the floodplain areas. The CE sites under the Wetlands Reserve Program (WRP) reached a mean annual surface water cover rate area of 8.07%, indicating the core wetland areas were inundated periodically or regularly. Other types of CEs serving upland conservation purposes had a lower level of inundation while these uplands conservation provided critical needs in soil erosion control. The mean annual surface water cover rate is 0.96% for the CE sites under the Grassland Reserve Program (GRP). The conservation of the CEs on uplands is an important component to reduce soil erosion and improve downstream wetland hydrological inundation performance. The findings support that the sites with higher inundation frequencies can be considered for future wetland-related conservation practices. The four typical wetland-based CE sites suggested that conservation performance can be improved by implementing hydrological restoration and soil erosion reduction at the watershed scale. The findings provided robust evidence to discover the surface water inundation information on conservation assessment to achieve the long-term goals of conservation easements.

Wetlands Reserve Program restorations improve floristic quality of understory plant community over time, but community differs from reference wetlands

The lower Mississippi River Valley and connecting tributaries have lost an estimated 80% of original bottomland hardwood forested wetlands to agricultural conversion. For the past three decades, the Wetlands Reserve Program has restored thousands of wetlands with the objective of recovering wetland functions and supporting wildlife diversity. To inform future restoration decisions, we assessed the recovery of the naturally colonizing understory plant community in wetlands restored from row‐crop agriculture in western Kentucky, U.S.A. We measured six floristic variables in 16 wetlands along a gradient of disturbance (degraded, restored, and reference) and a chronosequence ranging from 0 to 13 years since restoration. We found that reference wetlands had significantly higher floristic quality and a higher proportion of woody and perennial species than restored wetlands. Over time, the proportion of non‐native species decreased in restored wetlands and floristic quality increased. The successional trajectory of naturally colonizing plant communities in restored wetlands was likely inhibited by dispersal limitations, thus future projects should focus on optimizing project locations to increase recruitment, continue afforestation efforts for heavy seeded trees, and consider planting native understory species. Long‐term project monitoring, approximately three decades, will likely provide deeper insight into recovery trajectory. With ongoing biodiversity loss and the effects of climate change, the success of wetland restorations has important local and global implications.

Conservation easement landowners' willingness to accept for forest thinning and the impact of information

After being subject to several decades of degradation, the bottomland hardwood (BLH) forests within the Lower Mississippi Alluvial Valley have undergone landscape-scale restoration regimes through conservation easement programs, such as the Wetland Reserve Program (WRP). Reforested easements offer an opportunity for landowners' adoption of forest management practices to fulfill the program's long-term conservation goals. Using the contingent valuation approach, we examine easement landowners' willingness to accept (WTA) to thin their forest subject to an easement to enhance forest health and wildlife habitat quality, and we test the effect of providing information about the benefits of thinning on WTA estimates. Results from an interval regression model suggest that ownership characteristics like years of ownership, involvement in non-timber activities like hiking and walking, and management characteristics like having past intention to thin, significantly decreased WTA while being an original easement grantor and ownership objectives like legacy increased WTA. The mean monetary compensation required to induce thinning adoption is $11.41 per ton of pulpwood. There is some evidence that the information intervention influences the WTA estimates downward, representing a potential policy instrument to achieve thinning objectives in the conservation easements efficiently.

Habitat use of spring migrating dabbling ducks in the Wabash River Valley, USA

AbstractStopover sites provide crucial habitat for waterfowl to rest and refuel during migration. Knowledge of which land-cover types are of greatest importance to migrating waterfowl and how the surrounding landscape influences their use can inform management decisions and conservation plans to adequately meet resource requirements. Specifically, spring migration habitat is essential for waterfowl preparing for breeding yet is an understudied period of the life cycle. We placed radio-transmitters on Mallards (Anas platyrhynchos) and Green-winged Teal (Anas crecca) between January and April 2016–2017 in the Wabash River Valley of Illinois and Indiana to assess habitat use and movement patterns. Both Mallards and Green-winged Teal primarily used emergent and woody wetlands, with 89% of use points in these land-cover types even though they made up <5% of the study area. Use of both dry and flooded row crops was minimal. While habitat selection of Mallards was similar for diurnal vs. nocturnal periods, Green-winged Teal used emergent wetlands at a higher rate during the day and shifted to woody wetlands at night. In general, sites surrounded by greater amounts of open water, upland forest, and upland herbaceous/grassland cover were more likely to be used than areas surrounded by row-crop agriculture. Additionally, private and public lands enrolled in conservation easement programs (such as the Wetlands Reserve Program) were frequently used by migrating waterfowl compared to other protected or public lands. These findings highlight the importance of a landscape-level approach to conservation, specifically focusing on wetland restoration while minimizing reliance on agricultural fields to fulfill habitat needs during spring migration in the Midwest.

Conservation significantly improves wetland conditions: evaluation of playa wetlands in different conservation status

This study assessed the conditions of wetland hydrology, hydrophyte and soil under different state and federal conservation programs, and then identified the restorable potential of conserved playas. The distribution of hydrology and hydrophyte were geospatially examined through annual tracking the quantity and quality of wetlands on historical hydric soil footprints under different conservation programs in the Rainwater Basin in Nebraska, USA during 2004–2015. The results show that the historical hydric soil footprints with the conservation programs had significantly better performance in ponded water and hydrophyte than non-conserved wetlands. The yearly average of ponded water areas within footprints varies at 12.59% for the Waterfowl Production Areas (WPAs), 14.78% for Wildlife Management Areas (WMAs), 27.37% for Wetlands Reserve Program’s conservation easements (WRPs), and 1.86% for non-conserved wetlands, respectively. The yearly average of hydrophyte plant community coverage within footprints reaches at 77.51% for WPAs, 79.28% for WMAs, and 66.53% for WRPs, and 8.82% for non-conserved hydric footprints. Within conserved lands, Massie/Water soil series demonstrated the prominent ability to hold ponding water, especially in the ponded footprints with higher ponding frequency. Nevertheless, the proportion of Fillmore, Rusco or Butler soil series roughly decreased when the ponding water frequency increased. The areas, with high likelihood to be restored, are the places between annual ponding/hydrophyte covered areas and 11 years’ maximized ponding/hydrophyte areas.

Public–Private Partnership Wetland Restorations Provide Quality Forage for Waterfowl in Northern New York

Abstract The Partners for Fish and Wildlife Program and Wetlands Reserve Program are U.S. federal programs that provide financial and technical assistance to restore wetland habitats on private property, and are important tools for the conservation and management of waterfowl. This study examined whether these wetland restorations successfully restored one important component of waterfowl habitat, the availability of vegetative forage, at sites in the St. Lawrence River valley of New York. We conducted surveys at 47 restored and 18 reference wetlands to characterize the vegetation assemblage in terms of its value as forage for waterfowl. Results suggest that these public–private partnership wetland restorations develop assemblages of wetland vegetation that are similar to reference wetlands. Vegetation assemblage metrics, including estimates of species richness, the richness of species of food value, the Vegetative Forage Quality Index, and the cover of species of food value, did not differ between restored–reference wetland pairs. However, invasive species were common at sites, and we detected a negative association between the cover of invasive species and the Vegetative Forage Quality Index at both restored and reference wetlands. On the basis of these results, we conclude that Partners for Fish and Wildlife Program and Wetland Reserve Program wetland restorations provide quality forage for breeding and migratory waterfowl in this region, but that the presence of invasive vegetation at sites has the potential to decrease the quality of vegetative forage at sites over time.

Effects of Land Use on Greenhouse Gas Flux in Playa Wetlands and Associated Watersheds in the High Plains, USA

In the High Plains, U.S., native prairie conversion to cropland agriculture has resulted in a loss of service delivery capabilities from most depressional wetlands as a result of sedimentation. Restoring historic hydrological conditions to affected wetlands may rejuvenate some services, however, there may be tradeoffs due to emissions of CH4 and N2O. We evaluated the influence of two predominant conservation programs (Wetlands Reserve Program, WRP and Conservation Reserve Program, CRP) on gas emissions (CO2, CH4, N2O) from 42 playas and uplands in the High Plains of Nebraska. Because playa restoration through the WRP is most prevalent in the Rainwater Basin (RWB), we studied 27 playas/uplands among reference condition, cropland, and WRP land uses. We studied 15 playas/uplands within native grassland, cropland, and CRP land uses in the Western High Plains (WHP) of Nebraska. Emissions were collected bi-weekly from April-October of 2012 and 2013 from four landscape positions extending outward from the wetland center into upland. In RWB playas, CH4 and N2O emissions were similar among land uses but CO2 was 28% higher in cropland than WRP wetlands. Cropland uplands emitted 648% more N2O than reference and WRP uplands. Overall, net CO2-equiv emissions were lower in playas/uplands in WRP, suggesting that benefits of playa restoration may include climate mitigation services as well as increased water storage capacity and biodiversity provisioning. In the WHP, cropland and grassland playas emitted 46 and 23 times more CH4, respectively, than CRP in 2013. Playas in CRP emitted 43% less N2O than cropland playas. In 2013, net emissions for cropland and native grassland playas were 75% and 39% greater, respectively, than CRP playas. In the WHP, the benefits of lower gas emissions must be appropriately weighted against tradeoffs of ecosystem services related to shorter hydroperiods as a result of reduced runoff into playas in CRP.

Are Waterfowl Food Resources Limited during Spring Migration? A Bioenergetic Assessment of Playas in Nebraska\u2019s Rainwater Basin

Accurate bioenergetic carrying capacity estimates of wetlands on public and private lands, as well as those managed for crop production are important for managing waterfowl populations and habitats. Given the importance of wetlands in the Rainwater Basin region of Nebraska for spring migrating waterfowl, we quantified and compared seed and aquatic invertebrate biomass and true metabolizable energy (TME) at three wetland types; public wetlands, wetlands enrolled in the Wetlands Reserve Program (WRP), and cropped wetlands. Median seed biomass estimates at public, WRP, and cropped wetlands were 593 kg/ha, 561 kg/ha, and 419 kg/ha respectively. Cumulative TME varied among wetland type, with greater TME at cropped wetlands (2431 kcal/kg) than public (1740 kcal/kg) and WRP wetlands (1781 kcal/kg). Seed biomass estimates from this study were statistically greater than those currently used for management planning in the RWB, however, TME estimates were statistically lower than estimates currently assumed for WRP and public wetlands. Our estimates for aquatic invertebrate biomass were approximately 40-fold less than seed biomass estimates. Based on spring ponding frequency at wetlands in Nebraska’s Rainwater Basin, and the caloric estimates derived for each wetland type, we concluded that the regions wetlands meet the energetic demand of spring migrating waterfowl during 10% of years.

Factors affecting landowner enrollment in wetland restoration in northeastern New York State

In the U.S. the Natural Resources Conservation Service (NRCS) administers the Wetland Reserve Program (WRP) that funds the restoration of wetlands on privately-owned lands under conservation easements. These programs provide a number of potential benefits to landowners along with the wetland including access roads and reduced property taxes on the easement land. To receive these benefits, landowners agree to limit development opportunities on their land but can continue to use it for other activities such as hunting, fishing, viewing wildlife, haying, or extracting wood for personal use. We surveyed 35 participants in the NRCS program in northeastern New York State to measure factors associated with willingness to enroll land in the WRP program beyond direct monetary incentives. In addition, we conducted follow up interviews with eight program participants to enhance our understanding of landowners’ motivations to participate in the programs. We found that valuing the conservation aspects of wetlands, being retired and a female respondent were associated with willingness to enroll lands without compensation. In addition, qualitative interviews provided context to these findings such that landowners enrolled land due to 1) lived experience with wetland use and preservation; 2) a conservation ethic in regards to preserving nature; and 3) the desire to use the restored wetland as a ‘showcase’ for family and community members.

Waterbird communities and seed biomass in managed and reference‐restored wetlands in the Mississippi Alluvial Valley

The Natural Resources Conservation Service (NRCS) commenced the Migratory Bird Habitat Initiative (MBHI) in summer 2010 after the April 2010 Deepwater Horizon oil spill in the Gulf of Mexico. The MBHI enrolled in the program 193,000 ha of private wet‐ and cropland inland from potential oil‐impaired wetlands. We evaluated waterfowl and other waterbird use and potential seed/tuber food resources in NRCS Wetland Reserve Program easement wetlands managed via MBHI funding and associated reference wetlands in the Mississippi Alluvial Valley of Arkansas, Louisiana, Mississippi, and Missouri. In Louisiana and Mississippi, nearly three times more dabbling ducks and all ducks combined were observed on managed than reference wetlands. Shorebirds and waterbirds other than waterfowl were nearly twice as abundant on managed than referenced wetlands. In Arkansas and Missouri, managed wetlands had over twice more dabbling ducks and nearly twice as many duck species than reference wetlands. Wetlands managed via MBHI in Mississippi and Louisiana contained ≥1.3 times more seed and tuber biomass known to be consumed by waterfowl than reference wetlands. Seed and tuber resources did not differ between wetlands in Arkansas and Missouri. While other studies have documented greater waterbird densities on actively than nonmanaged wetlands, our results highlighted the potential for initiatives focused on managing conservation easements to increase waterbird use and energetic carrying capacity of restored wetlands for waterbirds.

Detecting soil and plant community changes in restored wetlands using a chronosequence approach

Wetland restoration aims to recreate or enhance valuable ecosystem services lost during wetland destruction. Regaining wetland ecosystem services depends on restarting basic wetland functions, like carbon (C) storage, which are unmeasured in many Wetlands Reserve Program (WRP) restoration sites. We collected soil and plant data from 17 WRP sites in western New York that were used for tillage or non-tillage agriculture and then actively restored as isolated depressional wetlands by excavating basins and disabling drainage systems. Sites had been restored for 0–15 years when sampled in August-October 2010. We analyzed data as chronosequences and tested whether soil and vegetation parameters in restored wetlands, over time, (1) departed from pre-restoration baselines, estimated using active agricultural fields paired to each WRP site, and (2) converged towards “natural” benchmarks, estimated from four naturally-occurring wetlands. Restored WRP soils remained similar to agricultural soils in organic matter, density, moisture, and belowground plant biomass across chronosequences, indicating negligible C storage and belowground development for 15 years following restoration. Soil changes were limited in sites restored after both tillage and non-tillage agriculture and throughout the upland meadow, emergent shoreline, and open-water habitat zones that characterize these sites. Many plant metrics like aboveground biomass matched natural wetlands within 15 years, but recovered inconsistently among tilled and untilled sites and across all habitat zones, suggesting land-use history impacts and/or zonation effects. Disparities in recovery times exists between vegetation, which can respond quickly to wetland restoration, and underlying soils, which show limited signs of recovery 15 years after being restored.

Public–private partnership wetland restoration programs benefit Species of Greatest Conservation Need and other wetland-associated wildlife

US federal conservation programs, including the National Resource Conservation Service’s Wetland Reserve Program (WRP) and the US Fish and Wildlife Service’s Partners for Fish and Wildlife Program (PFWP), partner with private landowners to conserve and restore wetland habitats. Despite the success of these programs in terms of wetland area enrolled, uncertainties exist as to whether they are meeting their stated goals, including the restoration of wildlife habitat. In the St. Lawrence Valley of New York State, we investigated two questions related to WRP and PFWP wetland restorations. First, was whether restorations provide habitat for wetland-associated wildlife, including Species of Greatest Conservation Need (SGCN) prioritized by the New York State Wildlife Action Plan (SWAP). Second, was whether restorations support wildlife assemblages that are comparable to natural reference wetlands. Bird, anuran, turtle, snake, and fish species assemblages were surveyed at 47 WRP and PFWP restorations, and 18 natural reference wetlands. We detected 31 SGCN at restorations, including SGCN from each assemblage surveyed. Assemblage metrics, including species richness and relative abundance, did not differ between restored and reference wetlands for any of the assemblages surveyed. These results indicate that restorations provide habitat for SGCN and other wetland-associated wildlife, and that assemblages at restorations are similar to those at natural reference wetlands. We conclude that WRP and PFWP wetland restorations in this region are meeting federal program-level goals related to the restoration of wildlife habitat, and are contributing to the recovery of SGCN.

Effects of conservation wetlands on stream habitat, water quality and fish communities in agricultural watersheds of the lower Mississippi River Basin

Wetland conservation programs (e.g., Wetland Reserve Program and Conservation Reserve Program) have been implemented throughout the Mississippi River Basin to reduce environmental impacts from agricultural activities. However, there is limited information on the overall effectiveness of these programs on improving stream ecological conditions. To address this issue, replicate streams from southeastern Arkansas draining watersheds containing predominately croplands (n=4, termed “cropland”) and created wetlands (n=4, termed “wetland”) were monitored monthly from August 2012 through July 2013. Although repeated-measures analyses of variance (ANOVA) detected many significant time×stream type interactions, several habitat parameters and total habitat scores exhibited a general improvement in wetland streams. Some water quality conditions were better in wetland streams (e.g., lower turbidity, total suspended solids, and nutrient) compared to cropland streams. The time (season) effect was significant (p<0.05) for 13 of the 14 water quality parameters measured, meaning that water quality varied seasonally. Among the water quality parameters measured, three (water temperature, pH, and turbidity) exhibited significant (p<0.05) time×stream type interaction, meaning that the stream type effect was not consistent through time (seasons). Fish community sampling collected 6543 specimens from 12 species during the study period; 4410 and 2133 fish specimens were collected from cropland and wetland streams, respectively. Fish community metrics such as species diversity, species evenness, and species richness index were not significantly (p>0.05) greater in wetland streams. Overall, the conservation wetlands in the Lower Mississippi River Basin appear to have significantly improved stream habitat and moderately improved water quality, though no significant fish community effect was detected.

Policy Drivers of U.S. Wetland Conversion Rates, 1955–2009

ABSTRACTWhile conversion of wetlands to nonagricultural purposes has persisted, the five U.S. national wetland inventory reports spanning 1955–2009 show a large decline in the rate of conversion of wetlands for agriculture, especially from the mid-1970s to the mid-1990s. Through regression and path analysis, this study identifies primary policy and economic drivers of this decline in wetland conversions. The Clean Water Act §404 is strongly and negatively related to conversion rates. Crop prices affect wetland conversions both directly, by influencing returns to investments for conversion, and indirectly, by influencing Conservation and Wetland Reserve Program enrollments as well as the regulatory impact of Swampbuster. Along with the proportion of wetlands remaining, these factors explain 90–94% of the annual variation in total wetland conversions, agricultural conversions, and conversion of forested and emergent wetlands.

Family Forest Owners’ Familiarity with Conservation Programs in Mississippi, USA

Conservation programs such the Conservation Reserve Program (CRP), Environmental Quality Incentives Program (EQIP), Wildlife Habitat Incentive Program (WHIP), and Wetlands Reserve Program (WRP) were introduced in the USA to create financial, educational, and technical incentives to enhance conservation of natural resources. This study examined Mississippi family forest owners’ familiarity with CRP, EQIP, WHIP, WRP, and conservation easements before the programmatic reorganization brought about by the Farm Bill of 2014. The research also determined the association of selected attitudinal and socioeconomic characteristics with landowner familiarity. A mail survey was sent to 2025 randomly selected family forest owners in Mississippi and an adjusted response rate of 37.1 % was obtained. Survey responses were analyzed using descriptive statistics and five binary logistic regression models were used to determine factors associated with landowner familiarity with conservation programs. Familiarity with conservation programs was positively associated with male landowners, forest land size, forest and conservation organization membership, and having a written forest management plan (p < 0.05). Findings suggest that membership in forestry- and agriculture-based organizations can help improve landowner knowledge of ecosystem services and enhance familiarity with conservation programs.

Landowner Satisfaction with the Wetland Reserve Program in Texas: A Mixed-Methods Analysis.

Using mail survey data and telephone interviews, we report on landowner satisfaction with permanent easements held by the Natural Resources Conservation Service (NRCS) throughout Texas. This study found that landowners were dissatisfied with the NRCS Wetland Reserve Program (WRP), conflicting with results of previous studies. The objective of this study was to explore specific reasons for frustration expressed by landowners with the program. We found three predominant themes underpinning program dissatisfaction: (1) upfront restoration failures, (2) overly restrictive easement constraints, and (3) bureaucratic hurdles limiting landowners' ability to conduct adaptive management on their easement property. The implications of this study suggest that attitudes of landowners participating in the WRP may limit the long-term effectiveness of this program. Suggestions for improving the program include implementing timely, ecologically sound restoration procedures and streamlining and simplifying the approval process for management activity requests. In addition, the NRCS should consider revising WRP restriction guidelines in order to provide more balance between protection goals and landowner autonomy.

Sensitivity of secretive marsh birds to vegetation condition in natural and restored wetlands in Wisconsin

ABSTRACTWetland loss, biological invasions, and ecological restoration are major factors altering wetland resources in the Midwestern United States. Large‐scale plant‐community change associated with these factors is an under‐investigated, potentially strong driver of habitat suitability for wetland‐dependent wildlife, such as secretive marsh birds (SMBs), which are of widespread conservation concern. We employed multi‐year, hierarchical Bayesian occupancy modeling to investigate sensitivity of 3 SMB species (American bittern, sora, and Virginia rail) to habitat and vegetation characteristics in Wisconsin, USA. We contrasted habitat characteristics and SMB occupancy in natural wetlands with those restored under the federally funded Wetlands Reserve Program (WRP). We also examined the extent to which SMB occupancy was explained by 3 levels of habitat assessment that encompassed different spatial scales and levels of sampling effort (landscape, rapid, and intensive). All species were significantly associated with variables derived from intensive assessment, and showed high sensitivity to differences in plant‐community composition and vegetation quality. Both American bittern and Virginia rail were negatively associated with abundance of the invasive wetland grass, Phalaris arundinacea (reed canarygrass), and were positively associated with an indicator of plant‐community quality (mean coefficient of conservatism, or C‐value). Sora occupancy was positively associated with Typha (cattail) abundance. For all 3 species, occupancy was greater in natural sites than in restored sites, which were characterized by greater Phalaris abundance and lower mean C‐values. Our results show broad agreement between botanical and avian indicators of wetland quality, suggesting that enhancing the condition of wetland vegetation can yield ancillary benefits for SMBs. In this region, efforts to control Phalaris and restore diverse, native‐dominated plant communities are likely to increase wetlands’ capacity to support SMBs. © 2015 The Wildlife Society.

Species richness and density of wintering ducks on wetlands reserve program easements in Mississippi

ABSTRACTThe Mississippi Alluvial Valley provides important habitats for migrating and wintering waterfowl and is a priority area for restoration of wetlands through the U.S. Department of Agriculture's Wetlands Reserve Program (WRP). Management of WRP wetlands varies from no management to active annual management of vegetation and water levels, which may influence wintering waterfowl use. We modeled variation in species richness and density of dabbling and diving ducks (Anatini, Aythyini) relative to a published Vegetative Forage Quality Assessment Index (VFQI; Fleming et al. 2012) of duck foods, other floristic metrics, and management type of WRP wetlands in Mississippi, USA, during autumns–winters 2007–2009. Duck species richness was correlated positively with wetland area when precipitation was below normal (winter 2007–2008), but not in 2008–2009 when landscape‐level flooding occurred. Duck densities varied positively with VFQI on wetlands with active management and late‐summer drawdown, but not on passive or active managed areas with early drawdown. Duck densities decreased with increasing woody vegetation. Models including VFQI explain ≤27% of the variation in duck densities, suggesting that ducks may also be selecting wetlands based on metrics that are not related to VFQI or wetland management. Active managed wetlands may produce the greatest VFQI, but our results suggest this technique need not always result in increased use by ducks. Nevertheless, we recommend active management of WRP wetlands to sustain food at the landscape level for migrating and wintering ducks. We also recommend continued study of metrics other than VFQI that may potentially influence use of wetlands by waterfowl. © 2015 The Wildlife Society.

Aquatic Invertebrate Food Base for Waterbirds at Wetland Reserve Program Easements in the Lower Mississippi Alluvial Valley

Migratory waterbirds depend on invertebrates as a key source of dietary protein, but few studies have quantified aquatic invertebrates or their response to management on privately owned wetlands. Our objectives were to quantify the effects of wetland management provided through the Migratory Bird Habitat Initiative (MBHI) on invertebrate biomass, family richness, and secondary production at Wetland Reserve Program (WRP) easements in Arkansas and Missouri. We collected core and sweep-net samples bi-weekly in autumn 2011 and sweep samples in winter 2012 at WRP easements enrolled in MBHI (n = 13), WRP easements not enrolled in MBHI (n = 12), and intensively managed public wetlands (n = 7) in Arkansas and Missouri. Overall mean (±SE) invertebrate biomass and production during autumn were 11.96 (±1.29) kg/ha and 1.57 (±1.09) kg/ha*season, and during winter were 3.96 (±0.55) kg/ha and 1.38 (±0.11), respectively. Macroinvertebrate biomass and family richness did not differ among wetland types or management practices, including inundation and mowing. Secondary macroinvertebrate production during autumn was 200 % greater on MBHI contracts compared to WRP easements. During winter, production was 40 % greater on MBHI and WRP easements compared to public wetlands. Our results suggest that with management, wetlands enrolled in conservation easement programs can be an important source of invertebrate production for migratory waterbirds.