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At least 1,747 records · Page 97Linked to original sources
USGS2019

A pragmatic approach for comparing species distribution models to increasing confidence in managing piping plover habitat

Conservation management often requires decision-making without perfect knowledge of the at-risk species or ecosystem. Species distribution models (SDMs) are useful but largely under-utilized due to model uncertainty. We provide a case study that utilizes an ensemble modeling approach of two independently derived SDMs to explicitly address common modeling impediments and to directly inform conservation decision-making for piping plovers in a heavily populated mid-Atlantic (USA) coastal zone. We summarized previously published Bayesian network and maximum entropy modeling approaches to highlight similarities and differences in model structure, and we compared the relative importance of predictors used. Despite marked differences in analytical approach, the relative importance of factors driving nest-site selection was consistent. Comparison of raw suitability scores revealed high dissimilarity between modeling approaches, but models demonstrated considerable agreement when comparing a binary (suitable/unsuitable) measure of suitability. Instances of model consensus (i.e., overlapping areas of predicted piping plover nesting habitat between models) provide a stronger ‘signal’ in model results, reducing uncertainty related to biases or errors associated with either model. We tested model accuracy using a common dataset of plover nests initiated within the focal areas between 2013 and 2015, and we examined congruency in model outputs. Nearly 90% of all nests occurred in areas predicted suitable by at least one model, and at least 33% of the total nests were predicted in areas suitable by both. Because models predominantly agreed on what drives piping plover nest-site selection, areas predicted suitable by a single model should not be discounted. This case study demonstrates how models can effectively inform conservation planning by explicitly identifying the management objective, presenting robust evidence to allow managers to evaluate outcomes of alternative management decisions, and clearly communicating results that address real-world conservation problems. The results presented here can greatly increase the piping plover management community’s ability to prioritize candidate sites for future protection, manage existing nesting habitat appropriately, and make a compelling case for conservation actions against competing land use objectives.

New Jersey, New York↗
USGS2024

Applying portfolio theory to benefit endangered amphibians in coastal wetlands threatened by climate change, high uncertainty, and significant investment risk

The challenge of selecting strategies to adapt to climate change is complicated by the presence of irreducible uncertainties regarding future conditions. Decisions regarding long-term investments in conservation actions contain significant risk of failure due to these inherent uncertainties. To address this challenge, decision makers need an arsenal of sophisticated but practical tools to help guide spatial conservation strategies. Theory asserts that managing risks can be achieved by diversifying an investment portfolio to include assets – such as stocks and bonds – that respond inversely to one another under a given set of conditions. We demonstrate an approach for formalizing the diversification of conservation assets (land parcels) and actions (restoration, species reintroductions) by using correlation structure to quantify the degree of risk for any proposed management investment. We illustrate a framework for identifying future habitat refugia by integrating species distribution modeling, scenarios of climate change and sea level rise, and impacts to critical habitat. Using the plains coqui ( Eleutherodactylus juanariveroi ), an endangered amphibian known from only three small wetland populations on Puerto Rico’s coastal plains, we evaluate the distribution of potential refugia under two model parameterizations and four future sea-level rise scenarios. We then apply portfolio theory using two distinct objective functions and eight budget levels to inform investment strategies for mitigating risk and increasing species persistence probability. Models project scenario-specific declines in coastal freshwater wetlands from 2% to nearly 30% and concurrent expansions of transitional marsh and estuarine open water. Conditional on the scenario, island-wide species distribution is predicted to contract by 25% to 90%. Optimal portfolios under the first objective function – benefit maximization – emphasizes translocating frogs to existing protected areas rather than investing in the protection of new habitat. Alternatively, optimal strategies using the second objective function – a risk-benefit tradeoff framework – include significant investment to protect parcels for the purpose of reintroduction or establishing new populations. These findings suggest that leveraging existing protected areas for species persistence, while less costly, may contain excessive risk and could result in diminished conservation benefits. Although our modeling includes numerous assumptions and simplifications, we believe this framework provides useful inference for exploring resource dynamics and developing robust adaptation strategies using an approach that is generalizable to other conservation problems which are spatial or portfolio in nature and subject to unresolvable uncertainty.

Puerto Rico↗
USGS2014

Error propagation in energetic carrying capacity models

Conservation objectives derived from carrying capacity models have been used to inform management of landscapes for wildlife populations. Energetic carrying capacity models are particularly useful in conservation planning for wildlife; these models use estimates of food abundance and energetic requirements of wildlife to target conservation actions. We provide a general method for incorporating a foraging threshold (i.e., density of food at which foraging becomes unprofitable) when estimating food availability with energetic carrying capacity models. We use a hypothetical example to describe how past methods for adjustment of foraging thresholds biased results of energetic carrying capacity models in certain instances. Adjusting foraging thresholds at the patch level of the species of interest provides results consistent with ecological foraging theory. Presentation of two case studies suggest variation in bias which, in certain instances, created large errors in conservation objectives and may have led to inefficient allocation of limited resources. Our results also illustrate how small errors or biases in application of input parameters, when extrapolated to large spatial extents, propagate errors in conservation planning and can have negative implications for target populations.

Journal of Conservation Planning↗
USGS2023

A genetic warning system for a hierarchically structured wildlife monitoring framework

Genetic variation is a well-known indicator of population fitness yet is not typically included in monitoring programs for sensitive species. Additionally, most programs monitor populations at one scale, which can lead to potential mismatches with ecological processes critical to species' conservation. Recently developed methods generating hierarchically nested population units (i.e., clusters of varying scales) for greater sage-grouse ( Centrocercus urophasianus ) have identified population trend declines across spatiotemporal scales to help managers target areas for conservation. The same clusters used as a proxy for spatial scale can alert managers to local units (i.e., neighborhood-scale) with low genetic diversity, further facilitating identification of management targets. We developed a genetic warning system utilizing previously developed hierarchical population units to identify management-relevant areas with low genetic diversity within the greater sage-grouse range. Within this warning system we characterized conservation concern thresholds based on values of genetic diversity and developed a statistical model for microsatellite data to robustly estimate these values for hierarchically nested populations. We found that 41 of 224 neighborhood-scale clusters had low genetic diversity, 23 of which were coupled with documented local population trend decline. We also found evidence of cross-scale low genetic diversity in the small and isolated Washington population, unlikely to be reversed through typical local management actions alone. The combination of low genetic diversity and a declining population suggests relatively high conservation concern. Our findings could further facilitate conservation action prioritization in combination with population trend assessments and (or) local information, and act as a base-line of genetic diversity for future comparison. Importantly, the approach we used is broadly applicable across taxa.

Ecological Applications↗
USGS2026

Restoration based on cost-benefit optimization: A grasslands pilot study

Ecological restoration is essential to meeting global biodiversity conservation goals. Given limited conservation budgets, deciding where to restore habitat is a key challenge for the coming decade. We developed a spatially explicit framework to optimize ecological restoration site selection by integrating land use history, species distributions, and economic costs. The framework includes the following steps: identify potential restoration area based on relevant environmental measures like land use; identify species of interest; calculate restoration benefits by modeling habitat and climate suitability and estimating reduced extinction risk associated with restoring a particular land parcel based on a modified species–area relationship; aggregate benefits across species; and compare to parcel-level land acquisition costs. We applied linear programming to maximize conservation benefit/restoration cost ratios to identify optimized restoration sites. We illustrate this approach using a case study for highly threatened grassland ecosystems in the Great Plains region of Kansas, USA. We selected five grassland animal species (greater prairie chickens [ Tympanuchus cupido ], lesser prairie chickens [ Tympanuchus pallidicinctus ], swift fox [ Vulpes velox ], pronghorn [ Antilocapra americana ], and regal fritillary [ Speyeria idalia ]) as indicators of restoration benefit across taxa. For the indicator species that we chose, shortgrass and mixed-grass prairies had the highest conservation benefit to cost ratio. Setting a minimum restoration threshold for each habitat type allowed us to identify high-priority tallgrass prairie sites. Despite increasing interest in ecological restoration, optimizing restoration site selection is challenging because one must consider habitat features that do not currently exist. The modeling approach described here is flexible and can be updated for different ecosystems, species, and conservation priorities. We outline potential alterations that can be made in future analyses, depending on desired restoration goals.

Kansas↗
USGS2023

Potential impacts of land-management schedules on grassland bird nests and fledglings

Trade-offs exist between timing of grassland habitat management activities (e.g., weed and brush control) while also ensuring other conservation objectives (e.g., grassland bird reproductive success) are met. On land set aside for grassland conservation (e.g., lands enrolled in the U.S. Department of Agriculture Conservation Reserve Program and some state and federal wildlife management areas), federal and state agencies set time frames for land management based on avoiding disturbance of grassland bird nests. However, recent calls for considering the needs of dependent fledglings in conservation plans imply a need to evaluate whether current time frames are adequate. We used initiation and end dates for 3,257 nests of 8 obligate grassland bird species in Illinois and Wisconsin and a simulation approach for fledgling survival to estimate the potential proportion of active nests at risk when management (e.g., mowing, fire) occurred on the 1st and 15th day of May, June, July, and August during the breeding season. Management during June had the potential to impact 24–61% of nests, depending on the species. Management during July had the potential to impact 4–52% of nests, depending on the species. If disturbance occurred during August, proportionately few active nests were at risk for any species (0–9% of nests on 1 August, 0–<0.5% on 15 August). Potential proportions of fledglings at risk from management were greatest in July for 7 of the 8 species (7–18%). Our study suggests that on lands where a primary conservation objective is to increase or ensure survival of grassland birds, delaying management activities until August could be beneficial for protecting both grassland bird nests and fledglings.

Illinois, Wisconsin↗
USGS2008

Using an ecological ethics framework to make decisions about the relocation of wildlife

Relocation is an increasingly prominent conservation tool for a variety of wildlife, but the technique also is controversial, even among conservation practitioners. An organized framework for addressing the moral dilemmas often accompanying conservation actions such as relocation has been lacking. Ecological ethics may provide such a framework and appears to be an important step forward in aiding ecological researchers and biodiversity managers to make difficult moral choices. A specific application of this framework can make the reasoning process more transparent and give more emphasis to the strong sentiments about non-human organisms held by many potential users. Providing an example of the application of the framework may also increase the appeal of the reasoning process to ecological researchers and biodiversity managers. Relocation as a conservation action can be accompanied by a variety of moral dilemmas that reflect the interconnection of values, ethical positions, and conservation decisions. A model that is designed to address moral dilemmas arising from relocation of humans provides/demonstrates/illustrates a possible way to apply the ecological ethics framework and to involve practicing conservationists in the overall decision-making process. ?? 2008 Springer Science+Business Media B.V.

Science and Engineering Ethics↗
USGS2019

Whooping Cranes past and present

The Whooping Crane ( Grus americana ), endemic to North America, is the rarest of all crane species. It is believed that in the early 1800s, the Whooping Crane was widespread in North America, though it was never very abundant. Whooping Crane numbers decreased precipitously as westward migration of Euro-American settlers converted prairie to cropland and the birds were hunted. By the early 1940s the total population was as low as 21 individuals; the migratory Aransas-Wood Buffalo Population, from which all extant Whooping Cranes are descended, dwindled to 16 in 1941. The threat of extinction was very real. These dire circumstances excited the interest of ornithologists and conservationists in the United States and Canada, and much has been accomplished since to conserve the species. To describe the historical and ongoing conservation activities for Whooping Cranes, we distinguish two eras of Whooping Crane Conservation: before 1950 and after 1950. The first era was characterized by publicizing the plight of the Whooping Crane and halting hunting and habitat destruction. The second era, continuing to the present, has been characterized by development of information about cranes through scientific study, conservation efforts of governmental and nongovernmental organizations, protection of the species under the Endangered Species Act in the United States and the Species at Risk Act in Canada, habitat protection, and reintroduction of new populations of Whooping Cranes. Publication of the monograph, The Whooping Crane by Robert Porter Allen, in 1952 stimulated much of the work of the second era, and still stands as the definitive work on the biology of Whooping Cranes. The remnant Aransas Wood Buffalo Population, which is crucial to species recovery, has grown to over 430 birds as of winter 2016–17. Four reintroduced populations were started in the second era; two are currently active efforts (the Eastern Migratory population and the Louisiana Nonmigratory Population), although neither population is selfsustaining. This volume gathers together the current scientific information about Whooping Cranes and the experiences of various reintroduction and management operations, to provide a baseline from which a third era of Whooping Crane conservation may be launched.

Book chapter↗
USGS2017

Using resilience and resistance concepts to manage persistent threats to sagebrush ecosystems and greater sage-grouse

Conservation of imperiled species often demands addressing a complex suite of threats that undermine species viability. Regulatory approaches, such as the US Endangered Species Act (1973), tend to focus on anthropogenic threats through adoption of policies and regulatory mechanisms. However, persistent ecosystem-based threats, such as invasive species and altered disturbance regimes, remain critical issues for most at-risk species considered to be conservation-reliant. We describe an approach for addressing persistent ecosystem threats to at-risk species based on ecological resilience and resistance concepts that is currently being used to conserve greater sage-grouse (Centrocercus urophasianus) and sagebrush ecosystems. The approach links biophysical indicators of ecosystem resilience and resistance with species-specific population and habitat requisites in a risk-based framework to identify priority areas for management and guide allocation of resources to manage persistent ecosystem-based threats. US federal land management and natural resource agencies have adopted this framework as a foundation for prioritizing sage-grouse conservation resources and determining effective restoration and management strategies. Because threats and strategies to address them cross-cut program areas, an integrated approach that includes wildland fire operations, postfire rehabilitation, fuels management, and habitat restoration is being used. We believe this approach is applicable to species conservation in other largely intact ecosystems with persistent, ecosystem-based threats.

Rangeland Ecology and Management↗
USGS2024

From eDNA to decisions using a multi-method approach to restoration planning in streams

Reintroduction efforts are increasingly used to mitigate biodiversity losses, but are frequently challenged by inadequate planning and uncertainty. High quality information about population status and threats can be used to prioritize reintroduction and restoration efforts and can transform ad hoc approaches into opportunities for improving conservation outcomes at a landscape scale. We conducted comprehensive environmental DNA (eDNA) and visual encounter surveys to determine the distribution of native and non-native aquatic species in two high-priority watersheds to address key uncertainties—such as the distribution of threats and the status of existing populations—inherent in restoration planning. We then used these occurrence data to develop a menu of potential conservation actions and a decision framework to benefit an endangered vertebrate (foothill yellow-legged frog, Rana boylii ) in dynamic stream systems. Our framework combines the strengths of multiple methods, allowing managers and conservation scientists to incorporate conservation science and site-specific knowledge into the planning process to increase the likelihood of achieving conservation goals.

Scientific Reports↗
USGS2013

An individual-based model for population viability analysis of humpback chub in Grand Canyon

We developed an individual-based population viability analysis model (females only) for evaluating risk to populations from catastrophic events or conservation and research actions. This model tracks attributes (size, weight, viability, etc.) for individual fish through time and then compiles this information to assess the extinction risk of the population across large numbers of simulation trials. Using a case history for the Little Colorado River population of Humpback Chub Gila cypha in Grand Canyon, Arizona, we assessed extinction risk and resiliency to a catastrophic event for this population and then assessed a series of conservation actions related to removing specific numbers of Humpback Chub at different sizes for conservation purposes, such as translocating individuals to establish other spawning populations or hatchery refuge development. Our results suggested that the Little Colorado River population is generally resilient to a single catastrophic event and also to removals of larvae and juveniles for conservation purposes, including translocations to establish new populations. Our results also suggested that translocation success is dependent on similar survival rates in receiving and donor streams and low emigration rates from recipient streams. In addition, translocating either large numbers of larvae or small numbers of large juveniles has generally an equal likelihood of successful population establishment at similar extinction risk levels to the Little Colorado River donor population. Our model created a transparent platform to consider extinction risk to populations from catastrophe or conservation actions and should prove useful to managers assessing these risks for endangered species such as Humpback Chub.

Arizona↗
USGS2019

Scenarios of climate adaptation potential on protected working lands from management of soils

Management of protected lands may enhance ecosystem services that conservation programs were designed to protect. Practices that build soil organic matter (SOM) on agricultural lands also increase soil water holding capacity, potentially reducing climatic water deficit (CWD), increasing actual evapotranspiration (AET) and increasing groundwater recharge (RCH). We developed nine spatially-explicit land use and conservation scenarios (2001 - 2100) in the LUCAS land use change model to address two questions for California working lands (cropland and rangeland): How does land use change limit opportunities to manage soils for hydrologic climate adaptation benefits? To what extent and where can soil management practices increase climate adaptation on protected working lands? Hydrologic benefits [∑(∆CWD, ∆AET, ∆RCH)] due to soil management were simulated in the Basin Characterization Model (a state-wide water balance model) for two Representative Concentration Pathway 8.5 climate models. LUCAS simulated land conversion and new conservation easements with potential for maximum hydrologic benefits. Climate drove differences in lost potential for water benefits due to urbanization (33.9 - 87.6 m3 x 106) in 2050. Conflict between development pressure and potential hydrologic benefits occurred most in Santa Clara County in the San Francisco Bay Area and Shasta County in Northern Sacramento Valley. Hydrologic benefits on easements were similar in magnitude to losses from development. Water savings from management of California Land Conservation (a.k.a. Williamson) Act contract lands were an order of magnitude greater, totaling over 460 m3 x106 annually in a drier climate by 2050. Few counties provide most benefits because of soil properties, climate and land area protected. The increase in hydrologic benefits varies by agricultural practice and adoption rate, land use type and configuration, and terms of conservation agreements. The effectiveness of programs designed to improve climate adaptation at county to state scales will likely increase by taking this variability into consideration.

California↗
USGS2025

Recovering the American horseshoe crab through a commitment to collaboration

American horseshoe crab Limulus polyphemus populations are recovering because of cooperation among diverse stakeholders and data-driven collective action. Limulus polyphemus is one of four extant species facing common threats, and conservation successes and limitations hold lessons applicable to all the species. We review the advancement in management and monitoring over recent decades, discuss the current population status throughout the species’ range, and describe the potential future status and recovery based on recent assessments. In retrospect, L. polyphemus conservation has followed the frameworks promoted by the International Union for the Conservation of Nature: mobilize networks to increase assessment capacity, engage diverse stakeholders, measure impacts, and amplify successes. Data show significantly increased populations in the Delaware Bay region and improved status in the Northeast. The average abundance of adults in Delaware Bay over the recent decade (2013–2022) is more than twice that in the previous decade (2003–2012). In 2022, the abundances for adult females and males in the Delaware Bay population were estimated to be 16 million and 40 million, respectively. However, reversing persistent poor conditions in some regions and mitigating the widespread threat of habitat loss from coastal development and sea level rise will rely on collaboration among diverse stakeholders to build upon the current conservation successes. Scientists and conservationists working on the horseshoe crab species indigenous to Asia are advancing along a similar track, establishing a monitoring network and mobilizing diverse stakeholders. However, there is a need for capacity building for robust assessment of the species in Asia to measure the impact of conservation, just as that need remains unmet for L. polyphemus in the Gulf of Mexico. The importance of partnerships and collaborations is apparent in their absence. The regions where partnerships and collaborations among researchers, conservationists, and agency scientists do not exist are those where the capacity for monitoring and assessment is notably lacking.

Fisheries↗
USGS2025

Summer roost site suitability analyses for 4 special status bat species in the Eastern United States

Data describing habitat suitability are crucial for implementing effective conservation planning but are often lacking at regional and continental scales. We address this gap for 4 bat species that are listed, proposed for listing, or under Endangered Species Act listing review by highlighting a framework for estimating summer roost suitability with a presence-background approach to aid development of conservation policy and management plans. The 4 species of concern are the Little Brown Bat ( Myotis lucifugus ), the Northern Long-eared Bat ( M. septentrionalis ), the Indiana Bat ( M. sodalis ), and the Tricolored Bat ( Perimyotis subflavus ). Our estimates of summer roost suitability were developed for the eastern United States at a fine spatial resolution (250 m pixels) suitable for conservation planning across multiple scales. Summer roost habitat suitability was higher in areas with higher tree canopy cover for each of these species, though subtle differences were observed between the species that often use buildings (e.g., Little Brown Bat), tree crevices, cavities, and elements of dead or dying trees (e.g., Northern Long-eared Bat and Indiana Bat), and foliage (e.g., Tricolored Bat). To this end, roost suitability was not identical among species, and each showed subtly different relationships to the environmental covariates considered here. We also use a novel approach, gradient surface metrics, to quantify differences in the spatial pattern of summer roost suitability among the 4 species and found that tricolored bats and northern long-eared bats showed the most homogeneous and spatially smooth habitat suitability surfaces. Estimates of summer roost suitability developed here were also used to identify areas of good summer habitat where our models showed the least uncertainty that may be beneficial for targeted conservation, such as limiting disturbance to potential roost habitat. We also identified areas where additional data would benefit future summer roost modeling efforts. This work provides a first step toward developing multistate inventories of summer roost habitat suitable for implementing effective conservation planning at multiple scales.

Journal of Mammalogy↗
USGS2017

Rehabilitating sea otters: Feeling good versus being effective

This chapter examines the complexities of assessing the merits and drawbacks of wildlife rehabilitation. Wildlife rehabilitation is often costly, and the resulting benefits differ depending on whether one’s interest is in the welfare of individual animals or conserving populations. Two examples of this dilemma include the rehabilitation of oiled sea otters following the Exxon Valdez spill in Prince William Sound, Alaska, and the rehabilitation of stranded sea otter pups in central California. In the first example, substantial financial investment resulted in little or no benefits for population conservation. In the second example, the potential for population-level benefits is context dependent: in populations near carrying capacity the conservation impacts are negligible, whereas in isolated, low-density populations rehabilitation and release can be an effective conservation tool. Wildlife rehabilitation is valued by people for various reasons, but recognizing and acknowledging the difference between individual and population welfare is an important step toward effective wildlife conservation.

Book chapter↗
USGS2018

Patterns of species richness hotspots and estimates of their protection are sensitive to spatial resolution

Aim Species richness is a measure of biodiversity often used in spatial conservation assessments and mapped by summing species distribution maps. Commission errors inherent those maps influence richness patterns and conservation assessments. We sought to further the understanding of the sensitivity of hotspot delineation methods and conservation assessments to commission errors, and choice of threshold for hotspot delineation. Location United States. Methods We created range maps and 30‐m and 1‐km resolution habitat maps for terrestrial vertebrates in the United States and generated species richness maps with each dataset. With the richness maps and the GAP Protected Areas Dataset, we created species richness hotspot maps and calculated the proportion of hotspots within protected areas; calculating protection under a range of thresholds for defining hotspots. Our method allowed us to identify the influence of commission errors by comparing hotspot maps. Results Commission errors from coarse spatial grain data and lack of porosity in the range data inflated richness estimates and altered their spatial patterns. Coincidence of hotspots from different data types was low. The 30‐m hotspots were spatially dispersed, and some were very long distances from the hotspots mapped with coarser data. Estimates of protection were low for each of the taxa. The relationship between estimates of hotspot protection and threshold choice was nonlinear and inconsistent among data types (habitat and range) and grain size (30‐m and 1‐km). Main conclusions Coarse mapping methods and grain sizes can introduce commission errors into species distribution data that could result in misidentifications of the regions where hotspots occur and affect estimates of hotspot protection. Hotspot conservation assessments are also sensitive to choice of threshold for hotspot delineation. There is value in developing species distribution maps with high resolution and low rates of commission error for conservation assessments.

Diversity and Distributions↗
USGS2021

SiteOpt: An open-source R-package for site selection and portfolio optimization

Conservation planning involves identifying and selecting actions to best achieve objectives for managing natural, social and cultural resources. Conservation problems are often high dimensional when specified as combinatorial or portfolio problems and when multiple competing objectives are considered at varying spatial and temporal scales. Although analytical techniques such as modern portfolio theory (MPT) have been developed to address these complex problems, open source computational platforms for executing these approaches are not readily available. We present a user-friendly R-package called SiteOpt for optimization of binary decisions while explicitly considering environmental or economic uncertainty and the risk tolerance of decision makers. We illustrate the package with spatially-explicit site selection problems (i.e. spatial conservation planning), including an option for divestment (i.e. selling assets), when accounting for future uncertainties in designing conservation areas. The tool is applicable to both spatial and non-spatial problems, such as budget allocation or species selection. Constraints for spatial design and spatial dependencies (e.g. connectivity among sites) can also be specified in SiteOpt. Users can optimize site selection based on two competing objectives by solving for the Nash bargaining solution. Importantly, by quantifying uncertainty and asset spatial correlation, a measure of risk can be included as one such objective to be traded off against portfolio benefits. Thus, SiteOpt can be used to explicitly manage risk in portfolio-based spatial optimization. This tool facilitates decisions in a variety of problem settings, including reserve selection, invasive species management, allocation of law enforcement activities for conservation, budget allocation and asset selection under uncertainty and risk.

Ecography↗
USGS2014

Predicted avian responses to bioenergy development scenarios in an intensive agricultural landscape

Conversion of native prairie to agriculture has increased food and bioenergy production but decreased wildlife habitat. However, enrollment of highly erodible cropland in conservation programs has compensated for some grassland loss. In the future, climate change and production of second-generation perennial biofuel crops could further transform agricultural landscapes and increase or decrease grassland area. Switchgrass ( Panicum virgatum ) is an alternative biofuel feedstock that may be economically and environmentally superior to maize ( Zea mays ) grain for ethanol production on marginally productive lands. Switchgrass could benefit farmers economically and increase grassland area, but there is uncertainty as to how conversions between rowcrops, switchgrass monocultures and conservation grasslands might occur and affect wildlife. To explore potential impacts on grassland birds, we developed four agricultural land-use change scenarios for an intensively cultivated landscape, each driven by potential future climatic changes and ensuing irrigation limitations, ethanol demand, commodity prices, and continuation of a conservation program. For each scenario, we calculated changes in area for landcover classes and predicted changes in grassland bird abundances. Overall, birds responded positively to the replacement of rowcrops with switchgrass and negatively to the conversion of conservation grasslands to switchgrass or rowcrops. Landscape context and interactions between climate, crop water use, and irrigation availability could influence future land-use, and subsequently, avian habitat quality and quantity. Switchgrass is likely to provide higher quality avian habitat than rowcrops but lower quality habitat than conservation grasslands, and therefore, may most benefit birds in heavily cultivated, irrigation dependent landscapes under warmer and drier conditions, where economic profitability may also encourage conversions to drought tolerant bioenergy feedstocks.

Nebraska↗