Optimizing conservation in species-specific agricultural landscapes.

Recovery of grassland birds in agricultural landscapes is a global imperative. Agricultural landscapes are complex, and the value of resource patches may vary substantially among species. The spatial extent at which landscape features affect populations (i.e., scale of effect) may also differ among species. There is a need for regional-scale conservation planning that considers landscape-scale and species-specific responses of grassland birds to environmental change. We developed a spatially explicit approach to optimizing grassland conservation in the context of species-specific landscapes and prioritization of species recovery and applied it to a conservation program in Kentucky (USA). We used a hierarchical distance-sampling model with an embedded scale of effect predictor to estimate the relationship between landscape structure and abundance of eastern meadowlarks (Sturnella magna), field sparrows (Spizella pusilla), and northern bobwhites (Colinus virginianus). We used a novel spatially explicit optimization procedure rooted in multi-attribute utility theory to design alternative conservation strategies (e.g., prioritize only northern bobwhite recovery or assign equal weight to each species' recovery). Eastern meadowlarks and field sparrows were more likely to respond to landscape-scale resource patch adjacencies than landscape-scale patch densities. Northern bobwhite responded to both landscape-scale resource patch adjacencies and densities and responded strongly to increased grassland density. Effects of landscape features on local abundance decreased as distance increased and had negligible influence at 0.8 km for eastern meadowlarks (0.7-1.2 km 95% Bayesian credibility intervals [BCI]), 2.5 km for field sparrows (1.5-5.8 km 95% BCI), and 8.4 km for bobwhite (6.4-26 km 95% BCI). Northern bobwhites were predicted to benefit greatly from future grassland conservation regardless of conservation priorities, but eastern meadowlark and field sparrow were not. Our results suggest similar species can respond differently to broad-scale conservation practices because of species-specific, distance-dependent relationships with landscape structure. Our framework is quantitative, conceptually simple, customizable, and predictive and can be used to optimize conservation in heterogeneous ecosystems while considering landscape-scale processes and explicit prioritization of species recovery.

La recuperación de las aves de pastizal en los paisajes agrícolas es una obligación mundial. Los paisajes agrícolas son complejos y el valor de los fragmentos con recursos puede variar sustancialmente entre especies. La magnitud espacial a la que las características del paisaje afectan a las poblaciones (es decir, la escala del efecto) también puede diferir entre especies. Existe la necesidad de una planeación de la conservación a escala regional que considere la escala de paisaje y las respuestas específicas de especie de aves de pastizal al cambio ambiental. Desarrollamos una estrategia espacialmente explícita para optimizar la conservación de pastizales en el contexto de los paisajes de especies específicas y la priorización de la recuperación de especies y la aplicamos a un programa de conservación en Kentucky (E.U.A.). Usamos un modelo jerárquico de muestreo a distancia con una escala integrada del efecto pronosticador para estimar la relación entre la estructura del paisaje y la abundancia de la alondra oriental de pradera (Sturnella magna), el gorrión de campo (Spizella pusilla) y la codorniz norteña (Colinus virginianus). Usamos un novedoso procedimiento de optimización espacialmente explícito basado en la teoría de utilidad multicaracterística para diseñar estrategias de conservación alternativas (p. ej.: priorizar solamente la recuperación de la codorniz norteña o asignar una importancia idéntica a la recuperación de cada especie). La alondra y el gorrión tuvieron una mayor probabilidad de responder a la proximidad de fragmentos con recursos a escala de paisaje que a la densidad de fragmentos a escala de paisaje. La codorniz respondió tanto a la proximidad de fragmentos con recursos a escala de paisaje como a la densidad y también respondió fuertemente al incremento en la densidad del pastizal. Los efectos de las características del paisaje sobre la abundancia local disminuyeron conforme incrementó la distancia, representando una influencia insignificante a los 0.8 km para la alondra (0.7-1.2 km 95% de intervalos de credibilidad bayesiana [ICB]), a los 2.5 km para el gorrión (1.5-5.8 km 95% ICB) y a los 8.4 km para la codorniz (6.4-26 km 95% ICB). Se pronosticó que la codorniz se beneficiaría enormemente con la conservación futura de los pastizales sin importar las prioridades de conservación, pero no fue el caso para la alondra y el gorrión. Nuestros resultados sugieren que especies similares pueden responder de manera diferente a las prácticas de conservación a escalas generalizadas debido a las relaciones específicas de especie y dependientes de la distancia con la estructura del paisaje. Nuestro marco de trabajo es cuantitativo, conceptualmente simple, adaptable y predictivo y puede usarse para optimizar la conservación en los ecosistemas heterogéneos a la vez que considera los procesos a escala de paisaje y la priorización explícita de la recuperación de las especies.

Small mammal responses to long-term large-scale woodland creation: the influence of local and landscape-level attributes.

Habitat loss and fragmentation greatly affect biological diversity. Actions to counteract their negative effects include increasing the quality, amount and connectivity of seminatural habitats at the landscape scale. However, much of the scientific evidence underpinning landscape restoration comes from studies of habitat loss and fragmentation, and it is unclear whether the ecological principles derived from habitat removal investigations are applicable to habitat creation. In addition, the relative importance of local- (e.g., improving habitat quality) vs. landscape-level (e.g., increasing habitat connectivity) actions to restore species is largely unknown, partly because studying species responses over sufficiently large spatial and temporal scales is challenging. We studied small mammal responses to large-scale woodland creation spanning 150 yr, and assessed the influence of local- and landscape-level characteristics on three small mammal species of varying woodland affinity. Woodland specialists, generalists, and grassland specialists were present in woodlands across a range of ages from 10 to 160 yr, demonstrating that these species can quickly colonize newly created woodlands. However, we found evidence that woodlands become gradually better over time for some species. The responses of individual species corresponded to their habitat specificity. A grassland specialist (Microtus agrestis) was influenced only by landscape attributes; a woodland generalist (Apodemus sylvaticus) and specialist (Myodes glareolus) were primarily influenced by local habitat attributes, and partially by landscape characteristics. At the local scale, high structural heterogeneity, large amounts of deadwood, and a relatively open understory positively influenced woodland species (both generalists and specialists); livestock grazing had strong negative effects on woodland species abundance. Actions to enhance habitat quality at the patch scale focusing on these attributes would benefit these species. Woodland creation in agricultural landscapes is also likely to benefit larger mammals and birds of prey feeding on small mammals and increase ecosystem processes such as seed dispersal.

Evaluating and supporting conservation action in agricultural landscapes of the Usumacinta River Basin.

There is increasing recognition that ecosystems and their services need to be managed at landscape scale and greater. The development of landscape-scale conservation strategies need to incorporate information from multiple sources. In this study, we combine various research tools to link landscape patterns with production units and systems in the Usumacinta River Basin, and inform the discussion of key questions around decision-making related to conservation action and policy in Southern Mexico. A typology based on policy-relevant farmer characteristics (land tenure, farm size, source of income, farming system) differentiated between farmers (traditional vs. cattle ranching) with different motivations that determine how management affects landscape configuration. Five main types of traditional farming systems were identified that combine different forms of land use and vary in their degree of land intensification. Major fragmentation and decrease in connectivity coincided spatially with floodplains dominated by large-scale commercial farms that specialize in livestock production. Traditional practices within large units with low-sloped high quality land were also seen to be intensive; however the presence of trees was notable throughout these units. Policies that promote livestock farming are among the principle causes motivating deforestation. Land intensification by traditional farmers decreased as the landscape became increasingly rugged. Traditional farmers are the focus of initiatives developed by the Biological Corridor project which seeks to increase forest cover and landscape connectivity. These initiatives have shown high levels of rural participation (10,010 farmers benefited from 27,778 projects involving 95,374 ha of land) and acceptance (producers carried out more than one project and several types of projects during the first eight years of work). Strong action is still required to take on the segment of large-scale ranchers. Changes in the structure of land tenure over the past decade are highlighted that could have a profound impact on conservation policies and programs.

Species mobility and landscape context determine the importance of local and landscape-level attributes.

Conservation strategies to tackle habitat loss and fragmentation require actions at the local (e.g., improving/expanding existing habitat patches) and landscape level (e.g., creating new habitat in the matrix). However, the relative importance of these actions for biodiversity is still poorly understood, leading to debate on how to prioritize conservation activities. Here, we assess the relative importance of local vs. landscape-level attributes in determining the use of woodlands by bats in fragmented landscapes; we also compare the role of habitat amount in the surrounding landscape per se vs. a combination of both habitat amount and configuration and explore whether the relative importance of these attributes varies with species mobility and landscape context. We conducted acoustic surveys in 102 woodland patches in the UK that form part of the WrEN project (www.wren-project.com), a large-scale natural experiment designed to study the effects of 160 yr of woodland creation on biodiversity and inform landscape-scale conservation. We used multivariate analysis and a model-selection approach to assess the relative importance of local (e.g., vegetation structure) and landscape-level (e.g., amount/configuration of surrounding land types) attributes on bat occurrence and activity levels. Species mobility was an important trait determining the relative importance of local vs. landscape-level attributes for different bat species. Lower mobility species were most strongly influenced by local habitat quality; the landscape became increasingly important for higher mobility species. At the landscape-scale, a combination of habitat amount and configuration appeared more important than habitat amount alone for lower mobility species, while the opposite was observed for higher mobility species. Regardless of species mobility, landscape-level attributes appeared more important for bats in a more homogeneous and intensively farmed landscape. Conservation strategies involving habitat creation and restoration should take into account the mobility of target species and prioritize landscape-level actions in more homogeneous and intensively farmed landscapes where habitat loss and fragmentation have been more severe.

Effects of a coordinated farmland bird conservation project on farmers' intentions to implement nature conservation practices - Evidence from the Swedish Volunteer & Farmer Alliance.

To increase the efficacy of agri-environmental schemes (AES), as well as farmers' environmental engagement, practitioners are increasingly turning to collective forms of agri-environmental management. As yet, empirical evidence from such approaches is relatively scarce. Here, we examined a farmland bird conservation project coordinated by BirdLife Sweden, the Swedish Volunteer & Farmer Alliance (SVFA). The key features of the SVFA were farmland bird inventories from volunteering birdwatchers and on-farm visits to individual farmers from conservation advisors for guidance on AES as well as unsubsidised practices. Using an ex-post application of the theory of planned behaviour across project participants and a randomly sampled control group of farmers we assessed how SVFA affected behavioural intentions relating to AES and unsubsidised conservation, and how the behaviour was affected by attitudes, perceived social norms and perceived behavioural control. We also included a measure of self-identity as a conservationist to assess its importance for behavioural intentions, and if SVFA stimulated this self-identity. SVFA farmers reported greater commitment to implementing AES and unsubsidised conservation, as compared to the control group. However, greater commitment was associated with more positive attitudes for unsubsidised conservation only and not for AES, underlining the inability of existing AES to prompt intrinsic motivation. There were also differences between farmers within SVFA, where farmers applying to the project were motivated by social influences, while farmers recruited by project managers were motivated by their personal beliefs regarding nature conservation. Finally, farmers' self-perceived ability to perform practices (i.e. perceived behavioural control) was important for their commitment to implementing AES as well as unsubsidised practices. Therefore, increasing farmers' awareness regarding the availability and, not least, practicability of available conservation options may be the key to successful biodiversity conservation in agricultural systems.

Using historical woodland creation to construct a long-term, large-scale natural experiment: the WrEN project.

Natural experiments have been proposed as a way of complementing manipulative experiments to improve ecological understanding and guide management. There is a pressing need for evidence from such studies to inform a shift to landscape-scale conservation, including the design of ecological networks. Although this shift has been widely embraced by conservation communities worldwide, the empirical evidence is limited and equivocal, and may be limiting effective conservation. We present principles for well-designed natural experiments to inform landscape-scale conservation and outline how they are being applied in the WrEN project, which is studying the effects of 160 years of woodland creation on biodiversity in UK landscapes. We describe the study areas and outline the systematic process used to select suitable historical woodland creation sites based on key site- and landscape-scale variables - including size, age, and proximity to other woodland. We present the results of an analysis to explore variation in these variables across sites to test their suitability as a basis for a natural experiment. Our results confirm that this landscape satisfies the principles we have identified and provides an ideal study system for a long-term, large-scale natural experiment to explore how woodland biodiversity is affected by different site and landscape attributes. The WrEN sites are now being surveyed for a wide selection of species that are likely to respond differently to site- and landscape-scale attributes and at different spatial and temporal scales. The results from WrEN will help develop detailed recommendations to guide landscape-scale conservation, including the design of ecological networks. We also believe that the approach presented demonstrates the wider utility of well-designed natural experiments to improve our understanding of ecological systems and inform policy and practice.