Lluís

A central tenet of ecology and biogeography is that the broad outlines of species ranges are determined by climate, whereas the effects of biotic interactions are manifested at local scales. While the first proposition is supported by ample evidence, the second is still a matter of controversy. To address this question, we develop a mathematical model that predicts the spatial overlap, i.e. co-occurrence, between pairs of species subject to all possible types of interactions. We then identify the scale of resolution in which predicted range overlaps are lost. We found that co-occurrence arising from positive interactions, such as mutualism (+/+) and commensalism (+/0), are manifested across scales. Negative interactions, such as competition (−/−) and amensalism (−/0), generate checkerboard patterns of co-occurrence that are discernible at finer resolutions but that are lost and increasing scales of resolution. Scale dependence in consumer–resource interactions (+/−) depends on the strength of positive dependencies between species. If the net positive effect is greater than the net negative effect, then interactions scale up similarly to positive interactions. Our results challenge the widely held view that climate alone is sufficient to characterize species distributions at broad scales, but also demonstrate that the spatial signature of competition is unlikely to be discernible beyond local and regional scales.

When wildlife habitat overlaps with industrial development animals may be harmed. Because wildlife and people select resources to maximize biological fitness and economic return, respectively, we estimated risk, the probability of eagles encountering and being affected by turbines, by overlaying models of resource selection for each entity. This conceptual framework can be applied across multiple spatial scales to understand and mitigate impacts of industry on wildlife. We estimated risk to Golden Eagles (Aquila chrysaetos) from wind energy development in 3 topographically distinct regions of the central Appalachian Mountains of Pennsylvania (United States) based on models of resource selection of wind facilities (n = 43) and of northbound migrating eagles (n = 30). Risk to eagles from wind energy was greatest in the Ridge and Valley region; all 24 eagles that passed through that region used the highest risk landscapes at least once during low altitude flight. In contrast, only half of the birds that entered the Allegheny Plateau region used highest risk landscapes and none did in the Allegheny Mountains. Likewise, in the Allegheny Mountains, the majority of wind turbines (56%) were situated in poor eagle habitat; thus, risk to eagles is lower there than in the Ridge and Valley, where only 1% of turbines are in poor eagle habitat. Risk within individual facilities was extremely variable; on average, facilities had 11% (SD 23; range = 0–100%) of turbines in highest risk landscapes and 26% (SD 30; range = 0–85%) of turbines in the lowest risk landscapes. Our results provide a mechanism for relocating high-risk turbines, and they show the feasibility of this novel and highly adaptable framework for managing risk of harm to wildlife from industrial development.

Evaluación del Riesgo para las Aves por el Desarrollo de Energía Eólica Industrial Mediante Modelos de Selección de Recursos Pareados.

Cuando el hábitat de la fauna silvestre se traslapa con el desarrollo industrial, los animales pueden resultar afectados. Como la fauna silvestre y la gente seleccionan recursos para maximizar la aptitud biológica y el reingreso económico, respectivamente; estimamos el riesgo y la probabilidad de que las águilas entren en contacto y sean afectadas por las turbinas al sobreponer modelos de la selección de recursos para cada entidad. Este marco de trabajo conceptual puede aplicarse en múltiples escalas espaciales para entender y mitigar los impactos de la industria sobre la fauna silvestre. Estimamos el riesgo para el águila dorada (Aquila chrysaetos) a partir del desarrollo de energía eólica en tres regiones distintas topográficamente de la parte central de las montañas Apalaches en Pennsylvania (E.U.A) basándonos en modelos de selección de recursos de las instalaciones eólicas (n = 43) y de las águilas que migraban hacia el norte (n = 30). El riesgo para las águilas fue mayor en las zonas de la Cresta y del Valle; las 24 águilas que pasaron por esa región usaron los paisajes con alto riesgo por lo menos una vez durante el vuelo de poca altitud. En contraste, sólo la mitad de las aves que entraron a la región de la Meseta Allegheny usaron paisajes de alto riesgo y ninguna los usó en las montañas Allegheny. Así mismo, en las montañas Allegheny, la mayoría de las turbinas eólicas (56%) estaban situadas en un hábitat pobre para las águilas; por esto el riesgo para las águilas es más bajo aquí que en el Risco y el Valle, donde solamente el 1% de las turbinas se encuentran en un hábitat pobre para las águilas. El riesgo dentro de las instalaciones individuales fue extremadamente variable: en promedio, las instalaciones tuvieron un 11% (SD 23; rango = 0 – 100%) de las turbinas en paisajes de alto riesgo y un 26% (SD 30; rango = 0 – 85%) de las turbinas en los paisajes con riesgo más bajo. Nuestros resultados proporcionan un mecanismo para reubicar a las turbinas de alto riesgo y muestran la factibilidad de este marco de trabajo novedoso y altamente adaptable para manejar el riesgo de dañar a la fauna silvestre con el desarrollo industrial.

Substantial declines in farmland biodiversity have been reported in Europe for several decades. Agricultural changes have been identified as a main driver of these declines. Although different agrienvironmental schemes have been implemented, their positive effect on biodiversity is relatively unknown. This raises the question as to how to reconcile farming production and biodiversity conservation to operationalize a sustainable and multifunctional agriculture. We devised a bioeconomic model and conducted an analysis based on coviability of farmland biodiversity and agriculture. The coviability approach extended population viability analyses by including bioeconomic risk. Our model coupled stochastic dynamics of both biodiversity and farming land-uses selected at the microlevel with public policies at the macrolevel on the basis of financial incentives (taxes or subsidies) for land uses. The coviability approach made it possible for us to evaluate bioeconomic risks of these public incentives through the probability of satisfying a mix of biodiversity and economic constraints over time. We calibrated the model and applied it to a community of 34 common birds in metropolitan France at the small agricultural regions scale. We identified different public policies and scenarios with tolerable (0–0%) agroecological risk and modeled their outcomes up to 2050. Budgetary, economic, and ecological (based on Farmland Bird Index) constraints were essential to understanding the set of viable public policies. Our results suggest that some combinations of taxes on cereals and subsidies on grasslands could be relevant to develop a multifunctional agriculture. Moreover, the flexibility and multicriteria viewpoint underlying the coviability approach may help in the implementation of adaptive management.

Del Análisis de Viabilidad Poblacional a la Co-Viabilidad de la Agricultura y la Biodiversidad de las Tierras de Cultivo

Se han reportado disminuciones sustanciales en la biodiversidad de las tierras de cultivo en Europa durante varias décadas. Los cambios agrícolas han sido identificados como los principales conductores de estas disminuciones. Aunque se han implementado diferentes esquemas agro-ambientales, su efecto positivo sobre la biodiversidad es prácticamente desconocido. Esto genera la pregunta de cómo reconciliar la producción agrícola y la conservación de la biodiversidad para operar una agricultura sostenible y multifuncional. Diseñamos un modelo bioeconómico y realizamos un análisis basado en la co-viabilidad de la biodiversidad de las tierras de cultivo y la agricultura. El acercamiento a la co-viabilidad extendió los análisis de viabilidad de población al incluir riesgos bioeconómicos. Nuestro modelo acopló dinámicas estocásticas tanto de la biodiversidad y el uso de suelo de la agricultura en un micro-nivel, como de las políticas públicas en un macro-nivel con base en los incentivos financieros (impuestos o subsidios) para el uso de suelo. La aproximación de co-viabilidad nos permitió evaluar los riesgos bioeconómicos de estos incentivos públicos a través de la probabilidad de una mezcla satisfactoria de biodiversidad y restricciones económicas a lo largo del tiempo. Calibramos el modelo y lo aplicamos a una comunidad de 34 especies de aves comunes en la Francia metropolitana con la escala de regiones agricultoras pequeñas. Identificamos diferentes políticas públicas y escenarios con riesgo agroecológico tolerable (0-0%) y modelamos sus resultados hasta el año 2050. Las restricciones presupuestales, económicas y ecológicas (basado en Farmland Bird Index) fueron esenciales para entender el conjunto de políticas públicas viables. Nuestros resultados sugieren que algunas combinaciones de impuestos sobre cereales y subsidios sobre pastizales podrían ser relevantes para desarrollar una agricultura multifuncional. Además, la flexibilidad y el punto de visto de criterios múltiples subyacentes al acercamiento de co-viabilidad puede ayudar en la implementación de un manejo adaptativo.

An important process for the persistence of populations subjected to habitat loss and fragmentation is the dispersal of individuals between habitat patches. Dispersal involves emigration from a habitat patch, movement between patches through the surrounding landscape, and immigration into a new suitable habitat patch. Both landscape and physical condition of the disperser are known to influence dispersal ability, although disentangling these effects can often be difficult in the wild. In one of the first studies of its kind, we used an invertebrate model system to investigate how dispersal success is affected by the interaction between the habitat condition, as determined by food availability, and life history characteristics (which are also influenced by food availability). Dispersal of juvenile and adult mites (male and female) from either high food or low food natal patches were tested separately in connected three patch systems where the intervening habitat patches were suitable (food supplied) or unsuitable (no food supplied). We found that dispersal success was reduced when low food habitat patches were coupled to colonising patches via unsuitable intervening patches. Larger body size was shown to be a good predictor of dispersal success, particularly when the intervening landscape is unsuitable. Our results suggest that there is an interaction between habitat fragmentation and habitat suitability in determining dispersal success: if patches degrade in suitability and this affects the ability to disperse successfully then the effective connectance across landscapes may be lowered. Understanding these consequences will be important in informing our understanding of how species, and the communities in which they are embedded, may potentially respond to habitat fragmentation.

The combined effects of vegetation and climate change on biosphere–atmosphere water vapor (H₂O) and carbon dioxide (CO₂) exchanges are expected to vary depending, in part, on how biotic activity is controlled by and alters water availability. This is particularly important when a change in ecosystem composition alters the fractional covers of bare soil, grass, and woody plants so as to influence the accessibility of shallower vs. deeper soil water pools. To study this, we compared 5 years of eddy covariance measurements of H₂O and CO₂ fluxes over a riparian grassland, shrubland, and woodland. In comparison with the surrounding upland region, groundwater access at the riparian sites increased net carbon uptake (NEP) and evapotranspiration (ET), which were sustained over more of the year. Among the sites, the grassland used less of the stable groundwater resource, and increasing woody plant density decoupled NEP and ET from incident precipitation (P), resulting in greater exchange rates that were less variable year to year. Despite similar gross patterns, how groundwater accessibility affected NEP was more complex than ET. The grassland had higher respiration (R_eco) costs. Thus, while it had similar ET and gross carbon uptake (GEP) to the shrubland, grassland NEP was substantially less. Also, grassland carbon fluxes were more variable due to occasional flooding at the site, which both stimulated and inhibited NEP depending upon phenology. Woodland NEP was large, but surprisingly similar to the less mature, sparse shrubland, even while having much greater GEP. Woodland R_eco was greater than the shrubland and responded strongly and positively to P, which resulted in a surprising negative NEP response to P. This is likely due to the large accumulation of carbon aboveground and in the surface soil. These long-term observations support the strong role that water accessibility can play when determining the consequences of ecosystem vegetation change.

The study of determinants of species’ ranges along elevational gradients may shed light on the ecological factors that constrain their distribution and fundamental niche. We analysed the influence of the climate, habitat at different spatial scales and topography on Water Pipit Anthus spinoletta density in mountain landscapes across a wide elevational gradient. Variables associated with spring and annual temperature values were the main determinants of Water Pipit density, especially at the lower distributional limit (700–1200 m asl), where the species avoided warmer areas. At high-elevation sites (1600–2300 m asl), the main constraint to the species’ distribution was habitat structure and composition, with steep rocky areas being avoided. Highest densities were found in open but locally heterogeneous habitat at intermediate to high elevations, and the habitat variables that played a major role at the landscape scale were medium-tall shrublands and woodlands, but with contrasting effects depending on elevation. These results suggest that different sets of variables may constrain density, and effects may differ at the upper and lower elevational limits, with climate being more important at lower elevations and local habitat more important at higher elevations. Ongoing global warming is likely to cause an upward shift in range boundaries of alpine species, but local habitat features could constrain the upward expansion, resulting in range contractions accompanying range shift.

1. Understanding species spatial occurrence patterns and their environmental dependence is one of the fundamental goals in ecology and evolution. Often, occurrence models are built with presence-only data because absence data are unavailable. We compare the strengths and limitations of the recently developed presence-only modelling method, Maxlike, with the more widely used Maxent.
2. In spite of disparities highlighted by the developers of Maxlike and Maxent, we show approximate formal relationships between the parameters of Maxlike and Maxent for two scenarios to illustrate their similarity. Using case studies based on real and simulated data, we show how these similarities manifest in practice.
3. We find more similarities than differences between Maxlike and Maxent, including coefficient values, predicted spatial distributions, similarity to presence–absence models, predictive performance and ranking the predicted suitability of cells. Maxlike reliably predicted absolute occurrence probabilities for very large data sets on landscapes where occurrence probability approximately spanned [0,1]. For smaller data sets, the uncertainty in predicted occurrence probability by Maxlike was very large, due to the inherent limitations of presence-only data. In contrast, Maxent is constrained to predicting relative occurrence probabilities or relative occurrence rates unless it is provided with additional information from presence–absence data. Both models can reliably predict relative differences in occurrence probability.
4. The choice of which model to use depends partly on sampling assumptions, which we discuss in detail. Due to limitations of presence-only data, ecologists should typically focus on interpretations relying on relative differences in occurrence probability or relative occurrence rates. We discuss how to remedy a number of concerns about the use of Maxent and how to avoid some potential pitfalls with Maxlike – particularly related to high variance predictions. We conclude that both methods are similarly valuable for understanding and predicting species’ distributions in terms of relative differences in occurrence probability when the models are specified carefully.

1. Vegetation structure is an important determinant of species habitats and diversity. It is often represented by simple metrics, such as canopy cover, height and leaf area index, which do not fully capture three-dimensional variations in density. Terrestrial Laser Scanning (TLS) is a technology that can better capture vegetation structure, but methods developed to process scans have been biased towards forestry applications. The aim of this study was develop a methodology for processing TLS data to produce vegetation density profiles across a broader range of habitats.
2. We performed low-resolution and medium-resolution TLS scans using a Leica C5 Scanstation at four locations within eight sites near Wollongong, NSW, Australia (34.38–34.41^oS, 150.84–150.91^oE). The raw point clouds were converted to density profiles using a method that corrected for uneven ground surfaces, varying point density due to beam divergence and occlusion, the non-vertical nature of most beams, and for beams that passed through gaps in the vegetation without generating a point. Density profiles were evaluated against visual estimates from three independent observers using coarse height classes (e.g. 5–10m).
3. TLS produced density profiles that captured the three-dimensional vegetation structure. Although sites were selected to differ in structure, each was relatively homogeneous, and yet we still found a high spatial variation in density profiles. There was also large variation between observers, with the RMS error of the three observers relative to the TLS varying from 16.2% to 32.1%. Part of this error appeared to be due to misjudging the height of vegetation, which caused an overestimation in one height class and an underestimation in another.
4. Our method for generating density profiles using TLS can capture three-dimensional vegetation structure in a manner that is more detailed and less subjective than traditional methods. The method can be applied to a broad range of habitats—not just forests with open understoreys. However, it cannot accurately estimate near-surface vegetation density when there are uneven surfaces or dense vegetation prevents sufficient ground returns. Nonetheless, TLS density profiles will be an important input for research on species habitats, microclimates and nutrient cycles.

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To address the challenges of biodiversity conservation and commodity production, a framework has been proposed that distinguishes between the integration (“land sharing”) and separation (“land sparing”) of conservation and production. Controversy has arisen around this framework partly because many scholars have focused specifically on food production rather than more encompassing notions such as land scarcity or food security. Controversy further surrounds the practical value of partial trade-off analyses, the ways in which biodiversity should be quantified, and a series of scale effects that are not readily accounted for. We see key priorities for the future in (1) addressing these issues when using the existing framework, and (2) developing alternative, holistic ways to conceptualise challenges related to food, biodiversity, and land scarcity.

Much of the biodiversity-related climate change impacts research has focused on the direct effects to species and ecosystems. Far less attention has been paid to the potential ecological consequences of human efforts to address the effects of climate change, which may equal or exceed the direct effects of climate change on biodiversity. One of the most significant human responses is likely to be mediated through changes in the agricultural utility of land. As farmers adapt their practices to changing climates, they may increase pressure on some areas that are important to conserve (conservation lands) whereas lessening it on others. We quantified how the agricultural utility of South African conservation lands may be altered by climate change. We assumed that the probability of an area being farmed is linked to the economic benefits of doing so, using land productivity values to represent production benefit and topographic ruggedness as a proxy for costs associated with mechanical workability. We computed current and future values of maize and wheat production in key conservation lands using the DSSAT4.5 model and 36 crop-climate response scenarios. Most conservation lands had, and were predicted to continue to have, low agricultural utility because of their location in rugged terrain. However, several areas were predicted to maintain or gain high agricultural utility and may therefore be at risk of near-term or future conversion to cropland. Conversely, some areas were predicted to decrease in agricultural utility and may therefore prove easier to protect from conversion. Our study provides an approximate but readily transferable method for incorporating potential human responses to climate change into conservation planning.

Uso de Cambios en la Utilidad Agrícola para Cuantificar Riesgos Futuros para la Conservación Inducidos por el Clima

Mucha de la investigación de los impactos del cambio climático relacionados con la biodiversidad se ha enfocado en los efectos directos sobre las especies y los ecosistemas. Se le ha prestado muy poca atención a las consecuencias ecológicas potenciales de los esfuerzos humanos para tratar los efectos del cambio climático, lo cual puede igualar o exceder los efectos directos del cambio climático sobre la biodiversidad. Es probable que una de las respuestas humanas más significativas sea mediada por los cambios en la utilidad agrícola del suelo. Mientras los granjeros adaptan sus prácticas a los climas cambiantes, pueden incrementar la presión en algunas áreas que son importantes de conservar (tierras de conservación) y disminuirla en otras. Cuantificamos cómo la utilidad agrícola de las tierras de conservación en Sudáfrica puede alterarse por el cambio climático. Asumimos que la probabilidad de que un área sea cultivada está relacionada con los beneficios económicos de hacerlo, usando los valores de productividad del suelo para representar el beneficio de la producción y la robustez topográfica como un sustituto para los costos asociados con la posibilidad de trabajo mecánico. Computamos valores actuales y futuros de la producción de maíz y trigo en tierras importantes de conservación usando el modelo DSSAT4.5 y 36 escenarios de respuesta de los cultivos al clima. La mayoría de las tierras de conservación tuvieron, y se predijo que seguirían teniendo, una utilidad agrícola baja por su ubicación en terreno escabroso. Sin embargo, se predijo que en varias áreas se mantendría o se ganaría una utilidad agrícola alta y por eso podría estar en riesgode convertirse en tierras de cultivo en poco tiempo o en el futuro. Inversamente, se predijo que en álgunas áreas disminuiría la utilidad agrícola y por eso podría ser más fácil protegerlas de la conversión. Nuestro estudio proporciona un método aproximado pero listo para transferirse para incorporar respuestas humanas potenciales al cambio climático a la planeación de la conservación.

Given that funds for biodiversity conservation are limited, there is a need to understand people's preferences for its different components. To date, such preferences have largely been measured in monetary terms. However, how people value biodiversity may differ from economic theory, and there is little consensus over whether monetary metrics are always appropriate or the degree to which other methods offer alternative and complementary perspectives on value. We used a choice experiment to compare monetary amounts recreational visitors to urban green spaces were willing to pay for biodiversity enhancement (increases in species richness for birds, plants, and aquatic macroinvertebrates) with self-reported psychological gains in well-being derived from visiting the same sites. Willingness-to-pay (WTP) estimates were significant and positive, and respondents reported high gains in well-being across 3 axes derived from environmental psychology theories (reflection, attachment, continuity with past). The 2 metrics were broadly congruent. Participants with above-median self-reported well-being scores were willing to pay significantly higher amounts for enhancing species richness than those with below-median scores, regardless of taxon. The socio-economic and demographic background of participants played little role in determining either their well-being or the probability of choosing a paying option within the choice experiment. Site-level environmental characteristics were only somewhat related to WTP, but showed strong associations with self-reported well-being. Both approaches are likely to reflect a combination of the environmental properties of a site and unobserved individual preference heterogeneity for the natural world. Our results suggest that either metric will deliver mutually consistent results in an assessment of environmental preferences, although which approach is preferable depends on why one wishes to measure values for the natural world.

Preferencias de Cuantificación para el Mundo Natural Usando Estudios de Valor Monetario y No Monetario.

Dado que los fondos para la conservación de la biodiversidad son limitados, hay una necesidad de entender las preferencias de la gente por sus diferentes componentes. A la fecha, estas preferencias se han medido principalmente en términos monetarios. Sin embargo, cómo la forma en que la gente valora la biodiversidad puede diferir de la teoría económica y hay poco consenso sobre si las métricas monetarias siempre son apropiadas o si el grado al cual otros métodos ofrecen perspectivas alternativas y complementarias sobre el valor. Usamos un experimento de opción para comparar las cantidades monetarias que los visitantes recreativos a las áreas verdes urbanas están dispuestos a pagar para la mejoría de la biodiversidad (incremento en la riqueza de especies de aves, plantas y macroinvertebrados acuáticos) con las ganancias psicológicas auto-reportadas en el bienestar derivado de las visitas a estos mismos sitios. Los estimados de la disponibilidad para pagar (DPP) fueron significativos y positivos; los que respondieron reportaron una ganancia alta en el bienestar a lo largo de tres ejes derivados de las teorías de psicología ambiental (reflexión, apego, continuidad con el pasado). Las dos medidas en general fueron congruentes. Los participantes con bienestar auto-reportado con puntaje por encima de la media estaban dispuestos a pagar cantidades significativamente más altas para mejorar la riqueza de especies, sin importar el taxón, que aquellos participantes con puntaje por debajo de la media. El trasfondo demográfico y socioeconómico de los participantes tuvo una involucración mínima en determinar si el bienestar o la probabilidad de elegir una opción de pago dentro del experimento de opciones. Las características ambientales a nivel de sitio sólo estuvieron un poco relacionadas con la DPP pero demostraron asociaciones fuertes con el bienestar auto-reportado. Ambos acercamientos probablemente reflejen una combinación de las propiedades ambientales de un sitio y la heterogeneidad de la preferencia individual no-observada para el mundo natural. Nuestros resultados sugieren que cualquiera de las dos medidas entregará resultados mutuamente consistentes en un estudio de preferencias ambientales, aunque cuál acercamiento es preferible depende de las razones por las que alguien desea medir los valores del mundo natural.

Drawing on the idea that biodiversity is simply the diversity of living things, and that everyone knows what diversity and living things mean, most conservation professionals eschew the need to explain the many complex ways in which biodiversity is understood in science. On many biodiversity-related issues, this lack of clarity leads to a communication gap between science and the general public, including decision makers who must design and implement biodiversity policies. Closing this communication gap is pivotal to the ability of science to inform sound environmental decision making. To address this communication gap, we propose a surrogate of biodiversity for communication purposes that captures the scientific definition of biodiversity yet can be understood by nonscientists; that is, biodiversity as a learning experience. The prerequisites of this or any other biodiversity communication surrogate are that it should have transdisciplinary relevance; not be measurable; be accessible to a wide audience; be usable to translate biodiversity issues; and understandably encompass biodiversity concepts. Biodiversity as a learning experience satisfies these prerequisites and is philosophically robust. More importantly, it can effectively contribute to closing the communication gap between biodiversity science and society at large.

Experimentando la Biodiversidad como un Puente sobre el Vacío entre la Comunicación Ciencia-Sociedad

Partiendo de la idea que la biodiversidad es simplemente la diversidad de seres vivos y que todos saben lo que significan diversidad y seres vivos, la mayoría de los profesionales de la conservación evitan la necesidad de explicar las diferentes formas complejas en las cuales la biodiversidad se entiende dentro de la ciencia. En muchos temas relacionados con la biodiversidad, esta falta de claridad lleva a un vacío en la comunicación entre la ciencia y el público en general, incluyendo a quienes toman las decisiones y deben diseñar e implementar políticas de biodiversidad. Disminuir este vacío es esencial en la habilidad de la ciencia para informar la toma de decisiones ambientales. Para tratar este vacío proponemos un sustituto de la biodiversidad para propósitos de comunicación que capture la definición científica de biodiversidad y pueda ser entendido por no-científicos; esto quiere decir que la biodiversidad es una experiencia de aprendizaje. Los prerrequisitos de esto, o cualquier otro sustituto de la comunicación, son que debe tener relevancia transdisciplinaria, no ser medible, ser accesible a un público amplio, ser útil para traducir temer de biodiversidad y ser entendible para englobar conceptos de biodiversidad. La biodiversidad como una experiencia de aprendizaje satisface estos prerrequisitos y es filosóficamente robusta. Más importante, puede contribuir efectivamente al cierre del vacío en la comunicación entre la ciencia de la biodiversidad y la sociedad en general.

Losses of both habitat area and connectivity have been identified as important drivers of species richness declines, but little theoretical and empirical work exists that addresses the effect of fragmentation on relative commonness of highly mobile species such as pollinating insects. With a large dataset of wild bee and butterfly abundances collected across Europe, we first tested the effect of habitat area and connectivity on evenness in pollinator communities using a large array of indexes that give different weight to dominance and rarity. Second, we tested if traits related to mobility and diet breadth could explain the observed evenness patterns. We found a clear negative effect of area and a weaker, but positive effect of connectivity on evenness. Communities in small habitat fragments were mainly composed of mobile and generalist species. The higher evenness in small fragments could thereby be generated by highly mobile species that maintain local populations with frequent inter-fragment movements. Trait analysis suggested an increasing importance of dispersal over local recruitment, as we move from large to small fragments and from less to more connected fragments. Species richness and evenness were negatively correlated indicating that the two variables responded differently to habitat area and connectivity, although the mechanisms underlying the observed patterns are difficult to isolate. Even though habitat area and connectivity often decrease simultaneously due to habitat fragmentation, an interesting practical implication of the contrasting effect of the two variables is that the resulting community composition will depend on the relative strength of these two processes.

Climate change is anticipated to alter plant species distributions. Regional context, notably the spatial complexity of climatic gradients, may influence species migration potential. While high-elevation species may benefit from steep climate gradients in mountain regions, their persistence may be threatened by limited suitable habitat as land area decreases with elevation. To untangle these apparently contradictory predictions for mountainous regions, we evaluated the climatic suitability of four coniferous forest tree species of the western United States based on species distribution modeling (SDM) and examined changes in climatically suitable areas under predicted climate change. We used forest structural information relating to tree species dominance, productivity, and demography from an extensive forest inventory system to assess the strength of inferences made with a SDM approach. We found that tree species dominance, productivity, and recruitment were highest where climatic suitability (i.e., probability of species occurrence under certain climate conditions) was high, supporting the use of predicted climatic suitability in examining species risk to climate change. By predicting changes in climatic suitability over the next century, we found that climatic suitability will likely decline, both in areas currently occupied by each tree species and in nearby unoccupied areas to which species might migrate in the future. These trends were most dramatic for high elevation species. Climatic changes predicted over the next century will dramatically reduce climatically suitable areas for high-elevation tree species while a lower elevation species, Pinus ponderosa, will be well positioned to shift upslope across the region. Reductions in suitable area for high-elevation species imply that even unlimited migration would be insufficient to offset predicted habitat loss, underscoring the vulnerability of these high-elevation species to climatic changes.

1. Studies of demographic processes are typically restricted to small geographic areas and short time periods due to the costs of marking and monitoring individuals. However, environmental changes are occurring at much broader spatial and temporal scales, and thus, inferences about the mechanisms governing population dynamics need to be scaled accordingly. Recently developed integrated population models (IPMs) represent an approach for doing so, by jointly analysing survey data and capture–recapture data.
2. Although promising, several shortcomings of conventional IPMs exist, including difficulties accounting for spatial variation in demographic, movement and detection parameters; limited ability to make spatially explicit predictions of abundance or vital rates; and a requirement that the survey data and the capture–recapture data are independent. We demonstrate how each of these limitations can be resolved by adopting a spatial population dynamics model upon which both the survey data and the capture–recapture data are conditioned.
3. We applied the model to 6 years of hair data collected on the threatened Louisiana black bear Ursus americanus luteolus. For years in which the hair samples were genotyped, the resulting data are information-rich (but expensive) spatial capture–recapture (SCR) data. For the remaining years, the data are binary detection data, of the type often analysed using occupancy models. We compared estimates of demographic parameters and annual abundance using various combinations of the SCR and detection data, and found that combining the SCR data and the detection data resulted in more precise estimates of abundance relative to estimates that did not use the detection data. A simulation study provided additional evidence of increased precision, as well as evidence that the estimators of annual abundance are approximately unbiased.
4. The ability to combine survey data and capture–recapture data using a spatially explicit model opens many possibilities for designing cost effective studies and scaling up inferences about the demographic processes influencing spatial and temporal population dynamics.

1. The movements of individuals – at almost any scale – are likely to depend on the behaviour of conspecifics. As an example, the movements of dispersing juveniles and their settling decisions may depend on the availability of mates and free territories, that is, both the presence and absence of other individuals. As another example, individuals can use the presence of conspecifics during foraging movements as an indicator of habitat quality.
2. We develop a general statistical framework for identifying and characterizing conspecific influence on movements from tracking data acquired simultaneously from a set of potentially interacting individuals.
3. We model conspecific attraction/repulsion through a functional response in which social behaviour is assumed to depend on proximity to other individuals. The model partitions variation in the functional response into a population component (common to all individuals), variation among individuals (modelled as random intercept-slope) and variation within an individual's trajectory (modelled through temporal autocorrelation).
4. We present a Bayesian approach for the estimation of the model and illustrate its use with simulated movement data generated from a number of contrasting scenarios. We then apply the method to a case study on eagle owl Bubo bubo juvenile dispersal, demonstrating that individual movements are generally influenced by the presence of conspecifics, with the level of attraction decreasing with increasing proximity to other individuals. We further show that female eagle owls are more attracted to conspecifics than males, and both males and females are more attracted to females than to males.

Developing conservation strategies for threatened species increasingly requires understanding vulnerabilities to climate change, in terms of both demographic sensitivities to climatic and other environmental factors, and exposure to variability in those factors over time and space. We conducted a range-wide, spatially explicit climate change vulnerability assessment for Eastern Massasauga (Sistrurus catenatus), a declining endemic species in a region showing strong environmental change. Using active season and winter adult survival estimates derived from 17 data sets throughout the species' range, we identified demographic sensitivities to winter drought, maximum precipitation during the summer, and the proportion of the surrounding landscape dominated by agricultural and urban land cover. Each of these factors was negatively associated with active season adult survival rates in binomial generalized linear models. We then used these relationships to back-cast adult survival with dynamic climate variables from 1950 to 2008 using spatially explicit demographic models. Demographic models for 189 population locations predicted known extant and extirpated populations well (AUC = 0.75), and models based on climate and land cover variables were superior to models incorporating either of those effects independently. These results suggest that increasing frequencies and severities of extreme events, including drought and flooding, have been important drivers of the long-term spatiotemporal variation in a demographic rate. We provide evidence that this variation reflects nonadaptive sensitivity to climatic stressors, which are contributing to long-term demographic decline and range contraction for a species of high-conservation concern. Range-wide demographic modeling facilitated an understanding of spatial shifts in climatic suitability and exposure, allowing the identification of important climate refugia for a dispersal-limited species. Climate change vulnerability assessment provides a framework for linking demographic and distributional dynamics to environmental change, and can thereby provide unique information for conservation planning and management.

The establishment of either forest or grassland on degraded cropland has been proposed as an effective method for climate change mitigation because these land use types can increase soil carbon (C) stocks. This paper synthesized 135 recent publications (844 observations at 181 sites) focused on the conversion from cropland to grassland, shrubland or forest in China, better known as the ‘Grain-for-Green’ Program to determine which factors were driving changes to soil organic carbon (SOC). The results strongly indicate a positive impact of cropland conversion on soil C stocks. The temporal pattern for soil C stock changes in the 0–100 cm soil layer showed an initial decrease in soil C during the early stage (<5 years), and then an increase to net C gains (>5 years) coincident with vegetation restoration. The rates of soil C change were higher in the surface profile (0–20 cm) than in deeper soil (20–100 cm). Cropland converted to forest (arbor) had the additional benefit of a slower but more persistent C sequestration capacity than shrubland or grassland. Tree species played a significant role in determining the rate of change in soil C stocks (conifer < broadleaf, evergreen < deciduous forests). Restoration age was the main factor, not temperature and precipitation, affecting soil C stock change after cropland conversion with higher initial soil C stock sites having a negative effect on soil C accumulation. Soil C sequestration significantly increased with restoration age over the long-term, and therefore, the large scale of land-use change under the ‘Grain-for-Green’ Program will significantly increase China's C stocks.

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Native plant species that have lost their mutualist partners may require non-native pollinators or seed dispersers to maintain reproduction. When natives are highly specialized, however, it appears doubtful that introduced generalists will partner effectively with them. We used visitation observations and pollination treatments (experimental manipulations of pollen transfer) to examine relationships between the introduced, generalist Japanese White-eye (Zosterops japonicus) and 3 endemic Hawaiian plant species (Clermontia parviflora, C. montis-loa, and C. hawaiiensis). These plants are characterized by curved, tubular flowers, apparently adapted for pollination by curve-billed Hawaiian honeycreepers. Z. japonicus were responsible for over 80% of visits to flowers of the small-flowered C. parviflora and the midsize-flowered C. montis-loa. Z. japonicus-visited flowers set significantly more seed than did bagged flowers. Z. japonicus also demonstrated the potential to act as an occasional Clermontia seed disperser, although ground-based frugivory by non-native mammals likely dominates seed dispersal. The large-flowered C. hawaiiensis received no visitation by any birds during observations. Unmanipulated and bagged C. hawaiiensis flowers set similar numbers of seeds. Direct examination of Z. japonicus and Clermontia morphologies suggests a mismatch between Z. japonicus bill morphology and C. hawaiiensis flower morphology. In combination, our results suggest that Z. japonicus has established an effective pollination relationship with C. parviflora and C. montis-loa and that the large flowers of C. hawaiiensis preclude effective visitation by Z. japonicus.

Remplazo Imperfecto de Especies Nativas por Especies No-Nativas como Polinizadores de Plantas Endémicas de Hawaii

Las especies nativas de plantas que han perdido a sus compañeros mutualistas pueden requerir de polinizadores no-nativos o dispersores de semillas para mantener su reproducción. Sin embargo cuando las especies nativas están altamente especializadas, parece dudoso que especies generalistas introducidas se acoplarán efectivamente con ellas. Usamos observaciones de visita y tratamientos de polinización (manipulaciones experimentales de transferencia de polen) para examinar las relaciones entre la introducida y generalista Zosterops japonicus y tres especies de plantas endémicas de Hawaii (Clermontia parviflora, C. montis-loa y C. hawaiiensis). Estas plantas se caracterizan por sus flores curveadas y tubulares, adaptadas aparentemente a la polinización por mieleros hawaianos de pico curvo. Zosterops japonicus fue responsable de más del 80% de visitas a flores de C. parviflora, de flores pequeñas, y de C. montis-loa, de flores mediadas. Las flores visitadas por Zosterops japonicus establecieron significativamente más semillas que aquellas flores embolsadas. Zosterops japonicus también demostró el potencial para fungir como dispersor ocasional de semillas de Clermontia, aunque la frugivoría terrestre de mamíferos no-nativos probablemente domine la dispersión de semillas. C. hawaiiensis, de flores grandes, no fue visitada por aves durante las observaciones. Ejemplares de C. hawaiiensis sin manipular y embolsadas establecieron un número similar de semillas. La examinación directa de las morfologías de Z. japonicus y Clermontia sugieren un desajuste entre la morfología del pico de Z. japonicus y la morfología floral de C. hawaiiensis. Combinados, nuestros resultados sugieren que Z. japonicus ha establecido una relación efectiva de polinización con C. parviflora y C. montis-loa y que las flores grandes de C. hawaiiensis evitan las visitas efectivas de Z. japonicus.

Migratory stopover habitats are often not part of planning for conservation or new development projects. We identified potential stopover habitats within an avian migratory flyway and demonstrated how this information can guide the site-selection process for new development. We used the random forests modeling approach to map the distribution of predicted stopover habitat for the Whooping Crane (Grus americana), an endangered species whose migratory flyway overlaps with an area where wind energy development is expected to become increasingly important. We then used this information to identify areas for potential wind power development in a U.S. state within the flyway (Nebraska) that minimize conflicts between Whooping Crane stopover habitat and the development of clean, renewable energy sources. Up to 54% of our study area was predicted to be unsuitable as Whooping Crane stopover habitat and could be considered relatively low risk for conflicts between Whooping Cranes and wind energy development. We suggest that this type of analysis be incorporated into the habitat conservation planning process in areas where incidental take permits are being considered for Whooping Cranes or other species of concern. Field surveys should always be conducted prior to construction to verify model predictions and understand baseline conditions.

Predicción y Mapeo del Hábitat Potencial de Descanso de la Grulla Americana para Guiar la Selección de Sitios para Proyectos de Energía Eólica.

Los hábitats de descanso migratorio frecuentemente no son parte de la planeación de la conservación o proyectos de desarrollo nuevos. Identificamos hábitats de descanso potenciales dentro de una vía de aves migratorias y demostramos cómo esta información puede guiar en la selección de sitios para nuevos desarrollos. Usamos el acercamiento del modelo de bosques aleatorios para mapear la distribución del hábitat de descanso predicho de la grulla americana (Grus americana), una especie en peligro cuya vía migratoria se traslapa con un área donde se espera que el desarrollo de energía eólica se vuelva cada vez más importante. Usamos esta información para identificar áreas para el desarrollo potencial de poder eólico en un estado de los E.U.A. dentro de la vía de vuelo (Nebraska) que minimicen los conflictos entre el hábitat de descanso de la grulla y el desarrollo de fuentes de energía limpias y renovables. Hasta el 54% de nuestra área de estudio fue predicha como inapropiada como un hábitat de descanso para la grulla y podría considerarse como de bajo riesgo para conflictos entre las grullas y el desarrollo de energía eólica. Sugerimos que este tipo de análisis sea incorporado al proceso de planeación de conservación de hábitat en áreas donde permisos de toma incidentales están siendo considerados para grullas americanas u otras especies de preocupación. El muestreo en campo deberá ser hecho siempre antes de la construcción para verificar las predicciones del modelo y entender las condiciones basales.

1. Agricultural intensification is a major cause of reptile and amphibian decline world-wide, prompting concern on how to best protect biodiversity in commodity production landscapes and meet global food demands. Agri-environment schemes (AES) attempt to integrate biodiversity conservation in agricultural landscapes but are often compromised by a lack of baseline data, monitoring and evaluation. Few studies have examined the benefits of AES in protecting biodiversity relative to the wider farming landscape, and no studies have explicitly quantified the effectiveness of AES to increase herpetofaunal diversity.
2. To examine whether AES protect and increase herpetofauna, we established a landscape-wide biodiversity monitoring programme in threatened semi-arid and temperate woodland communities in south-eastern Australia.
3. With 31 species recorded, regional herpetofaunal diversity was relatively high, whereas local diversity was low. Herpetofaunal richness and reptile assemblage structure did not differ significantly between sites under AES and sites managed for livestock production. A gradient in species richness as a function of time-since-management intervention was not evident, although the abundance of one lizard species increased under vegetation management. Reptile richness and frog abundance differed significantly among vegetation types.
4. Herpetofaunal richness was positively related to native plant richness and bare ground cover, whereas Boulenger's skink Morethia boulengeri was negatively affected by bare ground cover. The ragged snake-eyed skink Cryptoblepharus pannosus was positively related to the amount of woody debris.
5. Synthesis and applications. In this system, strong habitat specificity implies local-scale management interventions under agri-environment schemes (AES) may not significantly increase herpetofaunal diversity in the short term. Vegetation management is likely to increase the abundance of common lizard species rather than increase local species richness due to barrier effects. Future incentive schemes should focus on improving habitat connectivity, enhancing pasture condition and increasing woody debris in the agricultural matrix to dissolve dispersal barriers and mitigate the legacy of historical land-use practices. We propose that AES, which manage mosaics of intergrading vegetation types at multiple spatial scales, will protect maximum herpetofaunal diversity. These recommendations have implications for AES world-wide, many of which currently do not adequately address the habitat requirements of herpetofauna.

1. Group dynamics are a fundamental aspect of many species' movements. The need to adequately model individuals' interactions with other group members has been recognized, particularly in order to differentiate the role of social forces in individual movement from environmental factors. However, to date, practical statistical methods, which can include group dynamics in animal movement models, have been lacking.
2. We consider a flexible modelling framework that distinguishes a group-level model, describing the movement of the group's centre, and an individual-level model, such that each individual makes its movement decisions relative to the group centroid. The basic idea is framed within the flexible class of hidden Markov models, extending previous work on modelling animal movement by means of multistate random walks.
3. While in simulation experiments parameter estimators exhibit some bias in non-ideal scenarios, we show that generally the estimation of models of this type is both feasible and ecologically informative.
4. We illustrate the approach using real movement data from 11 reindeer (Rangifer tarandus). Results indicate a directional bias towards a group centroid for reindeer in an encamped state. Though the attraction to the group centroid is relatively weak, our model successfully captures group-influenced movement dynamics. Specifically, as compared to a regular mixture of correlated random walks, the group dynamic model more accurately predicts the non-diffusive behaviour of a cohesive mobile group.
5. As technology continues to develop, it will become easier and less expensive to tag multiple individuals within a group in order to follow their movements. Our work provides a first inferential framework for understanding the relative influences of individual versus group-level movement decisions. This framework can be extended to include covariates corresponding to environmental influences or body condition. As such, this framework allows for a broader understanding of the many internal and external factors that can influence an individual's movement.