Lluís

With rates of climate change exceeding the rate at which many species are able to shift their range or adapt, it is important to understand how future changes are likely to affect biodiversity at all levels of organisation. Understanding past responses and extent of niche conservatism in climatic tolerance can help predict future consequences. We use an integrated approach to determine the genetic consequences of past and future climate changes on a bat species, Plecotus austriacus. Glacial refugia predicted by palaeo-modelling match those identified from analyses of extant genetic diversity and model-based inference of demographic history. Former refugial populations currently contain disproportionately high genetic diversity, but niche conservatism, shifts in suitable areas and barriers to migration mean that these hotspots of genetic diversity are under threat from future climate change. Evidence of population decline despite recent northward migration highlights the need to conserve leading-edge populations for spearheading future range shifts.

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Land-use change is both a cause and consequence of many biophysical and socioeconomic changes. The CLUMondo model provides an innovative approach for global land-use change modeling to support integrated assessments. Demands for goods and services are, in the model, supplied by a variety of land systems that are characterized by their land cover mosaic, the agricultural management intensity, and livestock. Land system changes are simulated by the model, driven by regional demand for goods and influenced by local factors that either constrain or promote land system conversion. A characteristic of the new model is the endogenous simulation of intensification of agricultural management versus expansion of arable land, and urban versus rural settlements expansion based on land availability in the neighborhood of the location. Model results for the OECD Environmental Outlook scenario show that allocation of increased agricultural production by either management intensification or area expansion varies both among and within world regions, providing useful insight into the land sparing versus land sharing debate. The land system approach allows the inclusion of different types of demand for goods and services from the land system as a driving factor of land system change. Simulation results are compared to observed changes over the 1970–2000 period and projections of other global and regional land change models.

Rising atmospheric CO₂ concentrations are placing spatially divergent stresses on the world's tropical coral reefs through increasing ocean surface temperatures and ocean acidification. We show how these two stressors combine to alter the global habitat suitability for shallow coral reef ecosystems, using statistical Bioclimatic Envelope Models rather than basing projections on any a priori assumptions of physiological tolerances or fixed thresholds. We apply two different modeling approaches (Maximum Entropy and Boosted Regression Trees) with two levels of complexity (one a simplified and reduced environmental variable version of the other). Our models project a marked temperature-driven decline in habitat suitability for many of the most significant and bio-diverse tropical coral regions, particularly in the central Indo-Pacific. This is accompanied by a temperature-driven poleward range expansion of favorable conditions accelerating up to 40–70 km per decade by 2070. We find that ocean acidification is less influential for determining future habitat suitability than warming, and its deleterious effects are centered evenly in both hemispheres between 5° and 20° latitude. Contrary to expectations, the combined impact of ocean surface temperature rise and acidification leads to little, if any, degradation in future habitat suitability across much of the Atlantic and areas currently considered ‘marginal’ for tropical corals, such as the eastern Equatorial Pacific. These results are consistent with fossil evidence of range expansions during past warm periods. In addition, the simplified models are particularly sensitive to short-term temperature variations and their projections correlate well with reported locations of bleaching events. Our approach offers new insights into the relative impact of two global environmental pressures associated with rising atmospheric CO₂ on potential future habitats, but greater understanding of past and current controls on coral reef ecosystems is essential to their conservation and management under a changing climate.

1. Many publications documenting large-scale trends in the distribution of species make use of opportunistic citizen data, that is, observations of species collected without standardized field protocol and without explicit sampling design. It is a challenge to achieve reliable estimates of distribution trends from them, because opportunistic citizen science data may suffer from changes in field efforts over time (observation bias), from incomplete and selective recording by observers (reporting bias) and from geographical bias. These, in addition to detection bias, may lead to spurious trends.
2. We investigated whether occupancy models can correct for the observation, reporting and detection biases in opportunistic data. Occupancy models use detection/nondetection data and yield estimates of the percentage of occupied sites (occupancy) per year. These models take the imperfect detection of species into account. By correcting for detection bias, they may simultaneously correct for observation and reporting bias as well. We compared trends in occupancy (or distribution) of butterfly and dragonfly species derived from opportunistic data with those derived from standardized monitoring data. All data came from the same grid squares and years, in order to avoid any geographical bias in this comparison.
3. Distribution trends in opportunistic and monitoring data were well-matched. Strong trends observed in monitoring data were rarely missed in opportunistic data.
4. Synthesis and applications. Opportunistic data can be used for monitoring purposes if occupancy models are used for analysis. Occupancy models are able to control for the common biases encountered with opportunistic data, enabling species trends to be monitored for species groups and regions where it is not feasible to collect standardized data on a large scale. Opportunistic data may thus become an important source of information to track distribution trends in many groups of species.

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1. Species distribution models are static models for the distribution of a species, based on Hutchinson's niche concept. They make probabilistic predictions about the distribution of a species, but do not have a temporal interpretation. In contrast, density-structured models based on categorical abundance data make it possible to incorporate population dynamics into species distribution modelling.
2. Using dynamic species distribution models, temporal aspects of a species' distribution can be investigated, including the predictability of future abundance categories and the expected persistence times of local populations, and how these may respond to environmental or anthropogenic drivers.
3. We built density-structured models for two intertidal marine invertebrates, the Lusitanian trochid gastropods Phorcus lineatus and Gibbula umbilicalis, based on 9 years of field data from around the United Kingdom. Abundances were recorded on a categorical scale, and stochastic models for year-to-year changes in abundance category were constructed with winter mean sea surface temperature (SST) and wave fetch (a measure of the exposure of a shore) as explanatory variables.
4. Both species were more likely to be present at sites with high SST, but differed in their responses to wave fetch. Phorcus lineatus had more predictable future abundance and longer expected persistence times than G. umbilicalis. This is consistent with the longer lifespan of P. lineatus.
5. Where data from multiple time points are available, dynamic species distribution models of the kind described here have many applications in population and conservation biology. These include allowing for changes over time when combining historical and contemporary data, and predicting how climate change might alter future abundance conditional on current distributions.

In order to understand population dynamics, data from many locations at multiple time points are needed. It can be very expensive and time-consuming to get precise estimates of abundance at such large scales. Instead, categorical abundance estimates (with categories such as “not seen”, “rare”, “occasional”, ...) are often used. Here, the authors describe ways of extracting approximate information on long-term population dynamics from data of this kind.

1. The past decade has seen an explosion in the development and application of models aimed at estimating species occurrence and occupancy dynamics while accounting for possible non-detection or species misidentification.
2. We discuss some recent occupancy estimation methods and the biological systems that motivated their development. Collectively, these models offer tremendous flexibility, but simultaneously place added demands on the investigator.
3. Unlike many mark–recapture scenarios, investigators utilizing occupancy models have the ability, and responsibility, to define their sample units (i.e. sites), replicate sampling occasions, time period over which species occurrence is assumed to be static and even the criteria that constitute ‘detection’ of a target species. Subsequent biological inference and interpretation of model parameters depend on these definitions and the ability to meet model assumptions.
4. We demonstrate the relevance of these definitions by highlighting applications from a single biological system (an amphibian–pathogen system) and discuss situations where the use of occupancy models has been criticized. Finally, we use these applications to suggest future research and model development.

1. Rapidly increasing atmospheric CO₂ is not only changing the climate system but may also affect the biosphere directly through stimulation of plant growth and ecosystem carbon and nutrient cycling. Although forest ecosystems play a critical role in the global carbon cycle, experimental information on forest responses to rising CO₂ is scarce, due to the sheer size of trees.
2. Here, we present a synthesis of the only study world-wide where a diverse set of mature broadleaved trees growing in a natural forest has been exposed to future atmospheric CO₂ levels (c. 550 ppm) by free-air CO₂ enrichment (FACE). We show that litter production, leaf traits and radial growth across the studied hardwood species remained unaffected by elevated CO₂ over 8 years.
3. CO₂ enrichment reduced tree water consumption resulting in detectable soil moisture savings. Soil air CO₂ and dissolved inorganic carbon both increased suggesting enhanced below-ground activity. Carbon release to the rhizosphere and/or higher soil moisture primed nitrification and nitrate leaching under elevated CO₂; however, the export of dissolved organic carbon remained unaltered.
4. Synthesis. Our findings provide no evidence for carbon-limitation in five central European hardwood trees at current ambient CO₂ concentrations. The results of this long-term study challenge the idea of a universal CO₂ fertilization effect on forests, as commonly assumed in climate–carbon cycle models.

Synthesis. Our findings provide no evidence for carbon-limitation in in the studied trees in a central European hardwood forest at current ambient CO₂ concentrations. The results of this long-term study challenge the idea of a universal CO₂ fertilization effect on forests, as commonly assumed in climate-carbon cycle models.

Climate change is altering phenology and distributions of many species and further changes are projected. Can species physiologically adapt to climate warming? We analyse thermal tolerances of a large number of terrestrial ectotherm (n = 697), endotherm (n = 227) and plant (n = 1816) species worldwide, and show that tolerance to heat is largely conserved across lineages, while tolerance to cold varies between and within species. This pattern, previously documented for ectotherms, is apparent for this group and for endotherms and plants, challenging the longstanding view that physiological tolerances of species change continuously across climatic gradients. An alternative view is proposed in which the thermal component of climatic niches would overlap across species more than expected. We argue that hard physiological boundaries exist that constrain evolution of tolerances of terrestrial organisms to high temperatures. In contrast, evolution of tolerances to cold should be more frequent. One consequence of conservatism of upper thermal tolerances is that estimated niches for cold-adapted species will tend to underestimate their upper thermal limits, thereby potentially inflating assessments of risk from climate change. In contrast, species whose climatic preferences are close to their upper thermal limits will unlikely evolve physiological tolerances to increased heat, thereby being predictably more affected by warming.

Conservation conflicts are increasing on a global scale and instruments for reconciling competing interests are urgently needed. Multicriteria decision analysis (MCDA) is a structured, decision-support process that can facilitate dialogue between groups with differing interests and incorporate human and environmental dimensions of conflict. MCDA is a structured and transparent method of breaking down complex problems and incorporating multiple objectives. The value of this process for addressing major challenges in conservation conflict management is that MCDA helps in setting realistic goals; entails a transparent decision-making process; and addresses mistrust, differing world views, cross-scale issues, patchy or contested information, and inflexible legislative tools. Overall we believe MCDA provides a valuable decision-support tool, particularly for increasing awareness of the effects of particular values and choices for working toward negotiated compromise, although an awareness of the effect of methodological choices and the limitations of the method is vital before applying it in conflict situations.

Uso de Análisis de Decisiones Multicriterio para Abordar Conflictos de Conservación

Los conflictos de conservación están incrementando en una escala global y se necesitan urgentemente instrumentos para reconciliar los intereses en competencia. El análisis de decisiones multicriterio (ADMC) es un proceso estructurado de apoyo a toma de decisiones que puede facilitar el diálogo entre grupos con intereses contrastantes e incorporar las dimensiones humanas y ambientales del conflicto. ADMC es un método estructurado y transparente de descomposición de problemas complejos e incorporación de objetivos múltiples. El valor de este proceso para efrentar a grandes obstáculos en el manejo de conflictos de conservación es que ADMC ayuda en la definición de metas reales, implica un proceso transparente de toma de decisiones y atiende a la desconfianza, visiones mundiales diferentes, asuntos transescalares, información turbia o impugnada y herramientas legislativas inflexibles. En general creemos que ADMC proporciona una herramienta valiosa de apoyo a la toma de decisiones, particularmente para incrementar la conciencia de los efectos de valores particulares y opciones para trabajar hacia compromisos negociados, aunque una conciencia de los efectos de las opciones metodológicas y las limitaciones del método es vital antes de aplicarlo en situaciones de conflictos.

Data on the location and extent of protected areas, ecosystems, and species’ distributions are essential for determining gaps in biodiversity protection and identifying future conservation priorities. However, these data sets always come with errors in the maps and associated metadata. Errors are often overlooked in conservation studies, despite their potential negative effects on the reported extent of protection of species and ecosystems. We used 3 case studies to illustrate the implications of 3 sources of errors in reporting progress toward conservation objectives: protected areas with unknown boundaries that are replaced by buffered centroids, propagation of multiple errors in spatial data, and incomplete protected-area data sets. As of 2010, the frequency of protected areas with unknown boundaries in the World Database on Protected Areas (WDPA) caused the estimated extent of protection of 37.1% of the terrestrial Neotropical mammals to be overestimated by an average 402.8% and of 62.6% of species to be underestimated by an average 10.9%. Estimated level of protection of the world's coral reefs was 25% higher when using recent finer-resolution data on coral reefs as opposed to globally available coarse-resolution data. Accounting for additional data sets not yet incorporated into WDPA contributed up to 6.7% of additional protection to marine ecosystems in the Philippines. We suggest ways for data providers to reduce the errors in spatial and ancillary data and ways for data users to mitigate the effects of these errors on biodiversity assessments.

Efectos de Errores y Vacíos en Conjuntos de Datos Espaciales sobre la Evaluación del Progreso de la Conservación

Los datos sobre la localización y extensión de áreas protegidas, ecosistemas y distribución de especies son esenciales para la determinación de brechas en la conservación de la biodiversidad y la identificación de prioridades de conservación futuras. Sin embargo, estos conjuntos de datos siempre tienen errores en los mapas y metadatos asociados. Los errores a menudo son soslayados en los estudios de conservación, no obstante sus efectos negativos potenciales sobre la extensión reportada de la protección de especies y ecosistemas. Utilizamos 3 estudios de caso para ilustrar las implicaciones de 3 fuentes de error en los reportes de progreso hacia los objetivos de conservación: áreas protegidas con límites desconocidos que son reemplazados por centroides amortiguadores, propagación de múltiples errores en los datos espaciales y conjuntos incompletos de datos de áreas protegidas. Hasta 2010, la frecuencia de áreas protegidas con límites desconocidos en la Base de Datos Mundial de Áreas Protegidas (BDMAP) provocó que la extensión de protección estimada de 37.1% de los mamíferos Neotropicales terrestres fuera sobreestimada en 402.8% en promedio y 62.6% de las especies fue subestimada en 10.9% en promedio. El nivel estimado de protección de los arrecifes de coral del mundo fue 25% mayor cuando se utilizaron datos recientes de resolución más fina, contrariamente a los datos de resolución gruesa disponibles globalmente. La inclusión de conjuntos de datos adicionales aun no incorporados a BDMAP contribuyó hasta en 6.7% a la protección adicional en los ecosistemas marinos de las Filipinas. Sugerimos formas para que los proveedores de datos reduzcan los errores en datos espaciales y ancilares y formas para que los usuarios de datos mitiguen los efectos de estos errores sobre las evaluaciones de biodiversidad.

Although agricultural intensification is thought to pose a significant threat to species, little is known about its role in driving biodiversity loss at regional scales. I assessed the effects of a major component of agricultural intensification, agricultural chemical use, and land-cover and climatic variables on butterfly diversity across 81 provinces in Turkey, where agriculture is practiced extensively but with varying degrees of intensity. I determined butterfly species presence in each province from data on known butterfly distributions and calculated agricultural chemical use as the proportion of agricultural households that use chemical fertilizers and pesticides. I used constrained correspondence analyses and regression-based multimodel inference to determine the effect of environmental variables on species composition and richness, respectively. The variation in butterfly species composition across the provinces was largely explained (78%) by the combination of agricultural chemical use, particularly pesticides, and climatic and land-cover variables. Although overall butterfly richness was primarily explained by climatic and land-cover variables, such as the area of natural vegetation cover, threatened butterfly richness and the relative number of threatened butterfly species decreased substantially as the proportion of agricultural households using pesticides increased. These findings suggest that widespread use of agricultural chemicals, or other components of agricultural intensification that may be collinear with pesticide use, pose an imminent threat to the biodiversity of Turkey. Accordingly, policies that mitigate agricultural intensification and promote low-input farming practices are crucial for protecting threatened species from extinction in rapidly industrializing nations such as Turkey.

Efectos del Uso Extensivo de Agroquímicos sobre la Diversidad de Mariposas en Provincias Turcas

Aunque se piensa que la intensificación agrícola representa una amenaza significativa para las especies, se sabe poco sobre su papel en la pérdida de biodiversidad en escalas regionales. Evalué los efectos de un componente principal de la intensificación agrícola, el uso de agroquímicos, la cobertura de suelo y variables climáticas sobre la diversidad de mariposas en 81 provincias de Turquía, donde la agricultura se practica extensivamente pero con diferentes niveles de intensidad. Determiné la presencia de especies de mariposas en cada provincia a partir de datos de las distribuciones conocidas y medí el uso de agroquímicos como la proporción de agricultores que utilizan fertilizantes y pesticidas químicos. Utilicé análisis de correspondencia constreñida e inferencia con multimodelos basados en regresiones para determinar el efecto de las variables ambientales sobre la composición y riqueza de especies, respectivamente. La variación en la composición de especies de mariposas en las provincias fue explicada principalmente (86%) por la combinación del uso de agroquímicos, particularmente pesticidas, y las variables climáticas y de cobertura de suelo. Aunque la riqueza total de mariposas fue explicada primariamente por variables climáticas y de cobertura de suelo, como la superficie de cubierta vegetal natural, la riqueza de mariposas amenazadas y el número relativo de especies de mariposas amenazadas disminuyó sustancialmente a medida que incrementó la proporción de agricultores que utilizan pesticidas. Estos resultados sugieren que el uso extensivo de agroquímicos, u otros componentes de la intensificación agrícola que pueden utilizados con pesticidas, representan una amenaza para la biodiversidad de Turquía. En consecuencia, las políticas que mitigan la intensificación agrícola y promueven las prácticas agrícolas de bajo insumo son cruciales para la protección de especies amenazadas en países con industrialización acelerada como Turquía.