International audienceRecent observations show that human-induced climate change (CC) and land transformation (LT) are threatening wildlife globally. Thus, there is a need to assess the sensitivity of wildlife on large spatial scales and evaluate whether national parks (NPs), a key conservation tools used to protect species, will meet their mandate under future CC and LT conditions. Here, we assess the sensitivity of 277 mammals at African scale to CC at 10' resolution, using static LT assumptions in a 'first-cut' estimate, in the absence of credible future LT trends. We examine the relationship between species' current distribution and macroclimatic variables using generalized additive models, and include LT indirectly as a filter. Future projections are derived using two CC scenarios (for 2050 and 2080) to estimate the spatial patterns of loss and gain in species richness that might ultimately result. We then apply the IUCN Red List criteria A3(c) of potential range loss to evaluate species sensitivity. We finally estimate the sensitivity of 141 NPs in terms of both species richness and turnover. Assuming no spread of species, 10-15% of the species are projected to fall within the critically endangered or extinct categories by 2050 and between 25% and 40% by 2080. Assuming unlimited species spread, less extreme results show proportions dropping to approximately 10-20% by 2080. Spatial patterns of richness loss and gain show contrasting latitudinal patterns with a westward range shift of species around the species-rich equatorial zone in central Africa, and an eastward shift in southern Africa, mainly because of latitudinal aridity gradients across these ecological transition zones. Xeric shrubland NPs may face significant richness losses not compensated by species influxes. Other NPs might expect substantial losses and influxes of species. On balance, the NPs might ultimately realize a substantial shift in the mammalian species composition of a magnitude unprecedented in recent geological time. To conclude, the effects of global CC and LT on wildlife communities may be most noticeable not as a loss of species from their current ranges, but instead as a fundamental change in community composition
The 400-500 wolves currently living in the Apennine range of peninsular Italy are slowly recolonizing the Alps and are expected to move northward. A nationwide management plan for the Italian wolf population is being prepared, and a zoning system with connecting corridors has been suggested. We developed a large-scale probabilistic model of wolf distribution as a contribution to the planning process. Thirteen environmental variables related to wolf needs and human presence were analyzed in 12 well-studied wolf territories and in 100 areas where the species has been absent for the past 25 years. These two areas were used as a training set in a discriminant analysis to evaluate potential wolf presence throughout the entire country. We used the Mahalanobis distance statistic as an index of environmental quality, calculated as the distance from the average environmental conditions of the wolf territories. Based on the Mahalanobis distance statistics, we constructed an actual and potential spatial distribution of the wolf for all of peninsular Italy. The jackknife procedure was used to assess the stability of the distance model and showed good confidence in our model (coefficient of variation Յ 13%). Distance from the wolf territories' centroid as an index of environmental quality for the wolf was tested using 287 locations where wolves have been found dead in the past 25 years as a consequence of human action (poison, shotgun, car accidents). A useful contribution to conservation planning resulted from comparing the frequency distribution of the Mahalanobis distance of the dead wolf locations with the percentage of study area within each distance class. This showed how the number of wolf casualties would greatly decrease with protection of only a minor part of the study area and indicated the usefulness of our approach for evaluation of other conservation options, such as core areas and corridor identification.Modelo de Larga Escala de la Distribución de Lobos en Italia para la Planeación de la Conservación Resumen: Los 400-500 lobos que viven en el rango Apennine de la Italia peninsular están recolonizando lentamente los Alpes y se espera que se muevan hacia el Norte. Se ha preparado un plan de manejo nacional para la población de lobos en Italia y se ha sugerido un sistema de zonación con corredores conectivos. Desarrollamos un modelo probabilístico de gran escala de la distribución de lobos como una contribución al proceso de planeación. Trece variables ambientales relacionadas con las necesidades de los lobos y la presencia de humanos fueron analizadas en 12 bien estudiados territorios de lobos y en 100 áreas donde la especie ha estado ausente en los últimos 25 años. Estas dos áreas fueron usadas como prueba en un ánálisis discriminante para evaluar el potencial de la presencia de lobos a lo largo de todo el país. Utilizamos la distancia estadística de Mahalanobis como un índice de calidad ambiental, calculada como la distancia de las condiciones ambientales medias de los territorios de lobos. En base a la distan...
Forcada, A., Valle, C., Sánchez-Lizaso, J. L., Bayle-Sempere, J. T., and Corsi, F. 2010. Structure and spatio-temporal dynamics of artisanal fisheries around a Mediterranean marine protected area. – ICES Journal of Marine Science, 67: 191–203. Marine protected areas (MPAs) have been proposed and established throughout the world, but few studies have adequately assessed the spatial adaptations of fishers to the limitations imposed by their placement. The main objectives of this work were to identify and describe the characteristics of the artisanal fisheries around Tabarca Marine Reserve (western Mediterranean Sea) and to define their activity in space and time. Data were collected through questionnaires to fishers and onboard sampling. The artisanal fisheries were complex owing to the multispecific nature of the landings, the variety of gears involved, and their marked seasonality. All boats of the three harbours around the MPA were assessed, for a total of 32 boats. The fishers exploit 18 fishing grounds with eight gear types, for a total of 17 métiers. Mullus trammelnet, Sepia trammelnet, and sparid longline are the most frequently used métiers. The main factors determining the spatial distribution of the fishing effort are proximity to home harbour, habitat heterogeneity, and closeness to the MPA. Total fishing effort appeared slightly concentrated around the MPA, but each métier showed different patterns of effort distribution. Although the sparid gillnet and the sparid longline concentrated along MPA boundaries, the Sepia trammelnet and the Mullus trammelnet did not.
Socioeconomic changes in many areas in the tropics have led to increasing urbanization, abandonment of agriculture, and forest re-growth. Although these patterns are well documented, few studies have examined the drivers leading to landscape-level forest recovery and the resulting spatial structure of secondary forests. Land cover transitions from agricultural lands to secondary forest in the island of Puerto Rico have been ongoing since the 1940s. This study is a glimpse into this landscape level trend from 1991 to 2000. First, we relied on Landsat images to characterize changes in the landscape structure for forest, urban, and agricultural land classes. We found that although forest cover has increased in this period, forest has become increasingly fragmented while the area of urban cover has spread faster and become more clustered. Second, we used logistic regression to assess the relationship between the transition to forest and 21 biophysical, socioeconomic, and landscape variables. We found that the percentage of forest cover within a 100 m radius of a point, distance to primary roads and nature reserves, slope, and aspect are the most important predictors of forest recovery. The resulting model predicts the spatial pattern of forest recovery with
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