RESUMO
As a landscape becomes increasingly fragmented through habitat loss, the individual patches become smaller and more isolated and thus less likely to sustain a local population. Metapopulation theory is appropriate for analyzing fragmented landscapes because it combines empirical landscape features with species-specific information to produce direct information on population extinction risks. This approach contrasts with descriptions of habitat fragments, which provide only indirect information on risk. Combining a spatially explicit metapopulation model with empirical data on endemic species' ranges and maps of habitat cover, we calculated the metapopulation capacity-a measure of a landscape's ability to sustain a metapopulation. Mangroves provide an ideal model landscape because they are of conservation concern and their patch boundaries are easily delineated. For 2000-20015, we calculated global metapopulation capacity for 99 metapopulations of 32 different bird species endemic to mangroves. Northern Australia and Southeast Asia had the highest richness of mangrove endemic birds. The Caribbean, Pacific coast of Central America, Madagascar, Borneo, and isolated patches in Southeast Asia in Myanmar and Malaysia had the highest metapopulation losses. Regions with the highest loss of habitat area were not necessarily those with the highest loss of metapopulation capacity. Often, it was not a matter of how much, but how the habitat was lost. Our method can be used by managers to evaluate and prioritize a landscape for metapopulation persistence.
Uso de la Teoría de Metapoblaciones para la Conservación Práctica de las Aves Endémicas de Manglares Resumen A medida que un paisaje se fragmenta cada vez más debido a la pérdida de hábitat, los parches se vuelven más pequeños y aislados y, por lo tanto, menos propensos a sostener a una población local. La teoría de metapoblaciones es adecuada para analizar paisajes fragmentados porque combina características empíricas del paisaje con información de cada especie para producir información directa sobre los riesgos de extinción de la población. Este enfoque contrasta con las descripciones de los fragmentos de hábitat que solo proporcionan información directa sobre el riesgo. Mediante la combinación de un modelo metapoblacional espacialmente explícito con datos empíricos de los rangos de distribución de especies endémicas y mapas de la cobertura del hábitat, calculamos la capacidad de la metapoblación - una medida de la capacidad del paisaje para sostener una metapoblación. Los manglares proporcionan un paisaje modelo ideal porque son de interés para la conservación y los límites de los parches son delineados fácilmente. Calculamos la capacidad de la metapoblación global para el período 2000-2015 de 99 metapoblaciones de 32 especies de aves endémicas de manglares. El norte de Australia y el sudeste de Asia tuvieron la mayor riqueza de aves endémicas de manglares. El Caribe, la costa del Pacífico de Centroamérica, Madagascar, Borneo y parches aislados en el sudeste de Asia en Myanmar y Malasia tuvieron las mayores pérdidas de metapoblaciones. Las regiones con mayor pérdida hábitat fueron necesariamente aquellas con mayor pérdida de capacidad de la metapoblación. A menudo no era una cuestión de cuánto, sino cómo se perdió el hábitat. Nuestro método se puede utilizar por manejadores para evaluar y priorizar un paisaje para la persistencia de la metapoblación.
Assuntos
Conservação dos Recursos Naturais , Modelos Biológicos , Animais , Austrália , Aves , Bornéu , Região do Caribe , América Central , Ecossistema , Madagáscar , Malásia , Mianmar , Dinâmica PopulacionalRESUMO
Central America is exceptionally rich in biodiversity, but varies widely in the attention its countries devote to conservation. Protected areas, widely considered the cornerstone of conservation, were not always created with the intent of conserving that biodiversity. We assessed how well the protected-area system of Central America includes the region's mammal diversity. This first required a refinement of existing range maps to reduce their extensive errors of commission (i.e., predicted presences in places where species do not occur). For this refinement, we used the ecological limits of each species to identify and remove unsuitable areas from the range. We then compared these maps with the locations of protected areas to measure the habitat protected for each of the region's 250 endemic mammals. The species most vulnerable to extinction-those with small ranges-were largely outside protected areas. Nevertheless, the most strictly protected areas tended toward areas with many small-ranged species. To improve the protection coverage of mammal diversity in the region, we identified a set of priority sites that would best complement the existing protected areas. Protecting these new sites would require a relatively small increase in the total area protected, but could greatly enhance mammal conservation.