Suchergebnisse

Our species has transitioned from being one among millions on Earth to the species that is single-handedly transforming the entire planet to suit its own needs. In order to meet the daunting challenges of environmental sustainability in this epoch of human domination - known as the Anthropocene - ecologists have begun to think differently about the interdependencies between humans and the natural world. This work provides the best available introduction to what this new ecology is all about - and why it matters more than ever before

National parks and bioreserves are key conservation tools used to protect species and their habitats within the confines of fixed political boundaries. This inflexibility may be their "Achilles' heel" as conservation tools in the face of emerging global-scale environmental problems such as climate change. Global climate change, brought about by rising levels of greenhouse gases, threatens to alter the geographic distribution of many habitats and their component species. With these changes comes great uncertainty about the future ability of parks and protected areas to meet their conservation mandates. We report here on an analysis aimed at assessing the extent of mammalian species turnover that may be experienced in eight selected U.S. national parks if climate change causes mammalian species within the continental U.S. to relocate to new geographic locations. Due to species losses of up to 20% and drastic influxes of new species, national parks are not likely to meet their mandate of protecting current biodiversity within park boundaries. This approach represents a conservative prognosis. As species assemblages change, new interactions between species may lead to less predictable indirect effects of climate change, increasing the toll beyond that found in this study.

This paper uses a quantitative dynamic ecosystem vegetation model to explore the potential impact of warming up to 9-12 degrees C on global ecosystems. The paper does not find evidence of a global collapse in terrestrial ecosystems but there is evidence of substantial changes. Temperate and tropical forests expand and replace boreal forests and forests shift to woodlands and parkland at high temperatures. Net primary productivity and standing forest biomass per hectare rise. These changes will affect dependent animal species. Further research is needed to measure the resulting benefits and damages to market and nonmarket services.