Anthropogenic climate change has emerged as a critical environmental problem, prompting frequent investigations into its consequences for various ecological systems. Few studies, however, have explored the effect of climate change on ecological stability and the underlying mechanisms. We conduct a field experiment to assess the influence of warming and altered precipitation on the temporal stability of plant community biomass in an alpine grassland located on the Tibetan Plateau. We find that whereas precipitation alteration does not influence biomass temporal stability, warming lowers stability through reducing the degree of species asynchrony. Importantly, biomass temporal stability is not influenced by plant species diversity, but is largely determined by the temporal stability of dominant species and asynchronous population dynamics among the coexisting species. Our findings suggest that ongoing and future climate change may alter stability properties of ecological communities, potentially hindering their ability to provide ecosystem services for humanity.

Massive seawall construction in coastal wetlands threatens biodiversity

The loss and degradation of wetlands worldwide has adversely affected waterbirds, which depend on wetland habitats. Many studies have indicated that effectively managed wetlands can provide alternative or complementary habitats for waterbirds and mitigate the adverse effects of wetland loss and degradation. We review the studies on the habitat variables affecting use of wetlands by waterbirds, and we suggest how wetlands can be managed to provide waterbird habitat. These habitat variables include water depth, water level fluctuation, vegetation, salinity, topography, food type, food accessibility, wetland size, and wetland connectivity. Overall, the practice of wetland management requires integrated knowledge related to the entire wetland ecosystem, and ecosystem-based approach is needed to improve the habitat quality of managed wetlands with considering multiple spatial scales, temporal variability, and trade-off among diverse habitat requirements of different waterbirds. Several priorities for future research and management are also suggested in this paper.

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This article uses tabulations from the 2000 Population Census of China along with a micro-level data sample from the census to provide a picture of China's floating population: migrants without local household registration ("hukou"), a status resulting in significant social and economic disadvantages. By 2000, the size of China's floating population had grown to nearly 79 million, if that category is defined as migrants who moved between provinces or counties and resided at their destinations for six months or more. Intra-county floating migration is similarly large, contributing another 66 million to the size of the floating population. The article also discusses the geographic pattern of the floating population and the reasons for moving as reported by migrants. Policy implications are noted. Copyright 2004 The Population Council, Inc..