Impacts of anthropogenic disturbances on plant species diversity in fragmented landscapes

目前的生物多样性危机鼓励了关于改变景观对当地物种多样性的影响的研究。其中，生境丧失和碎片化已被证明改变了孤立生态系统的物种多样性，并促进了外来物种的入侵。在这些支离破碎的生境中，景观配置的空间成分已成功地与物种多样性的改良联系在一起。然而，目前的物种多样性可以更好地反映历史景观格局，这可能意味着孤立生境的物种组成进一步发生变化，而不会造成额外的生境丧失或碎片化。应该同时使用空间和时间尺度来预测栖息地丧失对当地物种多样性的真正影响。外来物种也被认为是本土物种减少的原因之一。然而，关于外来物种的研究大多集中在相关性上，关于外来物种真正影响的经验证据仍然薄弱。我的研究计划的长期目标是促进一般生态学理论的发展，预测人为干扰对碎片化景观中物种多样性的影响。本研究以湿地为研究对象，旨在1)测量现在和过去的景观配置对湿地植被的影响，2)通过实验评估湿地中干扰、外来入侵和本地物种衰退之间的因果联系。这一研究计划解决了植物生态学和生态系统管理之间的前沿问题。在生物多样性下降的世界里，解决植物多样性如何受到区域和当地过程的影响是一个令人严重关切的问题。

The current biological diversity crisis has encouraged research on the impact of transformed landscapes on local species diversity. Among others, habitat loss and fragmentation have been shown to modify species diversity of isolated ecosystems and to promote exotic species invasions. Spatial components of landscape configuration have been successfully associated with modified species diversity in these fragmented habitats. However, present-day species diversity could better reflect historical landscape configuration, which could imply further changes in species composition of isolated habitats without additional habitat loss or fragmentation. Both spatial and temporal scales should be used to predict the real impact of habitat loss on local species diversity. Exotic species have also been identified as a causing agent in native species decline. However, studies on exotic species have mostly focused on correlations and empirical evidences of the real impact of exotic species are still weak. The long term objective of my research program is to contribute to the development of general ecological theories predicting the impacts of anthropogenic disturbances on species diversity in fragmented landscapes. My research is focused on wetlands and intends 1) to measure the impact of present and past landscape configuration on wetland vegetation and 2) to assess experimentally the causal link between disturbances, exotic invasion, and native species decline in wetlands. This research program addresses crucial questions at the frontier between plant ecology and ecosystem management. In a world of declining biodiversity, addressing how plant diversity is influenced by both regional and local processes is of critical concern.