Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544, USA.
Proc Natl Acad Sci U S A. 2013 Apr 16;110(16):6296-300. doi: 10.1073/pnas.1302558110. Epub 2013 Apr 1.
The increasing pressure of climatic change and anthropogenic activities is predicted to have major effects on ecosystems around the world. With their fragility and sensitivity to hydrologic shifts and land-use changes, wetlands are among the most vulnerable of such ecosystems. Focusing on the Everglades National Park, we here assess the impact of changes in the hydrologic regime, as well as habitat loss, on the spatial configuration of vegetation species. Because the current structuring of vegetation clusters in the Everglades exhibits power-law behavior and such behavior is often associated with self-organization and dynamics occurring near critical transition points, the quantification and prediction of the impact of those changes on the ecosystem is deemed of paramount importance. We implement a robust model able to identify the main hydrologic and local drivers of the vegetation species spatial structuring and apply it for quantitative assessment. We find that shifts in the hydropatterns will mostly affect the relative abundance of species that currently colonize specific hydroperiod niches. Habitat loss or disruption, however, would have a massive impact on all plant communities, which are found to exhibit clear threshold behaviors when a given percentage of habitable habitat is lost.
气候变化和人为活动的压力不断增加，预计将对全球各地的生态系统产生重大影响。湿地因其脆弱性以及对水文变化和土地利用变化的敏感性，成为最易受影响的生态系统之一。本文以大沼泽地国家公园为例，评估了水文状况变化以及生境丧失对植被物种空间配置的影响。由于大沼泽地目前的植被群集结构呈现出幂律行为，而这种行为通常与自组织和临界点附近的动力学有关，因此量化和预测这些变化对生态系统的影响被认为至关重要。我们实施了一个强大的模型，能够识别植被物种空间结构的主要水文和局部驱动因素，并将其应用于定量评估。我们发现，水模式的转变将主要影响目前占据特定水文期小生境的物种的相对丰度。然而，生境丧失或破坏将对所有植物群落产生巨大影响，当丧失一定比例的可居住生境时，所有植物群落都表现出明显的阈值行为。
