D'Odorico Paolo, Laio Francesco, Ridolfi Luca
Department of Environmental Sciences, Box 400123, University of Virginia, 291 McCormick Road, Charlottesville, VA 22903, USA.
Proc Natl Acad Sci U S A. 2005 Aug 2;102(31):10819-22. doi: 10.1073/pnas.0502884102. Epub 2005 Jul 25.
Dryland plant ecosystems tend to exhibit bistable dynamics with two preferential configurations of bare and vegetated soils. Climate fluctuations are usually believed to act as a source of disturbance on these ecosystems and to reduce their stability and resilience. In contrast, this work shows that random interannual fluctuations of precipitation may lead to the emergence of an intermediate statistically stable condition between the two stable states of the deterministic dynamics of vegetation. As a result, there is an enhancement of ecosystem resilience and a decrease in the likelihood of catastrophic shifts to the desert state.
旱地植物生态系统往往表现出双稳态动态，具有裸露土壤和植被覆盖土壤两种优先配置。通常认为气候波动是这些生态系统的干扰源，并会降低其稳定性和恢复力。相比之下，这项研究表明，降水的随机年际波动可能导致植被确定性动态的两个稳定状态之间出现一种统计上稳定的中间状态。因此，生态系统的恢复力增强，向沙漠状态发生灾难性转变的可能性降低。
