Scheffer Marten, Szabo Sandor, Gragnani Alessandra, Van Nes Egbert H, Rinaldi Sergio, Kautsky Nils, Norberg Jon, Roijackers Rudi M M, Franken Rob J M
Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University, P.O. Box 8080, 6700 DD, Wageningen, The Netherlands.
Proc Natl Acad Sci U S A. 2003 Apr 1;100(7):4040-5. doi: 10.1073/pnas.0737918100. Epub 2003 Mar 12.
Invasion by mats of free-floating plants is among the most important threats to the functioning and biodiversity of freshwater ecosystems ranging from temperate ponds and ditches to tropical lakes. Dark, anoxic conditions under thick floating-plant cover leave little opportunity for animal or plant life, and they can have large negative impacts on fisheries and navigation in tropical lakes. Here, we demonstrate that floating-plant dominance can be a self-stabilizing ecosystem state, which may explain its notorious persistence in many situations. Our results, based on experiments, field data, and models, represent evidence for alternative domains of attraction in ecosystems. An implication of our findings is that nutrient enrichment reduces the resilience of freshwater systems against a shift to floating-plant dominance. On the other hand, our results also suggest that a single drastic harvest of floating plants can induce a permanent shift to an alternative state dominated by rooted, submerged growth forms.
从温带的池塘和沟渠到热带湖泊，自由漂浮植物席的入侵是淡水生态系统功能和生物多样性面临的最重要威胁之一。厚厚的漂浮植物覆盖下的黑暗、缺氧环境几乎没有动植物生存的机会，并且会对热带湖泊的渔业和航行产生重大负面影响。在这里，我们证明了漂浮植物占主导地位可能是一种自我稳定的生态系统状态，这或许可以解释其在许多情况下声名狼藉的持久性。我们基于实验、实地数据和模型得出的结果，为生态系统中吸引子的替代域提供了证据。我们研究结果的一个含义是，营养物质富集降低了淡水系统抵御向漂浮植物占主导地位转变的恢复力。另一方面，我们的结果还表明，对漂浮植物进行一次大规模采收可以促使其永久性地转变为以扎根的、沉水生长形式为主导的替代状态。
