Alternative Stable States
Alternative Stable States
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DOI：
10.1007/0-387-21613-8_12
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发表时间：
2020-11
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影响因子：
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通讯作者：
Garry D. Peterson
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文献类型：
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作者：
Garry D. Peterson
结论本实验室研究的模型展示了生态系统如何以替代稳定状态存在，以及当从一个站点移动到整个景观时，替代稳定状态的动态如何变化。在这个例子中，一个网站可以持续作为一个年轻的，经常被烧毁的网站（主要是长叶松）或一个老的，很少被烧毁的网站（主要是橡树）。然而，有趣的是，当一个特定的地点被置于其景观的背景下时，该地点的动态发生了变化，而一个地点的动态在很大程度上取决于它所处的特定景观背景。此外，任何一个地点的动态都与整个景观的动态大不相同。当站点被组合在一起形成景观时，站点倾向于将其相邻站点推向其特定状态，从而减少了可持续替代稳定状态的系统参数范围。在北方佛罗里达的森林中，火蔓延的能力，以及因此硬木或松树的生长或萎缩的速度，受到硬木和松树在整个景观中的格局的影响。空间异质性和正反馈的结合使得森林的动态很难从当地的研究中预测，因为控制一个站点的过程可能会受到其邻居的属性的影响。然而，使用模型可以检查如何配置的栖息地在整个景观可以影响景观在面对干扰的恢复力。此外，虽然本实验中使用的模型是基于北方佛罗里达的森林动态，但许多生态系统表现出替代的稳定状态（都柏林等人，1990;诺尔顿，1992; Scheffer等人，1993年）。这些生态系统的动态可以使用类似的模型和技术进行分析。
ConclusionsThe models investigated in this lab demonstrate how an ecological system can exist in alternative stable states and how the dynamics of alternative stable states change when moving from a site to an entire landscape. In this exam-ple, a site could persist as either a young, frequently burned site (dominated by longleaf pine) or an old, infrequently burned site (dominated by oaks). In-terestingly, however, the dynamics of a particular site changed when the site was placed within the context of its landscape, and the dynamics of a site greatly depended on thespecificlandscape context in which it was placed. Also, the dynamics of any single site were quite different from those of the entire landscape. When sites were grouped together to create a landscape, a site tended to push its neighboring sites toward its own particular state, re-ducing the range of system parameters for which alternative stable states could persist. In the forests of northern Florida, the ability of fire to spread, and conse-quently the rate at which patches of hardwood or pine either grow or shrink, is influenced by the pattern of hardwoods and pine across the landscape. The combination of spatial heterogeneity and positive feedbacks makes the dy-namics of forests difficult to predict from the study of a local site, since the processes that control a site can be affected by the properties of its neighbors. However, the use of models allows one to examine how the configuration of habitats across a landscape can affect the resilience of landscapes in the face of disturbance. Furthermore, while the models used in this lab are based on the forest dynamics of northern Florida, many ecosystems exhibit alternative stable states (Dublin et al., 1990; Knowlton, 1992; Scheffer et al., 1993). The dynamics of these ecosystems can be analyzed using similar models and techniques.