Alternative Stable States on Rocky Intertidal Shores

9529564彼得雷蒂斯本提案的目标是确定维持缅因湾藻类林和贻贝和藤壶的生态机制，使之成为独特的、自给自足的群落。贻贝、藤壶和大型藻类是受保护的海湾岩石潮间带海岸上最常见的物种。作为海岸沿线自然群落的主要结构组成部分，这些物种是许多鱼类和无脊椎动物的家园。岩藻林立，贻贝和藤壶林立，尽管它们在海岸上的位置非常相似，但它们是不同的，很少重叠。目前认为，在捕食、竞争和补充等生态过程中，当地特定地点的差异控制着这两个群落的物种组成。这项研究项目将检验这样一种观点，即藻类林和贻贝-藤壶床的起源是历史事件，一旦建立，两个独特的群落都由各自内部的正反馈机制维持。因此，地方特定地点的差异是正反馈的结果，而不是社区差异的原因。在生态学中，这一观点通常被称为“另类稳定状态”。该项目将是这一想法在沿海海洋生态系统中的第一次大规模试验。

9529564 Petraitis The goal of this proposal is to determine the ecological mechanisms that maintain stands of algae and beds of mussels and barnacles in the Gulf of Maine as distinct, self-sustaining communities. Mussels, barnacles, and macroalgae are the most common species on the rocky intertidal shores of sheltered bays. As the major structural components of the natural communities that line the shore, these species are the home for many species of fish and invertebrates. Stands of rockweed and beds of mussels and barnacles are distinct and rarely overlap even though they occupy very similar places on the shore. Currently, it is thought that local site-specific differences in ecological processes such as predation, competition, and recruitment, control the species composition of these two communities. This research project will test the idea that the origins of algal stands and mussel-barnacle beds are historical events and that once established, the two distinctive communities are maintained by positive-feedback mechanisms within each. Thus local site- specific differences are the result of positive-feedbacks and not the cause of community differences. In ecology, this idea is generally known as "alternative stable states." This project will be the first large-scale test of this idea in a coastal marine ecosystem.