Assessment of Community Size Structure in Adjacent Habitats: An Exploratory Experimental Study of the Benthic-Pelagic System

9528840 Threlkeld植物和动物群落经常受到来自邻近生境的物质流动或生物运动的影响，尽管对邻近群落的影响程度尚不清楚。在水生系统中，这些邻域影响通过水循环、沉积、再悬浮或主要食用者或猎物物种的生活史运动来调节。虽然自然群落中生物的大小频率分布已被用于了解单个群落的营养相互作用，但拟议的研究将调查相邻生境中大小结构变化的相互关联程度，这可能表明重要的生境间联系。拟议的研究将使用28个池塘的实验，通过评估实验引起的一个栖息地的大小结构变化是否会导致邻近栖息地的相似或互补的群落大小结构变化，来检查底部和开放水域栖息地的群落之间的联系。已知影响两个栖息地之一的生物量和颗粒磷大小分布的各种营养和消费者处理组合将用于测量相邻栖息地的群落如何相互联系。由于异质性在生境的空间安排中很常见，因此，组织一个生境的群落的过程可能会影响邻近生境的群落，甚至超出了经常存在并有充分记录的边缘效应。该池塘实验是第一个直接评估一个栖息地的大小结构变化是否与邻近栖息地的大小结构变化相关以及在多大程度上相关的水生研究，为水生系统的群落联系提供了证据，并为评估其他系统的景观水平格局提供了一种手段。

9528840 Threlkeld Plant and animal communities are often influenced by material flows or organism movements from adjacent habitats, although the extent of influence on neighboring communities is poorly known. In aquatic systems, these neighborhood influences are mediated through water circulation, sedimentation, resuspension, or the life history movements of key consumer or prey species. Although the size frequency distribution of organisms in natural communities has been used to understand trophic interactions in individual communities, the proposed research will investigate the extent to which size structure changes in adjacent habitats are related to each other, which might suggest important inter-habitat linkages. The proposed research will use a 28-pond experiment to examine the link between communities in bottom and open water habitats by evaluating if experimentally-induced changes in size structure in one habitat result in similar or complementary community size structure changes in the adjacent habitat. A broad array of nutrient and consumer treatment combinations known to influence size distributions of biomass and particulate phosphorus in one of the two habitats will be used to measure how communities in adjacent habitats are linked. Because heterogeneity is common in the spatial arrangement of habitats, it follows that processes organizing the community of one habitat may influence those of adjacent habitats, even beyond edge effects which are often present and well documented. The proposed pond experiment is the first aquatic study to evaluate directly if and to what extent size structure changes in one habitat are related to those in adjacent habitats, providing evidence of community linkage in aquatic systems and a means for evaluating landscape level patterns in other systems.