LTREB: Long-Term Studies of Population and Community Ecology in an Experimentally Fragmented Landscape

0076064理解斑块和空间动态的含义是生态学中许多问题的基础，包括许多应用问题。生境破碎化是全球变化的一个主要特征，这一点尤其如此。栖息地破碎化的长期实验正在进行中的草原-森林交错带东部堪萨斯旨在研究破碎化的影响，二次演替，广义上定义为包括关键的消费群体，以及植物动态。实验的物理布局（始于1984年）是一个大的修剪过的领域栖息地补丁群岛。在该项目的第一阶段，小哺乳动物的分布有显着的斑块大小的影响，但没有斑块大小对演替的整体效果。到1993年，木本植物的殖民化开始加速。据推测，这将导致斑块大小的影响。这一假设已被证实：对木本植被的演替率增加斑块的大小和减少与林地源池的距离。在小型哺乳动物群落中也出现了相应的演替和空间转移，小型哺乳动物已被证明对木本幼苗造成相当大的损害。1998年，偶然出现了17年一次的周期性蝉，造成了很高的损害，大面积的损害更大。将继续监测植物和小型哺乳动物的动态，以确定斑块大小和距离对演替轨迹的影响的持久性。由于大量的个别标记的木本取样存在，木本物种的演替的人口后果的特点，包括潜在的影响，树苗人口的出现事件。这个项目是独一无二的，因为没有实验研究存在的斑块大小对植物和动物动态的影响进行了测量。

0076064HoltUnderstanding the implications of patchiness and spatial dynamics is fundamental to many issues in ecology, including many applied problems. This is particularly true of habitat fragmentation, which is a dominant feature of global change. A long-term experiment on habitat fragmentation is underway in the prairie-forest ecotone of eastern Kansas aimed at examining the impact of fragmentation on secondary succession, defined broadly to include key consumer groups, as well as plant dynamics. The physical layout of the experiment (initiated in 1984) is an archipelago of habitat patches in a large mown field. During the first phases of the project, there wre dramatic patch size effects on the distribution of small mammals, but no overall effect of patch size on succession. By 1993, colonization of woody plants was beginning to accelerate. It was hypothesized that this would lead to patch size effects on succession. This hypothesis has been borne out: the rate of succession towards woody vegetation has increased with patch size and decreased with distance from woodland source pools. There has been corresponding succession and spatial shifts in the small mammal community, and small mammals have been shown to inflict considerable damage on woody seedlings. In 1998 there was a serendipitous emergence of 17-year periodical cicadas, which imposed high levels of damage, with more damage in large patches. Monitoring of plant and small mammal dynamics will continue to determine the persistence of patch size and distance effects on successional trajectories. Because a large number of individually marked woody samplings exists, the demographic consequences of succession on woody species can be characterized, including the potential impact of the cicada emergence event on sapling demography. This project is unique in that no experimental studies of succession exist in which patch size effects on plant and animal dynamics have been measured.