REU: Patch Size, Herbivory, and Secondary Succession: An Experimental Study

旧生境次生演替的研究主要强调生活史策略和种间竞争的因果作用。然而，演替的速率或模式可能受到正在演替和草食的面积大小的影响。鉴于草食是重要的，草食的强度也应该随着演替斑块的大小而系统地变化。将测试一个概念模型，该模型预测在殖民和竞争能力之间的权衡下，小块地的演替应该更慢，哺乳动物食草动物在小块地的数量和多样性应该更少，并且偏向于小体物种。这项实验研究将在堪萨斯州东部的一个连续斑块群岛上进行。这些斑块的面积跨越两个数量级，并通过定期修剪保持隔离。将记录植物和小型哺乳动物的移民、人口增长或下降、空间格局和物种更替。小型哺乳动物对植物演替的影响将通过封闭来衡量。斑块大小也可能通过对资源可用性的影响间接影响植物和动物的演替（例如，小斑块相对更容易暴露于风中，可能比大斑块更干燥）。将监测系统中水和氮的可用性。

The study of secondary succession in old fields has largely emphasized the causal role of life history strategies and interspecific competition. Yet the rate or pattern of succession may be influenced by the size of the area undergoing succession and herbivory. Given that herbivory is important, the intensity of herbivory should also vary systematically with successional patch size. A conceptual model will be tested which predicts that given a trade-off between colonizing and competitive abilities, succession should be slower on small patches and that mammal herbivores should be less abundant and diverse on small patches, and biased toward small-bodied species. The experimental study will use an archipelago of successional patches in eastern Kansas. The patches span two orders of magnitude in area and are kept isolated through regular mowing. Immigration, population growth or decline, spatial patterns, and species turnover for plants and small mammals will be documented. The effects of small mammals on plant succession will be gauged using exclosures. Patch size may also indirectly affect plant and animal succession through effects on resource availability (e.g., small patches are relatively more wind-exposed and may be drier than large patches). The availability of water and nitrogen in the system will be monitored.