Linking Dispersal and Population Dynamics of White-footed Mice to Tree Seed Predation in Patchy Landscapes

9807115理查德·S.作者：Charles D. Canham，Felicia Keesing这项研究将把两个关键的生态过程联系起来，到目前为止，这两个过程一直被视为概念上不同的现象：移动的动物在斑块景观中的扩散动力学，以及种子消费者对森林景观中树木再生的影响。 主要目标是（1）确定白足鼠（Peromyscus leucopus）的种群是否在美国东北部的斑块，后农业景观中表现出源-库动态，以及（2）揭示小鼠传播模式（无论是源-库还是替代模型）对树木种子生存和最终森林再生的影响。 这将使动物扩散动力学与植物群落动力学联系起来。三种景观斑块类型将被研究：橡树为主的森林，枫树为主的森林，灌木和草本为主的老田。所有三种斑块类型都沿着沿着广泛的、尖锐的边缘彼此连接，并且小鼠占据所有三种斑块类型。假设栎类斑块在橡子-桅杆后年份支持源种群，在此期间，枫树和Oldfield斑块是汇，PI将：（1）测量斑块类型之间的净扩散方向：（2）使用死亡率和出生率的直接测量来估计每个斑块类型种群内的平均适合度;（3）在斑块类型（oldfield）中封闭种群并遵循生长轨迹。总之，这些方法将区分源-汇动态与替代模型。

9807115Richard S. Ostfeld, Charles D. Canham, Felicia KeesingThis research will link two key ecological processes that until now have been treated as conceptually distinct phenomena: dispersal dynamics of mobile animals in a patchy landscape, and the effects of seed consumers on tree regeneration in forested landscapes. The primary goals are to (1) determine whether populations of white-footed mice (Peromyscus leucopus) demonstrate source-sink dynamics in the patchy, postagricultural landscapes of northeastern U.S. and (2) reveal the consequences of dispersal patterns by mice (whether source-sink or an alternative model) for the survival of tree seeds and ultimately for forest regeneration. This will allow for linkage of animal dispersal dynamics with community dynamics of plants. Three landscape patch types will be studied: oak-dominated forests, maple-dominated forests, and shrub- and herb-dominated oldfields. All three patch types are connected to one another along extensive, sharp edges, and mice occupy all three patch types. It is hypothesized that oak patches support source populations in post-acorn-mast years, during which maple and oldfield patches are sinks and the PIs will: (1) measure the net direction of dispersal between patch types; (2) estimate the mean fitness within populations in each patch type, using direct measurements of mortality and natality; and (3) enclose populations and follow growth trajectories in the patch type (oldfield). Together, these approaches will distinguish source-sink dynamics from alternative models.