Edge dynamics in the cold-temperate deciduous forest of eastern Canada

边缘的特点往往是进程的速率与相邻生态系统的典型速率不同：速率较高-动力增强;速率较低-动力减弱。可以确定三种类型的边缘：一个开放的边缘是一个最近形成的边缘沿着森林结构尚未发生变化;一个边缘关闭随着时间的推移，树木接壤的边缘产生一个密集的树冠和灌木林下产生一个密集的树叶;嵌入的边缘随着时间的推移，灌木和树木物种被招募到相邻的老领域在逐步更大的距离。因为边缘在其性质上不同，所以跨边缘的处理速率的差异可能或多或少是明显的。在这个提议中，我想确定边缘类型如何影响森林和非森林植物物种的人口统计过程。我的一般假设是，边缘对人口过程的影响取决于边缘的性质：我认为，开放的边缘是那些人口过程的差异是最显着的，差异随着边缘变得封闭或嵌入时间而减少。我还建议，在不同的林下功能组，春季开花短命物种是那些受边缘类型，空间对比沿着边缘的主要环境变量在春季比夏季更温和的影响较小。由于环境异质性通常是更大的边缘比在“内部”的任何相邻的生态系统，边缘代表理想的系统来测试的多样性生产关系与环境异质性。由于开放、封闭和嵌入边缘的特征不同，可以使用不同类型的边缘来检验环境异质性对多样性-生产关系的重要性。我认为，开放的边缘是那些跨环境异质性较高，与更大的影响，对多样性生产关系。这项研究具有重要的保护意义，因为边缘附近的种群动态变化可能会导致高度分散的景观灭绝的风险更大。

Edges are often characterized by processes with rates that differ from those typical of either type of adjacent ecosystems: higher rates - hyperdynamism; lower rates - hypodynamism. Three types of edge can be identified: an open edge is a recently-formed edge along which no change in forest structure has yet occurred; an edge closes with time as trees bordering the edge produce a denser canopy and as the shrub understory produces a denser foliage; an embedded edge develops with time as shrub and tree species are recruited at progressively greater distances into the adjacent old-field. Because edges differ in their nature, differences in process rates across edges may be more or less apparent. In this proposal, I want to determine how edge type affects the demographic processes of both forest and non-forest plant species. My general hypothesis is that edge effects on population processes depend on the nature of the edge: I suggest that open edges are those where differences in the rates of demographic processes are most significant, differences decreasing as edges become closed or embedded with time. I also propose that, among the different understory functional groups, spring-flowering ephemeral species are those that are less affected by edge type, spatial contrasts along edges in major environmental variables being more moderate in spring than in summer. Because environmental heterogeneity is typically greater across edges than in the 'interior' of either adjacent ecosystem, edges represent ideal systems to test the diversity-production relationship with regard to environmental heterogeneity. As open, closed and embedded edges differ in their characteristics, the significance of environmental heterogeneity for the diversity-production relationship can be tested using different types of edge. I suggest that open edges are those across which environmental heterogeneity is higher, with greater effects on the diversity-production relationship. This research has significant conservation implications as altered population dynamics near edges may lead to greater risks of extinction in highly fragmented landscapes.