Disturbance and Environmental Variability Effects on Plant Colonization and Establishment

生态学家、生物地理学家和其他科学家最近对影响不同类型地点内生物多样性的形式和程度的因素的研究给予了相当大的关注。在深入研究的因素中，包括各种自然和人为干扰(如火灾或洪水)的影响，以及植物群落和动物群对一般环境条件变化(如温度或降水变化)的反应。然而，相对较少的研究致力于这些一般因素之间的相互作用。该项目将重点描述和分析纽约州北部Huyck保护区的混合落叶森林生态系统中的植被变化。该项目将重点回答两个问题：(1)干扰在决定森林和老农田群落的物种组成和丰富度方面起到什么作用？以及(2)林下森林植被物候和空间种群动态与年内和年间的环境变异性有什么关系？这些问题将使用通过各种手段收集的数据来回答，包括植被普查和测绘、树木年轮测量、植被空隙测量、土壤样本测试以及控制环境变量以复制不同气候制度的实验。该项目将提供关于不同形式的干扰和不同类型的环境变化如何影响温带混合落叶生态系统中不同物种的数量、形式和位置的新信息和新见解。由于对这两个一般因素的分析将同时进行，该项目还将加强对干扰和影响植被的不同形式的环境变化之间的相互作用的了解。因此，该项目的结论将有助于增加对植物群落内部和之间的精细动态的了解，并将推动开发更全面的区域和全球模式，将自然变化与人类和身体活动联系起来。

Ecologists, biogeographers, and other scientists recently have devoted considerable attention to the study of factors that influence the form and extent of biological diversity within various types of locales. Among the factors that have been studied intensively are the impacts of various types of natural and human- induced disturbances (like fires or floods) and the response of vegetative and faunal communities to changes in general environmental conditions (like changes in temperature or precipitation). Relatively little research has been devoted to interactions between these general factors, however. This project will focus on description and analysis of vegetation change in the mixed deciduous forest ecosystems of the Huyck Preserve in upstate New York. The project will focus on answering two questions: (1) What role does disturbance play in determining the species composition and richness of forest and old field communities? and (2) What responses in understory forest-vegetation phenology and spatial population dynamics can be related to environmental variability within and between years? These questions will be answered using data gathered through a variety of means, including vegetation censuses and mapping, tree-ring measurements, measurement of vegetation gaps, testing of soil samples, and experiments in which environmental variables are controlled to replicate different climatic regimes. This project will provide new information about and new insights into the ways that different forms of disturbance and different types of environmental change affect the number, form, and location of different species in temperate mixed deciduous ecosystems. Because analyses of these two general factors will be conducted simultaneously, the project will also enhance understandings of interactions among disturbances and different forms of environmental variability as they affect vegetation. The conclusions of this project therefore will contribute to increased knowledge of the fine-scale dynamics within and between vegetative communities, and they also will advance the development of more comprehensive regional and global models that relate natural change to human and physical activities.