Doctoral Dissertation Research: Patterns of Species Composition and Stand Age: The Importance of Dispersal, Species Interactions, and Habitat Preference

博士论文研究：物种组成和林龄的模式：扩散、物种相互作用和栖息地偏好的重要性

• 批准号: 0117207
• 负责人: Susan Beatty
• 金额: $ 0.99万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-15 至 2003-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0117207&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Patterns; Species

The plant species composition of deciduous forest communities varies considerably from place to place. It is not fully understood what determines whether or not a given plant will be located in a given area. Plants are sometimes limited to specific areas because of their inability to tolerate certain environmental conditions, which may be the result of differences in the soil where they grow or the result of changes brought about by other plants or trees already growing at a site. Elsewhere, plants may be limited by their ability to get seeds or other reproductive material to a new site. This doctoral dissertation research project will examine the role that plant dispersal and forest age have in determining spatial pattern in the herbaceous vegetation located underneath the canopy trees in the hardwood-hemlock forest of the Edmund Niles Huyck Preserve in central New York State. The Huyck Preserve provides the opportunity to study forest change over the last 150 years, because most of the area of the preserve was logged sometime during that time period, thereby providing a mosaic of forest types of varying age. The goals of this project are to determine if the type of dispersal a plant uses is related to whether or not it is present in a forest stand of a certain age and to determine if the likelihood of a species being contained in an area is dependent on that species being present in a nearby area. These relationships will be determined by examining the vegetation and the age of 30 to 40 forest stands of the Huyck Preserve. The locations of these stands will be specificed along with their distances from each other. The plant species located in these areas will be grouped by the type of dispersal they use to propogate themselves (wind, animal, gravity, etc.) as well as patterns associated with the age of forest stands. Among the hypotheses that will be explored is whether species using rapid, long-distance dispersal will appear in younger areas before species using slower, more geographically restricted modes of dispersal. Species composition in each area will be compared with species composition in adjacent areas. A hypothesis to be tested in this facet of the project is whether the species composition of an area is dependent on the species composition of other areas. This dependency may also be influenced by physical factors like wind or slope direction, as there may be greater concentration of species in areas located immediately downwind or downslope from established species. These results should help to clarify role that dispersal plays in determination of species composition patterns.This research will help advance understanding of the role plant dispersal plays in determining which species live where. This will complement what already is known about other factors that influence where plants live, such as how plants interact with the environment and how they interact with other plant species. This type of knowledge is necessary in a conservation context, because knowing the processes that maintain species diversity will help design plans for preservation of species, communities, and ecosystems. Land managers must know which processes increase or decrease species diversity on their lands before they can make informed decisions about the types of actions that should be taken to best preserve them or restore habitat. Understanding which processes are necessary to preserve maximum diversity can lead to more informed decisions about assigning protection priorities to various areas in scenarios involving limited monetary resources. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.

落叶林群落的植物物种组成因地而异。 目前尚不完全清楚是什么决定了特定工厂是否位于特定区域。 植物有时被限制在特定的区域，因为它们无法忍受某些环境条件，这可能是它们生长的土壤差异的结果，或者是某个地点已经生长的其他植物或树木带来的变化的结果。 在其他地方，植物将种子或其他繁殖材料带到新地点的能力可能会受到限制。 该博士论文研究项目将研究植物传播和森林年龄在确定纽约州中部埃德蒙·奈尔斯·赫伊克保护区阔叶铁杉林冠层树下草本植被空间格局中的作用。 Huyck 保护区提供了研究过去 150 年来森林变化的机会，因为保护区的大部分面积都在该时期的某个时间被砍伐，从而提供了不同年龄的森林类型的镶嵌图。 该项目的目标是确定植物使用的传播类型是否与它是否存在于一定年龄的林分中有关，并确定某个物种包含在某个区域的可能性是否取决于该物种存在于附近区域。 这些关系将通过检查 Huyck 保护区的植被和 30 至 40 个林分的年龄来确定。 这些展位的位置及其相互之间的距离将被指定。 位于这些地区的植物物种将根据它们用于繁殖的传播类型（风、动物、重力等）以及与林分年龄相关的模式进行分组。 将探讨的假设之一是，使用快速、长距离扩散的物种是否会先于使用较慢、地理上更受地理限制的扩散方式的物种出现在较年轻的地区。 每个区域的物种组成将与邻近区域的物种组成进行比较。 该项目这方面要检验的假设是一个地区的物种组成是否依赖于其他地区的物种组成。 这种依赖性也可能受到风向或坡向等物理因素的影响，因为在紧邻已建立物种的顺风或下坡区域，物种可能会更加集中。 这些结果应有助于阐明扩散在确定物种组成模式中所起的作用。这项研究将有助于加深对植物扩散在确定物种生活地点中所起的作用的理解。 这将补充已知的影响植物生活地点的其他因素，例如植物如何与环境相互作用以及它们如何与其他植物物种相互作用。 此类知识在保护环境中是必要的，因为了解维持物种多样性的过程将有助于设计保护物种、群落和生态系统的计划。 土地管理者必须知道哪些过程会增加或减少其土地上的物种多样性，然后才能就应采取的最佳保护或恢复栖息地的行动类型做出明智的决定。 了解哪些流程对于保持最大程度的多样性是必要的，可以在涉及有限货币资源的情况下做出更明智的决策，将保护优先级分配给各个领域。 作为博士论文研究改进奖，该奖项还将为有前途的学生建立强大的独立研究生涯提供支持。