How Landscape Connectivity and Heterogeneity Affect Wind Dispersal

生物的扩散，即生物体、其繁殖体或其基因远离其源头的运动，是一个极其重要的过程，随着生境丧失和片断化等人类活动改变了生物的景观和运动路径，这一过程在生态学和保护生物学中日益受到重视。空气和水的流动以及景观的结构模式可以相互作用，影响被动生物如孢子、花粉、种子、幼虫和昆虫的传播轨迹。对于风散种子，风速是决定散布距离的最重要因素，而风速可以通过景观结构来改变散布距离。因此，人类引起的当地景观结构的变化(例如，生境碎片化)可能会导致物理流动和扩散轨迹的变化。了解景观结构异质性如何改变栖息地的空间分布及其如何影响动态流动，对于理解和预测人类诱导的景观变化如何影响被动扩散的繁殖体的扩散至关重要。这位研究人员建议使用南卡罗来纳州萨凡纳河遗址的受控实验景观来测试景观结构异质性如何改变散布在风中的种子的轨迹。将对连通性和斑块形状不同的斑块中的风动态进行量化，并将其用于预测种子风传播的模型。然后将对该模型进行实验验证。这项研究将帮助保护生物学家为正在经历全球变化的异质景观中的植物确定适当的保护行动，包括栖息地碎片化和气候变化。

Dispersal, or the movement of organisms, their propagules, or their genes away from their source, is a critically important process and is increasingly receiving attention in ecology and conservation biology as landscapes and the movement pathways of organisms are altered by human activities such as habitat loss and fragmentation. The flow of air and water and the structural pattern of the landscape can interact to affect the dispersal trajectory of passive organisms like spores, pollen, seeds, larvae, and insects. For wind-dispersed seeds, wind velocity is the most important determinant of dispersal distance, which can be altered by landscape structure. Therefore, human-induced changes in local landscape structure (e.g., by habitat fragmentation) may lead to shifts in physical flows and dispersal trajectories. Understanding how landscape structural heterogeneity alters both the spatial distribution of habitat and how it affects dynamic flows will be critical for understanding and predicting how human-induced landscape changes affect the dispersal of passively-dispersed propagules. The investigator proposes to test how landscape structural heterogeneity alters the trajectory of wind-dispersed seeds using a controlled experimental landscape at the Savannah River Site in South Carolina. Wind dynamics in patches that differ in their connectivity and patch shape will be quantified and used to parameterize a model predicting the wind-dispersal of seeds. This model will then be experimentally validated. The research will help conservation biologists determine appropriate conservation actions for plants in heterogeneous landscapes undergoing global change, including habitat fragmentation and climate change.