Demography and Dispersal: Models for Biological Invasions

该项目将通过构建一个数学理论来描述种群在到达一个新区域后如何反应，从而开发和分析生物入侵的模型。 该理论将提供人口表现的衡量标准，可以补充那些习惯上用于衡量人口生存能力的标准（例如，增长率和灭绝概率）。该理论将结合人口统计学（即，个体从一个生命周期阶段移动到另一个生命周期阶段的速率）和扩散（即，迁移的倾向以及个体在生命周期的每个阶段迁移的方向和距离）。入侵是一个重要的问题。首先，入侵的有害物种对环境和经济造成巨大影响。这个问题不仅是农业方面的;来自入侵物种的压力对世界各地濒危的特有物种产生了重大影响。了解决定入侵成功和速度的因素可以为管理策略提供重要指导。其次，栖息地改变或气候变化的后果将是物种迁移到它们以前无法生存的地区。这是另一种形式的入侵，了解控制它的因素是了解气候变化影响的重要组成部分。从积极的方面来看，当保护工作取得成功时，以前从一个地区消失的物种会以同样的入侵机制所控制的速度扩大它们的范围。

This project will develop and analyze models of biological invasions by constructing a mathematical theory describing how populations respond upon arrival in a new area. That theory will provide measures of population performance that can complement those customarily used to measure population viability (e.g., rates of increase and extinction probabilities). The theory will incorporate both demography (i.e., the rates at which individuals move from one life cycle stage to another) and dispersal (i.e., the propensity to move and the directions and distances moved by individuals at each stage of the life cycle).Invasion is an important problem. First, invasive pest species have enormous environmental and economic impact. The problem is not only agricultural; pressures from invasive species are a major impact on endangered endemic species around the world. Understanding the factors determining the success and speed of invasions can provide important guidance for management tactics. Second, a consequence of habitat alteration or climate change will be the movement of species into areas where they previously could not survive. This is another form of invasion, and understanding the factors controlling it is an important part of understanding the effects of climate change. On a positive note, when conservation efforts are successful, species previously eliminated from an area expand their ranges at speeds governed by the same invasion mechanisms.