| 英文摘要: | Global changes to natural communities are threatening biodiversity and ecosystem structure worldwide. Large numbers of species are transported globally through international trade and human traffic. Non-native species invade myriad habitats that include natural areas, agricultural landscapes, and timber forests, altering natural ecological communities, reducing ecosystem services, and causing economic losses that are estimated at up to billions of dollars annually. Damages and costs increase further as invasive species spread across larger regions. Understanding the conditions that facilitate and prevent range expansion are critical to both predicting the spread of invasive species and informing species conservation efforts. At species range edges, natural and human-assisted movement interplay with local population dynamics in complex ways to determine spread dynamics. This project centers on a fundamental question: What are the drivers of species range expansion and how do multiple processes interact to shape invasion patterns? Researchers will address this question by studying the invasion pattern of an infamous North American invader, the gypsy moth. The gypsy moth periodically defoliates large tracts of hardwood forest, negatively affecting ecological communities, timber production, and recreational activities. The gypsy moth invasion front stretches from Minnesota to North Carolina and is expanding at an average rate of approximately 10 kilometers per year. Knowledge gaps filled by this project will inform management and conservation strategies to ultimately reduce the environmental and economic costs of non-native invaders and maintain biodiversity in the United States.
The researchers will use an exhaustive spatiotemporal dataset that annually quantifies the 2000 km long range edge of the gypsy moth. This project combines cutting-edge landscape genetics with detailed analyses of local population dynamics to inform model simulations used to elucidate how local population processes, landscape connectivity, and anthropogenic movement of this species interact to drive spread patterns. The proposed research tests hypotheses associated with three main objectives: 1) quantify effects of landscape features and spatial covariance on the dynamics of low-density populations, 2) use spatial genetic lineages to understand how landscape features and human traffic patterns affect genetic structure and movement, and 3) integrate demographic and genetic information to determine how landscape features, human movement, and local population processes drive large-scale invasion patterns by simulating invasion on layered maps of population dynamic and movement parameters. |