Persistence and Spreading Speeds in Multi-Species Models with A Shifting Habitat Edge

栖息地边缘变化的多物种模型中的持久性和传播速度

• 批准号: 1515875
• 负责人: Bingtuan Li
• 金额: $ 22.5万
• 依托单位: University of Louisville Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1515875&HistoricalAwards=false
• 关键词: Persistence; Spreading; Speeds; Multi; Species

Whether or not a species can persist and spread in an environment is a fundamental and long-standing question in ecology. Recently, this question has been brought to the forefront by climate change and landscape conversion. Due to the processes of climate change, habitat regions suitable for population growth of many species have been shifting geographically. Climatically induced shifts may interface with population demographic processes in complex ways, setting the stage for impacts on species population growth and spread, long-term dynamics and interactions between species. This project aims to produce new frameworks for the analysis of persistence and spreading speeds of species in a shifting habitat. It addresses the question of how ecosystems are being affected by climate change and how ecosystems might respond in the future. It contributes to the growing body of information identifying species at a high risk for extinction and predicting the spread of invasive species under ongoing climate change. The outcomes of the project help improve strategies for coping with challenges of natural resource management. This project further stimulates interdisciplinary collaboration between mathematicians and biologists to address issues beyond the reach of single disciplines. In addition, it contributes to human resources development, focusing on training and skill development of graduate students, and providing them with experience in interdisciplinary interaction and exploration. In this project, the investigator formulates and analyzes spatial population models that describe species growth, interactions, and dispersal in shifting habitats. The goal is to understand and accurately describe how climate change affects biological invasion processes. Multi-species reaction-diffusion competition models and predator-prey models, as well as semi-discrete stage-structured spatial models with a shifting habitat edge, are studied to emphasize the role of changing habitat suitability in persistence and spread of an invasive species interacting with an existing species. In these models, shifts in habitat ranges are incorporated in species growth functions that propagate as traveling waves. Species spatial dynamics are investigated for the following cases: (i) one species spreads into a shifting habitat preoccupied by a resident species; and (ii) two species consecutively invade an open shifting habitat and the earlier species is still in the process of expanding its spatial range. New techniques are developed to determine the behaviors of solutions of the models on appropriate bounded and unbounded spatial intervals that expand and shift in time. Methods from differential equations, integral equations, and dynamical systems are employed to detect conditions under which species go extinct and to determine spreading speeds of persisting species in space. The results of this research also have impacts in other disciplines where wave propagation is studied.

物种是否可以在环境中持续和传播是生态学中的一个基本和长期的问题。 最近，由于气候变化和景观转换，这个问题已成为最前沿的问题。 由于气候变化的过程，适合许多物种人口增长的栖息地区域在地理上一直在转移。 气候诱导的转移可能会以复杂的方式与人口人群过程接触，从而为物种种群生长和传播，长期动态和物种之间的相互作用的影响奠定了基础。 该项目旨在生产新的框架，以分析变化的栖息地中物种的持久性和传播速度。 它解决了一个问题，即生态系统如何受到气候变化的影响以及生态系统将来如何反应。 它有助于不断增长的信息识别灭绝风险高的物种，并预测在持续的气候变化下入侵物种的传播。 该项目的结果有助于改善应对自然资源管理挑战的策略。 该项目进一步刺激了数学家和生物学家之间的跨学科合作，以解决超出单一学科的问题。 此外，它有助于人力资源的发展，专注于研究生的培训和技能发展，并为他们提供跨学科互动和探索的经验。 在这个项目中，研究人员制定并分析了描述物种生长，相互作用和分散在变化栖息地中的空间人群模型。 目标是了解并准确描述气候变化如何影响生物学入侵过程。 研究了多种物种反应扩散竞争模型和捕食者 - 捕集模型，以及具有变化栖息地边缘的半混凝土阶段结构的空间模型，以强调改变栖息地在持久性和与现有物种相互作用的入侵物种相互作用的栖息地适用性和传播的作用。 在这些模型中，栖息地范围的变化纳入了传播为行进波的物种生长函数中。 在以下情况下研究了物种空间动力学：（i）一种物种扩散成一个被居民物种全神贯注的栖息地； （ii）两个物种连续入侵开放的栖息地，而早期的物种仍在扩大其空间范围。 开发了新技术来确定模型解决方案的行为，以适当的有限和无限的空间间隔扩展和变化。 使用微分方程，积分方程和动态系统的方法来检测物种灭绝并确定空间中持续物种的扩散速度的条件。 这项研究的结果在研究波传播的其他学科中也有影响。