DISSERTATION RESEARCH: Elucidating the Roles of Abiotic and Biotic Factors in Exotic Species Establishment: A Trait-based Approach

论文研究：阐明非生物和生物因素在外来物种建立中的作用：基于性状的方法

• 批准号: 1502071
• 负责人: Priyanga Amarasekare
• 金额: $ 2万
• 依托单位: University of California-Los Angeles
• 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: 2015-06-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1502071&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Elucidating; Roles; Abiotic

Invasions of non-native species are one of the greatest environmental challenges of the 21st century, threatening not only native flora, fauna, and the ecosystem services that they provide, but also agriculture, human health, and the economy. Invasion and establishment of non-native species is driven by both physical (abiotic) factors, such as temperature, and by interactions with native species (biotic factors), such as predation and competition. Understanding how these biotic and abiotic factors magnify or cancel one another is necessary for forecasting the conditions under which invasive species establish in new localities, and for developing methods to control the spread of such species. Yet, most studies overlook the joint effects of abiotic and biotic factors on invasion success because they examine on only one type of factor. This project addresses this problem by examining the joint effect of environmental temperature and competition for resources on invasion by an insect in California. The research combines laboratory experiments, field observations, and mathematical models to forecast the conditions that allow the invasive species to spread. Currently, the U.S. spends hundreds of millions of dollars annually on invasive species control. This project aims to reduce this cost by providing the scientific knowledge needed to develop more cost-effective control measures.The project integrates manipulative experiments, field observations and mathematical models to examine how temperature and competition impact population dynamics and species interactions of an ecologically related pair of insects, one native and one invasive. The impetus for this work comes from a native-invasive interaction occurring in the California coastal sage scrub community in which two Hemipterans (Family: Pentatomidae), native Murgantia histrionica and recent North American invasive Bagrada hilaris, compete for their primary host, the perennial shrub Cleome isomeris. This study aims to (i) quantify the joint effect of temperature and density on life history traits (fecundity, development, mortality) of the two species, and (ii) parameterize a mathematical model of stage-structured population dynamics that incorporates mechanistic descriptions of vital rate temperature responses, and time-dependent developmental delays that arise due to temperature variation. These goals are achieved through (i) a fully factorial lab experiment with density and temperature treatments, (ii) estimation of model parameters using maximum likelihood methods applied to experimental data, which are used to analyze a delay differential equation model of population dynamics, and (iii) field collection of insect abundances to test the model's predictions.

非本土物种的入侵是21世纪世纪最大的环境挑战之一，不仅威胁到本土植物群、动物群及其提供的生态系统服务，还威胁到农业、人类健康和经济。非本地物种的入侵和定居既受物理（非生物）因素（如温度）的驱动，也受与本地物种（生物因素）的相互作用（如捕食和竞争）的驱动。了解这些生物和非生物因素如何相互放大或抵消，对于预测入侵物种在新的地方建立的条件以及开发控制这些物种传播的方法是必要的。然而，大多数研究忽略了非生物和生物因素对入侵成功的共同影响，因为他们只研究了一种类型的因素。本研究针对这一问题，在加州考察了环境温度和资源竞争对昆虫入侵的共同影响。该研究结合了实验室实验、实地观察和数学模型，以预测允许入侵物种传播的条件。目前，美国每年花费数亿美元用于控制入侵物种。该项目旨在通过提供制定更具成本效益的控制措施所需的科学知识来降低这一成本，该项目结合了操纵实验、实地观察和数学模型，以研究温度和竞争如何影响生态相关的一对昆虫（一个本地昆虫和一个入侵昆虫）的种群动态和物种相互作用。这项工作的动力来自本地入侵的相互作用发生在加州沿海鼠尾草灌丛社区，其中两个半翅目（家庭：Pentatomidae），本地Murgantia histrionica和最近的北美入侵Bagrada hilaris，竞争他们的主要主机，多年生灌木醉蝶花。本研究的目的是（一）量化的温度和密度对生活史性状（繁殖力，发展，死亡率）的两个物种的联合效应，和（ii）参数化的阶段结构的人口动态的数学模型，结合机械描述的生命率温度响应，和时间依赖性的发育延迟，由于温度变化而产生的。这些目标是通过以下方式实现的：（i）密度和温度处理的完全析因实验室实验，（ii）应用于实验数据的最大似然方法估计模型参数，该方法用于分析种群动态的延迟微分方程模型，以及（iii）实地收集昆虫丰度以测试模型的预测。