Effects of Plant Diversity and Functional Characteristics on Species Invasions

植物多样性和功能特征对物种入侵的影响

• 批准号: 9974159
• 负责人: David Hooper
• 金额: $ 20万
• 依托单位: Western Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2002-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9974159&HistoricalAwards=false
• 关键词: Effects; Plant; Diversity; Functional; Characteristics

9974159HooperEcologists have hypothesized for decades that more diverse communities are more difficult for species to invade because greater species richness should leave less available resources for a potential invader to exploit. This research seeks to address three fundamental questions (1) Does diversity influence invasibility of communities? (2) Do functional attributes of invaders related to resource acquisition influence the success of their invasion? (3) Is there a greater probability of invasion success when the invader differs from community members in functional attributes related to resource capture? The experimental design allows separation of effects due to differences in plant composition from effects due to differences in functional group richness. Unlike previous studies that have inferred answers to these questions by surveying communities which have already been invaded, this project will directly test the patterns of invasion into communities that differ in both composition and richness of plant functional groups. It will study the role of competition as a mechanism involved in invasion outcome. The research will use already-established experimental communities in California serpentine grassland. These experimental communities allow control of several factors, including disturbance regime, soil fertility, and community history, which confound attempts to study these questions in already invaded ecosystems. By directly seeding in species that are not already a part of those experimental communities, but that occur in the local area, it also will be possible to control for the rate of propagule arrival. This control is critical for determining what limits the success of an invasion once propagules have arrived. Overall, this set of experiments will provide a direct test of hypotheses concerning community invasibility and its underlying mechanisms.

9974159Hooper 生态学家几十年来一直假设，群落越多样化，物种就越难以入侵，因为物种丰富度越高，可供潜在入侵者利用的可用资源就越少。本研究旨在解决三个基本问题（1）多样性是否会影响社区的入侵性？ （2）入侵者与资源获取相关的功能属性是否影响其入侵的成功？ （3）当入侵者与群落成员在资源获取相关的功能属性不同时，入侵成功的概率是否更大？实验设计允许将植物组成差异造成的影响与官能团丰富度差异造成的影响分开。与之前的研究通过调查已被入侵的群落来推断这些问题的答案不同，该项目将直接测试植物功能群的组成和丰富度不同的群落的入侵模式。它将研究竞争作为涉及入侵结果的机制的作用。该研究将使用加州蛇纹草原上已经建立的实验群落。这些实验群落可以控制多种因素，包括干扰方式、土壤肥力和群落历史，这使得在已经被入侵的生态系统中研究这些问题的尝试陷入困境。通过直接播种尚未属于这些实验群落但发生在当地的物种，也可以控制繁殖体到达的速度。这种控制对于确定繁殖体到达后限制入侵成功的因素至关重要。总的来说，这组实验将为有关群落不可入侵性及其潜在机制的假设提供直接检验。