Ecosystem- and community-level effects of biological invasion

生物入侵对生态系统和群落水平的影响

• 批准号: RGPIN-2014-03846
• 负责人: Rooney, Rebecca
• 金额: $ 1.75万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=610682
• 关键词: Ecosystem; community; level; effects; biological

Invasive species are at the forefront of current environmental issues. Biological invaders can disrupt ecosystems by altering fundamental ecosystem processes like competition, plant growth and decay. To manage invasions, we must first understand the consequences of invasion and weigh these against the environmental costs of control activities. Understanding how invasive species influence ecosystems and communities also provides us with insight into how communities assemble, and what determines the capacity of ecosystems to resist or recover from disturbance. These fundamental ecological issues are the focus of my research program. As a model system, I propose to examine the ecosystem effects of invasion by non-native Phragmites australis (Common Reed) in freshwater marshes. Our knowledge of the effects of this aggressive invader in freshwater is woefully out-dated and inadequate. To better understand how Common Reed invasion affects: i) wetland structure; ii) wetland ecosystem processes (e.g., plant growth and decomposition); and, iii) use of wetlands by migratory and imperiled birds, I am proposing an innovative field-based research program with two major components. 1. A comparison of basic ecosystem processes between invaded and uninvaded wetland plots. Plant growth, decay, and carbon storage will be compared between plots invaded by Common Reed and plots in cattail and marsh meadow communities. This component of the research program will include a litter transplant experiment and direct soil characterizations to tease apart whether differences in growth and decay between invaded and uninvaded plots are due to differences in litter composition or due to variability in environmental conditions. 2. A comparison of bird abundance and community composition between time periods that represent pre-invasion, new invasion, and established invasion. Limited previous work has shown that in the early stages of invasion effects on the bird community composition can be minor, and that bird abundance can actually be enhanced by Common Reed. However, it is unlikely that any positive effect of Common Reed will persist once the invasion has become established. For this first phase of my Discovery program, research will be conducted at Long Point, Ontario. The Long Point wetlands constitute 70% of all wetland habitat on the north shore of Lake Erie, and are a migratory bird staging area of continental importance. The dense, impenetrable monocultures characteristic of established Common Reed stands could imperil species at risk (e.g., Least Bittern) in this and other wetlands, and further study is urgently needed to inform management decisions and set restoration priorities. Results of this research will also contribute to addressing larger questions about invasion ecology and the resiliency of wetlands. Additionally, my proposed program will foster partnerships and knowledge transfer between the University of Waterloo, Bird Studies Canada, the Long Point National Wildlife Area, and the Long Point Research and Education Centre. This will lead to the training of highly skilled personnel: the next generation of environmental scientists and conservation biologists who will tackle ecological crises of the future.

入侵物种是当前环境问题的前沿。生物入侵者可以通过改变竞争、植物生长和腐烂等基本生态系统过程来破坏生态系统。为了管理入侵，我们必须首先了解入侵的后果，并将这些后果与控制活动的环境成本进行权衡。了解入侵物种如何影响生态系统和群落，也为我们了解群落是如何聚集的，以及是什么决定了生态系统抵抗或从干扰中恢复的能力。这些基本的生态问题是我研究项目的重点。