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: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=631881
• 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.

入侵物种处于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扰乱生态系统。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，也让我们深入了解群落是如何聚集的，以及是什么决定了生态系统抵抗干扰或从干扰中恢复的能力。这些基本的生态问题是我研究计划的重点。作为一个模型系统，我建议研究淡水沼泽中非本地芦苇入侵的生态系统影响。可悲的是，我们对淡水中这种侵略性入侵者的影响的了解是过时的和不足的。为了更好地了解芦苇入侵如何影响：i)湿地结构；ii)湿地生态系统过程(例如，植物生长和分解)；以及iii)候鸟和濒危鸟类对湿地的利用，我提出了一个创新的实地研究计划，包括两个主要部分。1.入侵湿地与未入侵湿地基本生态系统过程的比较。植物生长、腐烂和碳贮量将在被芦苇入侵的地块和香茅和沼泽草甸群落的地块之间进行比较。研究计划的这一部分将包括凋落物移植实验和直接的土壤特性，以梳理入侵和未入侵地块之间生长和腐烂的差异是由于凋落物组成的差异还是由于环境条件的差异。2.入侵前、新入侵和已确定入侵时间段的鸟类丰度和群落组成的比较。有限的以前的工作表明，在入侵的早期阶段，对鸟类群落组成的影响可能很小，而且鸟类的丰度实际上可以通过芦苇来增加。然而，一旦入侵已经确立，普通芦苇的任何积极影响都不太可能持续下去。对于我的探索计划的第一阶段，研究将在安大略省的Long Point进行。朗点湿地占伊利湖北岸湿地栖息地的70%，是具有大陆重要性的候鸟中转区。已建立的普通芦苇林的密集、难以渗透的单一栽培特征可能危及该湿地和其他湿地中的濒危物种(例如，至少是Bittern)，迫切需要进一步研究，以便为管理决策提供信息并确定恢复优先事项。这项研究的结果也将有助于解决关于入侵生态和湿地恢复能力的更大问题。此外，我提议的项目将促进滑铁卢大学、加拿大鸟类研究、Long Point国家野生动植物区域和Long Point研究和教育中心之间的伙伴关系和知识转移。这将导致高技能人才的培训：下一代环境科学家和保护生物学家，他们将解决未来的生态危机。