DISSERTATION RESEARCH: Comparison of direct, indirect and ecosystem engineering effects using earthworms as model ecosystem engineers

改变或创造栖息地的生物被认为是生态系统工程师，如果他们的活动实质上改变了大量其他物种的资源可用性。例如，河狸建造水坝可以提高当地的地下水位，为湿地、河岸和水生植物创造适宜的栖息地。除了改变栖息地，生态系统工程师也可能是竞争对手，猎物和/或捕食者。实验操作的蚯蚓，被认为是生态系统工程师在栖息地的实验将进行，蝾螈，另一种常见的物种在同一栖息地，将被用来同时检查栖息地改造的蝾螈的影响，蚯蚓的作用，蝾螈的食物来源，以及蚯蚓的影响，蝾螈的间接竞争对手。用入侵物种取代本地物种的后果将通过测试本地和非本地的入侵物种来检查。该项目的新奇在于，它同时将生态系统工程，直接掠夺和间接竞争的影响，在一个单一的实验设计的方式，可以比较的程度的个人影响。此外，该研究将进一步科学地了解生态相似的本地和非本地生态系统工程师在生态群落中的作用。该项目将为一名博士生提供资金，并促进本科生的教学和培训。该项目将包括对高中生和本科生的宣传，展示植物提取方法，并以此为跳板解释北美非本土物种的历史和普遍性。

Organisms that modify or create habitat are considered ecosystem engineers if their activity substantially alters the availability of resources to a large number of other species. For example, dam building by beavers can raise the local water table and create habitat suitable for wetland, riparian, and aquatic plants. In addition to modifying habitat, ecosystem engineers are also likely to be competitors, prey, and/or predators. Experimental manipulations of earthworms, considered ecosystem engineers in the habitat where the experiments will be conducted, and salamanders, another common species in the same habitat, will be used to simultaneously examine the effect on salamanders of habitat modification by earthworms, the role of earthworms as a food source for salamanders, and the effect of earthworms as indirect competitors of salamanders. Consequences of replacing a native species with an invasive species will be examined by testing both native and non-native earthworm species. The novelty of this project is that it simultaneously incorporates ecosystem engineering, direct predatory, and indirect competitive effects within a single experimental design in a way that the magnitude of the individual effects can be compared. In addition, the research will further scientific understanding of the role of ecologically similar native and non-native ecosystem engineers in ecological communities. This project will provide funding for a PhD student and facilitate the teaching and training of undergraduate students. The project will include outreach to high school students and undergraduate students, demonstrating earthworm extraction methods and using this as a springboard to explain the history and ubiquity of non-native species in North America.