Tracing the spread of European earthworms into North America using molecular markers and field experiments

北美大部分地区没有原生的南极洲物种，可能是由于威斯康星冰川期土著南极洲动物群的灭绝。自欧洲定居者到来以来，欧洲蚯蚓一直在入侵北美生态系统，它们的存在通过改变土壤结构、养分循环、植物生长以及土壤微生物和动物的组成和功能，对当地的植物群和动物群产生了深远的影响。尽管他们的生态相关性和作为生态系统工程师的功能，与人类有关的传播，遗传变异和适应欧洲蚯蚓在北美的重要性是几乎没有investigated.The拟议的项目打算调查欧洲蚯蚓入侵北美生态系统，通过分析种内遗传变异在大陆规模和人口遗传学在当地和区域规模。我们专注于两个最常见的入侵欧洲蚯蚓物种，蚯蚓terrestris和蚯蚓rubellus，代表理想的生物体，调查入侵过程，因为他们拥有不同的生活史，传播能力和喂养策略。该项目旨在回答北美的非本地的美洲原住民种群是由于从许多来源引进而具有遗传多样性，还是由于少数遗传谱系占主导地位而具有遗传同质性，并打算确定殖民化路线。此外，生态因素的重要性，如夏季干旱和冬季冷冻，作为驱动程序的遗传构成的种群。该项目分为三个主要工作包（WP）。WP1研究了L. terrestris和L.在大陆范围内的Rubellus。WP 2探讨了最近人类介导的扩散在区域和地方尺度上的作用，以及这两个生态不同的物种之间的迁移和基因流的差异。WP3研究了L.利用田间围隔生态系统和分子标记技术研究陆生植物对环境因子的响应。蚯蚓代表了一种迄今为止未被充分认识的模型，通过结合分子方法和补充的田间实验来回答入侵生物学中的一般问题。

Large parts of North America are devoid of native earthworm species, presumably due to extirpation of the indigenous earthworm fauna during the Wisconsinan Glaciation. European earthworms have been invading North American ecosystems since the arrival of European settlers, and their presence has profound effects on the native flora and fauna by altering soil structure, nutrient cycling, plant growth, and the composition and functions of soil microorganisms and animals. Despite their ecological relevance and their functioning as ecosystem engineers, the importance of human-related dispersal, genetic variability and adaptation of European earthworms in North America is hardly investigated.The proposed project intends to investigate the invasion of European earthworms into North American ecosystems by analyzing intraspecific genetic variability at the continental scale and population genetics at local and regional scales. We focus on two of the most common invasive European earthworm species, Lumbricus terrestris and Lumbricus rubellus, representing ideal organisms to investigate invasion processes as they possess different life-histories, dispersal abilities and feeding strategies. This allows differentiation between genetic patterns caused by anthropogenic use, mobility and tolerance to abiotic factors.The project aims at answering if non-native earthworm populations in North America are genetically diverse due to introduction from many sources or genetically homogenous due to the dominance of few genetic lineages, and intends to identify colonization routes. Further, the importance of ecological factors, such as drought in summer and freezing in winter, as drivers of the genetic constitution of earthworm populations is investigated. The project is separated into three main work packages (WPs). WP1 investigates the genetic diversity and expansion routes of L. terrestris and L. rubellus at the continental scale. WP2 explores the role of recent human mediated dispersal at regional and local scales as well as differences in migration and gene flow between these two ecologically different earthworm species. WP3 investigates the adaptability of L. terrestris to environmental factors using field mesocosms and molecular markers. Earthworms represent a heretofore underappreciated model for answering general questions in invasion biology by combining molecular methods and complementary field experiments.