Collaborative Research: Species Introductions as Ecological Experiments-Linking Biogeographical Patterns and Ecological Mechanisms

外来物种的引入为研究物种在本地和区域尺度上的分布和丰度的决定因素提供了独特的机会。将鱼类引入湖泊特别有用，因为它们类似于实验；它们通常是复制的（向多个湖泊进行介绍），有控制（附近没有进行介绍的湖泊），并且通常是记录的（由执行介绍的机构记录）。例如，红翻车鱼（原产于美国东南部）目前正被引入密歇根州的湖泊，南瓜子翻车鱼是当地的。红豆和南瓜籽在形态和生态上相似（都主要以蜗牛为食），预计会有很强的竞争。事实上，密歇根州的初步研究表明，重新引进南瓜籽后，南瓜籽的数量下降了80%。目前的研究利用过去和正在引进的翻车鱼到密歇根州的湖泊，再加上对卡罗来纳州（这两个物种都是本地的）的翻车鱼的比较研究，探索物种引进对本地物种的影响，检查地理分布的原因，并调查驱动这些关系的一些生态机制。物种引入是人类对自然系统影响的一个日益普遍的来源，但目前几乎没有能力预测其影响，减轻其影响，或区分具有重大影响的引入和相对良性的引入。这项工作试图将功能形态学、群落生态学和生物地理学整合到一个框架中，以帮助解决这些缺点，并在一组经济和娱乐重要的鱼类中解决这些问题。

9622787 Mittelbach The introduction of species outside their native ranges can provide unique opportunities to study the factors determining species distributions and abundances on both local and regional scales. Introductions of fishes into lakes are particularly useful because they resemble experiments; they are often replicated (introductions are made to multiple lakes), have controls (nearby lakes that did not receive introductions), and are often documented (recorded by agencies performing the introductions). For example, the redear sunfish (native to the southeastern US) is currently being introduced into Michigan lakes, where the pumpkinseed sunfish is native. The redear and pumpkinseed are similar in morphology and ecology (both feed primarily on snails), and are expected to compete strongly. Indeed, initial studies in Michigan suggest that pumpkinseed populations decline by 80% following redear introduction. The present research makes use of past and ongoing introductions of sunfish into Michigan lakes, coupled with comparative studies of sunfishes in the Carolinas (where both species are native), to explore the consequences of species introductions on native species, examine the causes of geographic distributions, and investigate some of the ecological mechanisms that drive these relationships. Species introductions are an increasingly common source of human impacts on natural systems, yet there is currently little ability to predict their impacts, mitigate their effects, or discriminate between introductions that have major effects and those that are relatively benign. This work attempts to integrate functional morphology, community ecology, and biogeography into a framework that can help resolve these shortcomings, and it addresses these issues in a group of economically and recreationally important fishes.