Department of Aquatic Ecology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.
PLoS One. 2012;7(9):e45400. doi: 10.1371/journal.pone.0045400. Epub 2012 Sep 20.
Factors such as increased mobility of humans, global trade and climate change are affecting the range of many species, and cause large-scale translocations of species beyond their native range. Many introduced species have a strong negative influence on the new local environment and lead to high economic costs. There is a strong interest to understand why some species are successful in invading new environments and others not. Most of our understanding and generalizations thereof, however, are based on studies of plants and animals, and little is known on invasion processes of microorganisms. We conducted a microcosm experiment to understand factors promoting the success of biological invasions of aquatic microorganisms. In a controlled lab experiment, protist and rotifer species originally isolated in North America invaded into a natural, field-collected community of microorganisms of European origin. To identify the importance of environmental disturbances on invasion success, we either repeatedly disturbed the local patches, or kept them as undisturbed controls. We measured both short-term establishment and long-term invasion success, and correlated it with species-specific life-history traits. We found that environmental disturbances significantly affected invasion success. Depending on the invading species' identity, disturbances were either promoting or decreasing invasion success. The interaction between habitat disturbance and species identity was especially pronounced for long-term invasion success. Growth rate was the most important trait promoting invasion success, especially when the species invaded into a disturbed local community. We conclude that neither species traits nor environmental factors alone conclusively predict invasion success, but an integration of both of them is necessary.
因素，如人类活动的增加、全球贸易和气候变化，正在影响许多物种的分布范围，并导致物种的大规模迁移，超出其自然分布范围。许多引入物种对新的当地环境有强烈的负面影响，并导致高经济成本。人们强烈希望了解为什么有些物种能够成功地入侵新环境，而有些则不能。然而，我们的大部分理解和概括都是基于对植物和动物的研究，而对微生物的入侵过程知之甚少。我们进行了一项微宇宙实验，以了解促进水生微生物生物入侵成功的因素。在一个受控的实验室实验中，最初在北美的原生动物和轮虫物种入侵到一个自然的、采集自欧洲的微生物群落中。为了确定环境干扰对入侵成功的重要性，我们要么反复干扰当地的斑块，要么将其作为未受干扰的对照保留。我们测量了短期建立和长期入侵成功，并将其与物种特异性的生活史特征相关联。我们发现，环境干扰显著影响了入侵成功。根据入侵物种的身份，干扰要么促进，要么降低入侵成功。栖息地干扰和物种身份之间的相互作用，尤其是在长期入侵成功方面尤为明显。增长率是促进入侵成功的最重要特征，尤其是当物种入侵到一个受干扰的当地社区时。我们的结论是，无论是物种特征还是环境因素都不能单独决定入侵成功，而是需要两者的综合考虑。
