大型底栖动物入侵种:它们是否对德国水生动物群落构成威胁?

在水体中发现大型底栖动物入侵种是一种世界范围普遍的现象。人类移动的同时将物品从一个大陆带到另一个大陆,这使许多水生动物物种能够突破自然的防线侵入到其他的区域和大陆。藉由人类现代的旅行方式,在不同区域间移动的物种数量显著增加,成功入侵种的数量也随之增多。成功入侵种需要具备一些特征,如可动性,小体型,适应性强和繁殖率高等,这些均有利于物种跨区域的入侵。当然,新生活环境也必须满足可适应的标准。对一个受人类活动破坏而丧失其原有物种的水环境来说,它对新物种入侵的抵抗力会很弱甚至缺乏。德国水体受人类活动的胁迫非常严重,许多自然水体受到的破坏已无法挽回,有些甚至已经完全成为了人工环境。这些水体由相互连接着的溪流河川网络组成,这很容易使新物种的入侵范围扩大。在外来物种的入侵面前,受人类活动胁迫和直接破坏的水体,比尚保持着天然环境状况的水体更加脆弱。

Invasive macrozoobenthic species: are they a threat to the aquatic communities of German water bodies?

Macrozoobenthic invasion is a common phenomenon which appears throughout the world.Humans travel worldwide transporting materials from one continent to another.This enables many aquatic species to breach natural boundaries and invade environments in other regions and continents.With modern travel the number of species moving between different regions has increased considerably and so the number of successful aquatic invasions has increased.To be a successful invading species,there are some necessary traits.Mobility,small body size,adaptability and a high reproductive rate for example,would contribute to a successful cross-regional invasion.But the new host environment must fit some accommodating criteria.Environments that are depleted of their historical species due to human impact damage,may make little or no resistance to new organism invasions.German water bodies are under serious stress from human impact.Many water bodies are irreparably disturbed and some are now totally artificial habitats.These water bodies are a complex network of connecting rivers and canals that facilitate the spread of invasive macrozoobenthic species.Our literature research and our own investigations show that water bodies,rivers and streams that are under stress from human impact,or damaged by direct interference,are more vulnerable to aquatic invasive species alien to the local natural environment,than water bodies more closely aligned to their original,natural conditions.