摘要
外来物种的入侵对生物多样性是一个主要的威胁。尽管公众对入侵物种的注意力主要集中在物种水平上，而“生物多样性公约”已经将其界定到了物种水平以下的实体。这种定义认识到了本土物种的异位种群散布可能也会对生物多样性产生贞面影响。实际上，目前我们对这种散布的范围、程度及其对自然基因库的影响知之甚少。已有的资料显示瑞典外来群落已经扩展了相当大的范围，最为常见的被散布物种有：河鳟、大西洋鲑、北极红点鲑、白鲑、欧洲赤松、挪威云杉、绿头鸭、灰鹧鸪、雉。尽管每年有几百万的树木、鱼类、鸟类被散布到大自然，但是少有文献资料记载其地理、基因来源，甚至它们的散布地点在很大程度上也模糊不清。文章对亟需的与外来群落所带来的风险和问题相关的初步行动提出了相应的措施，和建议。
Introduction of alien species is a major threat to biological diversity.Although public attention typically focuses on the species level,guidelines from the Convention of Biological Diversity define alien species to include entities below species level.This inclusion recognizes that re- lease of nonlocal populations of native species may also result in negative effects on biodiversity.In practice,little is known about the extent,degree of establishment,or the effects on natural gene pools of such releases. Existing information on the releases in Sweden shows that alien populations are spread to a great extent.The most commonly released species include brown trout, Atlantic salmon,Arctic char,common whitefish,Scots pine,Norway spruce,mallard duck,gray partridge,and pheasant.Although millions of forest trees,fish,and birds are released annually,poor documentation makes the geographic and genetic origin of these populations,as well as the sites where they have been released,largely unclear.We provide recommendations for urgently need- ed first steps relating to the risks and problems associ- ated with release of alien populations.
