外来植物入侵的全境性研究进展与展望

由于外来种入侵地一般都远离其自然分布区(原产地), 如果只在其入侵地或者原产地进行研究, 很难真正发现其入侵性形成和成功入侵的根本原因。目前, 许多学者开始关注和倡导对入侵种在原产地和入侵地的表现同时进行研究, 即入侵种的全境性研究(whole-range studies), 为入侵生物现有地理分布格局的形成原因和入侵机制等提供解释。本文结合国内外关于入侵植物全境性研究的进展和成果, 分别针对研究的主要目的、内容、意义等进行了全面的阐述, 探讨了存在的问题与不足, 并对未来相关研究进行了展望。目前已有的全境性研究主要是通过野外直接观测和同质种植园实验来比较入侵种在入侵地和原产地的生长、繁殖和生理生态等表型性状的差异, 以及应用分子标记方法比较入侵地种群和原产地种群遗传多样性的差异, 进行入侵植物的分子系统地理学研究, 从而有效检验生物入侵机制的理论和假说, 深入阐明植物入侵的机制, 为制定入侵植物的防控策略提供指导。值得注意的是, 由于外来植物入侵的全境性研究起步较晚, 现有研究的方法和内容还不够完善, 今后需要在加强国际合作的基础上进一步改善。

Whole-range studies on alien plant invasion:recent progress and future prospects

The regions invaded by alien species are normally disjunct from their native ranges, so it is difficult to understand the reasons for successful invasion through studies conducted only in native or invasive ranges. Many researchers have engaged in whole-range studies of invasive species, i.e. studying the exotics both in their introduced and native ranges, in order to explain the present geographical patterns and invasion mechanisms of alien plants. Here, we review progress in whole-range studies on invasive plants by summarizing their main contents, achievements and significance. We also point out the problems and shortcomings of existing studies and provide prospects for further studies. There are two main approaches in whole-range studies: (1) comparison of phenotypic traits (e.g. growth, reproduction, and ecophysiology) between invasive and native populations through direct observation and common garden experiments; (2) genetic diversity analysis and phylogeographic research using molecular markers. Such studies have tested major hypotheses of plant invasion mechanisms, and provided advice for management and control of invasive plants. However, the methods and contents of existing whole-range studies are imperfect, and further improvements based on increased international cooperation are needed.