干扰对植物群落物种组成及多样性的影响

在介绍了干扰的概念及其性质和干扰对物种多样性影响的有关假说基础上,以森林干扰为主要对象,探讨了干扰对植物群落物种组成的影响,并从干扰类型、干扰强度和干扰频率等几个方面阐述了干扰对植物群落物种多样性的影响;另外,还分析了重要的小尺度干扰——林隙在该方面的影响。分析总结出干扰对植物群落的影响差异主要与干扰特征、植物群落特征及植物的生物学特性和受干扰地点的资源条件有关。最后,总结分析了国内外在该方面研究存在的问题,并对今后研究提出一些建议,为相关工作提供参考。

Effects of disturbances on species composition and diversity of plant communities

During succession of plant communities, the processes are continually influenced by a variety of disturbances, which may be caused by natural disasters or anthropogenic activities. Although the characteristics of disturbances are different, they can all result in the changes in species composition and diversity, structures and functions of plant communities. Recently, effects of disturbances on ecosystems have become more and more complex for the gradually frequent and strong activities of human beings. It is therefore, important to understand the occurrence processes of disturbances and to forecast the results of different disturbances, which are in favour of the conservation of natural ecosystems and other human practices. In this paper, concepts and characters of disturbances were introduced. Some hypotheses of effects of disturbances on biodiversity were enumerated. Of which, the intermediate disturbance hypothesis was the most popular one, which had become the basics of many researches in this field. Then, the effects of disturbances on plant species composition were discussed. The influences of disturbances on plant species diversity were also analyzed in the aspects of the type, the intensity and the frequency of disturbances. It could be found that the effects of disturbances on plant species composition and diversity were related to the characteristics of disturbances and plant communities, bionomic of plant species, and the resources of the disturbed locations. In addition, we analyzed the effects of canopy gap, which is one kind of the important small-scale disturbances in forest ecosystems, on the maintaining of diversity and succession of forest ecosystems. Finally, some problems in this research field were summarized and propositions were made to offer the references for further studies.