喜旱莲子草对不同生境植物群落多样性的影响

为了测定外来入侵植物——喜旱莲子草对其他物种的影响,采用样方法对喜旱莲子草的不同生境内植物群落进行了调查,测定了其伴生植物的种类、数量和盖度,检测了喜旱莲子草的植株茎长、分枝数、叶长、叶宽、节间距等形态指标,分析了该入侵植物在不同生境中的重要值和群落多样性。结果表明,1)在湿生环境中,喜旱莲子草的生长状态较好,植株的茎长、叶面积和节间距等均与其他生境中的植株呈显著性差异;但是,在人为干扰较强生境中(农田、路边)的植株叶面积和节间距明显较其他生境中的相应指标减小或者缩短。2)当喜旱莲子草的重要值超过一定值(60.96%)时,群落内植物的多样性指数呈下降趋势,表明喜旱莲子草的入侵影响了群落内植物种类的丰富度,即当该入侵植物形成一定的优势时,将导致群落内其他物种的减少甚至消失。

Effect on species diversity of plant communities caused by invasion of Alternanthera philoxeroides in different habitats

Alternanthera philoxeroides is one of the most notorious invasive weeds and has been introduced to regions with warm to subtropical humid climates worldwide.To ascertain the effect of the invasive species on plant communities in different habitats,field surveys of species diversity of plant communities and morphological traits associated with the host plant were investigated.1) The species had good growth in wetlands where the morphological traits (including stem length,leaf area and node length) of A.philo...