种间竞争对入侵植物和本地植物生长的影响

Effects of interspecific competition on the growth of invasive and native species

为了探讨入侵植物与本地同属和异属植物之间的关系,本研究以入侵植物喜旱莲子草(Alternanthera philoxeroides)、三裂叶蟛蜞菊(Wedelia trilobata)和本地植物莲子草(A.sessilis)、蟛蜞菊(W.chinensis)为试验材料开展了温室控制实验。实验设置了单种种植和混种种植两种方式,测定了每种植物生物量及其他生长指标,并分析了种间关系。结果表明:(1)对入侵植物而言,同属和异属种间竞争均增加了喜旱莲子草的生物量、根冠比和分节数,而降低了三裂叶蟛蜞菊的株高和分节数;(2)对本地植物而言,同属种间竞争降低了莲子草的株高和蟛蜞菊的分节数,异属种间竞争增加了莲子草的生物量、株高和分枝数,而降低了蟛蜞菊的总生物量和株高;(3)同属种间竞争对入侵种喜旱莲子草具有促进作用,异属种间竞争对本地种莲子草也具有促进作用,同属和异属种间竞争对其他两个物种的影响不大。未来应加强野外原位下入侵植物与本地植物研究,为入侵植物防控提供理论依据。

To explore interspecific relationship between invasive and native plants,we conducted a greenhouse experiment with two invasive plants（ Alternanthera philoxeroides and Wedelia trilobata） and their native congeners（ A. sessilis and W. chinensis） across monoculture and mixture plantings. Biomass and morphological indexes were measured and the interspecific relationships between species were analyzed. The results showed that：（ 1） Congener and heterogeneric interspecific relationship increased the biomass,root / shoot ratio and number of nodes of A. philoxeroides,but decreased the height and number of nodes of W. trilobata.（ 2） Congener interspecific relationship decreased the height of A. sessilis and number of nodes of W. chinensis,heterogeneric interspecific relationship increased the biomass,height and number of branches of A. sessilis,but decreased the total biomass and height of W. chinensis.（ 3） Congener interspecific competition had a positive effect on the growth of A. philoxeroides,while heterogeneric interspecific competition had a positive effect on the growth of A. sessilis. In future studies,relationships of cooperation and competition between invasive and native plants in the field need to be advanced to provide a theoretical basis for prevention and control of invasive plants.