外来入侵植物胜红蓟种群构件生物量结构特征

胜红蓟是广泛分布于我国长江流域及以南地区的主要外来入侵植物之一。通过样方调查,从构件水平研究了胜红蓟各构件的结构特征及其生物量间的关系模型,并进行了定量分析,探讨了其与入侵性的关系。结果表明,胜红蓟种群各构件生物量之间的关系为茎(3.62 g)叶(2.18 g)根(1.36 g)花序(0.60 g),总生物量平均值为7.76 g,植株高度平均值为61.62 cm,平均花序数为79.15个。各构件生物量所占比率表现为茎(47.11%)叶(29.04%)根(17.54%)花序(6.31%)。胜红蓟种群各构件生物量之间呈显著的正相关关系,均可用线性函数模型较好地表达。胜红蓟种群各构件较强的表型可塑性极大地提高了其入侵能力,而在繁殖器官相对较低的生物量分配显示了在其花期开展防控的针对性和实效性。

MODULE BIOMASS STRUCTURE TRAITS OF THE ALIEN INVASIVE PLANTAGERATUM CONYZOIDES

Ageratum conyzoides is one of the alien invasive plants distributied abroadly in Yangtse river drainage area and the south area of it in China. Biomass structure characteristic and correlation models among different modules ofA. conyzoidespopulation were studied at module level by sampling surveys. Their quantitative analysis and the relation between the characteristics and its invasiveness were also done in this paper. The results showed that the modules biomass ofA. conyzoideswas decreased in the sequence of stem, leaf, root, capitulum, and the biomass proportion of each module to the whole plant biomass was decreased in the same sequence. The biomass of each module had significant positive correlations, and all the correlations could be well expressed by linear model. Stronger phenotypic plasticity of eachA. conyzoides module greatly enhanced its invasive ability, and lower reproductive biomass allocation indicated the pertinence and efficiency for its control during flowering phase.