【摘要】 采用温室盆栽模拟实验研究了不同养分水平对外来入侵植物飞机草(Chromolaena odorata)的生长性状、生物量积累以及生物量分配格局的影响。实验共设置5种养分浓度处理,分别为Hoagland标准营养液的10%、25%、50%、100%和200%溶液。结果表明:养分水平对飞机草植株的生长性状以及生物量的积累、分配产生显著影响。随着养分水平的增加,飞机草的总分枝数量、长度以及一级分枝数量、长度持续增加,并且100%、200%处理还能促进二级分枝的萌发生长。飞机草的叶片数、总叶面积、总生物量以及茎、叶两器官生物量随养分水平的上升显著增加,但株高、根生物量不受养分浓度变化的影响。根生物量比、根冠比随养分水平的提高显著下降,叶生物量比则显著上升,但茎生物量比在各养分浓度保持稳定。叶面积比、叶根比、RGR亦随养分含量的上升显著增加。说明养分资源丰富的环境将促进飞机草的地上部生长,而生物量分配格局的变化可能是其在入侵蔓延过程中适应养分异质性生境的重要生态策略。更多还原

【Abstract】 The effects of different nutrient levels on plant growth, biomass accumulation and biomass allocation patterns of invasive Chromolaena odorata were studied by using a series of greenhouse pot experiment. Five treatments were set up with different concentration gradient treatments of 10%, 25%, 50%, 100% and 200% of the Hoagland standard nutrient solution. The results showed that total and primary branch numbers, total and primary branch length of C. odorata continuously increased with the increasing nutrient levels; moreover, the 100% and 200% treatments could facilitate the sprout and growth of secondary branches of the plant. Total leaf numbers, total leaf area, total biomass, stem biomass and leaf biomass significantly increased with the nutrient increasing treatments, but plant height and root biomass were not affected by the change of nutrient concentrations. Root mass fraction and root mass/crown mass significantly reduced with the nutrient increasing treatments while leaf mass fraction notably increased, and stem mass fraction remained constant under all the nutrient conditions. Leaf area ratio, leaf area to root mass ratio and relative growth rate of C. odorata remarkably increased with the nutrient increasing treatments as well. The results indicated that habitats with rich soil nutrients could benefit the aboveground growth and spread of C. odorata, and the change of biomass allocation patterns might be one of very important ecological strategies which are helpful for its invasion to nutrient heterogeneous environment.更多还原