土壤水分变化对外来入侵植物飞机草生长的影响

以外来入侵植物飞机草为研究对象,设计3个水分梯度(15mm,10mm,5.83mm),研究飞机草的叶绿素含量、生物量、光合生理特征等指标对土壤含水量变化的响应。结果表明,随着土壤水分含量的降低,飞机草的单位叶面积干质量、叶绿素含量、净光合速率、气孔导度、蒸腾速率、胞间CO2摩尔分数、光饱和点等都呈下降趋势。同时,根冠比和水分利用率随着水分胁迫的加重而有所提高,表明飞机草对土壤水分胁迫有一定的适应能力,但总体而言,土壤水分胁迫不利于飞机草的生长,限制了其向降雨量较少的地区入侵。

Effects of soil water regimes on the growth of the exotic invasive plant: Chromolaena odorata

This article studied how the growth of Chromolaena odorata, one of the exotic invasive weeds in China, response to the soil water regimes. Three soil water gradients (15 mm, 10 mm and 5.83 mm)were designed according to the annual precipitation in different areas. The results showed that with the decrease of soil water content, the leaf dry weight per unit area, chlorophyll content, net photosynthetic rate, stomatal conductance, transpiration rate, intercellular CO2 concentration and light saturation point declined, while the water use efficiency and the ratio of belowground and aboveground biomass increased. It suggested that Chromolaena odorata could adapt to the soil water stress to some extent. As a whole, water stress could affect the growth of Chromolaena odorata and the spread of Chromolaena odorata to areas with less rainfall.