假高粱在中国海南岛入侵种群的个体生长、竞争能力以及群体水平的生物量

• 作 者: Weiqian Wang Ya Wang Xiaoxia Li Yan Liu Qiaoqiao Huang
• 出 处: 植物生态学报（英文版）
• 发表日期: 2021年5期
• 关键词: competitive ability invasive plant non-outbreaking population root-shoot ratio S

假高粱(Sorghum halepense)是一种在世界范围内造成严重危害的多年生入侵杂草,包括海南岛的部分区域.在本研究中,我们比较了暴发(覆盖面积大的密集林分)和非暴发(覆盖面积较小的稀疏林分)种群假高粱的表现.我们又验证了有较高种内竞争能力的植物在高密度生长时群体水平的生物量会较低这一假设.我们在每个花盆里将假高粱单独种植、与一个同种植物竞争、与两个异种植物竞争以及来自同一种群的3或6株植物一起种植,并检验了暴发和非暴发种群的表现是否存在差别.我们也检验了群体水平的生物量(当3或6株植物在一起生长时的总生物量)是否与单独生长时的总生物量以及种内和种间竞争能力相关.研究结果表明,假高粱暴发和非暴发种群在单独生长时生物量有显著差异,但在竞争时或当3或6株植物在一起生长时的生物量没有显著差异.在种群之间,植物在单独生长时的生物量与其种内和种间竞争能力负相关,表明单独生长和竞争能力之间存在权衡关系.群体水平的生物量与单独生长时的生物量以及种内和种间竞争能力之间不相关,说明单独生长时的低生物量和高竞争能力不会降低假高粱在高密度种植时的生长表现.“,”Aims Sorghum halepense is a perennial invasive weed causing great harm worldwide,including some regions on Hainan island.In this study,we compared the performance between plants from outbreaking(dense stands covering large areas)and those from non-outbreaking(less dense stands covering smaller areas)populations.We also tested the hypothesis that plants with greater intraspecific competitive ability will have a lower stand biomass when grown under high-density conditions.Methods We grew plants of S.halepense individually,with an intraspecific competitor,with two interspecific competitors and with three or six plants from the same population per pot,and tested whether outbreaking and non-outbreaking populations differed in their performance.We also tested whether stand biomass(i.e.total biomass when three or six plants were grown together)was related to total biomass of individuals grown alone,and intra-or interspecific competitive ability.Important Findings Outbreaking and non-outbreaking populations of S.halepense differed in their biomass when individuals were grown alone,but not when grown in competition or when three or six plants from the same population were grown together.Across populations,biomass of individuals grown alone was negatively correlated with intra-and interspecific competitive ability,indicating that there is a trade-off between individual growth and competitive ability.Stand-level biomass was not related to total biomass of individuals grown alone,and intra-or interspecific competitive ability,indicating that low biomass when grown alone and high competitive ability may not reduce the performance of S.halepense when grown in dense monocultural stands.