Competition overwhelms the positive plant-soil feedback generated by an invasive plant
Competition overwhelms the positive plant-soil feedback generated by an invasive plant
复制标题
DOI：
10.1007/s00442-016-3759-2
复制
发表时间：
2017-01-01
期刊：
影响因子：
2.7
通讯作者：
Knight, Tiffany M.
中科院分区：
文献类型：
--
作者：
Crawford, Kerri M.;Knight, Tiffany M.
入侵植物物种能够以一种比本地物种更有利于其适应性的方式改变土壤。然而，植物物种之间的竞争如何改变植物-土壤反馈的强度和方向尚不清楚。我们测试了群落环境如何改变非本地入侵植物胡枝子与9种共生的本地草原物种之间的植物-土壤反馈。在一系列的温室试验中，我们分别在不同土壤来源的土壤（被L. cuneata入侵或未被入侵）和活土壤与无菌土壤中单独种植植物。在没有竞争的情况下，被入侵土壤的L. cuneata生物量比未被入侵土壤的L. cuneata生物量多60%以上，而本地物种的生物量表现不受影响。土壤源效应在无菌土壤中不存在，说明植物-土壤正反馈是由土壤生物群的差异引起的。但在竞争条件下，土壤来源对羊草生长的积极作用逐渐消失。这些结果表明，在种间竞争对手较少的干扰景观中，楔形L.在建立种群时可能受益于正的植物-土壤反馈，但不支持植物-土壤反馈影响楔形L.与本地植物之间竞争结果的假设。这些结果强调了考虑竞争是否影响植物和土壤之间相互作用结果的重要性。
Invasive plant species can modify soils in a way that benefits their fitness more than the fitness of native species. However, it is unclear how competition among plant species alters the strength and direction of plant-soil feedbacks. We tested how community context altered plant-soil feedback between the non-native invasive forb Lespedeza cuneata and nine co-occurring native prairie species. In a series of greenhouse experiments, we grew plants individually and in communities with soils that differed in soil origin (invaded or uninvaded by L. cuneata) and in soils that were live vs. sterilized. In the absence of competition, L. cuneata produced over 60% more biomass in invaded than uninvaded soils, while native species performance was unaffected. The absence of a soil origin effect in sterile soil suggests that the positive plant-soil feedback was caused by differences in the soil biota. However, in the presence of competition, the positive effect of soil origin on L. cuneata growth disappeared. These results suggest that L. cuneata may benefit from positive plant-soil feedback when establishing populations in disturbed landscapes with few interspecific competitors, but does not support the hypothesis that plant-soil feedbacks influence competitive outcomes between L. cuneata and native plant species. These results highlight the importance of considering whether competition influences the outcome of interactions between plants and soils.