An invasive aster (Ageratina adenophora) invades and dominates forest understories in China:: altered soil microbial communities facilitate the invader and inhibit natives
An invasive aster (Ageratina adenophora) invades and dominates forest understories in China:: altered soil microbial communities facilitate the invader and inhibit natives
复制标题
DOI：
10.1007/s11104-007-9230-8
复制
发表时间：
2007-05-01
期刊：
影响因子：
4.9
通讯作者：
Liu, Bo
中科院分区：
文献类型：
--
作者：
Niu, Hong-Bang;Liu, Wan-Xue;Liu, Bo
外来植物入侵可能会改变地下微生物群落，入侵引起的土壤生物群的变化也可能影响入侵植物与本地物种之间的相互作用。越来越多的证据表明，土壤生物群对入侵植物和本地植物的反馈导致了外来植物的成功入侵。为了研究这种潜在的入侵机制，对紫茎泽兰入侵原生森林群落的土壤微生物群落进行了研究。设计了植物-土壤生物群反馈实验，以评价入侵诱导的土壤生物群变化对植物生长的影响，以及紫茎泽兰与3种本土植物之间的相互作用。土壤分析表明，重侵害区土壤硝态氮(NO3--N)、氨氮(NH4+-N)、速效磷、速效钾含量显著高于新侵害区。土壤微生物群落结构在所有四个地点都有明显的不同。紫茎泽兰入侵显著增加了土壤中泡状丛枝菌根真菌(VAM)的丰度和菌菌比。温室试验表明，重度入侵地土壤生物群对土生植物的抑制作用大于对紫茎泽兰的抑制作用，土生植物地土壤生物群对土生植物的生长有抑制作用，而对紫茎泽兰的抑制作用不明显。与3种乡土植物相比，4个样地的土壤生物量都增加了紫茎泽兰的相对优势度，重度入侵样地的土壤生物群对紫茎泽兰相对优势度指数(平均提高20%)的有利作用大于未入侵样地的土壤生物群。我们的结果表明，与原住民群落相关的土壤群落对紫茎泽兰的影响比原住民更积极，一旦入侵者确立，它就会以一种有利于自己和抑制原住民的方式进一步改变土壤群落，帮助促进入侵。紫茎泽兰建成后的土壤生物群变化可能是其入侵过程中促进自身生长和抑制本土植物生长的重要环节。
Exotic plant invasion may alter underground microbial communities, and invasion-induced changes of soil biota may also affect the interaction between invasive plants and resident native species. Increasing evidence suggests that feedback of soil biota to invasive and native plants leads to successful exotic plant invasion. To examine this possible underlying invasion mechanism, soil microbial communities were studied where Ageratina adenophora was invading a native forest community. The plant-soil biota feedback experiments were designed to assess the effect of invasion-induced changes of soil biota on plant growth, and interactions between A. adenophora and three native plant species. Soil analysis showed that nitrate nitrogen (NO3--N), ammonium nitrogen (NH4+-N), and available P and K content were significantly higher in a heavily invaded site than in a newly invaded site. The structure of the soil microbial community was clearly different in all four sites. Ageratina adenophora invasion strongly increased the abundance of soil VAM (vesicular-arbuscular mycorrhizal fungi) and the fungi/bacteria ratio. A greenhouse experiment indicated that the soil biota in the heavily invaded site had a greater inhibitory effect on native plant species than on A. adenophora and that soil biota in the native plant site inhibited the growth of native plant species, but not of A. adenophora. Soil biota in all four sites increased A. adenophora relative dominance compared with each of the three native plant species and soil biota in the heavily invaded site had greater beneficial effects on A. adenophora relative dominance index (20% higher on average) than soil biota in the non-invaded site. Our results suggest that A. adenophora is more positively affected by the soil community associated with native communities than are resident natives, and once the invader becomes established it further alters the soil community in a way that favors itself and inhibits natives, helping to promote the invasion. Soil biota alteration after A. adenophora establishment may be an important part of its invasion process to facilitate itself and inhibit native plants.