丛枝菌根真菌在内的土壤真菌对入侵植物紫茎泽兰的正反馈：证据来自野外实验

包括紫茎泽兰在内的许多外来植物都能够与新入侵生境的丛枝菌根真菌（ AMF）形成互利共生，因此菌根真菌如何调节外来植物种的入侵是当前亟待研究的问题。测定了紫茎泽兰入侵不同阶段（紫茎泽兰呈零星丛状分布于本地植物群落中部分入侵生境]及紫茎泽兰单优群落形成期入侵生境]）的土壤化学性状，而后通过野外试验，采用杀真菌剂处理，研究了包括AMF在内的土壤真菌对紫茎泽兰入侵的反馈作用。紫茎泽兰入侵改变了土壤化学性状。施用杀真菌剂降低了紫茎泽兰叶面积、叶片碳、氮、磷、和δ13 C含量。综合分析发现，在紫茎泽兰与本地植物混生群落中，土壤真菌能够增加紫茎泽兰叶片碳和δ13 C含量，但是不能提高紫茎泽兰的光合作用，表明碳和δ13 C含量的提高，不是光合作用的结果，而是通过其他机制实现的。因此可以得出，在部分入侵生境中，碳从土壤或临近植物经由菌丝网向紫茎泽兰转移。紫茎泽兰入侵不同阶段土壤养分的变化利于紫茎泽兰种群建立，同时利于紫茎泽兰借助真菌（尤其是AMF）从土壤或临近植物转移碳，促进种群扩散，这可能是紫茎泽兰入侵的机制之一。

Positive feedback of soil fungi, including arbuscular mycorrhizal fungi, to the invasive weed Ageratina adenophora: evidence from field studies

Background Many alien plant species including Ageratina adenophora can establish a mutualistic symbiotic relationship with arbuscular mycorrhizal fungi （AMF） in their newly invaded habitats.Therefore, how these alien species invasions are mediated by mycorrhizal fungi urgently needs to be explored .Method]To explore the feedback of soil fungi , including AMF to the invasive plant A.adenophora, the soil chemical properties at different invasion stages （ A.adenophora grown with native plants around Par-tially invaded habitats ];and grown as its single species Invaded habitats ] ） were measured , and then the feedback of soil fungi in-cluding AMF to A.adenophora were investigated in the field with fungicide treatment .Result]The chemical properties of soil were changed under A.adenophora invasion.Fungicide decreased the leaf area, carbon, nitrogen, phosphorus, andδ13C content of A.ad-enophora.Conclusion and significance]Synthetic analysis found that soil fungi increased the carbon and the δ13 C content of A.ade-nophora leaves, but didn′t increase the photosynthesis of A.adenophora in partially invaded habitats , indicating that the increased carbon andδ13 C content of A.adenophora leaves was not the result of photosynthesis but of some other mechanism .We supposed that carbon was transported from the soil or adjacent native weeds to A.adenophora through a mycelial network in partially invaded habi-tats.The changes in soil nutrients at different invasion phases may be one mechanism of A.adenophora invasion, and favors its es-tablishment via fungi especially AMF , and transfer of carbon from soil or native plants stimulates its further spread .