Arbuscular mycorrhizal communities in different stages of succession after loss of pristine forest

丛枝菌根真菌（AMF）与根的结合是热带树木生长和存活的先决条件。申请人先前的调查显示，厄瓜多尔山地雨林中的本地热带树木以及河对岸重新造林地块中的种植幼苗与大量丛枝菌根真菌有关。AMF的多样性和丰富度同样高，但球囊霉A组序列类型组成出现明显不同。幼苗上缺乏大部分原始森林AMF可能表明在清除原始森林树木后确实存在损失，但也可能只是一个采样假象。因此，应调查不同演替阶段退化草地中残留热带森林树木和再生木本植物的AMF群落。研究结果将表明，如果和多长时间的残余林木可以保持原始AMF的潜力，在何种程度上和如何快速的原始AMF社区可能会再生木本植物演替。AMF群落的确定变化或恢复可能决定退化热带地区自然更新林的最终类型，次生林或原生林。

Association of arbuscular mycorrhizal fungi (AMF) with roots is a pre-requisite for growth and survival of tropical trees. Previous investigations of the applicant revealed that native tropical trees in the Ecuadorian mountain rain forest as well as planted seedlings in reforestation plots on the opposite river side were associated with large numbers of arbuscular mycorrhizal fungi. Diversity and richness of AMF was found similarly high, but Glomus Group A sequence type composition appeared as distinctly different. The lack of most of pristine forest AMF on seedlings may indicate definite loss after clearing of the primary forest trees, but may also be just a sampling artefact. AMF communities of remnant tropical forest trees and regenerating woody plants in the degraded pastures of different succession stages shall therefore be investigated. Results shall show if and how long remnant forest trees can preserve the original AMF potential and to which extent and how fast the original AMF community may regenerate with woody plant successions. Definite change or rehabilitation of the AMF community may determine the final type, secondary or primary, of naturally regenerating forest on degraded tropical sites.