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。申请人以前的调查表明，厄瓜多尔山地雨林中的本土热带树木以及河对岸重新造林地块中种植的苗木与大量丛枝菌根真菌有关。AMF的多样性和丰富度同样很高，但Glomus Group A序列类型组成明显不同。原始林木AMF在苗木上的缺失，可能是原始林木采伐后一定的损失，但也可能只是一种采样伪影。因此，应调查不同演替阶段退化草地中残留热带森林乔木和更新木本植物的AMF群落。结果应显示残存林木是否能够保持原始AMF潜力以及保留多久，以及原始AMF群落可以在多大程度上以多快的速度通过木本植物演替进行更新。AMF群落的明确变化或恢复可能决定退化热带地点自然更新森林的最终类型，次生林或初级林。

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.