Previous studies indicated that early- and mid-successional plants generally suffered from negative to neutral plant–soil feedback (PSF). However，the role of such plant–soil feedback during the postglacial primary succession of plants and microorganisms is not fully understood. 

In a study published in Science of The Total Environment, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) and Chengdu Institute of Biology (CIB) tried to uncover the factors for ecosystem succession during glacial retreat based on plant competition, microbial community structure and plant–soil–microbial interactions. They tested whether plant–soil–microbial interactions explain plant primary succession in the Gongga Mountain glacial retreat chronosequence. 

To ascertain how plant–soil–microbial interactions mediate the vegetation dynamics, the researchers treated soils from three stages of primary succession in Mount Gongga glacial retreat with sterilized soil and living soil as controls, and then planted with combinations of intra- and inter-species competition.  

The researchers then used plant biomass to assess inter-plant competitiveness and the effects of habitat legacies. Afterwards, they measured microbial community (bacteria and fungi) composition in the soil and mycorrhizal colonization rate to estimate the patterns and influence factors of plant–soil–microbial interactions on aboveground plant succession.  

They found that plant–soil–microbial interactions were coincident with the occurrence of pioneer plants during primary succession in glacial retreat areas. Habitat legacy effect shifted from negative in the early stages to positive in the middle and late stages due to increasing nutrient availability and the presence of specific microbial groups.Ectomycorrhizal fungal specialists were most important for the plant–microbial interactions during the late successional stages. Turnover of pathogenic fungi determined habitat legacy effect, especially during the early stage. 

“Our results provide a better ecological understanding and allow predictions of vegetation succession on young soil and new ecosystem development,” said LI Weitao of XTBG. 

Contact 

LI Weitao Ph.D 

Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China     

E-mail: liweitao@xtbg.ac.cn