Climate Change

Biography

Biography: Lili Wei

Abstract

Arbuscular mycorrhizal fungi (AMF) are the most widespread obligate biotrophic plant symbionts and their extra-radical hyphae have the potential in the regulation of carbon (C) cycling by enhancing soil aggregation or by stimulating priming effect. When exposed to the elevated CO2,hyphae growth and colonization rate were increased, and consequently lead to more profound effects on C cycling. However, previous studies on AMF functions in the decomposition of organic C have focused on hyphosphere (i.e. at presence of hyphae), very limited information is available formyco rhizosphere (i.e. at presence of roots and hyphae). This study was set to test the differences in organic matter decomposition (indicated by CO2 efflux) between myco rhizosphere and hyphosphere. Two microcosm experiments were carried out using rhizobox method to separate soil environment into root- and hyphae-compartment. AMF inoculation induced an increase of CO2 efflux from the root-compartment, while there was no change in the hyphae-compartment. Stable C isotope analyses combing with the soil microbial abundance analys is indicated that the increased production of CO2 in root-compartment was related to the increase of the exudates (i.e. the easy decomposed organic C input) from roots which stimulated by AMF. The crucial role of AMF presence in C cycling was confirmed with differential CO2 efflux associated with mycorhizosphere vs hyphosphere environment.