Different plant covers change soil respiration and its sources in subtropics

Abstract

Heterotrophic soil respiration (RH) and autotrophic soil respiration (RA) by a trenching method were monitored in four vegetation types in subtropical China from November 2011 to October 2012. The four vegetation types included a shrubland, a mixed-conifer, a mixed-legume, and a mixed-native species. The average RH was significantly greater in soils under the mixed-legume and the mixed-native species than in the shrubland and the mixed-conifer soils, and it affected the pattern of soil total respiration (RS) of the four soils. The change in RH was closely related to the variations of soil organic C, total N and P content, and microbial biomass C. The RA and the percentage of RS respired as RA were only significantly increased by the mixed-native species after reforestation. Probably, this depended on the highest fine root biomass of mixed-native species than the other vegetation types. Soil respiration sources were differently influenced by the reforestation due to different changes in soil chemical and biological properties and root biomass.