title: Are variations in heterotrophic soil respiration related to changes in substrate availability and microbial biomass carbon in the subtropical forests?
abstract: Soil temperature and moisture are widely-recognized controlling factors on heterotrophic soil respiration (Rh), although they often explain only a portion of Rh variability. How other soil physicochemical and microbial properties may contribute to Rh variability has been less studied. We conducted field measurements on Rh half-monthly and associated soil properties monthly for two years in four subtropical forests of southern China to assess influences of carbon availability and microbial properties on Rh. Rh in coniferous forest was significantly lower than that in the other three broadleaf species-dominated forests and exhibited obvious seasonal variations in the four forests (P < 0.05). Temperature was the primary factor influencing the seasonal variability of Rh while moisture was not in these humid subtropical forests. The quantity and decomposability of dissolved organic carbon (DOC) were significantly important to Rh variations, but the effect of DOC content on Rh was confounded with temperature, as revealed by partial mantel test. Microbial biomass carbon (MBC) was significantly related to Rh variations across forests during the warm season (P = 0.043). Our results suggest that DOC and MBC may be important when predicting Rh under some conditions, and highlight the complexity by mutual effects of them with environmental factors on Rh variations.
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wei
authors.affiliation: School of Geographical Sciences, Guangzhou University, Guangzhou 510006, China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Chen
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Guoliang
authors.initials: G
authors.lastname: Xiao
authors.affiliation: Laboratoire des Sciences du Climat et de l'Environnement, Centre National de Recherche Scientifique, Gif Sur Yvette 91190, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Guenet
authors.affiliation: Research Group of Plant and Vegetation Ecology, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
authors.forename: Sara
authors.initials: S
authors.lastname: Vicca
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors.forename: Weijun
authors.initials: W
authors.lastname: Shen
mesh_terms: D018533:Biomass; D002244:Carbon / Q000378:metabolism*; D065928:Forests; D012987:Soil; D014329:Tropical Climate
chemical_list: D012987:Soil; D002244:Carbon