title: Phosphatase activity in relation to key litter and soil properties in mature subtropical forests in China.
abstract: Phosphatase-mediated phosphorus (P) mineralization is one of the critical processes in biogeochemical cycling of P and determines soil P availability in forest ecosystems; however, the regulation of soil phosphatase activity remains elusive. This study investigated the potential extracellular activities of acid phosphomonoesterase (AcPME) and phosphodiesterase (PDE) and how they were related to key edaphic properties in the L horizon (undecomposed litter) and F/H horizon (fermented and humified litter) and the underlying mineral soil at the 0-15cm depth in eight mature subtropical forests in China. AcPME activity decreased significantly in the order of F/H horizon>L horizon>mineral soil horizon, while the order for PDE activity was L horizon=F/H horizon>mineral soil horizon. AcPME (X axis) and PDE (Y axis) activities were positively correlated in all horizons with significantly higher slope in the L and F/H horizons than in the mineral soil horizon. Both AcPME and PDE activities were positively related to microbial biomass C, moisture content and water-holding capacity in the L horizon, and were positively related to soil C:P, N:P and C:N ratios and fine root (diameter≤2mm) biomass in the mineral soil horizon. Both enzyme activities were also interactively affected by forest and horizon, partly due to the interactive effect of forest and horizon on microbial biomass. Our results suggest that modulator(s) of the potential extracellular activity of phosphatases vary with horizon, depending on the relative C, P and water availability of the horizon.
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; Griffith School of Environment, Griffith University, Nathan, Qld 4111, Australia.
authors.forename: Enqing
authors.initials: E
authors.lastname: Hou
authors.affiliation: Griffith School of Environment, Griffith University, Nathan, Qld 4111, Australia. Electronic address: c.chen@griffith.edu.au.
authors.forename: Chengrong
authors.initials: C
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. Electronic address: dzwen@scbg.ac.cn.
authors.forename: Dazhi
authors.initials: D
authors.lastname: Wen
authors.affiliation: Griffith School of Environment, Griffith University, Nathan, Qld 4111, Australia.
authors.forename: Xian
authors.initials: X
authors.lastname: Liu
mesh_terms: D002681:China; D017753:Ecosystem; D004784:Environmental Monitoring; D065928:Forests; D010744:Phosphoric Monoester Hydrolases / Q000032:analysis*; D010758:Phosphorus / Q000032:analysis; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D014329:Tropical Climate
chemical_list: D012987:Soil; D010758:Phosphorus; D010744:Phosphoric Monoester Hydrolases
keywords: Acid phosphomonoesterase; C:N:P stoichiometry; Fine root biomass; Mature forest; Microbial biomass C; Phosphodiesterase