title: Rates of litter decomposition and soil respiration in relation to soil temperature and water in different-aged Pinus massoniana forests in the Three Gorges Reservoir Area, China.
abstract: To better understand the soil carbon dynamics and cycling in terrestrial ecosystems in response to environmental changes, we studied soil respiration, litter decomposition, and their relations to soil temperature and soil water content for 18-months (Aug. 2010-Jan. 2012) in three different-aged Pinus massoniana forests in the Three Gorges Reservoir Area, China. Across the experimental period, the mean total soil respiration and litter respiration were 1.94 and 0.81, 2.00 and 0.60, 2.19 and 0.71 µmol CO2 m(-2) s(-1), and the litter dry mass remaining was 57.6%, 56.2% and 61.3% in the 20-, 30-, and 46-year-old forests, respectively. We found that the temporal variations of soil respiration and litter decomposition rates can be well explained by soil temperature at 5 cm depth. Both the total soil respiration and litter respiration were significantly positively correlated with the litter decomposition rates. The mean contribution of the litter respiration to the total soil respiration was 31.0%-45.9% for the three different-aged forests. The present study found that the total soil respiration was not significantly affected by forest age when P. masonniana stands exceed a certain age (e.g. >20 years old), but it increased significantly with increased soil temperature. Hence, forest management strategies need to protect the understory vegetation to limit soil warming, in order to reduce the CO2 emission under the currently rapid global warming. The contribution of litter decomposition to the total soil respiration varies across spatial and temporal scales. This indicates the need for separate consideration of soil and litter respiration when assessing the climate impacts on forest carbon cycling.
authors.affiliation: State Forestry Administration Key Laboratory of Forest Ecology and Environment, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, PR China.
authors.forename: Wenfa
authors.initials: W
authors.lastname: Xiao
authors.affiliation: State Forestry Administration Key Laboratory of Forest Ecology and Environment, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, PR China; Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Fuyang, Zhejiang, PR China.
authors.forename: Xiaogai
authors.initials: X
authors.lastname: Ge
authors.affiliation: State Forestry Administration Key Laboratory of Forest Ecology and Environment, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, PR China.
authors.forename: Lixiong
authors.initials: L
authors.lastname: Zeng
authors.affiliation: State Forestry Administration Key Laboratory of Forest Ecology and Environment, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, PR China.
authors.forename: Zhilin
authors.initials: Z
authors.lastname: Huang
authors.affiliation: State Forestry Administration Key Laboratory of Forest Silviculture, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, PR China.
authors.forename: Jingpin
authors.initials: J
authors.lastname: Lei
authors.affiliation: Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Fuyang, Zhejiang, PR China.
authors.forename: Benzhi
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Swiss Federal Research Institute WSL, Birmensdorf, Switzerland; State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, PR China.
authors.forename: Maihe
authors.initials: M
authors.lastname: Li
mesh_terms: D057486:Carbon Cycle; D002245:Carbon Dioxide / Q000737:chemistry*; D002681:China; D065928:Forests; D057232:Global Warming; D007700:Kinetics; D028223:Pinus / Q000737:chemistry / Q000502:physiology*; D018515:Plant Leaves / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D012987:Soil; D014867:Water; D002245:Carbon Dioxide