title: Microbial properties explain temporal variation in soil respiration in a grassland subjected to nitrogen addition.
abstract: The role of soil microbial variables in shaping the temporal variability of soil respiration has been well acknowledged but is poorly understood, particularly under elevated nitrogen (N) deposition conditions. We measured soil respiration along with soil microbial properties during the early, middle, and late growing seasons in temperate grassland plots that had been treated with N additions of 0, 2, 4, 8, 16, or 32 g N m(-2) yr(-1) for 10 years. Representing the averages over three observation periods, total (Rs) and heterotrophic (Rh) respiration were highest with 4 g N m(-2) yr(-1), but autotrophic respiration (Ra) was highest with 8 to 16 g N m(-2) yr(-1). Also, the responses of Rh and Ra were unsynchronized considering the periods separately. N addition had no significant impact on the temperature sensitivity (Q10) for Rs but inhibited the Q10 for Rh. Significant interactions between observation period and N level occurred in soil respiration components, and the temporal variations in soil respiration components were mostly associated with changes in microbial biomass carbon (MBC) and phospholipid fatty acids (PLFAs). Further observation on soil organic carbon and root biomass is needed to reveal the long-term effect of N deposition on soil C sequestration.
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875,China.|Academy of Disaster Reduction and Emergency Management, Beijing Normal University, Beijing 100875, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875,China.|College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Yinghui
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875,China.|College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Shanmei
authors.initials: S
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875,China.|College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Niu
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875,China.|Academy of Disaster Reduction and Emergency Management, Beijing Normal University, Beijing 100875, China.
authors.forename: Yuqiang
authors.initials: Y
authors.lastname: Tian
mesh_terms: D018533:Biomass; D002244:Carbon / Q000737:chemistry / Q000378:metabolism; D065948:Grassland; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism; D025341:Principal Component Analysis; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D012987:Soil; D014867:Water; D002244:Carbon; D009584:Nitrogen