title: Soil Respiration in Semiarid Temperate Grasslands under Various Land Management.
abstract: Soil respiration, a major component of the global carbon cycle, is significantly influenced by land management practices. Grasslands are potentially a major sink for carbon, but can also be a source. Here, we investigated the potential effect of land management (grazing, clipping, and ungrazed enclosures) on soil respiration in the semiarid grassland of northern China. Our results showed the mean soil respiration was significantly higher under enclosures (2.17 μmol.m(-2).s(-1)) and clipping (2.06 μmol.m(-2).s(-1)) than under grazing (1.65 μmol.m-(2).s(-1)) over the three growing seasons. The high rates of soil respiration under enclosure and clipping were associated with the higher belowground net primary productivity (BNPP). Our analyses indicated that soil respiration was primarily related to BNPP under grazing, to soil water content under clipping. Using structural equation models, we found that soil water content, aboveground net primary productivity (ANPP) and BNPP regulated soil respiration, with soil water content as the predominant factor. Our findings highlight that management-induced changes in abiotic (soil temperature and soil water content) and biotic (ANPP and BNPP) factors regulate soil respiration in the semiarid temperate grassland of northern China.
authors.affiliation: Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot, 010010, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot, 010010, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Ji
authors.affiliation: Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot, 010010, China.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Hou
authors.affiliation: Semiarid Prairie Agricultural Research Center (SPARC), AAFC-AAC, Box 1030, Swift Current, Saskatchewan, S9H 3X2, Canada.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Schellenberg
mesh_terms: D003247:Conservation of Natural Resources; D017753:Ecosystem; D008986:Mongolia; D006109:Poaceae; D012987:Soil
chemical_list: D012987:Soil