title: Effects of plant species richness on13C assimilate partitioning in artificial grasslands of different established ages.
abstract: Artificial grasslands play a role in carbon storage on the Qinghai-Tibetan Plateau. The artificial grasslands exhibit decreased proportions of graminate and increased species richness with age. However, the effect of the graminate proportions and species richness on ecosystem C stocks in artificial grasslands have not been elucidated. We conducted an in situ13C pulse-labeling experiment in August 2012 using artificial grasslands that had been established for two years (2Y), five years (5Y), and twelve years (12Y). Each region was plowed fallow from severely degraded alpine meadow in the Qinghai-Tibetan Plateau. The 12Y grassland had moderate proportions of graminate and the highest species richness. This region showed more recovered13C in soil and a longer mean residence time, which suggests species richness controls the ecosystem C stock. The loss rate of leaf-assimilated C of the graminate-dominant plant species Elymus nutans in artificial grasslands of different ages was lowest in the 12Y grassland, which also had the highest species richness. Thus the lower loss rate of leaf-assimilated C can be partially responsible for the larger ecosystem carbon stocks in the 12Y grassland. This finding is a novel mechanism for the effects of species richness on the increase in ecosystem functioning.
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xinning Road 31, Xining 810008, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Longhua
authors.initials: L
authors.lastname: Xu
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xinning Road 31, Xining 810008, China.|The Key Laboratory of Restoration Ecology in Cold Region of Qinghai Province, Xining, 810008, China.
authors.forename: Buqing
authors.initials: B
authors.lastname: Yao
authors.affiliation: College of Life Science and Geography, Qinghai Normal University, Wusi west 38, Xining 810008, China.
authors.forename: Wenying
authors.initials: W
authors.lastname: Wang
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xinning Road 31, Xining 810008, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Fangping
authors.initials: F
authors.lastname: Wang
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xinning Road 31, Xining 810008, China.|The Key Laboratory of Restoration Ecology in Cold Region of Qinghai Province, Xining, 810008, China.
authors.forename: Huakun
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Qinghai Academy of Animal and Veterinary Sciences, Hutai A lane 3, Xining 810016, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Shi
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xinning Road 31, Xining 810008, China.
authors.forename: Xinquan
authors.initials: X
authors.lastname: Zhao
mesh_terms: D044822:Biodiversity; D018533:Biomass; D002244:Carbon / Q000032:analysis; D002247:Carbon Isotopes / Q000032:analysis*; D019069:Cell Respiration; D065948:Grassland; D018517:Plant Roots / Q000737:chemistry; D018520:Plant Shoots / Q000737:chemistry; D012987:Soil / Q000737:chemistry; D013045:Species Specificity; D013997:Time Factors
chemical_list: D002247:Carbon Isotopes; D012987:Soil; D002244:Carbon; C000615229:Carbon-13