title: Biomass partitioning and its relationship with the environmental factors at the alpine steppe in Northern Tibet.
abstract: Alpine steppe is considered to be the largest grassland type on the Tibetan Plateau. This grassland contributes to the global carbon cycle and is sensitive to climate changes. The allocation of biomass in an ecosystem affects plant growth and the overall functioning of the ecosystem. However, the mechanism by which plant biomass is allocated on the alpine steppe remains unclear. In this study, biomass allocation and its relationship to environmental factors on the alpine grassland were studied by a meta-analysis of 32 field sites across the alpine steppe of the northern Tibetan Plateau. We found that there is less above-ground biomass (M A ) and below-ground biomass (M B ) in the alpine steppe than there is in alpine meadows and temperate grasslands. By contrast, the root-to-shoot ratio (R:S) in the alpine steppe is higher than it is in alpine meadows and temperate grasslands. Although temperature maintained the biomass in the alpine steppe, precipitation was found to considerably influence M A , M B , and R:S, as shown by ordination space partitioning. After standardized major axis (SMA) analysis, we found that allocation of biomass on the alpine steppe is supported by the allometric biomass partitioning hypothesis rather than the isometric allocation hypothesis. Based on these results, we believe that M A and M B will decrease as a result of the increased aridity expected to occur in the future, which will reduce the landscape's capacity for carbon storage.
authors.affiliation: The Key Laboratory of Mountain Environment Evolution and Its Regulation, Institute of Mountain Hazard and Environment, CAS, Chengdu, China.
authors.forename: Jianbo
authors.initials: J
authors.lastname: Wu
authors.affiliation: The Key Laboratory of Mountain Environment Evolution and Its Regulation, Institute of Mountain Hazard and Environment, CAS, Chengdu, China ; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Hong
authors.affiliation: The Key Laboratory of Mountain Environment Evolution and Its Regulation, Institute of Mountain Hazard and Environment, CAS, Chengdu, China.
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Wang
authors.affiliation: The Key Laboratory of Mountain Environment Evolution and Its Regulation, Institute of Mountain Hazard and Environment, CAS, Chengdu, China ; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.affiliation: The Key Laboratory of Mountain Environment Evolution and Its Regulation, Institute of Mountain Hazard and Environment, CAS, Chengdu, China.
authors.forename: Xuyang
authors.initials: X
authors.lastname: Lu
authors.affiliation: The Key Laboratory of Mountain Environment Evolution and Its Regulation, Institute of Mountain Hazard and Environment, CAS, Chengdu, China.
authors.forename: Jihui
authors.initials: J
authors.lastname: Fan
authors.affiliation: The Key Laboratory of Mountain Environment Evolution and Its Regulation, Institute of Mountain Hazard and Environment, CAS, Chengdu, China.
authors.forename: Yanjiang
authors.initials: Y
authors.lastname: Cai
mesh_terms: D000531:Altitude; D018533:Biomass; D002244:Carbon / Q000737:chemistry*; D057486:Carbon Cycle; D002980:Climate; D017753:Ecosystem; D018517:Plant Roots / Q000502:physiology*; D018520:Plant Shoots / Q000502:physiology*; D006109:Poaceae / Q000502:physiology*; D013696:Temperature; D018609:Tibet
chemical_list: D002244:Carbon