Spatial and temporal patterns of above- and below- ground biomass over the Tibet Plateau grasslands and their sensitivity to climate change

Yatang Wu; Fu Li; Jing Zhang; YiLiang Liu; Han Li; Bingrong Zhou; Beibei Shen; Lulu Hou; Dawei Xu; Lei Ding; Shiyang Chen; Xiaoni Liu; Jinbang Peng

doi:10.1016/j.scitotenv.2024.170900

Spatial and temporal patterns of above- and below- ground biomass over the Tibet Plateau grasslands and their sensitivity to climate change

Sci Total Environ. 2024 Apr 1:919:170900. doi: 10.1016/j.scitotenv.2024.170900. Epub 2024 Feb 13.

Authors

Yatang Wu¹, Fu Li², Jing Zhang³, YiLiang Liu³, Han Li³, Bingrong Zhou², Beibei Shen⁴, Lulu Hou⁵, Dawei Xu⁵, Lei Ding⁶, Shiyang Chen⁵, Xiaoni Liu⁷, Jinbang Peng⁸

Affiliations

¹ Key Laboratory of Grassland Ecosystem, Ministry of Education, Sino-U.S. Centers for Grazing Land Ecosystem Sustainability, Ministry of Science and Technology, Pratacultural Engineering Laboratory of Gansu Province, Pratacultural College, Gansu Agricultural University, Lanzhou 730070, China.
² Qinghai Institute of Meteorological Sciences, Xining 810001, China.
³ National Remote Sensing Center of China, No. 8A Liulinguan Nanli, Haidian District, Beijing 100036, China.
⁴ Aerospace Science and Industry (Beijing) Spatial Information Application Co., Ltd., Beijing 100070, China; State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
⁵ State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
⁶ State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China; College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
⁷ Key Laboratory of Grassland Ecosystem, Ministry of Education, Sino-U.S. Centers for Grazing Land Ecosystem Sustainability, Ministry of Science and Technology, Pratacultural Engineering Laboratory of Gansu Province, Pratacultural College, Gansu Agricultural University, Lanzhou 730070, China. Electronic address: liuxn@gsau.edu.cn.
⁸ State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: pengjinbang@caas.cn.

PMID: 38354804
DOI: 10.1016/j.scitotenv.2024.170900

Abstract

The sensitivity of grassland above- (AGB, gC m^-2) and below-ground biomass (BGB, gC m^-2) to climate has been shown to be significant on the Tibetan Plateau, however, the spatial patterns and sensitivity of biomass with altitudinal change needs to be quantitated. In this study, large data sets of AGB and BGB during the peak growth season, and the corresponding geographical and climate conditions in the grasslands of the Tibetan Plateau between 2001 and 2020 were analyzed, and modelled using a Cubist regression trees algorithm. The mean values for AGB and BGB were 61.3 and 1304.3 gC m^-2, respectively, for the whole region over the two decades. There was a significant change in spatial AGB of 64.8 % on the Plateau (P < 0.05, with areas where AGB increased being twice as large as areas where AGB decreased), while BGB did not change significantly in majority the of the region (≥ 90.1 %, P > 0.05). In general, the areas where AGB showed positive partial correlations with precipitation were larger than the areas where AGB had positive correlations with temperature (P < 0.05). However, these trends varied depending on the climatic conditions: in the wetter regions, temperature had a greater effect on the size of the areas with positive AGB responses than precipitation (P < 0.05), while precipitation had a greater effect on the size of areas with positive BGB changes than temperature (P < 0.05). In the drier areas, however, precipitation affected the AGB response significantly compared to temperature (P < 0.05), while temperature influenced the BGB response greater than precipitation (P < 0.05). The response and sensitivity of grassland biomass to temperature and precipitation varied according to the altitude of the Plateau: the response and sensitivity were stronger and more sensitive at medium altitudes, and weak at the higher or lower altitudes. Likely, this phenomenon was resulted from the natural selection of plants to maintain the efficient use of resources during un-favourable and stressed conditions for maximum plant development and growth. These findings will help assess the ecological consequences of global climate change for the grasslands of the Tibetan Plateau, particularly in those regions with highly variable altitudes.

Keywords: Alpine grassland; Altitude; Belowground biomass; Carbon; Climate change; Cubist.

MeSH terms

Biomass
Climate Change*
Ecosystem
Grassland*
Plants
Tibet