Welcome to Acta Prataculturae Sinica ! Today is

Acta Prataculturae Sinica ›› 2025, Vol. 34 ›› Issue (12): 33-49.DOI: 10.11686/cyxb2025004

Previous Articles     Next Articles

Carbon and water fluxes of different grassland types in the growing season based on the Common Land Model

Yang CHENG(), Chang-qing JING()   

  1. College of Grassland Science,Xinjiang Agricultural University,Key Laboratory of Grassland Resources and Ecology,Key Laboratory of Grassland Resources and Ecology of Western Arid Region,Ministry of Education,Urumqi 830052,China
  • Received:2025-01-07 Revised:2025-03-04 Online:2025-12-20 Published:2025-10-20
  • Contact: Chang-qing JING

Abstract:

Grassland ecosystems occupy the largest area among the terrestrial ecosystems in China, and their carbon and water fluxes play an important role in the land-air carbon and energy cycles. In this study, we optimized the root water uptake function (RWUF) and soil respiration function (SRF) of a Common Land Model, evaluated the applicability of the model to the simulation of carbon and water flux in different grassland ecosystems, simulated and analyzed trends in the seasonal and daily variation of carbon and water flux in different grassland types, and discussed the key factors influencing water and carbon processes in different grassland types. It was found that the Common Land Model was suitable for simulating carbon and water fluxes in different grassland ecosystems during the growing season, and the simulation results of evapotranspiration (ET) were better than those of carbon fluxes (gross primary productivity, ecosystem respiration, net ecosystem exchange). The total evapotranspiration of temperate desert, temperate steppe, desert steppe and mountain meadow in the growing season is greater than precipitation, and the carbon uptake of temperate steppe, desert steppe and mountain meadow in the growing season is -28.2, -41.5, and -152.0 g C·m-2, respectively, showing carbon fixation and carbon sequestration capacity ranking as: Mountain meadow>desert steppe>temperate steppe. Precipitation and net radiation were the most important factors affecting evapotranspiration of different grassland types during the growing season, and were significantly positively correlated with carbon and water flux (P<0.01). With low vegetation cover in arid land, evapotranspiration was more significantly affected by soil evaporation than was the case with grassland, and evapotranspiration of grassland with good vegetation cover was more affected by plant transpiration. Leaf area index (LAI) was the most important factor affecting carbon exchange in grassland ecosystems, followed by precipitation and net radiation. This study provides a framework for understanding the carbon and water cycling processes of grassland ecosystems and their responses to climate change in arid and semi-arid areas.

Key words: carbon flux, water flux, Common Land Model, parameter optimization of grassland ecosystem