Chin J Plant Ecol ›› 2022, Vol. 46 ›› Issue (12): 1461-1472.DOI: 10.17521/cjpe.2021.0426

Special Issue: 生态遥感及应用 光合作用 生态系统碳水能量通量

• Special feature: Ecosystem carbon and water fluxes in ecological vulnerable areas of China • Previous Articles     Next Articles

Temporal and spatial variations of ecosystem photosynthetic parameters in arid and semi-arid areas of China and its influencing factors

LIN Yong1,2, CHEN Zhi1,2,3,*(), YANG Meng1,2, CHEN Shi-Ping2,4, GAO Yan-Hong5, LIU Ran2,6, HAO Yan-Bin2, XIN Xiao-Ping7, ZHOU Li8, YU Gui-Rui1,2,3   

  1. 1Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
    2College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
    3Yanshan Earth Critical Zone and Surface Fluxes Research Station, University of Chinese Academy of Sciences, Beijing 100049, China
    4State Key Laboratory of Vegetation and Environment Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    5Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
    6State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi 830011, China
    7Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
    8Chinese Academy of Meteorological Sciences, Beijing 100081, China
  • Received:2021-11-20 Accepted:2022-03-11 Online:2022-12-20 Published:2023-01-13
  • Contact: *CHEN Zhi(chenz@igsnrr.ac.cn)
  • Supported by:
    National Natural Science Foundation of China(41991234);Science and Technology Basic Investigation Program of China(2019FY101302)

Abstract:

Aims Ecosystem apparent quantum yield (α) and maximum photosynthetic rate (Pmax) are important parameters reflecting the photosynthetic characteristics of ecosystem, and also important physiological parameters in ecosystem model simulation and remote sensing inversion. The objectives of this study were to: (1) analyze the characteristics and spatial-temporal variations of the light response parameters of ecosystems in arid and semi-arid areas; and (2) reveal the key factors affecting the photosynthetic parameters and its underlying mechanisms in arid and semi-arid areas, so as to provide a scientific basis for the study of ecosystem photosynthesis and response to climate change on a regional scale.

Methods The observational fluxes and synchronous meteorological data of 9 stations in arid and semi-arid area were integrated from ChinaFLUX. The non-rectangular hyperbolic equations were used to fit the light response parameters and which influencing factors were identified by linear regression, multiple stepwise regression and path analysis.

Important findings There were obvious spatial and temporal variations in ecosystem photosynthetic parameters in arid and semi-arid areas. The photosynthetic parameters increased gradually from desert, desert grassland, typical grassland to meadow grassland. Precipitation was the dominant environmental factor of the spatial variations of photosynthetic parameters, and it also affected the spatial variation of leaf area index, both of them jointly determine the spatial variation of photosynthetic parameters. α and Pmax have an obvious increasing trend with the increase of precipitation, and there was a significant negative correlation between temperature and α, but the effect of radiation on the spatial variation of photosynthetic parameters was not significant. In the growing season, Pmax and α increased first and then decreased, but the monthly variability and peak time of different vegetation types were different, the photosynthetic parameters of meadow grassland had the greatest monthly variability. The monthly dynamics of α was mainly controlled by temperature and radiation, while Pmax was regulated by temperature and radiation in desert and desert grassland, and by soil water content in typical grassland and meadow grassland. Ecosystem α were 0.000 47-0.002 12 mg·μmol-1, and Pmax were 0.11-0.78 mg·m-2·s-1 in arid and semi-arid area, which were at a low level compared with other grassland ecosystems. High temperature and low soil water supply were likely the main factors restricting the photosynthetic parameters in arid and semi-arid areas.

Key words: apparent quantum yield, maximum photosynthetic rate, arid and semi-arid region, photosynthetic parameter, eddy-covariance (EC) technique