Chinese Journal of Agrometeorology ›› 2025, Vol. 46 ›› Issue (10): 1425-1437.doi: 10.3969/j.issn.1000-6362.2025.10.005

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Energy Partitioning of a Pinus sylvestris var. mongolica Plantation in the Western Liaoning Province, China

GAO Xiang, PEI Song-yi, CAI Jin-feng, HUANG Hui, ZHANG Jin-song   

  1. 1. Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China; 2. Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forest University, Nanjing 210037; 3. Henan Xiaolangdi Forest Ecosystem National Observation and Research Station, Jiyuan 454650; 4. State-owned Jianping County Heishui Mechanized Forest Farm, Chaoyang 122000
  • Received:2024-12-10 Online:2025-10-20 Published:2025-10-16

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Abstract:

Eddy covariance method and corresponding meteorological system were used to observe a Pinus sylvestris var. mongolica plantation in the western Liaoning province, to ascertain the process of energy flow, to reveal the relationship between the key parameters of energy partitioning and environmental factors in two years, and finally to provide support for a deep understanding of the complex relationship between terrestrial vegetation and climate change. In 2021 and 2022, downward longwave radiation offset 82% and 81% of upward longwave radiation, 12% and 11% of downward shortwave radiation (Sd) was reflected back to the atmosphere by the land surface, 20% and 21% of downward radiation was transformed into net radiation (Rn), respectively. In the non−growing season, the average ratio of soil heat flux (G) and latent heat flux (LE) to Rn were −0.20 and 0.20, respectively. In the growing season, the average ratio of sensible heat flux (H) and LE to Rn were 0.57 and 0.39, respectively. At half−hour and daily time scales, the general trend of evaporative fraction (EF) was contrary to that of Bowen ratio. Among the environmental factors that obviously influenced daily EF during the growing season of 2021, daily Sd, vapor pressure deficit and wind speed were negative effect, daily air relative humidity (Ha), top soil water content (SWC), and normalized difference vegetation index (NDVI) were positive effect, and the correlation coefficient between daily EF and SWC was highest. The important controlling factors of daily EF during the growing season of 2022 were daily Sd, air temperature, Ha, SWC and NDVI, all of those factors were positive effect, and the correlation coefficient of NDVI was highest. In the Pinus sylvestris var. mongolica plantation of the western Liaoning province, G was an important energy source during the non−growing season, H was the main energy consumption during the growing season, and water supply and vegetation growth dominated the energy partitioning in this plantation. 

Key words: Pinus sylvestris var. mongolica plantation, Energy partitioning, Evaporative fraction, Bowen ratio