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辐射变化对中亚热带杉木人工林净CO2交换的影响

1. 1中南林业科技大学生命科学与技术学院, 长沙 410004;
2湖南会同杉木林生态系统国家野外科学观测研究站, 湖南会同 418307
• 收稿日期:2021-03-10 接受日期:2021-07-01 出版日期:2022-01-15 发布日期:2022-07-15
• 通讯作者: * E-mail: 460749197@qq.com
• 作者简介:彭 丽, 女, 1995年生, 硕士研究生。主要从事生态系统生态学研究。E-mail: pengli1995@163.com
• 基金资助:
湖南省林业科技创新计划项目(XLKPT201712)和国家林业和草原局林业科技创新平台运行补助项目(2019132159)

Effects of radiation changes on net ecosystem exchange of carbon dioxide in a middle subtropical Chinese fir plantation

PENG Li1, ZHAO Zhong-hui1,2*, XIANG Wen-hua1,2, DENG Xiang-wen1,2, OUYANG Shuai1,2

1. 1College of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China;
2Huitong National Field Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystem in Hunan Province, Huitong 418307, Hunan, China
• Received:2021-03-10 Accepted:2021-07-01 Online:2022-01-15 Published:2022-07-15

Abstract: Total solar radiation is an important factor affecting carbon exchange in forest ecosystem. In order to understand the effects of radiation change on carbon exchange in Chinese fir plantation, long-term monitoring data of carbon dioxide flux and meteorological factors measured by open eddy covariance system and meteorological gradient observation system were used in this study. The clearness index (kt) was used to represent the condition of solar radiation. We analyzed the effects of kt on net ecosystem exchange of carbon dioxide (NEE) in the central subtropical Chinese fir plantation during the growing season (from April to October). The results showed that total solar radiation in clear sky was usually higher in the morning than that in the afternoon, and that NEE was lower in the morning than in the afternoon. Such difference in NEE reached the maximum when the solar elevation angle was about 50°. At the medium kt(0.42-0.52), carbon absorption of Chinese fir plantation was the strongest. The ave-rage maximum relative change of NEE in 10 years in different solar elevation angles ranged from 11.0% to 29.4%, while the minimum and maximum critical values appeared at 35°-40° and 45°-50°, respectively. When kt was at the moderate degree due to the existence of clouds, carbon absorption and diffuse photosynthetically active radiation of Chinese fir plantation reached the maximum, and the latter might be the main reason for the former. Moderate radiation condition with the presence of cloud clould promote NEE of Chinese fir plantation and lead to largest carbon absorption.