摘要
高寒草地是青藏高原分布面积最广的植被类型,开展不同类型高寒草地生态系统碳通量的研究,有助于科学评估该地区生态系统碳收支对区域乃至全球碳平衡的贡献。文章利用高寒荒漠草地涡度相关观测数据,分析了生态系统CO_(2)净交换(Net Ecosystem Exchange,NEE)的日变化和季节变化特征,并定量评估了NEE与环境因子的关系。结果表明:在生长季(6—9月),高寒荒漠草地NEE日变化呈现U形曲线,在季节尺度上则为明显的碳汇,生长季碳净吸收量为105.67 g C/m_(2);白天NEE显著受到光合有效辐控制(R^(2)≥0.63、p<0.01),而同时与气温、饱和水气压差均呈显著负相关(R^(2)≥0.9、p<0.05);生长季冠层水平的水分利用效率为3.15 g CO_(2)/kg H 2 O,逐日的水分利用效率与蒸散量呈显著负相关(R^(2)=0.55、p<0.01)。
Alpine grassland is most widely distributed across the Qinghai-Tibet Plateau,so carrying out studies on the carbon flux in different alpine grassland ecosystems is helpful to scientifically assess the contribution of carbon budget in this ecosystem to regional and even global carbon balance.Based on measurement data of the eddy covariance system in an alpine desert grassland,the characteristics of diurnal and seasonal changes of Net Ecosystem Exchange(NEE)were analyzed,and the correlation between NEE and environmental factors was also quantitatively evaluated.The results showed that the diurnal variation of NEE in alpine desert grassland exhibited a U-shaped curve during the growing season(June to September),while its seasonal variation showed an obvious carbon sink,with the total carbon uptake of 105.67 g C/m_(2).NEE was mainly controlled by photosynthetic active radiation during the daytime(R^(2)≥0.63,p<0.01),but was significantly negatively correlated with air temperature and vapor pressure deficit(R^(2)≥0.9,p<0.05).The averaged water use efficiency(WUE)on the canopy scale was 3.15 g CO_(2)/kg H 2O during the growing season,and there was a significant negative correlation between daily WUE and evapotranspiration(R^(2)=0.55,p<0.01).
作者
朱志鹍
张翼翱宇
ZHU Zhikun;ZHANG Yiaoyu(Editorial Department of Journal of Shandong Jianzhu University,Jinan 250101,China;Shandong Jianzhu University Design Group Co.,Ltd.,Jinan 250013,China)
出处
《山东建筑大学学报》
2023年第3期108-115,共8页
Journal of Shandong Jianzhu University
基金
山东建筑大学博士科研基金项目(XNBS1845)。
