CO2 Flux Estimation by Different Regression Methods from an Alpine Meadow on the Qinghai-Tibetan Plateau

• Published in: Advances in atmospheric sciences Vol. 27; no. 6; pp. 1372 - 1379
• Main Author: 姜春明 于贵瑞 曹广民 李英年 张世春 方华军
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Science Press 01.11.2010; Springer Nature B.V
• Subjects: Atmospheric Sciences; Carbon dioxide; CO2通量; Earth and Environmental Science; Earth Sciences; Emissions; Estimating techniques; Fluctuations; Geophysics/Geodesy; Growing season; Meadows; Meteorology; Regression analysis; Trees; 二氧化碳; 回归方法; 温度敏感性; 青藏高原; 高寒草甸; 高山草甸; Tibetan Plateau; emission; CO; nonlinearity; static chamber technique; Qinghai-Tibetan Plateau; underestimation
• ISSN: 0256-1530; 1861-9533
• DOI: 10.1007/s00376-010-9218-9

CO2 efflux was estimated using different regression methods in static chamber observation from an alpine meadow on the Qinghai-Tibetan Plateau. The CO2 efflux showed a seasonal pattern, with the maximun flux occurring in the middle of July. The temperature sensitivity of CO2 efflux （Q10） was 3.9, which was at the high end of the range of global values. CO2 emissions calculated by linear and nonlinear regression were significantly different （p 〈0.05）. Compared with the linear regression, CO2 emissions calculated by exponential regression and quadratic regression were 12.7% and 11.2% larger, respectively. However, there were no significant differences in temperature sensitivity values estimated by the three methods. In the entire growing season, the CO2 efflux estimated by linear regression may be underestimated by up to 25% compared to the real CO2 efflux. Consequently, great caution should be taken when using published flux data obtained by linear regression of static chamber observations to estimate the regional CO2 flux in alpine meadows on the Qinghai-Tibetan Plateau.