第六届青年地学论坛

1587 / 2019-08-22 08:48:23

光合对呼吸的影响及矫正

10、干旱区环境与风沙科学 > 专题4：干旱区生态、水文前沿

Although photosynthetic and environmental regulations of the dynamics of soil respiration have been frequently reported, few studies have so far tested their generality and interactive effects. Using decade-long continuous measurements of soil respiration and eddy covariance records of net ecosystem exchange of CO2 at a forest site in the central USA, we examined the intrinsic linkage of photosynthesis and environmental factors with soil respiration. Results showed that gross primary production (GPP) regulated soil respiration on diurnal scale with a time lag of four to eleven hours. The variations in this time lag were affected by past trajectories of moisture and temperature. GPP played a more important role in regulating soil respiration during dry than wet seasons, probably due to stronger water limitation on soil respiration under dry conditions. Precipitation shortened the mean time lag between soil respiration and GPP. Finally, we found that models incorporating GPP as an input explained more variation in soil respiration than using soil temperature and moisture alone. Our findings suggest that photosynthesis and environmental conditions interactively drive the dynamics of soil respiration.