Short-term effects of pruning on stem surface and soil CO_2 effluxes in a Chinese fir plantation

LIU Lan-lan;WANG Si-long;YANG Qing-peng;State Key Laboratory of Forest and Soil Ecology,Institute of Applied Ecology,Chinese Academy of Sciences;Huitong National Research Station of Forest Ecosystem;University of Chinese Academy of Sciences;

photosynthate supply;;stem sap flow;;stem respiration;;soil respiration.

Carbon dioxide releases from stem surface and soil are important parts of forest ecosystem carbon cycle,but how pruning treatment impacts stem surface and soil CO2effluxes is unclear. In this paper,we examined the effect of photosynthate supply on stem surface and soil CO2effluxes in a Chinese fir plantation forest by pruning branches( CK,light pruning,and heavy pruning). Stem surface and soil CO2effluxes were measured with the LI-6400-09 portable photosynthesis system for a month. The results showed that pruning had no significant effect on stem surface CO2efflux,although the maximum sap flow velocity decreased slightly. Pruning treatment decreased soil CO2efflux slightly,with reductions by 11. 8% and 17. 9% for light and heavy pruning treatments,respectively compared to the control. However,there was no significant difference among the three treatments. Our results indicated that short-term effects of pruning on stem surface and soil CO2effluxes were negligible in the Chinese fir plantation forest.