Abstract: The classic harvest method is most reliable to estimate forest biomass and net primary productivity (NPP) but not suitable in an urban green area due to its high heterogeneity. Therefore, a nondestructive method based on gas exchange measurements for estimating photosynthetic carbon sequestration was used to establish apparent characteristics and biomass and NPP models for Cinnamomum camphora, which is the most abundant greening species in Shanghai. The results showed that annual net primary productivity (ANPP) of individual trees based on the harvest method was 23%±4% of aboveground biomass (AVB), AVB=1.37D_2.15 (D: Crown, R²=0.97, P<0.01), ANPP =0.32D_2.13 (D: Crown, R²=0.97, P<0.01). The estimated biomass or ANPP based on the gas exchange method was tightly colse to that based on the harvest method with an accuracy rate of 87.3%. The system and environmental errors were the main sources of the difference between the two methods. When tuning the relevant correction factors, the gas exchange method could be applied to estimate carbon sink of urban greening with highprecision remote sensing monitoring without destruction.

Key words: integrated crop-livestock system, livestock, crop, carbon fixation., carbon emission