Abstract: As an important part of commercial forest, economic fruit forest occupies nearly onefifth of Shanghai’s total forest land area, playing an important role in the evaluation of carbon sink of forest ecosystems in Shanghai. Taking the peach orchard and citrus orchard ecosystems with large distribution areas in Shanghai as the objects, and based on the biomass investigation, the biomass and net productivity equations for the two main tree species in the orchard ecosystems were established, and the carbon storage in the vegetation layers and soil as well as the annual net carbon sequestration in tree layer was calculated. There was a good fitting effect of the established equations on the basal diameter of the two main tree species (R²>0.9). In the peach orchard and citrus orchard ecosystems, the carbon storage was averagely 118.31 and 86.31 t·hm^-2, and the annual net productivity was averagely 4.87 and 6.51 t·hm^-2·a^-1, respectively. Among the carbon storage in the peach orchard and citrus orchard ecosystems, tree layer accounted for 13.4% and 27.3%, herb layer accounted for 1.0% and 1.3%, and soil accounted for 85.6% and 71.4%, respectively.

Key words: otolith, carbon stable isotope, Schizothorax kozlovi, oxygen stable isotope.