Carbon storage changes for major forest types in Beijing

In order to clarify carbon storage changes for major forest types in Beijing,this research used the national forest inventory data surveyed by the State Forestry Administration of China to estimate biomass and carbon storage of forest ecosystems during a 5 year period for Beijing.Regression equations for timber volume of dominant tree species and biomass were established,and based on which the changes in carbon storage were assessed.Results indicated that forest carbon storage in Beijing rose from 7.96 million to 8.52 million tons within a 5 year period from 1998 to 2003 with changes in carbon storage of forest types and forest area being positively correlated.Quercus,Populus had a great effect on carbon storage.Improper composition of stand age limited the carbon sink capacity of Beijing.Young and middle-aged forests had a large area but only take over less than 30% of the total carbon storage,whereas nearly 50% for mature forests.Different vegetation types and carbon density of age structure showed a slight declining trend,while carbon density increased with the growth of the age structures,and other stand factors also play a important role in the carbon sink.[Ch,4 tab.20 ref.]