PARENT SESSION
Oral Session #24: Forests: Carbon allocation, carbon budgets. Presiding: C. Reid.
Tuesday, August 7, 2001. 8:00 AM to 11:15 AM. Hall of Ideas F.
Quantifying historic carbon budgets of forest ecosystems in Ontario.
Peng, Changhui1,2, Liu, Jinxun2, Dang, Qinglai2, Apps, Michael2,4, 1 2 4
ABSTRACT- Carbon (C) budgets of forest ecosystems in Ontario from 1920 to 1990 were calculated using the Carbon Budget Model-Canadian Forest Sector (CBM-CFS2). Results show that total forest biomass C in Ontario increased from 1.83 Pg (10^15 g) to 2.56 Pg between 1920 and 1970, then decreased to 1.70 Pg by 1990. Carbon in soil and forest floor dead organic matter increased from 8.30 Pg to 11.00 Pg between 1920 and 1985 but decreased slightly to 10.95 Pg by 1990. Forest ecosystems in Ontario acted as a C sink storing from 41 to 74 Tg (10^12 g) C/yr from 1920 to 1975, but became a C source releasing 7 to 32 Tg C /yr (five-year average) after 1975. Disturbances (fire, insects and harvesting) enhanced both direct and indirect C emissions, and also affected average forest age and C sequestering. Forests in the boreal, cool temperate and moderate temperate regions had different C dynamics. However, boreal forests dominated forest C budgets of Ontario because of their large area and associated C stock.
KEY WORDS: Climate Change, Carbon Sequestration, Forest Management, Kyoto Protocol