PARENT SESSION
Oral Session # 50: Forest Ecology III: Modeling; Nutrient Cycling.
Presiding: L Comas
Wednesday, August 6. 1:30 PM to 5:00 PM, SITCC Meeting Room 100.

Quantifying carbon sequestration of the Lake Abitibi Model Forest in Ontario.

Peng, Changhui^{*,1, 2}, Zhou, Xiaolu², Dang, Qinglai², Chen, Jiaxin², ¹ Institute of Atmospheric Sciences, Rapid City, SD, USA² Faculty of Forestry and the Forest Environment, Thunder Bay, Ontario, Canada

ABSTRACT- Boreal forest ecosystems play a significant role in the global carbon cycles and are sensitive to global climate change, especially to the changes in temperature and precipitation over the next century. In this study, we use a process-based forest growth and carbon dynamic model of TRIPLEX to simulate carbon dynamics in boreal forest ecosystems of the Lake Abitibi Model Forest (LAMF) in northern Ontario, Canada. The simulations are performed not only for forest structure (growth and composition) but also for ecosystem function (including productivity, carbon, water, and nitrogen cycles) in order to investigate the dynamics of carbon stocks and fluxes, which are dependent on the annual change of temperature, precipitation, soil texture and moisture, and nitrogen dynamics. The model input data sets include climate conditions, soil initial carbon, tree mortality, and tree form; The model outputs provide about 50 variables including each part of biomass (stem, foliage, coarse and fine root), soil carbon (slow and passive pool), and growth and yield (tree density, height, DBH, and volume). More than 40,000 stands are simulated from 1990 to 2000. The input and output of these stand polygons are processed using GIS technology to integrate different spatial themes for the LAFM. Our results suggest that total net C sequestrations through forest growth (NPP) were estimated at about 1.35, 1.36, and 1.39 Mt C for 1990, 1995 and 2000, respectively. The total biomass carbon stocks were 35.0, 36.8 and 40.1 Mt C for the years of 1990, 1995, and 2000. The net balances of carbon sequestrations were between 0.39 and 0.41 Mt C without the harvest removal, and the net biome production (NBP: remainder of carbon balance after harvesting) was approximately 0.27 Mt C/year during l990-2000, suggesting that the LAMF forest ecosystem was acting as a carbon sink (about 0.4 Mt C) in 1990s.

Key words: boreal forest, carbon cycle, TRIPLEX model, forest growth