Modeling peatland carbon stock in a delineated portion of the Nayshkootayaow river watershed in Far North, Ontario using an integrated GIS and remote sensing approach

摘要

Peatlands are known to have accumulated and stored carbon over thousands of years and play a vital role in global greenhouse gas balances. However, there are still inadequate high quality estimates of peatland carbon stock at regional level especially in the James Bay Lowlands in Far North Ontario, Canada. The aim of this study is to estimate regional peatland carbon stock in a delineated watershed region in northern Ontario. SPOT 5 satellite data was used to delineate and classify peatland types using maximum likelihood standard algorithm. The peatland map derived from remote sensing was integrated with peat depth, carbon content and bulk density data in geographic information system (GIS) in order to estimate regional peatland carbon stock. The total regional peatland carbon stock was estimated using the following equation: area of peatland (ha) x depth of peat (m) x mean bulk density of peat (g m(-3)) x carbon content of dry mass (%) x conversion factor (10,000 m(2) ha(-1)). Peatlands in the study area covered a geographic area of about 130,429 ha and stored about 128 +/- 0.05 Tg of carbon. Peat carbon per unit area varied among peatland types with a mean +/- SD of 100 +/- 17 kg C m(-2). This high quality account of carbon stock estimates clearly demonstrates the high carbon stored by northern peatlands which makes them major carbon storehouses.