Estimation of Carbon Balance over a Mountainous Forest Region Based on Landsat TM Data

Abstract

The carbon budget over a forested mountainous area in Hiroshima Prefecture, western Japan was estimated using Landsat TM data . The estimation was conducted pixel-wise on a study area of 6 X 4 km using a three-step procedure which began with biomass estimation and mapping using topographically corrected Landsat TM data. A map of stand age was then derived from the biomass map using the functional relation ship observed on the ground between stand biomass and age for each of the three forest types (deciduous broadleaved forest, pine forest, cedar or cypress plantation) identified in the study area. Finally, the carbon budget of the study area was estimated using the relationship between stand age and carbon balance obtained by model calculation for each of the three forest types. The resultant mean carbon balance was +2.76tC ha^-1 y^-1, amounting to + 5.63 X 103 tC y^-1 over the entire forested study area. This indicates that the typical forest ecosystems in the western Japan are significant atmospheric CO₂sinks.