Vertical distribution analysis of forest biomass changes

Abstract

Forest plays an important role in the global carbon cycle, carbon sequestration based on forest biomass is an important part in the global efforts to reduce emissions. Research on distribution of the biomass can deepen the understanding of the carbon cycle. Remote sensing with the characteristics of cyclical and regional coverage has become an effective means of forest biomass regional survey. we established regression model between NDVI (Normalized Difference Vegetation Index) and forest biomass based on Landsat TM and ETM data, on this basis, calculated forest biomass of 1970s, 1980s and 1990s in Changbai Mountain area of Heilongjiang, Combined with GIS software the spatial changes pattern of forest biomass of the study area was discussed, especially the trend of the forest biomass with elevation, slope, aspect changes respectively. It concluded that the spatial vertical distribution of forest biomass in the study area is: in the elevation of 300 meters the forest biomass is maximum, about 35%, the higher elevation the smaller forest biomass; the distribution of forest biomass with the slope of the descending order is the gentle slope> flat slope> incline slope> steep slope> urgent slope> dangerous slope; and forest biomass in the region of aspect less than 5° is the largest, reaching 28%. In the past three decades, forest biomass change with the aspect almost consistent, all emerged the following rules: forest biomass in southeast slope and southwest slope has the proportion of the smallest is about 7%.