Estimating biomass and carbon dioxide sequestration in a hardwood forest area

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Experimental plots were established in a secondary forest dominated by mizunara oak (Quercus crispula). DBH and height of all trees on the plots were measured and sample oak trees were felled just outside the plots. The biomass of each tree organ was measured and other root variables such as root length, area and volume were also measured. First, equations to estimate the root variables from other tree variables were created. Missing root parts were estimated from the diameter of broken root ends with regression equations created between the four root variables and root diameter. Allometric regressions between root variables and other tree variables were analyzed both by root diameter classes and for the total root system. DBH proved to be a good predictor of root variables for different root classes and for the total root system. Second, the growth process of stand volume and tree volume for an old closed hardwood secondary forest was modeled. A growth equation for predicting volume g … More rowth from stem volume was derived under biological assumptions on respiration and photosynthesis. Parameters of the equation were estimated from the stem volume at the time of measurement and their latest growth of the stem-analysis trees.Species composition in secondary hardwood forests was estimated using measurements on plots and GIS. The study area was forest around Takigashira Bog and in Akashibayama national forest, in Niigata Prefecture. The subject species were Siebold's beech (Fagus crenata), konara oak (Quercus serrata) and mizunara oak, which were dominated in this area. Species composition was investigated in sample plots, and DEM was created from digitized contour lines. The relationship between relative basal area and topographical and environmental factors calculated from the DEM was examined using multiple regression analysis and regression equations were derived. Applying the equations on GIS, the relative basal area of main species was estimated and mapped.The leaf area index (LAI) in natural deciduous hardwood forests dominated by Siebold's beech, konara oak and mizunara oak was estimated based on topographical features, using a GIS. Twenty-two plots were selected in the area, and four litter traps were set in each plot. The dry weight of leaves collected in the litter traps was measured, and LAI was estimated for each plot. The relationship between LAI and topographical factors was analyzed, based on type I quantification theory, and an equation to predict LAI from elevation and slope was derived. The LAI in deciduous broad-leaved forests was estimated and mapped for the area using the derived equation. Less