关键词: 森林地上生物量, 胸高断面积, 普通克里格, 协同克里格, 空间分布格局图

Abstract: Estimation of forest above-ground biomass is great significant for evaluation of the role of forests in decelerating climate change and adaptive management. Based on bureau-level permanent plot data of forest inventory in Jincang Forest Farm, Wangqing Forest Bureau, Jilin Province, using both ordinary kriging and cokriging estimate forest above-ground biomass in the study area (above-ground biomass as a main variable and basal area as a covariate in cokriging). Meanwhile, compared these two interpolation methods, the results show that ordinary kriging is not a suitable method to estimate biomass in this study area; but contrasted to ordinary kriging, cokriging can significantly improve the prediction accuracy, generating the root mean square error (RMSE) and the average standard error (ASE) decrease by 49.0% and 39.4% respectively, and the correlation coefficient between predicted values and measured values increases by 68.4%. The spatial distribution pattern map of forest above-ground biomass in the forest farm can be obtained by cokriging interpolation approach. Spatially, the forest above-ground biomass varies obviously in this region from 21.48 to 261.60 t·hm^-2, and the average above-ground biomass is 111.9 t·hm^-2. Total above-ground biomass of this region is up to 3.578 Tg. In addition, biomass significantly varies with forest types and age groups. The results provide a method and reference for the region-scale biomass estimation based on the permanent plot and geostatistics.

Key words: forest above-ground biomass, basal area, ordinary kriging, cokriging, spatial distribution pattern map