Remote sensing estimation of biomass of Simao pine artificial forest at different ages based on random forest regression

Taking the Simao pine（Pinus kesiya var. langbianensis）plantations in Jinggu county as the research object，this paper constructed the biomass model of single tree and calculated the biomass of Simao pine`s per unit of 90 sample plots of Jinggu county. Nine indexes of vegetation were selected as the alternative variables using TM remote sensing image of Jinggu country in 2005. The estimation model of Simao pine`s per unit biomass of the overall sample and the sample of different ages was established based on random forest regression. The biomass of Simao pine`s per unit artificial forest was predicted in study area by taking the pixel as unit in 2005. The results were as follows：R2 > 0.900， RMSE < 7.00，prediction accuracy（ P）> 87.00%. The biomass of per unit artificial forest was 59.0889 t/hm2，the biomass of young forest was 38.5170 t/hm2，the biomass of half-mature forest was 53.6626 t/hm2，the biomass of near mature forest was 94.8018 t/hm2 .