A Study On Evergreen Board-leaved Forests Present Carbon Sequestration And Mechanism In Midwest Of Yunnan

In order to explored the evergreen board-leaved forests allocated its biomass, carbon density and effect of different factors in Yunnan,15plots of subtropical monsoon evergreen broad-leaved forest and36plots of semi-humid evergreen broad-leaved forest were established in midwest of Yunnan. We used optimum regression models which have established to estimated the biomass of the tree in the sample. The biomass of Other layers were surveyed in following way:shrubs layer (ten25m2); herb layer (ten1m2); CWD (ten0.25m2) and litter falls (ten0.25m2). We analysis the allocation of biomass and carbon density in different layers of two type of evergreen broad-leaved forest, different factors affected the carbon density and carbon sequestration capability of different size class. There follows the results:(1) The total biomass of subtropical monsoon evergreen broad-leaved forest was741.885t·hm-2, the living biomass was741.097t·hm-2and the dead biomass was0.788t·hm-2.The biomass of tree layer was734.354t·hm-2, the shrubs layer was6.155t·hm-2, the herb layer was1.398t·hm-2, the CWD was0.430t·hm-2and the litter falls was0.358t·hm-2. The total biomass of subtropical monsoon evergreen broad-leaved forest was541.77t·hm-2, the living biomass was519.389t·hm-2and the dead biomass was22.381t·hm-2. The biomass of tree layer was514.055t·hm-2, the shrubs layer was4.127t·hm-2, the herb layer was1.207t·hm-2, the CWD was0.145t·hm-2and the litter falls was22.236t·hm-2.(2) The total carbon density of subtropical monsoon evergreen broad-leaved forest was375.885t·hm-2, the living carbon density was370.953t·hm-2and the dead carbon density was1.824t·hm-2. The carbon density of tree layer was367.177t·hm-2, the shrubs layer was3.077t·hm-2, the herb layer was0.699t·hm-2, the CWD was0.215t·hm-2and the litter falls was1.609t·hm-2. The total carbon density of subtropical monsoon evergreen broad-leaved forest was261.495t·hm-2, the living carbon density was251.246t·hm-2and the dead carbon density was11.691t·hm-2. The carbon density of tree layer was247.137t·hm-2, the shrubs layer was2.064t·hm-2, the herb layer was0.603t·hm-2, the CWD was0.573t·hm-2and the litter falls was11.118t·hm-2. The carbon density of two type of evergreen broad-leaved forest mainly focused on living plant, the carbon density of tree layer was a key components of living plant. The carbon density of tree layer stored in branch, the carbon density of shrubs layer stored in leaf, the carbon density of herb layer stored in aboveground part, the litter layer had the biggest carbon density in dead plant.(3) The mean DBH was significantly positively correlated with total carbon density of subtropical monsoon evergreen broad-leaved forest and semi-humid evergreen broad-leaved forest, the carbon density increased with the addition of mean DBH.(4) The Small DBH plants occupied a large amount in froest,but its carbon density were very low. On the contrary the large DBH plants were few in number,but the carbon density were pretty high. The sample plots existed large DBH plants had greater carbon density capability than which with small DBH plants, but the evergreen broad-leaved forest which had the small DBH in Yunnan had huge carbon sequestration capability.