The Carbon Mitigaton Potential And Present Situation Of Coniferous Forests And Plantations In The Midwest Of Yunnan

Based on field syrvey and experiment research, we studied the forest carbon sink in the Midwest of Yunna. In Chuxiong, Dali, Lincang, Baoshan and Dehong for the Midwest of Yunnan had 78 plots setted to study estimating the biomass, the carbon density, and the carbon sequestration rate of tree layer, shrub layer, herb layer and floor litter. We studied on changes and causes of the forest carbon sink. The results showed:(1) In the Midwest of Yunnan, the biomass of tree layer was 200.85Mg/hm2 in Pinus yunnanensis forests, its carbon density was 100.98MgC/hm2, net production was5.02Mg/hm2 a and carbon sequestration rate was 2.52MgC/hm · a. The average carbon density of the forest was about 102.97MgC/hm2. The average carbon density was significant positive correlation to the average height and average DBH. These were able to effect on carbon density of Pinus yunnanensis forest and were main biological factors.(2) In the Midwest of Yunnan, the biomass of tree layer was 106.38Mg/hm2 in Pinus armandi forests, its carbon density was 52.01MgC/hm, net production was 2.66Mg/hm2 a and carbon sequestration rate was 1.30MgC/hm2 · a. The average carbon density of the forest was about 55.05MgC/hm2. The average carbon density was significant negative correlation to the average height and average DBH, but it was significant positive correlation to the average density. These were able to effect on carbon density of Pinus armandi forest and were main biological factors. The average carbon density was significant positive correlation to elevation of area, but it was significant negative correlation to annual mean temperature of area. These were able to effect on carbon density of Pinus armandi forest and were main environmental factors.(3) In Lincang for the Midwest of Yunnan, the biomass of tree layer was 106.44Mg/hm2 in Pinus kesiya var langbianensis forests, its carbon density was 53.16MgC/hm2, net production was 2.66Mg/hm2 a and carbon sequestration rate was 1.33MgC/hm2 · a. The average carbon density of the forest was about 58.67MgC/hm2.(4) In the Midwest of Yunnan, the biomass of tree layer was 230.52Mg/hm2 in rubber forests, its carbon density was 115.26MgC/hm, net production was 9.22Mg/ hm2 a and carbon sequestration rate was 4.61MgC/hm2 · a. The average carbon density of the forest was about 116.52MgC/hm2. The average carbon density was significant positive correlation to the average height, average DBH and average density. These were able to effect on carbon density of rubber forest and were main biological factors. The average carbon density was significant positive correlation to length of year. It was able to effect on carbon density of rubber forest.(5) In the Midwest of Yunnan, the biomass of tree layer was 106.42Mg/hm2 in Eucalyptus forests, its carbon density was 46.29MgC/hm2, net production was 17.74Mg/hm2 a and carbon sequestration rate was 7.72MgC/hm2 · a. The average carbon density of the forest was about 46.86MgC/hm2. The average carbon density was significant positive correlation to the average density. That was able to effect on carbon density of Eucalyptus forest and was main biological factor.(6) In Dehong for the Midwest of Yunnan, the biomass of tree layer was 75.85Mg/hm2 in Betula alnoides forests, its carbon density was 39.54MgC/hm2, net production was 7.59Mg/hm2 a and carbon sequestration rate was 3.95MgC/hm2 · a. The average carbon density was significant negative correlation to the elevation of area. That was able to effect on carbon density of Betula alnoides forest.(7) The carbon density in coniferous forests had no significant difference with those in plantations. But the carbon density of evergreen broad-leaf forests were significantly higher than coniferous forests and plantation in Midwest of Yunnan. If the coniferous forests and plantations mainly converted into evergreen broad-leaf forest, the carbon density of forests in the Midwest of Yunnan will be enhanced.