The Dynamic Change And Mechanism Of Mature Forest Form Every Different Elevation

As a important part of the output of soil carbon of the mature forest, the soil respiration is the estimation confined the mature forest ecosystem carbon accumulates the very important research content. We used trenching-plot and infrared gas exchange analyzer approaches to determine heterotrophic(RH) and autotrophic respiration(RA)in soil surface CO2flux for mature forest of different elevation gradient which is also preliminary show the rule and provide the basic science data for the correct estimation of carbon assembling and the function of the carbon source of Chinese mature forest in the global climate.The research shows that the evergreen broad-leaf wood(780m) and the evergreen and fallen broad-leaf mix wood(1670m) diurnalvariation assumes the unimodal curve basically. The maximum value appears at 12:00~16:00,and the minimum value appears at 5:00~6:00. The fallen and broad-leaf wood (1970m), the mountain coniferous wood (2570m) diurnalvariation assumes the split-blip curve basically, which of the maximum value appears at about 10:00 and 19:00, the minimum value appears at 2:00. The research area soil breath seasonal variation characteristic is: Before July, the soil respiration speed change performance shows as: the fallen broad-leaf wood > the evergreen broad-leaf wood > the evergreen and fallen broad-leaf mix wood > the mountain coniferous wood. In July, the mountain coniferous wood > the evergreen broad-leaf wood > the evergreen and fallen broad-leaf mix wood > the fallen broad-leaf wood. After july, the evergreen broad-leaf wood>the fallen broad-leaf wood>the evergreen and fallen broad-leaf mix wood>the mountain coniferous wood.2 The CO2 flux of vegetation season of every type wood is:: the evergreen broad-leaf wood(780m)436.87gC m-2,the evergreen and fallen broad-leaf mix wood(1670m)394.90 gC m-2,the fallen broad-leaf wood(1970m)438.77gCm-2,the mountain coniferous wood(2570m) 316.68 gC m-2. The contribution rate of the root respiration in the soil respiration of every forest ecosystem is 23.05%~28.23%. The RC of the evergreen and fallen broad-leaf mix wood is only about 10%. The contribution rate(RC) of the heterotrophic respiration in the research area is 76.34%～91.35% which is obviously higher than the contribution rate of root respiration.3 The RS of research area mature forest and temperature of the soil 10cm below assumes the remarkable correlational dependence(R2=0.564～0.629;p<0.01). The soil moisture content is not remarkable to the RS influence(p>0.05). Under natural condition, in research area, the different elevation gradient RS mainly influenced by soil temperature, but the moisture content is not the main factor to local soil respiration.