A Study On Carbon Storage Of Tropical Seasonal Rain Forest In Xishuangbanna, Yunnan

Tropical forests play an important role in the global carbon cycle, because they store large quantities of carbon in vegetation and soil as well as exchange carbon with the atmosphere through photosynthesis and respiration. It is of theoretical importance to understand carbon storage in forests ecosystems, especially in the tropical forests.Tropical seasonal rain forest (TSRF), one of the five important primary forest vegetation types in Xishuangbanna, is similar to the equatorial rain forest of tropical Asia on floristic composition, forest profile, physiognomy and species richness. However, there is little information available on carbon sequestration in the tropical seasonal rain forest.This research was conducted in Xishuangbanna Nature Reserve, which is located in southwest China. Biomass regression models of tree layer relating to its DBH (diameter at breast height, 1.3 m) were developed and a power-law allometric relationship of the form W=aDb was used to estimate the tree biomass, where W is the biomass of a species (kilogram for leaves, branches, stems or roots); a and b are constants; D the DBH (cm). Other biomass components were sampled in the following way: live shrubs (ten 25 m2 samples); herbs (ten 4 m2 samples); dead wood (the whole plot); large fallen branches (twenty-five 25 m2 samples); forest floor (twenty-five 1 m2 samples). This method was applied to three permanent plots with each covering 1 hectare. Analyses of carbon concentration were performed by the Biogeochemical Laboratory in XTBG. The following aspects were included in this research: 1) Biomass in the tropical seasonal rain forest; 2) The carbon concentration of plant and soil; 3) Carbon storage in the living plants and its distribution in different layers and organs; 4) Distribution of carbon storage among different DBH classes, height levels and species of tree layer; 5) Carbon storage in the litter and coarse woody debris; 6) Soil carbon storage and distribution pattern; 7) Total carbon storage in the tropical seasonal rain forest and the distribution pattern among different carbon pools; 8) The comparison of carbon storage between TSRF in Xishuangbanna and other tropical forests.The results and conclusions were drawn as follows:1)The estimate of biomass included all of live and dead plant materials (trees, seedlings, shrubs, herbs, woody lianas, epiphytes, coarse woody debris, litters) above-and below-ground with the exception of soil organic matter. The total biomass of the plots was 370.163 t·hm-2, 550.119 t·hm-2 and 351.442 t·hm-2, an average of 423.908 t·hm-2 (±109.702 t·hm-2, 95%...