Abstract: In order to understand the tree layer carbon storage and sequestration in the subtropical evergreen broadleaf forests in Ailao Mountain, an analysis was made on the tree layer carbon storage and sequestration in three dominant forests in the Mountain, based on the field surveys in 2005 and 2008. The tree layer carbon storage in the primary evergreen broadleaf forest, secondary Populus bonatii forest, and secondary Alnus nepalensis forest in the Mountain was 257.90, 222.95, and 105.39 t C·hm^-2, respectively. The tree layer carbon storage of the primary evergreen broadleaf forest was mainly contributed by the trees with DBH ≥91 cm (34.68%), while that of the two secondary forests was mainly contributed by the trees with DBH from 21 cm to 41 cm (77.29% for P. bonatii secondary forest, and 69.28% for A. nepalensis secondary forest), suggesting that the tree layer of primary evergreen broadleaf forest played an important role in the carbon storage in Ailao Mountain. The tree layers of the three forests all had the capability of carbon sequestration. The mean annual increment of tree layer carbon sequestration in primary evergreen broadleaf forest was 2.47 t C·hm^-2·a^-1, and that in the two secondary forests was about two times of the primary evergreen broadleaf forest, suggesting a great potential of carbon sequestration in secondary forests. Based on the above-mentioned results,it was estimated that the mean annual increment of tree layer carbon sequestration within the Ailao Mountain National Nature Reserve was 8.52×10.4 t C·a^-1.

Key words: Sanjiang Plain, Peat, Nutrient elements, Distribution character