Carbon Storage And Carbon Density Of Forest Ecosystem In Jiangsu Province

In this study, we have analyzed the carbon storage and carbon density of vertical distribution (tree layer, shrub-grass layer, litter layer and soil horizon) of six main types of forest ecosystems (Poplar forest, Other broad-leaved forest, Broad-leaved mixed forest, Coniferous forest, Bamboo forest and Coniferous-broad leaved mixed forest) in Jiangsu by using forest resources inventory data and field investigation data, and estimated the carbon storage and carbon density of forest ecosystems and root to shoot (R/S) ratio of shrub-grass layer in Jiangsu Province. The purpose of this study was to understand the status quo of carbon storage of Jiangsu Province and provide basic data for Carbon sink function study of forest ecosystems. Major results were summarized as follows:(1) Carbon storage of different forest ecosystems from high to low were as follows:Carbon storage of Poplar forest reached the maximum with a number of112.99Tg C. Carbon storage of Other broad-leaved forest, Broad-leaved mixed forest, Coniferous forest, Bamboo forest and Coniferous-broad leaved mixed forest were26.57Tg C,16.78Tg C,9.93Tg C,4.33Tg C,4.21Tg C, respectively. Broad-leaved mixed forest had a maximum carbon density with a number of129.05Mg C· hm-2, and carbon density of Other broad-leaved forest, Coniferous forest, Coniferous-broad leaved mixed forest, Poplar forest and Bamboo forest were128.60Mg C· hm-2,127.44Mg C·hm-2,124.12Mg C·hm-2,121.80Mg C·hm-2and120.84Mg C·hm-2. In the carbon storage and density, soil horizon store a maximum percent of total, and tree layer, litter layer, and shrub-grass layer reduced in turn.(2) The total carbon storage of the forest ecosystems was174.81Tg c, accounting for0.6%～1.1%of national forest carbon storage. The carbon storages of forest vegetation, litter layer, and soil were37.56Tg C,137.24Tg C, and4.64Tg C, accounting for0.6%～1.2%,0.7%～1.2%,0.5%of total of national forest carbon storage, respectively. The area of forest ecosystems of Jiangsu accounts for0.7%of national forest ecosystems area. That means the forest ecosystems of Jiangsu has a strong Carbon sink function. The carbon density of the forest ecosystems was126.05Mg C· hm-2, with24.39Mg C· hm-2of tree layer,0.66Mg C· hm-2of shrub-grass layer,3.80Mg C· hm-2of litter layer, and97.20Mg C· hm-2of soil.(3) There was a significant linear relationship between aboveground and underground biomass of shrub-grass layer. In all forest types, root to shoot (R/S) ratio in pure forest was slightly higher than that in mixed forests. The ratio in the needle and broad-leaf mixed forest was higher than that in broad-leaf mixed forest. The proportional values were consistent in pure broad and needle-leaf forest. Most of pure forests were plantation in Jiangsu province, where the young, middle-aged forest area together accounted for87.96%of the total area. Mixed forest were natural mature forest. Soil organic matter, nitrogen, potassium and other nutrients content under mixed forest were higher than that under pure forest. Based on the soil nutrient competition stress response, root of shrub-grass layer in pure forest was more developed than that in mixed forest, and it had higher root to shoot (R/S) ratio.