Effects of tending on carbon storage in the ecosystems of young Chinese fir plantations at the middle region of Guizhou Province, southwestern China

This study was conducted to quantify the response of carbon storage in forest ecosystems to the tending works, which are often necessary and important measures to promote the survival rate and growth of young trees. In this study, the density of organic carbon and its components (above- and below-ground biomass C, forest floor C, and soil C at the layer of 0-60 cm) were measured and compared between tended stands (TS) and non-tended stands (CK) of 10-year-old young plantation of Chinese fir (Cunninghamia lanceolata) in the middle region of Guizhou Province of China. The results showed that the canopy density, survival rate, diameter at breast height (DBH) and height of trees were higher in TS than in CK. The carbon fixing ability of individual trees was greatly enhanced, demonstrated by that the carbon storage of individual trees in TS was 4.93 times of that in CK. The total carbon storage in the whole ecosystems of Chinese fir young plantation was also significantly elevated by the tending, from 78.61 in CK to 106.37 t/ha in TS. The carbon storage components of young Chinese fir plantation ecosystems responded differently to tending works. The vegetation layer carbon storage was 26.07 t/ha in TS, 5.62 times of CK (4.64 t/ha). The humus layer carbon storage was increased by 0.38 t/ha in TP compared with CK. Compared with CK, the organic carbon content was decreased by 5.44 g/kg in the 0-10 cm soil layer, the organic carbon content was increased in the soil layers below 10 cm in depth, and the organic carbon density in the 0-60 cm soil layer was increased by 3.30 t/ha in TS than in CK. Thus, it can be concluded that the measure of tending can enhance the tree growth, the carbon storage of vegetation and soil and the service of carbon sequestration of the ecosystem of young Chinese fir plantation in the studied region.