Soil organic carbon pool characteristics of Pinus kesiya var. langbianensis plantation
CHEN Wei, MENG Meng, LI Jiang, QIU Qiong, PEI Yan-Hui, GUO Yong-Qing, FENG Xuan, YANG Bin
1. Yunnan Laboratory for Conservation of Rare, Endangered & Endemic Forest Plants, Public Key Laboratory of the State Forestry Administration, Yunnan Provincial Key Laboratory of Cultivation and Exploitation of Forest Plants, 650201, Kunming, China; 2. Yunnan Academy of Forestry, 650201, Kunming, China
Abstract：In Simao district of Pu’er City of Yunnan Province, we chose a series of plantations involving eight different planting densities and seven stand ages as the research objects. Through measuring the soil organic carbon contents and carbon densities (0-50cm depth), the effects of Pinus kesiya var. langbianensis planting on soil organic carbon (SOC) were investigated and analyzed. The results were as follows: 1) The SOC contents of P. kesiya var. langbianensis plantations decreased with the soil depth. Under all the eight planting densities, in the stand age of 13 years, the SOC contents (0 - 50 cm depth) were higher than those of natural P. kesiya var. langbianensis forest. As far as the ages of plantations were concerned, from the 4th year to the 10th year after planting, the contents of SOC were in a declining stage, and began to increase since the 12th year. 2) Vertically, the dissolved organic carbon (DOC) decreased with the increase of soil depth, and the accumulated spatial distribution of microbial biomass carbon (MBC) was at the layer of 0 -10 cm. 3) The SOC densities of eight involved planting densities ranged from 64.48 t/hm2 to 84.30 t/hm2,among which, the SOC density of the planting density of 2m×4m was the highest, where as that of 1 m ×1 m was the lowest. The values of DOC density and MBC density ranged from 0.30 to 0.42 t / hm2 and from 0.49 to 1.29 t / hm2 , respectively. Both SOC density and DOC density of studied plantations from 4 years old to 14 years old showed the characteristics of decreasing and then increasing as the planting age increased. The SOC density and DOC density of 14 years old plantation were 92.14 and 0.42 t / hm2 , respectively, and the peak value of MBC density occurred at the plantation of 10 years old, which was 0.92 t /hm2 . The results of this study verified that P. kesiya var. langbianensis plantation has promising ability of carbon storage.
2014, Vol. 12 
