关键词: 土壤, 有机碳, 山地森林, 海拔梯度, 凋落物层厚度

Abstract: To explore distribution pattern of soil organic carbon(SOC)contents along altitudinal gradient and its relationships with vegetation type and litter thickness,17 transects(10m×120m each)were set up,one in every 100m in altitude from 300 m to 1900 m along a slope of the Shikengkong Mountain,the highest peak of Guangdong in the Nanling National Nature Reserve and soil litter samples collected in all the transects for analysis.Results show that SOC contents in the 0-20 cm and >20-40 cm soil layers varied sharply(P<0.001)along the altitudinal gradient and between the four tupes of forest stands (P<0.01).Generally SOC content increased with elevation,and thickness of the litter layer showed significant effect only on the SOC content in the 0-20cm soil layer.Obviously elevation is the leading factor that determines distribution of SOC contents,and type of the forest stand is another that affects organic carbon content in the topsoil.All these factors reflect changes in the land use and history of the nature conservation.All the findings suggest that reducing anthropogenic interference and maintaining a litter layer proper in thickness may help increase the carbon pool in the forest ecosystem.

Key words: soil, organic carbon, montane forest, altitudinal gradient, litter thickness