庐山亚热带森林土壤有机碳空间变异特征研究

Study on Spatial Variability of Soil Organic Carbon in Subtropical Forest of Lushan

研究森林土壤有机碳空间变异特征对准确评价森林生态系统碳储量具有重要意义。以亚热带地区的庐山南、北坡典型森林土壤为研究对象,系统研究该地区森林土壤有机碳的剖面变化特征。结果表明:1) 庐山森林土壤整个土层(0~60 cm)南坡土壤有机碳含量高于北坡;北坡土壤有机碳含量随着海拔高度的上升呈现增加的趋势,而南坡土壤表现规律不明显。2) 北坡整个土层土壤有机碳密度分布与海拔呈正相关,南坡则没有明显的规律。3) 南北坡各森林土壤的有机碳含量随土层深度增加而整体呈降低趋势,且底层(40~60 cm)土壤有机碳含量受海拔和土壤类型的影响较小。4) 南北坡高海拔森林土壤表层(0~20 cm)有机碳含量高于低海拔;在海拔梯度上所表现出来的土壤有机碳含量的差异明显低于在土壤剖面上的差异。5) 庐山亚热带森林土壤有机碳密度低于全国和世界平均水平,但依然是我国森林生态系统重要的土壤碳库。

Investigating the forest soil organic carbon (C) spatial variation characteristics is of great signifi-cance for accurately evaluating forest ecosystem C storage. Taking the typical forest soil on the south and north slope of Lushan in the subtropical region as the research subject, systematic re-search was carried out to study the profile variation characteristic of forest soil organic C in this area. The results show that: 1) The soil organic C content in the south slope of the whole soil layer (0 - 60 cm) in Lushan forest soil was higher than that on the north slope;the soil organic C content on the north slope showed an upward trend with the increase of altitude, while the regularity of soil on the south slope didn’t perform obviously. 2) The distribution of soil organic C density in the whole soil layer on the north slope was positively correlated with the altitude, while the south slope had no obvious regularity. 3) The organic C content of forest soils on the north and south slopes decreased with the increase of soil depth, and the soil organic C content of the bottom layer (40 - 60 cm) was less affected by altitude and soil type. 4) The organic C content in the surface layer (0 - 20 cm) of the high-altitude forest in the north and south slope was higher than that in the low altitude;the difference of soil organic C content in the altitude gradient was significantly lower than that in the soil profile. 5) The soil organic C density in the subtropical forests of Lushan was lower than average of the national and world, but it is still an important soil C pool in China's forest ecosystem.