金沙江头塘小流域人工林有机碳及其剖面分布特征

SOIL ORGANIC CARBON AND ITS DISTRIBUTION CHARACTERISTICS IN THE SOIL PROFILE UNDER DIFFERENT VEGETATION RECOVERY MODES IN TOUTANG SMALL WATERSHED OF JINSHA RIVER

采用野外调查、室内分析并结合相关的方法,研究探讨了金沙江头塘小流域7种不同植被恢复人工林土壤剖面层次有机碳（SOC）含量、有机碳密度（SOCD）和有机碳储量及分布特征。结果表明,不同林分类型及土层间土壤SOC含量存在明显差异：就整个土层（0~100 cm）而言,7种林分土壤SOC平均含量介于6.46±1.67~24.95±2.32 g·kg–1,大小依次为柳杉林〉旱冬瓜林〉圆柏林〉栓皮栎林〉圣诞树林〉墨西哥林〉藏柏林,且差异显著（p〈0.05）;7种林分土壤SOC含量均出现表聚现象,从表层到深层都呈现递减趋势,且具有一定的规律性;7种林分土壤容重总体上均表现为随土层深度的增加逐渐增加,土壤容重表现为：柳杉林〉栓皮栎林〉圣诞树林〉圆柏林〉旱冬瓜林〉墨西哥柏林、藏柏林;7种林分土壤有机碳密度垂直分布和土壤有机碳含量垂直分布特征一致,随土层深度增加土壤有机碳密度减少,以表土10 cm的土壤有机碳密度最大;有机碳储量均随着土层加深所占比例逐渐降低,同时土壤有机碳主要集中于土层0~40 cm内,分别占总有机碳的65.60%（圣诞树林）、63.16%（旱冬瓜林）、54.41%（墨西哥柏林）、58.56%（圆柏林）、62.96%（藏柏林）、61.70%（栓皮栎林）和56.37%（柳杉林）,0~40 cm土层土壤有机碳占总有机碳的百分比均达到50%以上。

Field investigation, laboratory analysis and related methods were used to investigate the level of soil organic carbon （SOC） content, organic carbon and organic carbon storage and density distribution of the vegetation under seven different recovery modes in a small watershed of the Jinsha River. The results showed that significant differences exist between the different forest types and soil layers, in terms of the whole soil （0-100cm）, SOC of the seven forest typesranged between the average content of 6.464-1.67-24.95±2.32 g.kg-1, with an order of Cryptomeriafortunei forest 〉 Alnus cremastogyne burk forest 〉 Cupressus duclouxiana forest 〉 Quercus variabilis forest 〉 Acacia dealbata forest 〉 Cupressus lusitanica forest 〉 Cupressus torulosa forest, and the difference was significant （p〈0.05）; SOC content of the soil in the 7 stands presented a table poly phenomenon, from the surface to the deep soil there was a decreasing trend, and with some regularity; seven kinds of soil bulk density increased gradually with the increase of soil depth on the whole, soil bulk density showed： Cryptomeria fortunei forest 〉 Quercus variabilis forest 〉 Acacia dealbata forest 〉 Cupressus duclouxiana forest 〉 Alnus cremastogyne burk forest 〉 Cupressus lusitanica forest, Cupressus torulosa forest; consistent seven kinds of stands vertical distribution of soil organic carbon density and vertical distribution of soil organic carbon content characteristics, soil depth increases with soil organic carbon density reduced to topsoil 10 cm of soil organic carbon density maximu; organic carbon reserves were as soil depth percentage decreased, while soil organic carbon was mainly concentrated in the 0--40 cm soil, accounting for 65.60% of total organic carbon （Acacia dealbata forest）, 63.16% （Alnus cremastogyne burk forest）, 54.41% （Cupressus lusitanica forest）, 58.56% （Cupressus duclouxiana forest）, 62.96% （Cupressus torulosa forest）, 61.70% （Quercus variabilis forest） and 56.37% （Cryptomeriafortunei forest）,SOC of the 0-40 cm soil layer accounted for more than 50% of the total.