三峡库区主要森林植被类型土壤有机碳贮量研究

根据全国森林资源清查资料，按主要优势树种和分布面积将三峡库区主要森林植被划分为马尾松针叶林、栎类混交林、灌木林等11种主要森林植被类型。基于196个土壤剖面数据，分析了11种主要森林植被类型下土壤有机碳含量、碳密度大小和分配特征。研究发现，三峡库区主要森林植被类型下土壤有机碳含量和碳密度均存在较大差异，二者总体上都随土层加深而降低。11种主要森林植被类型中以杉木针叶林土壤有机碳密度最大，达16.0 kg/m2，温性松林下土壤碳密度最小，仅为7.9 kg/m2。不同植被类型下土壤有机碳贮量在土层中的分配比例也不同，以灌木林和柏木林土壤碳贮量在土层间的差异最大。11种主要森林植被类型土壤平均厚度为56.3～98.5 cm，其中杉木针叶林土壤最厚，达98.5 cm，灌丛土壤最薄，平均厚度仅56.3 cm。三峡库区11种主要森林植被类型总面积为3 313 251 hm2，土壤总有机碳贮量为 366.36 t，其中0～10、10～20、20～40和＞40 cm土层分别占22.90%、18.36%、28.33%和30.41%。

ORGANIC CARBON STORAGE IN SOIL UNDER THE MAJOR FOREST VEGETATION TYPES IN THE THREE GORGES RESERVIOR AREA

Based on the data of forest inventory，the forest vegetation types of the Three Gorges Reservoir 〖JP2〗Area (TGRA) were divided into 11 types by its dominant tree species and acreages，such as 〖WTBX〗Pinus massoniana〖WTBZ〗〖JP〗 forest，mixed forest of 〖WTBX〗Quercus〖WTBZ〗，and shrubs etc.In this paper，the concentration，density and distribution of soil organic carbon (SOC) were studied based on 196 soil profiles.The results were as follows：the concentrations and densities of SOC under 11 forest of vegetation types were significantly different and generally decreased with depth;the density of SOC of forest of 〖WTBX〗Cunnighamia Lanceolata〖WTBZ〗 was the highest (16.0 kg/m2)，and that of the forest of 〖WTBX〗Pinus armaridii 〖WTBZ〗or〖WTBX〗 Pinusbenryi〖WTBZ〗 was the lowest (7.9 kg/m2)，among 11 vegetation types;the SOC storages of different soil layers under different vegetations were also different;the differences of carbon storage between soil layers under shrubs and forest of 〖WTBX〗Cupessus funebris〖WTBZ〗 was larger than that under other vegetation types;the average soil thickness of 11 forest of vegetation types was 56.3～98.5 cm，the soil thickness of forest of 〖WTBX〗Cunnighamia Lanceolata〖WTBZ〗 was the largest (98.5 cm)，and that of shrubs was the smallest (56.3 cm);the total acreage of 11 main forest vegetation types in the TGRA was 3 313 251 hm2，and the total storage of SOC under those vegetation types was 366.36 t，with 22.90%，18.36%，28.33% and 30.41% in 0～10，10～20，20～40 and ＞40 cm soil depth interval，respectively