贵州省主要森林类型土壤有机碳密度特征及其影响因素

森林土壤有机碳是全球土壤有机碳库的重要组成部分,研究森林土壤有机碳对于减缓大气中CO2浓度持续升高具有重要的意义。本研究采用野外调查和室内分析相结合的方法,以贵州桦木、栎类、柏木、云南松、杉木、马尾松、华山松等7种主要森林类型为主要对象,分析贵州主要森林类型土壤有机碳密度特征,探讨不同植被类型和环境因子对其的影响。结果表明:(1)贵州森林土壤有机碳密度约为180.62Mg/hm2,高于同纬度地区江西省森林土壤平均有机碳密度102.1Mg/hm2,表现出贵州森林土壤具有较高的固碳能力;(2)不同森林类型土壤有机碳密度变化范围为:114.52~388.29Mg/hm2,且差异显著(P0.05)。各种森林类型土壤有机碳密度大小为:华山松林杉木林柏木林栎类林马尾松林桦木林云南松林;(3)不同植被类型下各层土壤有机碳密度大小均以表层土壤为最大,且随土壤深度增加而降低;(4)在立地条件上,贵州森林土壤有机碳密度与海拔显著相关,与坡度、经度、纬度相关关系均不显著。

Soil Organic Carbon Density and Its Influencing Factors for the Forest Region of Guizhou Province, China

Soil organic carbon(SOC)in the forest ecosystem is the vital component of global carbon reservoir, and plays an important role in global carbon cycle and mitigation of global warming. Adopting field investigation and indoor analysis methods, the seven main forest types, i.e. Birch, Querous sclerophyllous, Cupressus funebris, Pinus yunnaniana, Cunninghamia lanceolat, Pinus massoniana and Pinus armandii were selected to investigate the variation of SOC densities and their controlling factors for the forest region of Guizhou Province, China. The main conclusions are drown as follows:(1)the average SOC density of Guizhou forest soil is 180.62 Mg/hm², higher than soil carbon density (102.1 Mg/hm²) in forests of Jiangxi Province, indicating a high carbon sequestration in forest soils of Guizhou Province; (2)the SOC density ranges from 114.52 Mg/hm² to 388.29 Mg/hm², and significantly different between forest types (P < 0.05) and decreases in the order of Pinus armandii > Cunninghamia lanceolat > Cupressus funebris > Querous sclerophyllous > Pinus massoniana > Birch > Pinus yunnaniana; (3)soil carbon density of forest declines with the increasing soil depth, and most of carbon was stored in the top soil (0-10 cm); and (4)Pearson correlation analysis shows that there is no significant correlation between SOC density and slope, latitude as well as longitude.