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为阐明广西森林土壤有机碳密度分布格局及其主要影响因素,基于森林资源清查资料和345个调查样地的土壤数据,估算了广西主要森林土壤有机碳储量,采用地统计学方法描绘了土壤有机碳密度的空间分布,并利用主成分分析和逐步回归分析方法分析了影响土壤有机碳密度的主要因子。结果表明:广西主要森林土壤有机碳储量(0–100 cm)达到1 686.88 Tg,土壤有机碳密度为124.70 Mg·hm~(–2),低于全国森林土壤平均水平。广西主要森林土壤有机碳密度最佳拟合模型为指数模型,呈中等强度空间相关,Kriging插值显示土壤碳密度高值区在东北区域,低值区在西北区域,表现为喀斯特区域低、非喀斯特区域高的特点。广西主要森林土壤碳密度在不同植被类型和土壤类型下表现出一定差异,其中竹林>落叶阔叶林>暖性针叶林>常绿落叶阔叶林>常绿阔叶林,黄壤>红壤>赤红壤>石灰土。主成分分析和逐步回归分析结果发现土层深度、经纬度、海拔是影响广西森林土壤有机碳的主要因子,其中以土层深度影响最大,主要受岩溶地貌的影响。
In order to clarify the distribution pattern of soil organic carbon density in Guangxi forest and its main influencing factors, based on the forest inventory data and the soil data of 345 surveyed plots, the soil organic carbon storage of main forest in Guangxi was estimated, and the geostatistics method was used to describe the soil organic The spatial distribution of carbon density and the main factors affecting soil organic carbon density by using principal component analysis and stepwise regression analysis. The results showed that: the main forest soil organic carbon storage (0-100 cm) in Guangxi reached 1 686.88 Tg, and the soil organic carbon density was 124.70 Mg · hm -2, which was lower than the national forest soil average. The best fitting model of soil organic C in Guangxi was an exponential model with medium intensity spatial correlation. Kriging interpolation showed that the highest value of soil carbon density was in the northeast region and the low value region was in the northwest region, which was characterized by low karst region, non-karst High area characteristics. The carbon density of main forest soils in Guangxi showed some differences under different types of vegetation and soil types, including bamboo> deciduous broad-leaved forest> warm coniferous forest> evergreen deciduous broad-leaved forest> evergreen broad-leaved forest, yellow soil> Red soil> lime soil. Principal component analysis and stepwise regression analysis showed that soil depth, latitude and longitude and altitude were the main factors affecting soil organic carbon in forest in Guangxi. Among them, soil depth had the greatest impact and was mainly affected by karst landform.