四川盆地森林土壤的有机碳储量及其空间分布特征

Forest Soil Organic Carbon Storage and Characteristics of Spacial Distribution in Sichuan Basin

根据朱鹏飞和李德融编著的《四川森林土壤》(1989)一书中四川盆地152个森林土壤剖面数据,估算了该地区森林土壤有机碳密度及储量,并分析气候因素和地形对有机碳密度的影响。四川盆地森林土壤平均有机碳密度为(35.492±21.099)kg/m2,变异系数为59.45%,整个盆地森林土壤有机碳储量约为6.744×1015g;其中亚高山草甸草原土有机碳密度最高,为118.477kg/m2,最低的是草类-马尾松林林下黄壤,为3.145kg/m2;不同林型下土壤的有机碳含量差异较大。森林土壤有机碳的贮存受到温度、降水和海拔的影响,年均温度与有机碳密度呈极显著的负相关关系,海拔与有机碳密度呈极显著的正相关关系,温度是影响四川盆地森林土壤有机碳密度的关键因子。在年均降雨量400～800mm和年均温度0～4℃,可形成有机碳密度的高值区,其有机碳密度可达80kg/m2;在年平均温度为14～16℃,降水1400～1600mm,可形成有机碳密度的低值区,其有机碳密度20kg/m2。

Soil organic carbon （SOC） density and storage of forest land in Sichuan Basin were studied based on data of 152 soil profiles, and some factors affecting SOC storage such as climate and landform were ana lyzed. The average SOC density of forest soil was （35. 492±21. 099） kg/m^2 with Cv59.45%, and the total SOC storage in forest land is 6. 744× 10^15 g in whole basin. The SOC density in the sub-alpine meadow- grassland soil was the highest with 118. 477 kg/m^2 , and the lowest value of SOC density was 3. 145 kg/m^2 for yellow soil under the grass-Masson pine vegetation. The SOC density had notably difference for soils under different vegetation types. The temperature,rainfall and elevation were main factors that affect SOC storage, the relationship between average annual temperature and SOC density was a significant negative correlation, and the relationship between elevation and the density of SOC was a significant positive corre lation. Among the rainfall, temperature and landform factors, the temperature was a key. That region where the annual average rainfall was 400-800 mm and annual average was 0-4℃, was a high-value area of mean SOC density with 80 kg/m^2. Where the temperature was 14-16℃ and the precipitation was 1400 -1600 mm had low density of SOC with 20 kg/m^2.