黄土高原丘陵区典型退耕恢复植被土壤碳分布特征及其影响因素  

Distribution of Soil Carbon and Its Driving Factors Under Typical Restored Vegetation in Hilly Areas of Loess Plateau

作　　者：沙国良 陈宇轩[1,2] 魏天兴 任康[1,2] 郭鑫 傅彦超 SHA Guoliang;CHEN Yuxuan;WEI Tianxing;REN Kang;GUO Xin;FU Yanchao(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Jixian National Forest Ecosystem Observation and Research Station,CFERN/CNERN,Beijing 100083,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]山西吉县森林生态系统国家野外科学观测研究站,北京100083

出　　处：《土壤》2022年第6期1265-1272,共8页Soils

基　　金：国家重点研发计划项目(2022YFF1300401)资助。

摘　　要：为深入了解退耕地植被恢复对土壤碳库的影响,选取黄土高原丘陵区典型退耕还林树种沙棘、油松、山杏和山杏油松混交林0~100 cm土壤为研究对象,以天然草地土壤为对照,运用方差分析、冗余分析和随机森林模型等方法,探究黄土高原丘陵区典型退耕恢复植被有机碳、无机碳、全碳含量分布特征及其影响因素。结果表明:(1)研究区各植被平均土壤全碳含量为1.685~1.898g/kg,平均土壤有机碳含量山杏(0.368 g/kg)>草地(0.299 g/kg)>沙棘(0.250 g/kg)>油松(0.233 g/kg)>油松山杏混交(0.209 g/kg),平均土壤无机碳含量为平均土壤有机碳含量的5.6倍;(2)所有植被土壤深层(60~100 cm)无机碳含量均无显著差异;除油松外各植被表层(0~20cm)土壤有机碳含量显著高于其他土层(P<0.05);(3)坡向、坡度、海拔、土地利用类型、土壤含水量、土壤黏粒、有效磷和速效氮共解释了78%、24%和77%的有机碳、无机碳和全碳含量变化,其中海拔、坡向和土壤含水量为研究区土壤碳含量变化的主要影响因素(P<0.05)。在黄土高原植被恢复过程中应充分考虑地形因子和土壤理化性质对土壤碳含量分布的影响。本研究结果可为正确评估人工林土壤碳储量及其生态效益提供基础数据和科学参考。To understand the impact of vegetation restoration on soil carbon in the Loess Plateau in China, soil samples(0–100 cm)were collected from grass land, Pinus tabuliformis, Armeniaca sibirica, A. sibirica and P. tabuliformis mixed plantations and Hippophae rhamnoides in Wuqi County, and then the distribution characteristics of soil carbon(SOC, SIC and TC) contents and their influencing factors were analyzed through random forest model and other methods. The results show that the average TC is ranged from 1.685 to 1.898 g/kg, average SOC content is in the order of A. sibirica(0.368 g/kg) > grass land(0.299 g/kg) > H. rhamnoides(0.250 g/kg) > P.tabuliformi(0.233 g/kg) > A. sibirica and P. tabuliformis mixed plantations(0.209 g/kg), and average SIC content is 5.6 times higher than that of SOC. SIC is not significantly different in all restored vegetation in 60–100 cm soil layer, SOC in 0–20 cm soil layer is significantly higher(P<0.05) than that in 20–100 cm soil layer in all plant communities except for P. tabuliformis. Slope aspect and gradient, elevation,land use type, soil moisture and the contents of soil clays, available phosphorus and nitrogen can explain a total of 78%, 24% and 77% of the variation in SOC, SIC and TC respectively. The elevation, slope aspect and soil moisture are the main factors influencing soil carbon content in the study area(P<0.05). In general, the influence of topographic factors and soil physiochemical properties should be fully considered in the process of vegetation restoration on the Loess Plateau. This study can provide basic data and scientific references for the accurate assessment of soil carbon stocks in plantation forests and their ecological benefits.

关 键 词：黄土高原 有机碳 无机碳 分布特征 影响因素 

分 类 号：S714.2[农业科学—林学]