Distribution Characteristics of Organic Carbon in Soil Water-stable Aggregates of Wutai Mountain
LI Xiongfei;LIU Fenwu;FAN Wenhua;College of Resources and Environment,Shanxi Agricultural University;National Experimental Teaching Demonstration Center for Agricultural Resources and Environment,Shanxi gricultural University;
To explore organic carbon distribution characteristics in different soil aggregates of Wutai Mountain vertical zone,the soil samples which including subalpine meadow soil,mountain meadow soil,brown soil,leached cinnamon soil and calcareous cinnamon soil were collected from high altitude to low altitude in August 2016.Water-stable aggregates in different levels(2mm,2~0.25 mm,0.25~0.053 mm and 0.053 mm)of different type soils were harvested through wet-sieving method and physical fractionation technique,and the TOC,POC and MOC of all level aggregates and soils were further analyzed.The results showed that subalpine meadow soil,mountain meadow soil and brown soil all mainly composed by 2mm aggregates,which accounted for 45.13% of all water-stable aggregates.However,cinnamon soil and calcareous cinnamon soil were mainly composed by 2~0.25 mm and 0.25~0.053 mm aggregates respectively,reached 33.79% and 39.95%.With the decrease of altitude,soil organic carbon content decreased.Besides,the organic carbon content of2mm and 2~0.25 mm aggregates in different type soils had a great significant positive correlation with the corresponding soil organic carbon content and the correlation coefficients were r2mm=0.986,r2~0.25mm=0.966(P0.01).Although with the decrease of soil aggregates diameter,the POC contents of subalpine meadow soil,mountain meadow soil and brown soildecreased,and the POC contents of leached cinnamon soil and calcareous cinnamon soil increased.The MOC content of subalpine meadow soil,mountain meadow soil and brown soil were highest in2mm aggregates,and the MOC content of leached cinnamon soil,calcareous cinnamon soil were highest in 2~0.25 mm and0.25~0.053 mm aggregates,respectively.The soil MOC content was significantly greater than the POC content,and these two showed a positive correlation in soils and all level macro-aggregates(P0.05).In addition,the content of POC and MOC in soils also showed a positive correlation with the content of soil organic carbon(P0.05).Therefore,the soil aggregates turned from macro-aggregates to micro-aggregates with the decrease of altitude,and the carbon capture ability of subalpine meadow soil,mountain meadow soil and brown soil was stronger than leached cinnamon soil and calcareous cinnamon soil.
【Key Words】： Wutai Mountain water-stable aggregates POC MOC
【CateGory Index】： S152.4
【CateGory Index】： S152.4