采煤沉陷对土壤团聚体及其有机碳的影响

Effects of Coal Mining Subsidence on Soil Aggregates and Organic Carbon

为了更好地了解采煤沉陷坡地土壤结构及其有机碳库的变化特征,以典型的焦煤集团九里山矿采煤沉陷坡地为研究对象,分析了采煤沉陷坡地不同坡位土壤团聚体的组成及其有机碳的空间分布特征。结果表明:采煤沉陷坡地大团聚体含量自坡顶至坡底不断下降,微团聚体含量不断增加,土壤结构和稳定性自坡顶至坡下越来越差,在坡底则有所好转。采煤沉陷坡地不同坡位<0.25 mm土壤团聚体有机碳含量最高,各粒级土壤团聚体有机碳含量自坡顶至坡下不断减少,在坡底则有所增加。采煤沉陷坡地土壤有机碳含量自坡顶至坡下不断减少而在坡底显著增加。采煤沉陷减少了不同坡位>5 mm土壤团聚体有机碳储量,增加了不同坡位<0.25 mm土壤团聚体有机碳储量,但对0.25~2 mm、2~5 mm土壤团聚体有机碳储量的影响没有明显规律性。采煤沉陷坡地坡顶、坡上、坡中、坡下土壤有机碳储量显著低于正常农田,分别比未塌陷地土壤有机碳储量减少了8.19 t/hm^2、8.21 t/hm^2、9.11 t/hm^2、11.34t/hm^2,煤炭开采引起的采煤沉陷对土壤有机碳库造成了不同程度的损失,并在一定程度上加剧了温室效应。

In order to understand the variation of the soil structure and its reservoir effect,the space distribution features of the soil aggregates and its organic carbon at the different positions of the mining subsidence slope were analyzed,with a typical mining subsidence slope as the study object. The study results showed that an increasing trend of macro-aggregates but declining of micro-aggregates was observed from the top to the bottom on the slope of coal mining subsidence,while the soil structure and stability was worse from the top but better at the bottom of the slope. The soil organic carbon content of <0.25 mm aggregates were the highest at the different sites of the coal mining subsidence slope. The soil organic carbon of all particle sizes′ aggregates were reduced unceasingly from the top to the lower,while were slightly increased at the bottom of the slope. The soil organic carbon content were reduced unceasingly from the top to the lower but increased markedly at the bottom of the coal mining subsidence slope. The coal mining subsidence has reduced the>5 mm aggregates′ soil organic carbon storage on different slopes,while increased the <0.25 mm aggregates′ soil organic carbon storage. But the0.25~2 mm,2~5 mm aggregates′ soil organic carbon storage affected by the coal mining subsidence have no obvious regularity. The soil organic carbon storage at the top,the upper,the middle,and the lower slope of coal mining subsidence was significantly lower than that of non-subsidence land by 8.19 t/hm^2,8.21 t/hm^2,9.11 t/hm^2,and 11.34 t/hm^2,respectively. Coal mining subsidence caused soil organic carbon storage loss by different level,and worsened the greenhouse effect to a certain extent.