不同复垦年限下土壤孔隙微结构特征及其与复垦年限的关系尚未明确。为了探明矿区不同复垦年限土壤孔隙的微结构特征,选取河南省辉县市赵固煤矿复垦3 a(FK3)和10 a(FK10)土壤处理,并以原状地貌(CK)为对照。利用显微CT技术扫描200 mm田间原状土柱,结合Image J软件及其插件对土壤孔隙结构进行三维重建及分析。结果表明,复垦土壤孔隙结构稳定具有空间和时间的层次性和顺序性。随着复垦年限的增加,土壤孔隙度、孔隙数量、成圆率、分形维数和欧拉值总体呈逐渐增加趋势。从土壤剖面来看,0～30 mm土壤孔隙结构尚处于紊乱状态,孔隙数量表现为FK3>CK>FK10,而40～80 mm土层趋于稳定,孔隙数量呈现为CK>FK3>FK10。土壤剖面孔隙度与孔隙数量变化趋势基本一致。与FK3相比,CK和FK10的分形维数分别显著(P<0. 05)增加了16. 1%和12. 3%,但FK10与CK间无显著差异(P<0. 05)。相关分析表明,分形维数能综合表征土壤孔隙数量和形态特征,可作为沉陷区复垦土壤结构恢复状况的定量评价指标。本研究表明,复垦年限对沉陷区土壤结构修复具有较大影响,土壤结构达到稳定状态需经过10 a左右的时间。

The quantification of complex pore structures under different reclamation times and their relationships to rec-lamation time remains elusive. The authors have compared the soil pore microstructures under 0 a (CK treatment),3 a ( FK3 treatment) and 10 a (FK10 treatment). Intact soil columns were taken from 200 mm depths with PVC tube (50 mm in diameter,200 mm in height) in Zhaogu subsidence area,Huixian County,Henan Province,China. The soil col-umns were scanned using X-ray computed tomography at a voxel resolution of 0. 23 mm×0. 23 mm×0. 20 mm. After the reconstruction by the Image J software and its plug-in,the characteristics of macropore networks were quantified, including soil pore number,circle rates,fractal dimension and Euler value. The analysis of variance indicated that the reclamation time significantly influenced the spatial and temporal hierarchy and sequence. The porosity,pore number,circle rates,fractal dimension and Euler value were of greater under CK and FK10 than FK3. From the reclamation soil profile,the soil pore structure at depths 0-30 mm was still in a disordered state,while the 40-80 mm soil layer tended to be stable. Soil pore number in size order were FK3>CK>FK10 at depths 0-30 mm and CK>FK3>FK10 at depths 40-80 mm. The change trend of soil porosity was similar to that of soil pore number at depths 0-200 mm. The fractal dimension of CK and FK10 was increased significantly (P