露天煤矿排土场不同植被土壤水分特征及其时间稳定性

选择晋陕蒙接壤区永利煤矿排土场沙打旺草地、紫花苜蓿草地、沙棘林地和原地貌草地土壤水分为对象,研究其蒸散、剖面分布、时间变化等特征,以期揭示土体重构及不同复垦植被模式对土壤水分及其时间稳定性影响。结果表明:排土场3种人工植被条件下土壤平均含水量同原地貌草地相比提高了50.7%~62.3%,另外,沙打旺复垦草地土壤含水量显著低于苜蓿复垦草地和沙棘复垦灌木林地(均降低了7.2%)。沙打旺和苜蓿会导致深层(120—260,120—220 cm)土壤水分亏缺,但有利于20—80 cm的土壤水分的保持;而沙棘易导致浅层(20—80 cm)土壤水分亏缺,但对深层(100—280 cm)土壤水分影响较小。上述结果说明,矿区排土场土体重构过程能够改善排土场土壤的水分条件,并且在进行植被重建的过程中,不同复垦植被对土壤水分的保持与利用形式有所不同,在本研究中,苜蓿和沙棘更有利于缓解土壤水分亏缺。

Soil Water Characteristics and Temporal Stability Under Different Vegetation Patterns in Opencast Coal Mine Dump

The objective of this study was to reveal the effect of different vegetation patterns on the soil water characteristic and its temporal stability in opencast coal mine dump.Three vegetation patterns including Astrgalus adsurgens grassland,alfalfa grassland and seabuckthorn shrubland were selected,and grassland in original landform was used as control.The results showed that the average soil water content under three kinds of artificial vegetation increased by 50.7%~62.3%,compared with the grassland in original landform.The soil water deficit in the deep layer(120—260 and 120—220 cm)was observed in astrgalus adsurgens grassland and alfalfa,while higher soil water content was observed in 20-80 cm.In seabuckthorn shrubland,soil water deficit was observed in the shallow layer(20—80 cm),while higher water content was detected in the deep layer(100—280 cm).These results showed that the soil reconfiguration can improve the soil moisture condition in the reclamation of the waste site,and the selection of alfalfa and sea-buckthorn is more conducive to the alleviation of soil moisture deficiency in vegetation reconstruction.