【摘要】 复垦排土场土壤的大孔隙、管状通道和植物根系是形成优先流的主要原因。论文采用野外染色示踪试验和室内理化分析等研究方法,系统研究不同土地利用方式土壤优先流的形态特征与变化规律,揭示排土场复垦植被恢复过程中优先流的形成机理及影响因素。结果表明:1)排土场各样地土壤优先流多发生在0~40 cm土层,占整个0~60 cm土壤层的93%以上;不同样地土壤优先流特征存在差异,0~5 cm土层染色面积比依次为榆树林地(90.37%)>刺槐林地(79.84%)>混交林地(65.37%)>农地(44.36%)>灌木林地(41.54%)>荒草地(38.38%),均表现为乔木林地大于灌木林地和草地;2)各样地0~60 cm土层染色面积比大小依次为刺槐林地(26.48%)>榆树林地(20.12%)>混交林地(17.32%)>农地(15.06%)>灌木林地(13.97%)>荒草地(10.07%),染色面积比与土层深度之间具有较好的线性关系;3)选取土壤因子、水分因子、植物因子3大类环境因子与染色面积比进行Spearman相关分析,其染色面积比与砾石含量、大孔隙平均半径、饱和导水率、根重密度和<1 mm根长密度呈极显著正相关(P<0.01),与容重和含水率呈极显著负相关(P<0.01),与1~2 mm和2~5 mm根长密度呈显著性正相关(P<0.05)。研究结果为认识排土场优先流的形成机制、完善优先流研究体系以及排土场植被恢复与重建提供科学依据。更多还原

【Abstract】 The macrospores,tubular channels and plant roots in the reclaimed soils of dump were the main reason for the formation of soil preferential flow.To better understand the morphological characteristics and variation of soil preferential flow in different land utilization styles in the dump,the dye staining experiment was carried out and physical and chemical analyses were used in the paper to investigate the formation mechanism and influencing factors of preferential flow in the process of revegetation.The results showed that:1) Soil preferential flow in dump centered in the 0-40 cm soil layer where the proportion of dyed area ratio occupied more than 93% of the 0-60 cm soil layer.The characteristics of soil preferential flow differed significantly in different soils.The dyed area ratio in the 0-5 cm soil layer of arbor forest was higher than those of shrub land and weeds,and the order was Ulmus pumila land(90.37%),Robinia pseudoacacia land(79.84%),mixed forests land(65.37%),farmland(44.36%),shrub land(41.54%) and weeds land(38.38%).2) The order of dyed area ratio in the0-60 cm soil layer of all samples in the dump was Robinia pseudoacacia land(26.48%),Ulmus pumila land(20.12%),mixed forests land(17.32%),farmland(15.06%),shrub land(13.97%)and weeds land(10.07%).There was a good linear relationship between the dyed area ratio and the depth of soil layer.The Spearman correlation analysis was carried out between the dyed area ratio and soil factors,water factors and vegetation factors.The dyed area ratio has significant positive correlation(P<0.01) with gravel content,mean radius of soil macrospores,soil saturated hydraulic conductivity,root weight density and density of root with length less 1 mm density and significant positive correlation(P<0.05) with density of root with length 1-2 mm and 2-5 mm,and it has significant negative correlation(P<0.01) with bulk density,water content.The results provide a scientific basis for understanding the formation mechanism of preferential flow,restoring and reconstructing vegetation in dumps.更多还原