露天煤矿排土场复垦区不同植被类型枯落物持水特性研究

Study on Water Holding Characteristics of Litter in Different Vegetation Types in the Reclaimed Land of Open-cut Coal Mine Dump

为揭示露天煤矿排土场复垦区不同植被类型水土保持效益,选取刺槐林地、榆树林地、混交林地(刺槐和榆树混交)、灌木林地(紫穗槐)和荒草地5种典型复垦植被下的枯落物作为研究对象,采用室内浸水法对5种植被类型枯落物的持水特性进行研究。结果表明:5个样地的枯落物厚度、蓄积量均表现为:乔木林地>灌木林地>荒草地,枯落物厚度在0.80~1.64cm之间,总蓄积量在0.72~7.51t/hm^2之间;枯落物最大持水量和有效拦蓄能力均表现为刺槐林地最大,枯落物最大持水率为145.58%~206.58%,最大持水量为13.11~123.98t/hm^2,有效拦蓄率为119.74%~166.05%,有效拦蓄量为10.09~98.76t/hm^2;林地枯落物持水量与浸泡时间的关系为Q=aln t+b;枯落物在0~1h内吸水速率最大,1~4h内吸水速率急剧下降,随后下降幅度逐渐减小,枯落物吸水速率与浸泡时间关系式为:V=atb。研究结果可为评价露天煤矿排土场不同类型复垦区枯落物层水源涵养效益提供参考,为排土场植被恢复与重建提供科学依据。

In order to investigate the beneficial regulations of soil and water conservation in different vegetation types of reclamation areas of open-cut coal mine dump,the research about the vegetation litter was carried out in the 5typical vegetations of the reclaimed land,including Robinia pseudoacacia,Ulmus pumila,mixed forests（Robinia pseudoacacia and Ulmus pumila）,shrub and weeds,by means of cutting ring method.The results showed that the litter thickness and cumulated amount in 5sample areas were in the order of forest〉shrub〉weeds land.The litter thickness was ranged from 0.8cm to 1.64 cm,the cumulated litter amount was ranged from 0.72t/hm2 to 7.51t/hm2;the maximum water holding capacity and water conservation ability of litter showed Robinia pseudoacacia maximum,the maximum water-holding rate of litter was145.58%—206.58%,the maximum water-holding capacity was 13.11—123.98t/hm2,the effective interception rate was 119.74%—166.05%,the effective interception was 10.09—98.76t/hm2.The relationship of forest land between litter water-holding capacity and the immersion time was logarithmic function（Q=aln t＋b）.The litter water absorption rate reached the maximum value at first 0—1h,then the water absorption rate rapidly decreased in 1—4h,and finally decreased gradually.The relationship between litter absorption rate and immersion time was power function（V =atb）.The study would provide reference for evaluating the water conservation efficiency of litter layer in different reclamation areas of open-cut coal mine dump,and provided scientific basis for the vegetation restoration and reconstruction of the dump.