冀北沙漠化土地黄柳生物沙障防风阻沙与土壤改良效益分析

Cost-benefit analysis of wind prevention and soil improvement of Salix gordejevii sand-barrier in desertification land of Northern Hebei

流沙固定及土壤改良是冀北沙漠化土地植被恢复与重建技术体系的关键环节之一。本研究通过对冀北沙漠化土地黄柳生物沙障内与裸露沙地的风速、积沙量及土壤理化性质的观测分析,研究了黄柳生物沙障的防风阻沙效益及土壤改良效益。结果表明：黄柳沙障后1 m,0.5 m高度处的防风效能为28.69%,黄柳沙障内下垫面粗糙度为裸露沙地的4.5倍,黄柳基部积沙量为0.09 m^3。黄柳沙障内0-10 cm、10-20 cm、20-40 cm土壤极粗砂粒（〉1.0 mm）含量分别比裸露沙地减少了92.84%、95.38%、82.85%,细砂粒（0.25-0.1 mm）含量则分别比裸露沙地增加了57.09%、44.93%、46.37%,土壤非毛管孔隙度较裸露沙地提高了24.85%、41.30%、22.86%。黄柳沙障内表层土壤有机质含量、微生物总量分别比裸露沙地高出30.93%、54.54%,沙障内土壤酶活性亦有增强,其中过氧化氢酶活性变化明显,其活性在0-40 cm土层比裸露沙地高出37.69%。

Shifting sand fixation and soil improvement are key aspects of vegetation restoration and reconstruction technology system in desertification land of Northern Hebei. As compared with bare sandy land, this study examined Salix gordejevii sand-barrier＇s ecological effect by observing wind speed, sand collection quantity and soil properties in sandy land with Salix gordejevii sandy-barrier. The results showed that the wind-break potency is 28. 69% at the height of 0.5 m, 1 m behind Salix gordejevii sandy-barrier. The ground roughness in sandy land with Salix gordejevii is 4.5 times of the bare sandy land. The coarse sand particle（〉1. 0 mm） at the 0-10 cm,10-20 cm,20-40 cm depth soil layer decreased by 92.84%,95.38%, 82.85% respectively, and the fine sand increased by 57.09%, 44. 93%, 46.37%, compared with those in bare sandy land. The soil organic matter content in sandy land with Salix gordejevii sandy-barrier increased by 30. 93% and the soil microorganism amount improved by 54.54%. Salix gordejevii sandy-barrier had enhanced soil enzyme activities also and soil catalase activities improved obviously by 37. 69% at the 0-40 cm depth soil layer.