不同生物沙障对科尔沁流动沙丘植被恢复及土壤湿度的影响

Effects of Different Biological Sand Barrier on Plant Restoration and Soil Moisture in Moving Sand Dunes of Horqin Sandy Land

科尔沁沙地广泛存在的流动沙丘是土地退化的极点,在该沙丘区进行植被恢复和沙丘固定十分困难。生物沙障是一种普遍采用的有效固沙措施,但目前对于不同沙障材料对植被恢复的影响缺乏足够的认识。为了研究不同沙障材料固沙对植被恢复的作用,并筛选出适合科尔沁沙地流动沙丘固定的沙障组合类型,于2014年在科尔沁沙地流动沙丘的迎风坡中部设置了白柠条(Caragana korshinskii)、沙枣(Elaeaanus angustifolia)、五角枫(Acer ginnala)、山竹子(Garcinia mangostana)和白榆(Ulmus pumila)的带状生物沙障。沙障设置3年后研究不同沙障材料的植物成活率、高度,沙障内和沙障间的群落植被组成、盖度和土壤湿度。结果表明,生物沙障的植物成活率均较高,白柠条、白榆和山竹子沙障的植物成活率(>70%)和高度(>50 cm)均显著高于沙枣和五角枫沙障。沙障内植被组成和盖度以沙枣和五角枫表现较好,沙障间的植被组成和盖度以白柠条-白榆和五角枫-白榆组合表现较好。生物沙障内不同深度的土壤湿度表现出不同的规律,其中在深度10～20cm和20～30 cm表现为沙枣、白榆和五角枫沙障内的土壤湿度显著高于白柠条和山竹子的土壤湿度,其他深度生物沙障内的土壤湿度未表现出显著差异。综合考虑生物沙障对植物群落的恢复和土壤湿度的影响,认为五角枫-白榆是该地区流动沙丘固定和植被恢复较理想的沙障组合类型。

Mowing sand dune is the extreme land degradation in Horqin Sandy Land,and vegetation restoration and dune stabilization is difficult in this region.Biological sand barrier is an effective measure for sand dune stabilization,but there is no sufficient acknowledges on the effects of different biological sand barrier on vegetation restoration.In order to study the effects of different biological sand barrier on plant restoration,this experiment built five biological sand barriers in the middle of windward in 2014,the plant of sand barrier including Caragana korshinskii,Elaeaanus angustifolia,Acer ginnala,Hedysarum fruticosum,Ulmus pumila.After three years,we examined plant survival rate and height of sand barrier,the composition and cover of plant and soil moisture in sand barrier and among the sand barriers.The survival rate and height of C.Korshinskii,U.pumila and H.Fruticosum were significantly higher than that of E.Angustifolia and A.Ginnala.Plant composition and cover in E.Angustifolia and A.ginnala were better than that in other three sand barriers in the sand barriers.Plant composition and cover among the sand barriers of C.korshinskii-U.pumila and A.ginnala-U.Pumila were better than other sand barriers.Soil moisture varied with the soil depth,the soil moisture in the sand barriers of E.Angustifolia,U.pumila and A.ginnala were higher than that of C.korshinskii and H.Fruticosum in the depth of 10~20 cm and 20~30 cm.No other differences were detected in the depth of 0~5 cm and 5~10 cm.Therefore,the combination of A.ginnala-U.pumila is a better combination type of sand barrier in the sand dune stabilization and plant restoration in this region.