污泥沙障对流动沙区植被恢复的作用

Effects of Sludge-Sand-barrier on Vegetation Restoration in Drifting Sand Area

利用城市生活污水处理厂脱水污泥制成成本低、吸水保湿性强和环境友好的污泥方格沙障、沙面上污泥平板沙障和沙面下污泥平板沙障,用于帮助恢复生态极端恶劣的流动沙区植被。调查撒播黄蒿(Artemisia scopara)种子后试验区沙丘植物的种类、覆盖度、生长状况等植被恢复指标。结果表明:污泥沙障处理下,人工播种的黄蒿、天然的沙米(Agriophyllum squarrosum)盖度、高度(除沙米)和生物量均显著高于裸沙区(对照)(p<0.05),雾滨藜(Bassia dasyphylla)、碱蓬(Suaeda glauca)和猪毛菜(Salsola ollina)的盖度、高度、多度、生物量(除雾滨藜)均高于对照;污泥方格沙障区的植物物种丰富度最高,沙面上污泥平板沙障区次之,沙面下污泥平板沙障及对照区较小;Shannon-Wiener多样性指数和Simpson多样性指数均为污泥方格沙障>沙面上污泥平板沙障>沙面下污泥平板沙障>对照;Pielou均匀度指数为污泥方格沙障>沙面下污泥平板沙障>沙面上污泥平板沙障>对照。综合考虑混合污泥成本、用量、植被恢复效果等诸因素,我们推荐采取污泥方格沙障治沙措施,使其在沙地植被恢复工作中发挥作用。

A new kind of sand barrier,which was composed of domestic sludge,could promote vegetation recovery of moving dunes in Minqin Country,Gansu Province.The seeds of Artemisia scopara were sown in the surface of sludge.The vegetation types,coverage,growth status and other recovery indicators were investigated.The effects of different treatments(sludge sand barrier,overlying sediment barrier,under cover of sediment barrier)of vegetation restoration were analysed.The results showed that:the biomass,coverage and height of artificial Artemisia scopara and natural Agriophylluma squarrosum,under the sludge(except Agriophylluma squarrosum)were significantly higher than the control(p<0.05).The cover,height,abundance and biomass(except demisting saltbush)of fog Atriplex suaeda and Salsola were greater than control.The highest species richness was found in grid sand barrier plots.And then the species richness in the surface of sand was greater than the area under the sand.Shannon diversity index and Simpson diversity index showed the following sequence,sludge squares>overlying sludge on sand surface>sludge under sand>control.And the Pielou uniform index was sludge squares>overlying sludge on sand surface>sludge under sand>control. Considering the cost of mixing sludge,quantity and the recovering effect,we recommend use sludge squares to fix dune and to rehabilitate vegetation in cold and arid area.