内蒙古赤峰流动沙地3种植物沙障效果比较

为了在内蒙古赤峰市选定适宜的沙障类型,选用黄柳、踏郎设置沙障,利用5 a连续观测数据,对比分析了黄柳、黄柳-踏郎、踏郎3种植物沙障植被覆盖度、沙丘移动距离、投入与产出比例。结果表明,黄柳、黄柳-踏郎、踏郎3种植物沙障设置后第5年平均植被盖度分别为44.9%、80.7%、79.7%。3种植物沙障设置后3 a间,仅第1年沙丘移动0.50~0.54 m,自第2年起沙丘基本被固定,3种植物沙障沙丘移动距离分别为0.54、0.51、0.50 m。3种植物沙障设置时种条用量不同,分别为7 000、6 400、6 000 kg·hm~(-2)。3种植物沙障种子(除黄柳外)和种条产量较高,5 a后种子和种条总产量分别为0、174.5、203.3 kg·hm~(-2),62 350、62 870、62 650 kg·hm~(-2)。随着治理时间推移,3种植物沙障投入与产出比逐年减小,自第3年起产出均高于投入。3种植物沙障投入与5 a总产出比为0.20、0.15、0.14,投入与5 a平均产出比为1.02、0.76、0.71。从植被恢复速度、投入成本、种子和种条产量、投入与产出比等方面综合分析,踏郎沙障最好、黄柳-踏郎沙障次之、黄柳沙障最差。

Comparison on 3 types of plant sand hedges for shifting sand lands in Chifeng of Inner Mongolia

In order to select the right sand hedge in Chifeng,Inner Mongolia,Salix gordejevii Y.L.Chang and Hedysarum fruticosum vat.mongolicum (Turcz.) were established in sand hedges of S.gordejevii,Salix-Hedysarum and H.fruticosum var.mongolicum,performances on vegetation coverage,sand dune shift distance,input-output ratio were monitored for 5 a.The results showed that average vegetation coverages for S.gordejevii sand hedges,Salix-Hedysarum sand hedges and H.fruticosum vat.mongolicum sand hedges were 44.9％,80.7％,79.7％ in the 5th year.Within 3 a after establishment,sand dunes were basically fixed since the 2nd year except for shifts of 0.54,0.51,0.50 m in the 1st year for 3 hedges,respectively.Cuttings for 3 hedge establishments were 7 000,6 400,6 000 kg · hm-2,respectively.Yields of seeds (except S.gordejevii) and cuttings were satisfactory,with overall yield of seeds and cuttings being 0,174.5,203.3 kg·hm-2,62 350,62 870,62 650 kg·hm-2 in the 5th year.Input-output ratio decreased with time,and the outputs exceeded the inputs since the 3rd year.Ratios of input to overall outputs for 5 a and the ratio of input to average output for 5 a were 0.20,0.15,0.14,1.02,0.76,0.71 respectively.To summarize,H.fruticosum var.mongolicum is the optimum species for sand hedge,followed by Salix-Hedysarum and S.gordejevii sand hedges in a descending order.