干旱荒漠风沙区沙化土地综合整治技术研究——以古浪县黄花滩治沙示范区为例

 采用“四带一体”的模式,对示范区沙漠化土地进行综合整治。试验结果表明：在干旱荒漠区,以低矮流动沙丘为主的沙漠化土地,采用“前沿阻沙林带+固沙林带+植物活体沙障阻沙带+封沙育林育草带”的“四带一体”防护模式,取得了显著的防护效果。示范区农作物受沙害面积从治理前的37.7%减少到治理后第1年的14.2%,第2、3年未受风沙危害;防护带后0.5 m和1.5 m高处平均风速较旷野分别降低75.9%和63.4%,平均输沙量从防护带前的2 556.1 mg·cm^-1·h^-1降低到防护带后的3.41 mg·cm^-1·h^-1;筛选出沙拐枣、花棒、沙枣、白榆、沙蒿为流动沙丘和丘间低地适宜的造林树种;粘土沙障设置以2 m×2 m为宜,麦草、尼龙网沙障1 m×1 m效果较好。造林初期,以沙米和碱蓬为主的一年生植物能够在林下大量繁衍, 盖度达到50.2%和34.1%, 对初期的沙丘固定发挥作用, 但也大量的消耗了浅层沙丘土壤水分。随着人工林的生长,一年生植物逐渐衰退,3年后深根系的天然沙蒿逐渐繁衍,盖度达到10%。

Techniques of Integrated Controlling Desertified Sandy Land in Arid Area:An Example in Huang-hua-tan Desert Control Demonstration Region in Gulang County, Gansu Province

An integrated controlling pattern of combining four belts was designed and applied to control the desertification land of the demonstration region in Huang-hua-tan of Gulang County, Gansu province. The integrated controlling pattern is comprised of the blocking sand belt, the fixing sand belt, the alive plant barrier blocking sand belt, and the enclosed sand belt. It was demonstrated that this pattern had achieved outstanding protection effect for controlling the desertification lands covered mainly by low shifting dunes. In the demonstration region, the crop area suffering from sand-encroaching had decreased from 37.7% in pre-control to 14.2% in the first year after control, and to 0% in the second and the third year. The mean wind speed at 0.5 m and 1.5 m height behind the protecting system could be reduced by 75.9% and 63.4% respectively in comparison with that in open field. The average sand transportation capacity could be reduced from 2 556.2 mg·cm^-1·h^-1 in front of the protecting system to 3.41 mg·cm^-1·h^-1 behind the system. Calligonum klementzii, Hedysarum scoparium,Ulmus pumila, Elaeagnus angustifolia and Artemisia arenasia had been selected as the available plant species for afforesting in shifting sand dunes and inter-dune lowlands. The clay barrier performed well in 2 m×2 m pattern, the straw and the nylon-net barriers performed well in 1m×1m pattern. In the early period of afforestation, annual plants such as Agriophyllum squarrosum and Suaeda gluace propagated flourishingly, their coverage could be 50.2% and 34.1% respectively, which played role on sand fixation in initial stages. The annual plants were gradually replaced by deep-rooted plants along with artificial plants growing, 3 years later the coverage of Artemisia arenasia could reach 10%.