额济纳旗人工绿洲生态建设试验研究

A Test Study of Ecological Construction of Artificial Oasis in Ejin Banner, Inner Mongolia

根据额济纳旗弱水下游近河戈壁区的立地条件和气候特点进行合理布局，利用春季河水浇灌补充地下水位，采取开沟积沙保墒，选用乡土树种，乔灌结合，封造结合等严格的管理技术措施，１５ａ造林１３００ｈｍ２以上，年经济效益１４０多万元。通过边营造边观测取得数据，从防风固沙，改善土壤结构，增加植被覆盖度、生物产量以及社会效益等方面进行分析研究。结果表明，近河戈壁是可以逆转为绿洲的，这为综合整治居延绿洲环境提供了科学依据。

The test study was conducted on the gobi area near the lower reaches of the Heihe River, where climate belongs to continental extre mely dry type. Taking local circumstance and urgent need as starting point, and the re habilitation and improvement of ecological environment as goal, the paper seeks ways to rebuilt and enlarge the oases in desert region. The test began at the ye ar of 1982. The technical measures include: ① making use of river water during ice melting season to irrigate and fill groundwater;② accumulating sands by d igging ditches for planting to improve soil texture; ③ selecting local tree spe cies suitable to the environment to heighten the survival rate;④ afforestating with trees and shrubs integrately; and ⑤ controlling sand by enclosure and pl anting alternatively. From 1982 to 1996, the area of enclosure added up to more than 1 300 hm 2, that of afforestation to 978 hm 2 and that of natural recover accelerated by man made function to 222 hm 2. The average preserving rate of trees planted during 1981￣1989 is 61 3%, the average closing degree of these fo rest lands is 0 4. The coverage degrees of shrubs and grasses are 15 1% and 40 8% respectively. The construction of the artificial oasis has turned the bare gobi to green and showed ecological, economic and social benefits more obviously wit h time. The wind speed in woodland decreased by 48 3% compared with that at front of fo rest belt and 55 3% compared with that over gobi. During late June, the daily m ean air temperature in woodland is 0 5℃ lower than that in gobi, but the groun d surface temperature has a larger lower value of 6 3℃. The relative humidity rises from 14% near gobi surface to 2 9% in the woodland. Meanwhile, large amount of sand particles and dusts are reta ined by forest belt, which accelerates the processes of soil formation. There is a 9 5 cm soil surface layer in a woodland after 15 years from afforestation. T he successive construction of artificial oasis has not only brought about direct and indirect economic benefit, but also encouraged the farmers and herdsmen to preserve and establish ecological environment.