黑河下游重要生态功能区植被防风固沙功能及其价值初步评估

在遥感和地理信息系统支持下,利用风蚀输沙率模型,对1986-2006年期间黑河下游重要生态功能区植被的防风固沙功能及其价值进行了估算。结果表明: 1986、1996和2006年研究区植被防风固沙量分别为9 056×10⁴ t、4 972×10⁴ t和6 296×10⁴ t;不同植被覆盖的土地类型中,有林地防风固沙能力最强,其次为灌木林,低覆盖度草地最小;1986-2006年,区域植被生态系统的防风固沙功能呈现出先减弱后增强的趋势;植被防风固沙功能的空间分布差异性明显,防风固沙能力较高的区域主要零散分布在河流、湖泊沿岸等植被覆盖状况较好的区域;研究区域植被生态系统的防风固沙功能价值较大,2006年达到53.1×10⁸元,明显高于当年研究区的GDP。

Assessment on the Sand-fixing Function and Its Value of the Vegetation in Eco-function Protection Areas of the Lower Reaches of the Heihe River

Assessing the ecosystem service function and its value was a hot topic in ecology and economics research, and the establishment of the key eco-function protection areas had great effect on the national security and the socio-economic development in China. This study offered a theoretical basis for the protection and construction of the key eco-function areas. The eco-function protection areas of the lower reaches of the Heihe River were located in Ejinaqi, Inner Mongolia, with an area of 5.1×10⁴ km². Supported by the techniques of RS and GIS, based on the RS data of 1986, 1996 and 2006, using the sand transport flux models, the sand-fixing function of vegetation and its economic value were assessed in the eco-function protection areas. The results showed that the amounts of the sand-fixing were 9056×10⁴ t, 4972×10⁴ t and 6296×10⁴ t in 1986,1996 and 2006 respectively; the sand-fixing ability of different vegetation covers differed greatly, the forest land was the highest(9532 t/km²), shrubbery land was the second(9494 t/km²), and the low cover grassland was the smallest(5182 t/km²); the sand-fixing function decreased during the period of 1986-1996 and increased during 1996-2006; the spatial difference of sand-fixing function was obvious and the areas having higher sand-fixing ability spread sparsely in the high vegetation fraction areas around rivers and lakes; and the value of the sand-fixing function was higher, reaching 53.1×10⁸ yuan in 2006, which was 5.1 times the value of the GDP in 2006.