乌兰布和沙地人工绿洲防护林体系模式生态和经济效益评价

对乌兰布和荒漠沙地生态经济型防护林体系的生态、经济、社会效益评价结果表明 :1 )在封沙育草灌木固沙林生产系统中 ,宽带模式的植物盖度比窄带模式提高 1 7～ 3 3 % ;风蚀量比窄带减少约 50 % ;花棒、杨柴、沙拐枣林带的全 N含量分别比裸沙地提高 75.3 5、66.2 0、6.3 4% ;全 P含量分别提高 1 2 8.1 8、1 40 .3 3、3 7.0 2 % ;全 K含量分别提高 0 .3 5、0 .76、0 .1 0 % ;有机质含量分别提高 1 49.0 5、1 75.65、76.5%。宽式林带的经济效益为窄式林带的 2 .0 1倍。2 )在防风阻沙林生产系统中 ,防风阻沙带防护范围内 ,风蚀量比荒漠区降低 91 .3～ 97.5%。小美旱杨与花棒和新疆杨与沙棘乔灌结合混交林的投入产出比分别是 1∶ 8.44、1∶ 1 8.0。 3 )在农田防护林生产系统中 ,林—农结构生产系统经济效益是农田生产系统的 1 .99倍 ;林—果结构生产系统经济效益比用材林增加 44 .8% ;林—牧结构人工草场比天然草场经济效益提高 4倍左右 ,即年盈利额平均为 461 7.84元 / hm2 。林—药结构生产系统模式 ,年盈利额平均高达1 90 86.3 6元 / hm2 。林—农、林—果、用材林等各生产系统的年盈利额分别为 2 2 89.3 0、1 3 2 7.50、91 6.80元 / hm2。 4) 1 982～ 1 994年 ,护渠林较无护渠林保护的干渠减少清淤投资

Evaluation on The Ecological and Economic Effects of Shelter Belt Patterns in Ulanbuhe Sandy Land

The evaluation on the ecological economic effects of the patterns of shelterbelt systems in Uanbuhe desert were taken.The results showed that:(1)In the production system of grasses, shrubs and trees shelter belt,The vegetative coverage of broad forest belt was raised by 17-33% comparing with that of narrow;The wind erosion amount decreased by 50%;The total nitrogen amount in the land of Hedysarum scoparium,Hedysarum mongolicum,and Calligonum mongolicum forest belt was raised by 75.35,66.20,and 6.34% respectively compared with uncovered sands;The total phosphorus amount was raised by 128.20,140.33,and 37.02% respectively;The total potassium amount was raised by 0.35,0.76,and 0.10% respectively;The organic matter amount was raised by 149.05,175.65,and 76.5%;the economic effects of the broad forest belt was raised by 2.01times compared with the narrow one.(2)In the production system of Forest shelter belt,the wind erosion amount reduced by 91.3~97.5% compared with the desert.The input-output ratio of the mixed forest of populus×Xiaozhuanica CV.'Popularis'with Hedysarum scoparium and Populus bolleana lauche with Hippophae rhamnoides was by 1∶8.44,1∶18.0 respectively.(3)In the production system of farmland shelter-forest,The economic benefits of forestry-fruit tree was increased by 44.8% compared with the timber-forest;The economic benefits of the forestry-stock structure of artificial grassland were 5 times of the natural grassland,The profit was 4617.84(RMB)/hm+2 per year. The profit of forestry-medicinal plantation pattern was as high as 19086.36(RMB)/hm+2 per year.The production types of the forestry-agriculture and the forestry-fruit tree and the timber-forest was by 152.62,85.50,61.12(RMB)/mu per year respectively.(4)The investment for elimination silt decreased by 146188(RMB) from 1982-1994 due to the benifit of sheltered irrigation. (5)Establishment of agriculture industry in wulanbuhe sandy land is feasible.Based on the loan interest rate 6.485 and the prices rise index 121.7 in 1993,if agriculture, forestry and stockraisng were established on the interest pattern,the investment would be taken back nine years later,and would be back 12 or 13 years later if loan interest was 12% or 16%.