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采用定位观测法,系统评价了杨树(脚Populus smonii)林的防风、抗蚀和滞尘等生态服务效能及其间接价值,同时定量探讨了风速减弱系数与实测林地叶面积指数的关系.结果表明,在研究区主害风(西北风)天气下,林地迎风区6 H(H为平均树高)、3 H、林地中央、林地背风区林缘、6和8 H处2 m高度的日平均风速与对照点(流动沙丘)相比均有不同程度减弱,风速减弱系数在18.3％～66.2％之间.林地背风区6 H处0.25、0.5、1和2 m 4个高度的月平均风速减弱系数与林地叶面积指数呈显著非线性相关,其间存在良好的三次曲线关系(P<0.0001,R2=0.43～0.94,n=80).在主害风天气下,林地各观测点的地表日风蚀量与对照点相比大幅度降低,平均降幅85.2％～99.9％.在观测期内,林地中央的日平均降尘量为13.2 kg·hm-2,而林地迎风区6H处的日平均降尘量为9.9 kg·hm-2,林地的日滞尘能力约为3.3 kg·hm-2.
By using the observational method, the ecological service performance and its indirect value of wind protection, erosion resistance and dust retention of poplar (Populus smonii) forest were systematically evaluated, and the relationship between the wind speed reduction coefficient and the measured LAI was quantitatively investigated. Results The results showed that in the study area the main wind (northwest wind) weather, the windward 6 H (H is the average tree height), 3 H, the forest center, the edge of the woodland leeward zone, the 2 m height at 6 and 8 H Compared with the control point (moving sand dune), the average wind speed weakened to some extent and the wind speed reduction coefficient was between 18.3% and 66.2% .At the same time, the mean monthly wind speeds of 0.25, 0.5, 1 and 2 m at 6 H in the leeward region There was a significant nonlinear relationship between the attenuation coefficient and the leaf area index of the forest land, with a good cubic curve relationship between them (P <0.0001, R2 = 0.43-0.94, n = 80). In the main windy weather, During the observation period, the average amount of dustfall in the center of forest land was 13.2 kg · hm-2, while the average amount of dustfall at 6H in the windward area of the woodland in the observation period was decreased by 85.2% -99.9% At 9.9 kg · hm-2, the daily dust-holding capacity of woodland was about 3.3 kg · hm-2.