乌鲁木齐河流域天山云杉林空间分布格局分析——基于GIS技术的应用

The spatial distribution pattern of Picea schrenkiana var. tianschanica at Urumqi River Basin: Based on the application of GIS technology

以天山中部乌鲁木齐河流域为研究区,基于研究区DEM数据、二类森林资源调查数据及Landsat数据,运用3S（GIS、RS、GPS）技术,采用分布频率指数、生境综合指数定量分析流域尺度1989~2013年云杉林与地形因子（坡度、坡向、海拔）的关系,结果表明：1）云杉林分布面积大小与海拔服从韦伯函数分布,83%的云杉林分布在海拔2000~2600m,海拔2200~2400m是其最宜分布区;2）云杉林在坡向上的分布受生境综合指数制约,在生境综合指数最优（0.7~0.8）的阴坡分布58.93%的云杉林,在西北坡和东北坡分布30.25%云杉林,在生境综合指数最低（0.3~0.4）的阳坡则无云杉林分布;3）使用高斯函数可定量刻画云杉林在不同坡度上的分布状况,83%的云杉分布在坡度16°~45°之间,陡坡（26°~35°）云杉分布频率最大,达35%;4）云杉林海拔分布下限为1770m。上述研究明确并量化了天山云杉林分布规律及其与环境因子间的关系,为研究区森林调整与经营提供理论依据。

Based on the field investigation for forest resources, DEM and Landsat data, the relationships between the topographic factors （slope, aspect, elevation） and spruce forests from 1989 to 2013 in the Urumqi river basin located at middle Tianshan Mountain were analyzed by the distribution of frequency index, habitat composite index and 3S（ GIS, RS and GPS） technologies. The results showed that： （1） The relationship between spruce distribution area and the elevation fitted the weibull function. 83% of the spruce forest distributed at an altitude of 2000- 2600 m, an elevation 2200 -2400m was the optimum distribution area. （2） The distributions of spruce forests at different slopes were conditioned by habitat composite index. 58.93% of the spruce forests grew in the shade slope with the optimal habitat index of 0.7 - 0.8. In addition, there was no spruce forest in the sun ny slopes where had the lowest habitat index of 0. 3 - 0.4. There were 30.25% of the spruce forest distributed in the northwest and northeast slopes. （3） By using Gauss function, the distribution of spruce forest on different slopes could be quantified; 83% of the spruce forest distributed in the slope from 16° to 45°, and 35% of the spruce forest distributed （the maximum frequency distribution） in the steep from 26° to 35°. （4） The lower elevation for spruce forest growth was 1770m. The study identified and quantified the Tianshan spruce forest distri- bution rule and the correlation with environmental factors, which will provide a scientific basis for adjustment and forest management in the study area.