GIS支持下的浠水县林地适宜性评价及林种结构调整研究

选取海拔、坡度、坡向、土层厚度和土壤类型5项因子,应用GIS技术对浠水县林地适宜性及林种结构调整方式进行了研究。结果表明,在浠水县63 054 hm2的参评土地中,最适宜林地占48.7%,适宜林地占33.0%,勉强适宜林地占17.5%,不适宜林地仅占0.8%。其中3,905 hm2大于25°的坡耕地5、792 hm2未利用滩地及302 hm2的荒草地均为最适宜和适宜林地,应通过实施退耕还林和荒山(荒滩)造林尽快充分利用。根据不同林种对立地条件及林地适宜度等级的要求,浠水县林业用地可增加经济林面积2 699 hm2、特用林面积6 378 hm2、防护林面积13 122 hm2,减少用材林面积11 797 hm2,通过林种结构调整可使生态公益林所占比例由调整前的8.3%提高到37.8%,从而充分合理地利用林地资源、改善林种结构,为浠水县比较完备的林业生态体系和比较发达的林业产业体系的建立奠定基础。

Forestland Suitability Evaluation and Forest Category Structure Adjustment in Xishui County Based on GIS

The paper studies the suitability of forestland and the modes of forest category structure adjustment of Xishui County by selecting five factors of elevation,slope,slope direction,soil thickness and soil type,applying with GIS technology.The outcomes show that among the 63 054 hm2 evaluated land areas in Xishui County,the highly suitable forestland,suitable forestland,moderately suitable forestland and not suitable forestland account for 48.7%,33.0%,17.5% and 0.8% respectively,of which,sloped farmland(> 25°) of 3 905 hm2,unutilized beach of 5 792 hm2 and waste-grassland of 302 hm2 are all classified as either highly suitable or suitable forestlands.They should be utilized through conversion of cropland to forest and afforestation on barren hills or uncultivated beach as early as possible.According to the demands of different forest categories for site condition and forestland suitability grade,the areas of economic forest,special use forest and shelter forest can be increased by 2 699 hm2,6 378 hm2 and 13 122 hm2 respectively and the area of timber forest reduced by 11 797 hm2.The proportion of ecological public forest area can be increased from 8.3% to 37.8%,thus fully and rationally utilizing the resources of forestland,improving the structure of forest category and laying a foundation for the establishment of relative completed forestry ecosystem and relative developed forest industry system in Xishui County.