吉林省各级沙化土地资源的分布状况

吉林省约有 97 8万h 的沙化土地 ,在根据“综合指数和法”将其划分的Ⅰ、Ⅱ、Ⅲ三个等级中表现出 :各等级在干燥度、沙土稳固性、有效土壤层次 (腐殖质层或土壤本身发育程度 )厚度、土壤有机质含量、土壤速效磷、土壤物理性粘粒和 10℃积温等方面皆有一定差异 ;其分布为Ⅱ等沙地面积居多 ,在耕、草、林的不同沙地利用类型中Ⅰ、Ⅱ、Ⅲ三个等级的占有面积差别明显。同时还明确了三个等级的沙地在各县的分布情况

Distribution conditions of sanddificated land resources at all grades in Jilin province

There are about 978 000 ha of sandificated land in Jilin province.In the three grades(Ⅰ?Ⅱ?Ⅲ)of sandificated land divided according to the method of composite index sum,the following are showed :There are all definite difference between the aridities,the stabilities of sandy soil,the depths of effective soil layers (hummus layers or soil itself developing extents),the contents of soil organic matter,soil quick_acting P,soil physical sticky particles,the total temperatures above 10℃of all grades of sandificated land.The area of sandificated land at grade Ⅱ is the biggest.In different sandy land utilization types of cultivated land,grassland,forest land,there are remarkable differences between the actual processing areas of the 3 grades.The thesis makes clear the distribution conditions of the 3 grades of sandificated land in all counties.