云台山森林土壤的特性和分类

连云港市云台山坡地上主要森林土壤的化学性质，是介于南京周围低山和鲁南低山的森林土壤之间，细土游离Fe2O3含量同鲁南的棕壤一致，但细土CEC7/粘粒比率、粘粒硅铝率和硅铁铝率却近似于南京地区的黄棕壤，表现出在南北方森林土壤之间的过渡特点。云台山土壤由于受地形、母介和成土时间差异的影响，有较大的区域内变异，按《中国土壤系统分类（首次方案）》，可划归3土纲5土类，其中占面积最大的是薄层土类和棕壤类，生产力中等水平；此外还有较小面积的酸性棕壤黄棕壤类和棕红壤类，生产力较高，土壤数据的主分量分析和土壤个体排序指出了各土类的相互关系及演变趋势。

CHARACTERISTICS AND CLASSIFICATION OF FOREST SOILS IN THE YUNTAI MOUNTAIN

The Yuntai Mt. of Lianyungang city is situated at the climatic boundary between the northern and the southern parts of China, and chemical properties of forest soils on its slopes lie between those in the lowmountains around Nanjing city and in the southern part of Shandong Provinec. It shows transitional characteristics of forest soils between the northern and southern parts, with the percentage of free Fe2O3 in fine earth coinciding with that of the brown earths in southern Shandong but the CEC7/clay ratio of fine earth and the silica-alumina ratio and silica-sesquioxide ratio of clay fraction similar to those of yellow-brown earths around Nanjing. Soils in this mountain has a rather gerat variation within the area due to the effects of relief, parent material and soil forming time on them, and can be allocated into 5 soil great groups under 3 soil orders, in which rankers and brown earths occupy a largest area and have soil productivity of medium level, and acidic brown earths, yellow-brown earths and brown-red earths occupy the smaller area but have higher soil productivity.