应用一元线性模型理论确定立地条件主导因子——朝阳低山丘陵区农田防护林立地条件类型的划分

本文用一元线性模型理论分析了辽宁西部朝阳、建平、喀左和北票(市)4县17个乡范围内的农田防护林主要树种——杨树(Populus spp.)、白榆(Ulumus pumila)的优势高与地形地貌、土壤肥力等立地条件因子的关系,确定地貌类型、坡位和土层厚度是本区农田防护林立地条件的主导因子,然后以地貌类型为单元将本区农田防护林的立地条件划分为3个大类型。在此基础上,再用坡位和土层厚度分级与3个大类型组合细分为6个基本类型。最后确定各立地条件类型的适宜树种,并定量地评价主要树种对各立地条件类型的适宜性。

Determination of dominant factors of site with linear model theory: division of farmland shelterbelt sites in Hilly Areas of Chaoyang.

It is a developing tendency to divide site quantitatively with considering comprehensive polyfactor. The grading combination of the dominant factors of site in some regions is a simple, precise and effective method, the key of which is the determination of dominant factors of site. The relationship between dominant height of main tree species (populus spp. and Ulumus pumila) and site factors such as landforms, soil fertility, etc, has been analysed with the linear model theory in 17 townships of Chaoyang, Jianping, Kazuo and Beipiao Counties in the west Liaoning province. The landform, position of slope and soil depth are considered as dominant factors of site in hilly areas. The farmland shelterbelt site was divided into 3 classes in the region according to geomorphic unit. Then,combining the gradations of slope position and soil depth with 3 classes, 6 sub-classes were classified. At last, the suitable tree species were selected for each site types, and its suitability was evaluated quantitatively.