Classification of tree and shrub covers and determination of their relation to some soil characteristics and topographic conditions in Shafaroud forests, Guilan province

In order to determine the relationship of soil characteristics and topographic conditions with tree and shrub species, three compartments of district 16 of Shafaroud forest, Guilan, Iran were sampled by sixty 0.1 ha plots. In each plot, diameter of all trees and shrubs (DBH>10 cm), altitude, slope and aspect were recorded and soil samples were taken at 0-20 cm depth. Total of basal area for every species in each plot was calculated. Using TWINSPAN (Two-Way Indicator Species Analysis), the forest was classified in five types, and then 6 soil profiles were excavated in them. The relationship of forest types with soil characteristics and topographic factors were analyzed by CCA (Canonical Correspondence Analysis), ANOVA (Analysis of variance) and Tukey's method. Based on the statistical methods, elevation, slope, soil pH and Ca showed significant relationship with forest types. Alnus- Juglans and mixed forest types had a significant relationship with elevation, soil pH and Ca. High correlation in Fagus- Tilia and Fagus- Fraxinus types with slope was recognized.