Relationship between vegetation and physical and chemical properties of soil in Fagetum communities (Case study: Kheiroudkenar forest)

This study was carried out in Carpino-Fagetum orientalis, Rusco-Fagetum orientalis, Fagetum oriental and Alno-Fagetum orientalis forest communities of Namkhaneh, Gorazbon and Chelir districts of Kheiroudkenar forest. The aim of the research was investigation on relationship between understory vegetation and soil condition and to determine the indicator species for predicting of specific site situation of Fagetum communities of the study area. Selective stratification sampling method was used to locate samples. One plot is sampled on each aspect in each community. Totally, 120 sample plots were selected in the Fagetum communities in the study area. The plot size was 400 m2 considering to minimal area method. At each sample plot, floristic list and an estimate of percent cover and abundance of each vascular plant in separate strata were recorded by using of Braun-Blanquet scale. At the center of sample plots, two soil samples were taken from 0-10 and 10-30 cm layers of mineral soil. The physical and chemical soil properties in each sample were analyzed. Two ordinations approach, DCA and CCA, were applied to determine the relationships between vegetation data and environmental variables. Results showed that the distribution of plant species is mainly associated with aspect, clay, total nitrogen, organic matter, phosphorous and exchangeable cations. Geranium robertianum, Mercurialis perennis and Ruscus hyrcanus indicate high soil fertility, while Festuca drymeia, Blechnum spicant and Epimedium pinnatum show low soil fertility. Carex remota, Sanicula europaea and Carex divulsa indicate a moderate soil fertility conditions.