Comparison of stand and soil characteristics of pure and mixed plantations of Populus deltoides and Alnus subcordata (case study: Chamestan, Mazandaran province)

The aim of the present study is to assess the effect of pure and mixed plantations of Eastern Cottonwood (Populus deltoides) and Alder (Alnus subcordata) on quantitative stand characteristics and soil properties. The experiment was established in 1994 using randomized block design with five treatments (1- P100%, 2- P67%-A33%, 3- P50%-A50%, 4- P33%-A67%, and 5- A100%) and four replicates in Chamestan Forest Research Center, Mazandaran province. All trees were measured and mixed soil samples were taken from 0-20 cm depth in all treatments in 2014. Result of ANOVA showed that after 20 years, there are significant differences in tree attributes including diameter at breast height, height, crown width, and leaf area index as well as stand attributes including basal area, volume and leaf area per hectare. The maximum growths of poplar were recorded in P33%:A67% treatments with an average of 35.0 cm DBH, and the maximum growth of Alder were recorded in 100%A treatment with an average of 25 cm. No significant difference was observed in soil properties between different treatments. Based on the results, P33%:A67% treatment is the best treatment for future plantations.