Forty four-year response of regeneration and stock growth to single tree selection cutting in a Hyrcanian forest.

In this study, the forty four-year response of natural regeneration and forest stock growth to single tree selection cutting system in Khalil Mahaleh and Abbas Abad forest of Hyrcanian zone was investigated. Diameter at breast height (DBH), height, density (number of tree per hectare) and stock growth (tree volume per hectare) of each species were collected and analyzed for forest structure in 1963 and 2007. Results indicated that across all plots surveyed in 2007 the density of trees in diameter classes of 15-30, 35-50 and 55-80 cm was more than those of in 1963. Before selection cutting, the mean stock growth of forest was 367 m ha. After four decades of single tree selection cutting with yearly intensity of 2.5 m ha, it decreased to 353 m ha. Single tree selection cutting increased the density of Fagus orientalis Lipsky, Carpinus betulus L., Acer velutinum Boiss and Alnus Subcordata C.A.M. after 44 years whereas other species density showed a decrease of 33%. The density of all species regeneration in 1963 was more than 2007.