Investigation on appropriate inventory method for determining structure of Northern Zagros Forests (Case study: Blake Forests, Baneh)

Quantitative, qualitative and structure data are vital for forest management at Zagros region of Iran. For this study, a site (40 hectare) at Blake forest located at Armardeh village of Baneh township was selected and 100 percent of the trees were measured, using 25 x 25 m. sampling plots. In addition to location of the trees in relation to the plot's corner, trees characteristics, including diameter at breast height (dbh),total height, crown height and crown diameters (biggest and smallest diameters) were measured at each plot. In order to identify the appropriate sampling method, for different methods were applied at 100 x 100 inventory net, consisting of: random sampling at three levels of sampling plots (40, 50 and 60 numbers, each at 10 R. area), and systematic-random at three levels of sample plots area (5, 10 and 20 R.), systematic-random with rectangular sample plots at two levels of area (10 x 50 and 20 x 50 m.) and transect 50 m. (length). The statistical methods of Anova and Duncan t were used to analyze the trees characteristics data and the %E2*T criteria to determine the appropriate inventory method. The horizontal and vertical structure of the forest was showed in 25 x 25 m. sample plot, using SVS software. The results showed that structure of Blake forest contains of two layers, in which Quercus infectoria and Quercus libani (average height of 7 and 6 m., respectively) make the over story, and Crataegus azarolus and Acer cinerascens (average height of 5 and 4.5 m., respectively) make the under storey. Furthermore, for diameter measurement (29222), transect and for total height (6048) and crown height (6668) measurements, Systematic –random with 5 R. sample plots at 100 x 100 sampling net system, recognized as the best inventory methods. Overall, the systematic-random inventory method with 5 R. sampling plots at 100 x 100 sampling net system is suggested to determine structure and measure characteristics of coppice and aged forests of Baneh township of Kurdistan province of Iran.