Calculation of uneven-aged stand structures with the negative exponential diameter distribution and Sterba's modified competition density rule

Depending on Sterba's modified Competition Density Rule [Sterba, H., 1975. Assmann's theorie der grundflächenhaltung die “Competition Density Rule” det Japaner Kira, Ando und Tadaki. Cbl. f.d. ges. Forstw. 92, 46-62], the maximum basal area (Gmax), quadratic mean diameter (dGmax), and stem numbers (NGmax), for uneven-aged stands of Abies nordmanniana in the Black Sea Region in Turkey were calculated. Then, an exponential diameter distribution as a function of dominant height for these stands was obtained by solving nonlinear system of equations, which uses the maximum basal area (Gmax) and the stem numbers (NGmax) as input values, and gives diminution coefficient (q) and the number of stems in the largest diameter class (N1) as outputs. The results are in accordance to Sterba and Monserud's findings [Sterba, H., Monserud, R.A., 1993. The maximum density concept applied to uneven-aged mixed species stands. For. Sci. 39 (3), 432-452] on the slope of the maximum density line, and with Susmel's [Susmel, L., 1956. Laws and the variation of the parameters in uneven-aged normal forests. L'Italia Forestale e Montana XI (3), 3-14] concept of decreasing q with increasing dominant height.