This research aims to determine absolute operation age of Populpous nigra. This means the age which average growth increment is maximized and equal to the current eruption.Considering that a study has never been done on such issue, studying this on this matter is required. In order to conduct this study, 100 base of Populus nigra in 5 plantation area located in the central Zagros has been used in five spacing (3×6), (3×5), (3×4), (3×3) and (3×2). After cutting down trees, disks were prepared from a height of 0.3 and 1.3 meter and other disks with 2 meter intervals from the diameter. Diameter growth and height growth were measured through the analysis of trunk. Medium growing and the current density were measured at different ages by measuring the trees shape coefficients in different age of volume inventory. The absolute operation age of trees has been obtained using the results of current and medium growth increment. The results showed that the optimal operation age of planting season at (3×6), (3×5), (3×4), and (3×3) meters occur respectively at 13, 11, 7, 10 and 11 years old. The trees at planting distances of (3×4) have the highest growth and volume inventory. It is recommended that reforestation with species Populus nigra be withdrawn at 3 × 4 plant spacing and at 10.4 years old. !
کلید واژگان :GROWTH INCREMENT; EXPLOITATION AGE; CENTRAL ZAGROS; CRITERION OF WOODSMAN.!
ارزش ریالی : 300000 ریال
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