Ozbayram, Ali KemalCicek, Emrah2024-08-232024-08-2320232602-4039https://doi.org/10.5152/forestist.2022.22047https://search.trdizin.gov.tr/tr/yayin/detay/1178681https://hdl.handle.net/20.500.12684/13744Narrow-leaved ash (Fraxinus angustifolia Vahl.) with its capacity for fast growth is a valuable wood crop. In 2005, a trial of thinning was established out in a narrow-leaved ash plantation in Sakarya, Turkey, and three different intensities were applied: strong (28% of basal area removed), moderate (19% of basal area removed), and unthinned. The 7-year effect of thinning intensity on the stem shape of narrow-leaved ash trees was evaluated in the present study. A total of 25 sample trees representing the quadratic mean diameter of the stand (TQMD) and the 100 largest trees per hectare (T100) were taken for cross-sectional analysis. Results showed that the 7 years breast-height diameter (d1.30) increments of sampled trees were increased with increasing thinning intensity, and thinning intensity had no effect on height increments of the trees. The 7-year d1.30 increment of the T100 was greater than that of the TQMD trees. Over 7 years, the numerical definition of stem shape was not affected by the thinning intensity. However, the stem shape was improved with increasing stem diameter/ age, especially in the T100. In conclusion, the NLA T100 trees, as a result of thinning, did not develop conically but rather became more cylindrical with an increase in diameter and age; therefore, it can be recommended that in future, heavy thinning treatments can be applied in narrow-leaved ash plantations.en10.5152/forestist.2022.22047info:eu-repo/semantics/openAccessFraxinus angustifoliastem formthinningTurkeyLong-Term ChangesTaper EquationsWater-StressPicea-AbiesFormGrowthPineIntensitySpruceStandsArticle73211786812-s2.0-85171254587WOS:001007973100005Q4Q4