In this study, we evaluated the performance of 18 competition indices composed of nine distance-dependent and nine distance-independent indices in explaining the variation in individual-tree diameter growth of Calabrian pine (Pinus brutia Ten.) in the central Mediterranean region of Turkey. The data were obtained from 432 sample plots with varying stand age, site index, and stand density. To evaluate the performance of each competition index, the mean square error reduction approach was used relative to the noncompetition. Also, this study compared fixed and mixed effects models to analyze diameter growth. Statistical analyses showed that the best distance-independent competition indices performed as well as the best distance-dependent competition indices. The distance-independent competition index of Schröder and Gadow (1999; Can. J. For. Res. 29(2): 280–283, doi: 10.1139/x98-199) performed best and is recommended for use in future growth and yield models to be used in the central Mediterranean region of Turkey. Also, the best selection of competitive neighbors was achieved using the area of influence overlap method, whereas the fixed-radius and angle count sampling methods had no significant improvement in quantifying the competition effects. On the other hand, all mixed effects models provided much better fits than their fixed model counterparts.

Here, we describe the leaf anatomical characters of 26 Cirsium taxa (33 accessions) native to the northeast region of Turkey, with the aim of evaluating their taxonomic significance within the taxa. Leaf anatomies of all taxa were characterized and compared using cluster analysis and multidimensional scaling analysis. The transverse sections of the leaves showed various numbers of vascular bundles and accessory bundles. In addition, significant differentiations were observed in the midrib and lamina thickness, the height and width of vascular bundle, and number of stomata, and epidermal cell wall patterns in the abaxial and adaxial surfaces among the taxa. These results demonstrate that the compared anatomical characters among taxa are partly in accordance with their sectional delimitation in the Flora of Turkey. However, our data suggest that some taxonomic re-arrangements might be necessary. Based on its anatomy, we propose that the Cirsium taxa can be treated as pioneers. Some ecological interpretations are also made.

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Özet: Bu çalışmada, Antalya ve Mersin yörelerinde yer alan saf ve doğal Kızılçam (Pinus brutia Ten.) meşcereleri için tek, bonitete dayalı tek ve çift girişli ağaç hacim tablolarının düzenlenmesi amaçlanmıştır. Bu amaçla 486 örnek ağaç ve bu ağaçlardan türetilen 6033 adet veri kullanılarak, ağaç hacim denklemleri geliştirilmiştir. Seçilen en uygun hacim fonksiyonlarının düzeltilmiş belirtme katsayısı ( ü .2 ), tahminin standart hatası (Sy.x), ortalama mutlak hata yüzdesi (% OMH) ve toplam hata yüzdesi (% TH) değerleri sırasıyla; tek girişli için 0. Tree Volume Tables for Calabrian Pine in Antalya and Mersin Region Abstract:In this study, it is proposed to construct single, single based on site index and double entry tree volume equations for the pure Calabrian Pine stands (Pinus brutia Ten.) within the border of Antalya and Mersin Regional Forest Directorates, Turkey. Tree volume equations were developed using totally 486 sample trees and 6083 data obtained from these trees. The coefficient of determination (adj-R 2 ), total percent error (PE), and mean absolute percentage error (MAPE) were 0.975, 52.84, -0.457 and 9.756 for single tree; 0.978, 44.84, -0.438 and 9.849 for single tree of the first site index class; 0.976, 54.44, -0.464 and 9.501for single tree of the second site index class; 0.969, 52.96, -0.452 and 9.256 for single tree of the third site index class, and 0.992, 41.26, 0.210 and 5.038 for double-entry tree volume equations, respectively. The first (%6.32) and the second (%0.45) site index values overestimated single-entry tree table values whereas the third site index values (%-4.28) underestimated the single-entry tree table values. The best fitted single, single based on site index and double entry tree volume equations were tested with independent data set for Calabrian Pine stands within the border of Antalya and Mersin Regional Forest Directorates, and concluded that these equations can be used for these stands at the 0.05 significant level.