Yılmaz Çatal

Comparison of some diameter-height models for brutian pine (Pinus brutia Ten.) afforestations in Ağlasun region

Bu calismada, Aglasun yoresi yapay kizilcam (Pinus brutia Ten.) mescerelerinden alinan 52 ornek alan verisi kullanilarak toplam 20 adet cap- boy (d-h) modeli test edilmistir. Kizilcam mesceresi 600 ha buyuklugunde ve 1975 yilinda dikim yoluyla getirilmistir. Ornek alan verileri iki gruba ayrilmis, birinci grup (%80) model gelistirmek ve ikinci grupta (%20) gelistirilen modellerin test edilmesi amaciyla kullanilmistir. Gelistirilen iki (n=7), uc (n=10) ya da dort parametreli (n=3) cap boy modellerinin boy tahminlerindeki performanslari, alti farkli olcut degerleri kullanilarak karsilastirilmistir. En basarili sonuclar sirasiyla, Korf, Sibbesen ve Meyer tarafindan gelistirilen modellerle elde edilmistir. Bagimsiz veri seti kullanilarak yapilan degerlendirmede de benzer sonuclar elde edilmistir. Sonuc olarak, yoresel bazda kizilcam mescerelerinde cap-boy iliskilerini en iyi sekilde aciklayan yoresel cap- boy modelleri gelistirilmistir.

Modelling of diameter distribution according to tree numbers in sample area of the Brutian pine stands in Isparta region

Kizilcam (Pinus brutia Ten.) 5.9 milyon hektar yayilisi ile ulkemizde en genis yayilis alanina sahip asli agac turudur. Bu alan ormanlarimizin %27’sine karsilik gelmektedir. Mescere parametrelerinin uygun bir orman yonetimi icin dogru tahmin edilmesi gerekir. Ayrica, ormanlarin gelecege yonelik fizibilitesinin yapilmasinda cap dagilimlari onemli bir mescere parametresidir. Cap dagiliminin sekli mescere yapisinin karakteristiklerinin en onemlilerinden birisidir. Son yillarda bircok arastirmaci istatistik dagilim modellerini ormancilik alaninda kullanmaktadir. Bu calismanin amaci, Isparta yoresinde dogal, ayni yasli, saf kizilcam mescerelerinde agac sayinin cap basamaklarina dagiliminin degisik yas ve bonitet siniflarinda degisimini ornek agac sayisi degisimine gore ortaya koyabilmektir. Ornek alanlardan elde edilen verilere Beta, Gamma, Weibull, Normal ve Log-normal istatistik dagilimini esas alan regresyon modelleri uygulanmistir. Bunun icin yorede 6’dan 21’e kadar degisen agac sayisina gore cesitli buyukluklerde 88 ornek alan alinmistir. Her istatistik dagilim modeli icin dogrusal bir model kurulmus ve modelin katsayilari cogul regresyon analizi ile hesaplanmistir. Regresyon modelinin uygunlugunun tespiti icin hesaplanan F test degeri ve belirtme katsayisi, Gamma dagilim modeli icin en yuksek bulunmustur (F=55.587; pl0.001; R2=0.519). Yorede cap dagilim modellemelerinde Gamma dagilim modelinin kullanilmasi uygundur.Anahtar kelimeler: Mescere cap dagilimi, Kizilcam, Bonitet, Mescere yasiBrutian pine (Pinus brutia Ten.) is the most widely distributed main tree species of Turkey and it covers approximately 5.9 million ha, accounting for 27% of the Turkey’s forests. The stand parameters must be accurately estimated for an appropriate forest management. Besides, it is important to know the stand diameter distribution for the determination of the technique, time and economic feasibility of a stand maintenance treatment. The shape of the diameter distribution is one of the important elements characterising forest stand structure. In recent years, many researches have used the statistical frequency distributions in the field of forestry. Aim of this study, alteration of the diameter distribution by site quality and age, presented by the actual structure of even aged brutian pine stands in the Isparta Forest region, has been related to the models constructed by basing on the distributions of Gamma, Beta, Normal and Weibull. The data used in the computations of models has been obtained different size 88 temporary plots contain from 6 to 21 trees. . A linear model has been constructed for each distribution, and the coefficients in the model have been computed with the help of regression analysis. Besides, standard error and multiple correlation coefficients have also been determined. Later, the estimated values that the determined models gave have been graphically compared with the actual measurements. Gamma Distribution model seems to be more suitable than other distribution models (F=55.587; p<0.001; R2=0.519). Gamma distrubution model is usable in the region for diameter distribution model. Keywords: Stand diameter distribution, Brutian pine, Site index, Stand age

THE DISTRIBUTION TO THE MONTHS IN THE VEGETATION PERIOD OF ANNUAL DIAMETER AND HEIGHT INCREMENT ON TAURUS CEDAR (Cedrus libani A.Rich.) AND STONE PINE (Pinus pinea L.)

In this study, were investigated distribution to the months in the vegetation period of a year diameter and height increment on Taurus cedar (Cedrus libani A. Rich.) and Stone pine (Pinus pinea L.) trees growing in the same site conditions. In this research, total 80 of numbers individuals from 13-15 years Taurus cedar (50) and Stone pine (30) in the Botanic garden Suleyman Demirel of University were selected. On the sample trees, diameter (mm) and height (mm) increment were periodically measured in the vegetation period between the last of March and the beginning of November of 2003. It was showed that annual diameter and height increment according to months on Taurus cedar and Stone pine was right skewed bell-shaped curve. According to normal distribution, while the bell-shape curves of Taurus cedar are flat, Stone pine is steeper. According to the results of two-way variance analysis applied to the repeated measurements for diameter and height increment it was found that; 1) from the stand point of species diameter increment was different but height increment was same, 2) from the stand point of months both diameter and height increment was different and 3) from the stand point of species and month interaction diameter and height increment was different. Keywords: Increment, Analysis of variance, Interaction, Normal distribution, Isparta.

SINGLE and DOUBLE ENTRY TREE VOLUME TABLE of BLACK LOCUST (Robinia pseudoacacia L.) in ISPARTA-GOLCUK REGION

In this study, a local single and double entry volume table was formed for artificially grown black locust (Robinia pseudoacacia L.). Regression analysis was used in forming the tree volume table. A total of 13 tree volume models were tested for single-entry (6) and double-entry (7) tables. Correlation coefficients for Dissescu-Meyer and Schumacher-Hall models selected were 0.994 and 0.997, respectively. Standard errors of the two regression models were 0.036 and 0.087 m3, total error percentages were –0.255 and 0.820, absolute mean error percentages were 2.426 and 5.370 for the first and second models, respectively. Valuations of these two volume functions were performed against an independent dataset, and it was concluded that they were suitable for black locust plantations in Isparta-Golcuk region with a 95% confidence. As a result, a single and double entry volume table was created for black locust. Keywords: Black locust, Robinia pseudoacacia L., Regression analysis, Single and double entry tree volume table.