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ŠUMARSKI LIST 3-4/2023 str. 19     <-- 19 -->        PDF

years in Alemdağ (1962), Yeşil (1992) and Çatal (2009), and 60 years in this study, respectively for good site (Figure 8).
Figure 9 compares the current and mean annual volume increment of Calabrian pine stands of this study in the medium class site index and at normal density with some earlier researchers (de-Miguel et al. 2010; Shater et al. 2011). The MAI and CAI values found for medium site in this study (SI:20 m) were much greater than those found in the de-Miguel et al. (2010)’s (SI:19 m) and Shater et al. (2011)’s (SI:18 m) studies (Figure 9). The maximal MAI was reached at 65 years for our study (7.42 m3/ha) while it was reached at 50 years for de-Miguel et al. (2010) (4.5 m3/ha) and 60 years for Shater et al. (2011) (5.2 m3/ha) (Figure 9).
Yaprak (1977) and Soykan (1978) examined the economic analysis of the Calabrian pine to determine the rotation period in Türkiye. According to Yaprak (1977), the goal of managing and operating the forests of Calabrian pine is to produce high-quality or thick-diameter products that are both accurate and cost-effective, but also have the highest volume possible to meet the demands of the growing forest products industry. The overall average volume increase also reached its maximum at this time. Soykan (1978) reported that the rotation periods must be established as 50, 60, and 70 years based on the information from the current income tables, and the technical maturity rotation age for the Calabrian pine. The administration period for Calabrian pine stands in the Eastern Mediterranean (Syria and Lebanon) was determined by de Miguel Magana (2014) to be 40, 49, and 71 years for the medium and bad site index classes. The General Directorate of Forestry (2008) changed its policy after 2004 by allowing each forest enterprise directorate to determine its own administration period for conditions such as operating objectives and priorities, silvicultural needs, the requirements of the market, and the marketing facilities, and other services of forests for Calabrian pine stands. However, the most current administration period for Calabrian pine stands is 60-80 years in manufacturing purposes and 100 years for protection function purposes (General Directorate of Forestry, 2008).
In this study, increment and growth models were established for pure Calabrian pine only stands in the central Mediterranean Region (Antalya and Mersin provinces). The stand models for Calabrian pine stands were developed as density-dependent yield tables. Using regression equations in the density-dependent yield tables, it was possible to compute the quadratic mean diameter, quadratic mean height, number of trees per hectare, basal area, and volume of standing trees of the stand as a function of stand age, SI, and stand density. Five-year age intervals, five levels of stand density, and three classes of SI were used to present the change in the elements of the density-dependent yield tables connected to standing and removed trees of the stands. While the number of trees in the stand declines with increasing tree age, the total stand volume increases with increasing tree age, SI quality, and stand density (Figure 4