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ŠUMARSKI LIST 3-4/2023 str. 32     <-- 32 -->        PDF

1965; Thanos 2000). Çetin (2010) germinated the seeds collected from different altitudes in the Mediterranean Region at different temperatures and the highest germination was achieved at 20 °C.
Differences in germination rates can be observed depending on the altitude at where the seeds are collected (Şefik 1965; Ürgenç 1977; Çetin 2010). Red pine cones generally mature in May, and the cones are opened and the seeds dispersed until August. However, some cones can remain on the tree for a long time without opening (Selik 1963; Şefik 1965; Thanos and Doussi 2000).
In particular, the importance of preserving the germination feature of red pine cone seeds emerges when they are in areas of fire-susceptible ecosystems. It is said to be effective in the re-formation of pine forests when these closed cones open after a fire and the seeds fall to the ground and germinate after the first rains (Boydak et al. 2006). Fernandes et al. (2019) determined that in general, serotinous cones make a significant contribution to the regeneration of Pinus pinaster and Pinus halepensis forests after a fire. Pine species may differ in terms of forming closed cones (Feduck et al. 2015). In addition, according to the ecosystems where they are found, varieties of the same pine species can differ in terms of the age and amount of closed cones. For example, Çetin (2010), in his study on the species, found that the lower altitude zone produced more cones and older cones than the higher altitude zone. He emphasized that serotinous cone level, tree age, and fire severity are important in a Pinus pinaster forest. The seeds obtained from these serotinous cones were determined to have a higher viability and germination percentage than those of non-serotinous cones (Cruz et al. 2019).
At the end of the germination period, a high rate of seed germination in a short time is just as important as a high percentage of seed germination. The success of planting and natural rejuvenation depends on the germination rate (speed) rather than the germination percentage (Saatçioğlu 1971). One seed with a high germination rate (i.e., with a steeper germination graph on the 7th, 10th, and 14th days) is more valuable in creating seedlings than two seeds with the same germination percentage (Saatçioğlu 1971). Consequently, seeds with a good germination rate are more beneficial in planting, natural rejuvenation, and rejuvenation occurring spontaneously after a fire because they germinate in a short time and have a good chance of developing and establishing a forest. In forests such as red pine that are constantly exposed to fire, it is extremely important to preserve the germination feature and contribute to the formation of progeny in the seeds of the older cones of other years, as well as in the normal three-year mature cones.
No previous study has investigated the genetic characteristics of the serotinous status of red pine. However, one study determined that Pinus halepensis had a significantly narrow serotinous status heritability (Hernandez-Serrano et al. 2014). In addition, Pinus concorta was mentioned as having gene diversity in serotiny, debatably under the influence of many genes rather than one or two genes (Parchman et al. 2012). In the areas of the closed cone-forming variety, the seeds preserved their germination feature and contributed to regeneration after fires (Su et al. 2015). In red pine, not only the seeds of the past year, but also the seeds of other years will join the progeny, and this progeny consisting of seeds of different years will have the opportunity to develop more forests that exhibit genetic diversity.
Finally, studies have shown that there may be differences in the germination rate of red pine seeds depending on the age of the cones and the altitude at where the cones are collected. This study aimed to determine the germination rate at 10 and 14 days and the total germination rate at the end of 28 days of seeds obtained from closed cones of five different ages (3/control, 4, 5, 6, and 7 years) collected at two different altitudes (0-200 and 800-1000 m).
MATERIAL AND METHODS
MATERIJALI I METODE
Sampling sites – Mjesta uzorkovanja
Seeds were collected from 20-25-year-old red pine stands, naturally distributed on the southern slopes of the Taurus Mountains, within the borders of the Anamur Forest Enterprise of the Mersin Regional Directorate of Forestry. The aged cones were selected from low-altitude (0-200 m) red pine stands in the Anamur Forest Chiefdom (N:36° 02’ 10’’, E:32° 42’ 25’’- UTM ED50 36N) and from the high-altitude (800-1000 m) forests of the Sarıdana Forest Chiefdom (N:36° 10’ 11’’, E:32° 41’ 34’’). Closed cones aged 3, 4, 5, 6, and 7 years were collected in summer (July) from trees at both elevation levels.
Method
Metoda
The collected cones were laid on a flat surface and in order to open them faster, they were sprayed and mixed with water under the sun, and they subsequently opened in a short time. The wings were separated from the winged seeds in the cone manually and by machine, and the cleaned seeds were placed in jars and stored in the refrigerator (1-4 °C) until the germination tests. Germination experiments were carried out at 20 °C ambient temperature in 9-cm-diameter glass Petri dishes, with seeds placed on filter paper in such a way that they did not touch each other. Trial units (2 × 5 = 10) were created for the seeds obtained from the cones collected at five different ages from both elevation levels.