Studying Turkish Hazelnut (Corylus colurna L.) populations in the Western Black Sea Region from ecological and silvicultural aspects

With its valuable wood and fruit, Turkish Filbert or Turkish Hazelnut(Corylus colurna L.) is one of the important, the secondary species of Turkey. It alsomakes great contributions to the plant diversity in the region. Sustaining Turkishhazelnut this species and its genetic potential as well as its multiple uses relies onexploring the site conditions and silvics of this valuable species. In this study, tenhazelnut population were selected in the western Black Sea Region, where thespecies is widely distributed, using the density method based on the conscioussampling methods.The sampled Turkish hazelnut populations distributed between 780-1460 mabove the sea level and were accompanied by maples (Acer spp.), Nordmann fir(Abies nordmanniana ssp. bornmulleriana), oaks (Quercus spp.), mountain-ashes(Sorbus spp.), hornbeams (Carpinus betulus), basswoods (Tilia rubra), eastern beech(Fagus orientalis), and Austrian pine (Pinus nigra).This species tended to grow into the form of the `wolf tree? where canopyclosure was insufficient whereas under normal closed canopies, it formed straightboles with little tapering. This suggests that Turkish hazelnut cannot grow undershade or in other words is shade intolerant.Height increment is linear up to the age of 80, culminates afterwards andstops at the of 170. Approximately, diameter at breast height reaches 20 cm in 50years and 40 cm in 100 years.In the sample areas, limestone, marl, basalt and dacite bedrock types weredetermined. Soil was mostly clayey with a pH ranging between 5.4-7.9. Soils can becalcareous or noncalcareous.The mean annual rainfall and temperature, growing period vary between550-908 mm, 6.5-10.1°C, and 117-176 days, respectively, in the sampled plots. Thehazelnut populations were mostly located on northeast slopes.Keywords: Turkish Hazelnut, Corylus colurna L., population, ecology, silviculture,biological diversity