Seasonal Changes in Biochemical Properties of Some Tree Species Growing in Humid, Semi-humid, Semi-arid and Arid Forests

Aim of study: In this study, biochemical properties of some forest tree species adapted to different climatic and ecological conditions; growing in humid forest Fagus orientalis, semi-humid Pinus pinea, semi-arid Pinus brutia and in arid forest Pinus eldarica were investigated during two vegetation seasons. Area of study: Four regions representing four different climates were selected as the study areas, for humid climate type Kahramanmaraş-Andırın, semi-humid climate Kahramanmaraş-Önsen, semi-arid climate Kahramanmaraş-Pazarcık and arid climate type Şanlıurfa-Akçakale, Türkiye. Material and method: Fresh leaf samples were collected from six different trees between June and October from four different study areas for two consecutive years of 2021-2022. Chlorophyll, proline and total soluble sugar contents were analyzed on samples taken every month during the two vegetation seasons. Main results: Results showed that a general decline was detected in chlorophyll a, chlorophyll b and total chlorophylls in all studied species from June to October. While a rise in proline and total soluble sugar content was determined in Pinus pinea and Pinus eldarica species during dry periods, no increase was detected in Fagus orientalis and Pinus brutia species. Research highlights: The main outcome of this study was that Pinus pinea and Pinus eldarica species exhibited effective biochemical adjustments to overcome seasonal drought.