A research on determination of some properties of seeds sampled from the origins of red pine (Pinus brutia ten.) in Mugla region

Global climate change—via rising temperatures, irregular precipitation regimes, and recurrent drought—directly affects forest ecosystem functioning and the natural regeneration of tree species. In this context, Turkish red pine (Pinus brutia Ten.), a dominant species of the Mediterranean ecosystem with high ecological and economic value, stands out as particularly sensitive to climate change. This study evaluated the quality and germination performance of P. brutia seeds collected from the forest sub-districts of Köyceğiz, Muratlar, Bağyaka, Çaldere, Ören, and Yaraş under the Muğla Forest Regional Directorate, as well as from the Marmaris and Milas regions. The dataset included 1000-seed weight (48–58 g), seed fill assessed by the cut test (66–100%), imbibition in a water-soak test (54–99%), and germination trials under greenhouse conditions. The findings indicate that large, well-filled seeds do not necessarily guarantee high germination: Marmaris exhibited the highest germination (81%), whereas Köyceğiz had the lowest (14%). Overall, the results show that climate change exerts complex effects on seed biology and that seed size and fill alone do not ensure germination success. Elevated heat stress, reduced soil moisture, and potential pathogen pressure emerge as key constraints on germination. These outcomes highlight that the natural regeneration potential of P. brutia is at risk under changing climatic conditions and underscore the critical importance of selecting appropriate seed sources for sustainable forestry.