نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Old trees play an important role in conserving genetic resources, maintaining ecosystem stability, and sustaining natural regeneration in Hyrcanian forests. However, limited information is available on the seed quality of these trees and its differences from that of mature non-old trees. This study aimed to examine and compare selected quantitative and qualitative seed traits, including moisture percentage, thousand-seed weight, seed diameter, and germination capacity, in old and control trees of three species: Hyrcanian beech (Fagus caspica Denk & G.W.Grimm), velvet maple (Acer velutinum Boiss.), and Caucasian alder (Alnus subcordata C.A. Mey.) in the Namkhaneh District of the Kheyrud Forest. For each species, five old trees with a minimum diameter at breast height of 1.5 m were identified, and the nearest healthy mature trees of the same species with a diameter at breast height of 50–70 cm were selected as controls. The results showed that seed moisture percentage did not differ significantly between old and control trees in any of the studied species. Thousand-seed weight and seed diameter were significantly lower in old trees of Hyrcanian beech and velvet maple than in their controls, whereas no significant difference was observed in Caucasian alder. In contrast, seed germination percentage was lower in old Caucasian alder trees than in control trees, while no significant difference was observed in Hyrcanian beech and velvet maple. These findings indicate that the effect of oldness on seed traits is species-specific and depends on the trait being evaluated; therefore, it cannot be interpreted as a general decline in seed quality in all old trees.
کلیدواژهها English
