Seed production and masting behaviour in oriental beech (Fagus orientalis lipsky) forests of Northern Iran

Mast-seeding behaviour of tree species has a key role in regeneration of plant populations. Seed production data were collected from 360 sampling plots to identify environmental factors influencing beech masting in the old-growth beech stands in the north of Iran. The mean seed number per m2 was 4687 ± 164 in the study sites. Seed production significantly correlated with tree diameter, height and crown diameter. In relation to the site properties the highest seeding recorded was close to the parent in the lower altitude and north facing slopes. The canonical correspondence analysis revealed that seed production correlated with first canonical axis, reflecting the soil nutrition including N, C, Cu, Ca, Fe, and Br. Results revealed that beech masting is affected by the amount of organic C, P, Fe, and Ca content of soil. Seed production varied from tree to tree, and site to site, and quantitative analyses in relation to both environmental factors and seed tree dimension showed a highly complex interplay of factors dictating seed production across the forest stands.