Growth and morphological responses of Mana oak (Quercus brantii) seedlings to different light levels at nursery in the first growing year

Manna oak (Quercus brantii) is the most important tree species in Zagross region of Iran that faces lack of natural regeneration by seed. Forest managers suggest reforestation by seeds or seedlings as the main silvicultural practice، in order to rehabilitate these sites. In spite of the importance of shade tolerance in reforestation or seedling production in nurseries، some species such as Mana oak have not been well characterized. A completely random experimental design with light factor at four levels (20%، 40%، 60%، and 100% of sunlight) was used to study morphological and growth response of Manna oak seedlings in the first growing year. There were two samplings i) 100 days after germination and ii) 190 days after germination، using 20 seedlings for each treatment. The results showed that at the lowest light radiation level (20% of full sunlight) height growth، slenderness coefficient، root/shoot biomass ratio، and mean of leaf area increased whreas collar diameter، shoot biomass، net assimilation rate، and relative growth rate decreased. Since، high relative growth rate implies high survival rate، so Manna oak can be considered as shade intolerant species that in nurseries with no humidity limitations has the most efficiency in full sunlight.