Effects of light and soil fertility on growth, leaf chlorophyll content and nutrient use efficiency of beech (Fagus sylvatica L) seedlings

Trials were conducted in a northern Apennine (Tuscany, Italy) beech stand to determine the interactive effect of light and soil fertility on the growth of beech seedlings. Three light environments (high light, intermediate light and low light conditions) and two soils, with high (soil O) and low (soil M) nutrient contents, were compared, Seedlings were kept well watered throughout the growing season. Light treatments significantly affected both seedling survival and growth. Survival rate, dry weight, leaf area and specific leaf weight increased as light increased; leaf area ratio decreased as light increased. Soil fertility affected seedling growth, but not survival, mainly in non-limiting light conditions where stem and leaf dry weight and leaf area were higher in O than in M soil, Root biomass and leaf area ratio were similar in the two soils. Leaf chlorophyll content decreased and nutrient use efficiency increased as light increased. In high light conditions, leaf chlorophyll concentration was higher in O than in M soil, whereas nitrogen and potassium use efficiency were higher in M than in O soil. Phosphorus use efficiency tended to be higher in O than in M soil, The implications of these findings for natural regeneration processes in beech stands are discussed.