Sprouting of seedlings of three Quercus species in relation to repeated pruning and the cotyledonary node

We studied sprouting of three oak species (Quercus humilis Miller, Q. ilex L. and Q. suber L.) at the seedling stage to examine the role of the cotyle donary node in the production of new shoots after disturbance. The aerial b iomass was removed three successive times above and below the point of atta chment of the cotyledons. All three Quercus species produced new shoots whe n the aerial biomass was removed above the cotyledonary node. However, the number of sprouts per seedling, the length and leaf number of the sprouts, and root diameter decreased with repeated pruning. Because of their undergr ound dormant buds only Q. suber seedlings could sprout and survive when the aerial biomass was removed below the cotyledons. These results show that i n Q. suber seedlings the cotyledonary node forms a true functional lignotub er and suggest that the presence of clusters of hidden underground cotyledo nary dormant buds is limited to Q. suber.