Brotación de encinas (Quercus ilex subsp. ballota) con edades elevadas. Experiencias en el monte de Riofrío (Segovia)

Results from an experiment with the objective of studying the sprouting capability —shoots of stump or root— on aged holm-oak trees are shown in this paper. Site of study is located in Riofrío forest, at 960 m a.s.l. at north facing slope of Guadarrama range (Central mountain range), on deep siliceous soils. After an ecological and dasonomic inventory 24 aged trees were fellen; dbh of fellen trees vary from 22.3 to 73.2 cm and age was estimated to be between 70 and 251 years. Contingence tables and logistic regression were used to test the dependence relationship among trees characteristics and the intensity of subsequent sprouting. One period growth after felling, 13 trees (62%) among the live ones (21) that had been felled present some shoots; after three growth periods, the same portion raised to 81% (17). We found only shoots of stump in 65% of the trees that had sprouted; 12% of trees that have only shoots of root and 23% of the trees with both types of shoots. Neither shoot production nor shoot type —stump or root— seems to be influenced by age.