Phenology of Quercus ithaburensis with emphasis on the effect of fire

Observations on the phenology of Quercus ithaburensis were carried out duri ng three consecutive years in Yahudia Nature Reserve, Israel. Bud-break occ urred mostly in February with minor bud breaks in March-April, May and Sept ember-October. Trees shed leaves in October through January with a peak in December-January, but even during these months at least 10% of the trees re mained evergreen. Branch growth took place during February-April. Shedding of 1-year old branches was recorded in half of the observations, accompanie d by the formation of abscission tissue. Acorns generally began to ripen in November and shedding extended from December until January. The percentage of acorns attaining full ripeness Varied considerably from branch to branc h and from year to year, reaching approx. 20% of the number of acorns found in May. Ripe acorns appeared exclusively on 2-year old branches. The degre e of fire damage to trees greatly depended on the intensity of the fire, wh ich in rum depended on weather conditions, quantity of dry pasture vegetati on, and the location of the tree relative to cairns. Most trees were locate d within cairns, which constituted insulation belts, as no herbaceous veget ation grows on them. The effect of grazing intensity was decisive to the ex tent that fire damaged trees. Reduction of the bulk of dry pasture vegetati on, affected the number of trees harmed, both as to their revival and their re-budding potential. Heavy grazing reduced to nearly half the number of t oes suffering damage. After an early summer fire, budding was monitored, bu t not after a late summer fire. (C) 1999 Elsevier Science B.V. All rights r eserved.