Regeneration of burned stands of pubescent oak (Quercus pubescens Willd.) and holm oak (Quercus ilex L.) in the Zadar area

Background and Purpose: Pubescent oak (Quercus pubescensWilld.) and holm oak (Quercus ilex L.) are climatozonal species in the area of Zadar, where the communities formed by these two species have an ecological- protective role. The aim of this research is to address the problem of the disturbed stability of these stands and the possibility of their post-fire regeneration. Materials and Methods: Research was undertaken in burned and unburned areas of the Zadar Forest Office. This included pubescent oak coppices, scrub, thickets, maquis and garrigue. The relevés were made according to the plant sociology method (Braun-Blanquet 1964, Dierschke 1994). Pedological research involved taking composite samples of the humus-accumulative horizon. Chemical soil analyses were performed according to the standard methods. Results: The number of pubescent oak individuals was about 2.5 times higher in burned areas compared to unburned ones. This was in contrast to holm oak, which showed poorer occurrence in burned areas in relation to unburned ones. The average number of all trees and shrubs in degraded forms of pubescent oak was 11.567 per hectare, whereas in degraded forms of holm oak forest this number was more than twice as high and amounted to 2.550 individuals per hectare. Conclusions: Forest fires are an important cause of soil degradation. Burned areas are subject to erosion, the disappearance of or a decrease in soil biological activity, and extreme ecological effects. In order to mitigate the problem, certain prescribed post-fire recovery methods should be urgently applied