Effects of grazing and fires on biodiversity of oak forest rangeland in W. Lesvos.

The abandonment of oak forests from rural populations because of the great decrease of economic value of their products leave the forest to fires, to illegally woodcutting, to clearcutting and to overgrazing. In west Lesvos there is an oak forest Quercus ithaburensis subsp. macrolepis of 5.000 h. Although numerous studies have been devoted to the impact of livestock on vegetation, information about effects of grazing on oak forest is still scarce. The aim of the present study is to analyse the biodiversity of plant communities in two different ecosystems of valonia oak which differ on management a) grazing “Filia” area b) grazing and fires “Antissa” area. The density of oaks was 41 trees/ 0,1 h in “Filia” and 18 trees/0,1 h in “Antissa”. The grazing pressure was bigger in ‘Filia’ area. The biomass of herbaceous plants was 824 kg/h in “Filia” and 420,6 kg/h in ‘Antissa”. The structure of ecosystems of the middlestory and understory was degraded with the dominance of undesirable vegetation for livestock mainly in “Antissa” area. The soil properties were better in “Filia” area but the differences were not significant. The richness and biodiversity indices increase in ‘Antissa” area mainly because of fire and the successional stage of ecosystem.