Clearing of vegetation in Mediterranean garrigue: Response after a wildfire

Plant resprouting and seedling establishment one year after a wildfire was evaluated in plots in which all vegetation was clipped three times a year for 5 years before the fire. Vegetation regeneration was compared between burned-cleared plots and: i) burned-uncleared plots; ii) unburned-cleared plots. Ground cover was not influenced by the vegetation clipping carried on before fire, except that there was less resprouting of the dominant resprouter Quercus coccifera in cleared-burned than in uncleared-burned plots. Number of seedlings and species richness was not significantly influenced by clearing treatments. When comparing burned-cleared plots with unburned-cleared plots, fire increased the ground cover of shrubs and resprouting species, but not the total ground cover and the cover of forbs, grasses or Q. coccifera. Seedlings were more abundant and species richness greater in burned-cleared plots than in unburned-cleared ones. Vegetation clearing does not appear to strongly affect the regeneration ability of the community, except for the decrease of some dominant species. Our results suggest that before the fire, the seed bank in burned-uncleared plots may be larger than in burned-cleared ones, but the higher temperatures reached in uncleared areas would deplete the seed bank able to germinate, leading to the observed lack of differences in seedling establishment. Seedling establishment in long-term cleared areas is largely dependent upon the seed output from neighbouring well-structured communities and, consequently, it may be affected by the size of cleared areas.