Interactions between mediterranean shrub species eight years after experimental fire

摘要

This paper is part of a wider study in which different combinations of species were assayed for the revegetation of experimentally burnt heathlands. In this particular case, we determined whether there was any interaction between the dominant species, Erica australis, which recovered by vegetative resprouting, and the only successful woody species sown, Cytisus sp., eight years after fire and seven years after sowing. A detailed study was carried out on each square metre of cover and height of both species in three 160 m(2) plots. Total cover exceeded 100% in all subplots sown with Cytisus, whereas it did not reach 65% in the others, when both species coexist together. There was an inverse correlation between the covers of both species and a positive correlation between the height of Erica australis and the cover and the height of Cytisus. There was no significant difference in Erica cover in plots sown with Cytisus and plots not sown. There could be some competition for light, but both species are capable of coexisting with high canopy overlap, for at least some time. Cytisus is expanding from the seeded subplots, suggesting that the dense cover of Erica australis does not impede the establishment of Cytisus.