The role of phanerogams and cryptogams in the recolonization of cork oak forests crossed by wildfire in Sicily

Abstract

The actual distribution and structure of cork oak woods is the result of a process of anthropogenic alteration (utilization of cork, deforestation, coppicing, overgrazing, changes in land use, fire). Additional causes of threats in Q suber woods are pests and fungal disease. Although cork oak is an active pyrophyte the decortication of trunks makes trees more vulnerable to external agents and to fire in particular. Post-fire species are mainly carbonicolous fungi, some Ascomycetes make their appearance after around six weeks while other fungi begin to appear from the second year. The proliferation of fungal hyphae in the ash, as well as of some pioneer mosse protonemata, promotes soil aggregation and storage of nutrients. Bryophyte phytocoenoses including species with rapid gametophyte development, spore germination favored by fire or high production of propagules. The association Funarietum hygrometricae is one of the first autotrophic plant communities that are already developing in the first year after the fire in numerous microsites within the forest areas. The dominant species is Funaria hygrometrica, one of the few mosses able to associate with mycorrhizal endophytes, that contribute to strengthen the tolerance (or sensitivity) of plants to passage of wildfire, but also influence the dynamics of regeneration of forest coenoses. Trees of genera Quercus, Pyrus, Fraxinus, Celtis and Arbutus express this dynamic together with some hemiparasites (Viscum, Loranthus) and epiphytes (Polypodium), shrubs (Calicotome, Chamaerops, Citysus, Cistus, Erica, Genista). Additional elements are species of the genera Asparagus, Daphne, Lavandula, Teucrium, Aira, Arisarum, Carex, Eryngium, Inula, Melica. Also parasitic plants (Limodorum, Cytinus), ferns (Asplenium), other bryophytes (Riccia , Bryum, Didymodon, Homalothecium), fungi (Amanita, Russula, Leccinum, Boletus) and lichens (Cladonia) characterize the post-fire forest coenoses in Sicily.