INVESTIGADORES
GHERMANDI luciana
artículos
Título:
Early post-fire succession in northwestern Patagonia grasslands
Autor/es:
GHERMANDI L., N. GUTHMANN AND D. BRAN
Revista:
JOURNAL OF VEGETATION SCIENCE
Referencias:
Año: 2004 vol. 15 p. 67 - 76
ISSN:
1100-9233
Resumen:
Abstract. Large-scale disturbances, notably fire and grazing, structure grass and shrubland dynamics in semi-arid environments. We studied early post-fire succession in two burned grasslands, one unburned grassland, and one shrubland near the burned area. We observed three processes: 1) establishment of a “phantom” community comprised of fugitive species.  Although transient, these species increase diversity and recharge the seed bank before the next disturbance. 2) regeneration of the original community by persistence of resprouter species and by auto-replacement. 3) early stages of invasion by seedling of the shrub Fabiana imbricata, which germinate next to shrubland and create new F. imbricata patches. Weed invasion was principally due to the ruderal exotic species Verbascum thapsus from the close road verge and by rapid increase of Rumex acetosella cover, other exotic species present before fire in the grasslands. Although post-fire climatic conditions are particularly important in semi-arid environments, succession depends greatly on the regeneration strategies and dispersal abilities of the species present in the burned area. The phantom community occurs only at the first stage of succession when there is little competition for resources. We could call this process "the race for occupation of the area”. The second stage, when competition for resources becomes progressively more important, could be denominated “the effort to maintain space”.