Species-abundance distribution patterns of soil fungi: Contribution to the ecological understanding of their response to experimental fire in mediterranean maquis (southern italy)

Experimental fires, of both low and high intensity, were lit during the summer of 2000 and the following two years in the Castel Volturno Nature Reserve, southern Italy. Soil samples were collected from July 2000 to July 2002 to analyze the soil fungal community dynamics. Species abundance distribution patterns (geometric, logarithmic, log normal, broken-stick) were compared. We plotted data sets with information both on species richness and abundance for total, xerotolerant and heat-stimulated soil microfungi. The xerotolerant fungi conformed to a broken-stick model for both the low- and high-intensity fires at 7 and 84 days after the fire; their distribution subsequently followed logarithmic models in the 2 years following the fire. The distribution of the heat-stimulated fungi changed from broken-stick to logarithmic models, and eventually to a log normal model during the post-fire recovery. Xerotolerant and, to a far greater extent, heat-stimulated soil fungi acquire an important functional role following soil water stress and/or fire disturbance; these disturbance events allow them to occupy unsaturated habitats and to become increasingly abundant over time.