Species-abundance distribution patterns of soil fungi: contribution to the ecological understanding of their response to experimental fire in Mediterranean maquis (southern Italy)

Abstract

Experimental fires, of both low and high intensity, were lit during summer 2000 and the following 2 y in the Castel Volturno Nature Reserve, southern Italy. Soil samples were collected Jul 2000–Jul 2002 to analyze the soil fungal community dynamics. Species abundance distribution patterns (geometric, logarithmic, log normal, broken-stick) were compared. We plotted datasets 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 d after the fire; their distribution subsequently followed logarithmic models in the 2 y 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 disturbances let them occupy unsaturated habitats and become increasingly abundant over time.

• community organization
• disturbance
• heat-stimulated fungi
• xerotolerant fungi

Acknowledgments

The authors gratefully acknowledge Paola Ganis for her statistical assistance.

This research was carried out within the project “Fire in Mediterranean environment: effects on vegetation and soil”, supported by the Italian Ministero dell’Università e della Ricerca Scientifica e Tecnologica. We thank Dr Jeffrey Stone and two anonymous referees for highly useful comments and improvements to the manuscript.