Fungal biodiversity in old-growth forests of Sicily: preliminary results

Abstract

According to several authors an old-growth forest in Italy is a natural forest in which human disturbance is absent or negligible, and in which natural dynamics create a mosaic of all the forest regeneration phases, including the senescing one. Such phase is characterized by large old trees, deadwood (snags logs and coarse woody debris) and a vascular plant species composition that is consistent with the bio-geographical context and it includes highly specialized taxa related to the small-scale disturbance and the microhabitats resulting from structural heterogeneity. Unmanaged forests are the main refugee for rare and endangered species, including fungi. In Sicily, 472 hectares were recognized as old-growth forests, mainly distributed in regional natural parks, reserves, Site of Community Importance (SCI) and, Special Protection Areas (SPA). Investigation was carried out in “Bosco Pomieri”, an old-growth forest included in the Madonie Park (Northern Sicily). In 2013, a multidisciplinary research team started to evaluate vascular plant and cryptogam diversity, and also carried out plant physiology tests and environmental monitoring. The “Bosco Pomieri” is a mixed oak wood characterized by the presence of many old trees of Quercus petraea (Matt.) Liebl. subsp. austrothyrrenica Brullo, Guarino & Siracusa and a dense shrub layer with Ilex aquifolium L. The forest area is also characterized by Fagus sylvatica L., Acer pseudoplatanus L., A. obtusatum W. & K., Ulmus glabra Huds., Sorbus torminalis L., Malus sylvestris (L.) Mill., and, sporadically, Quercus cerris L. and Q. pubescens s.l. Shrubby species, such as Daphne laureola L., Crataegus laciniata Ucria, Ruscus aculeatus L. and, Rhamnus catharticus L., are also included in the investigated area. Fungi are currently represented by 62 saprotrophs and mycorrhizal species (59 Basidiomycetes and 3 Ascomycetes) belonging to 34 genera of 21 families. The most represented genera are Boletus (12 taxa, 19.4 %), Russula (6 taxa, 9.7 %), Lactarius and Cortinarius (4 taxa, 6.5 %). As regards ecological categories (sensu Arnolds) the preliminary results of investigation carried out in “Bosco Pomieri” showed the following figures: 8 taxa (12.9 % of total recorded fungi) belong to terrestrial saprotrophs (St), 42 taxa (67.7 %) are ectomycorrhizal species (Em), 6 taxa (9.7 %) belong to lignicolous saprotrophs (Sh), 2 taxa (3.2 %) are necrotrophic parasites (Pn) and, 4 taxa (6.5 %) could not be attributed to any ecological category sensu Arnolds and are here reported as unknown (UNK). Preliminary data analysis confirms the interpretation on the need to develop for old-growth forests long-term partnerships among professional mycologists, resource managers and other scientists, and to apply mycological expertise to complex species and habitat conservation issues in an interdisciplinary setting. Acknowledgements: Financial support by University of Palermo (2012-ATE-0496, FFR projects) is gratefully acknowledged.