Protection forests have an important role in reducing the effects of natural hazards, such as avalanches, rock falls and debris flow. An adequate understanding of the disturbances that these forests may undergo is a prerequisite for the successful maintenance of the protection function. Wood decay fungi may affect the stability of trees and thus they may behave as natural disturbances. In this work we investigated the presence of root rot, butt rot and stem rot fungi in some protection forests of Piedmont and Aosta Valley (western Italian Alps). Tree species composition was variable depending on sites, and included both conifers and broadleaves. Fungi were identified through traditional techniques or DNA sequencing. The most frequent fungi were Fomitopsis pinicola, Heterobasidion annosum sensu lato and Stereum sanguinolentum. In a Norway spruce-dominated subalpine stand, approximately 150 trees were sampled at the root collar by drilling them with a 4 mm diameter, 43 cm long bit. Fungal DNA was extracted from wood and analyzed by using universal and taxon-specific primers. 56% of trees were found to be infected by root and butt rot fungi. Heterobasidion annosum sensu lato accounted for the 70% of infected trees, while Armillaria mellea sensu lato for the 8%. Remaining trees were infected either by both fungi or by unknown fungi. These results suggest that H. annosum sensu lato is by far the most frequent root and butt rot agent in the site.
PRESENCE AND ABUNDANCE OF ROOT ROT, BUTT ROT AND STEM ROT FUNGI IN PROTECTION FORESTS OF THE WESTERN ALPS
GIORDANO, LUANA;NICOLOTTI, Giovanni;GONTHIER, Paolo
2010-01-01
Abstract
Protection forests have an important role in reducing the effects of natural hazards, such as avalanches, rock falls and debris flow. An adequate understanding of the disturbances that these forests may undergo is a prerequisite for the successful maintenance of the protection function. Wood decay fungi may affect the stability of trees and thus they may behave as natural disturbances. In this work we investigated the presence of root rot, butt rot and stem rot fungi in some protection forests of Piedmont and Aosta Valley (western Italian Alps). Tree species composition was variable depending on sites, and included both conifers and broadleaves. Fungi were identified through traditional techniques or DNA sequencing. The most frequent fungi were Fomitopsis pinicola, Heterobasidion annosum sensu lato and Stereum sanguinolentum. In a Norway spruce-dominated subalpine stand, approximately 150 trees were sampled at the root collar by drilling them with a 4 mm diameter, 43 cm long bit. Fungal DNA was extracted from wood and analyzed by using universal and taxon-specific primers. 56% of trees were found to be infected by root and butt rot fungi. Heterobasidion annosum sensu lato accounted for the 70% of infected trees, while Armillaria mellea sensu lato for the 8%. Remaining trees were infected either by both fungi or by unknown fungi. These results suggest that H. annosum sensu lato is by far the most frequent root and butt rot agent in the site.
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