Diversity of Mat-Forming Fungi in Relation to Soil Properties, Disturbance, and Forest Ecotype at Crater Lake National Park, Oregon, USA

• Main Authors: James M. Trappe, Robert P. Griffiths, Bruce A. Caldwell, Kermit Cromack, Matthew J. Trappe
• Format: Article
• Language: English
• Published: MDPI AG 2012-04-01
• Series: Diversity
• Subjects: ectomycorrhizal mats; litter mass; saprotrophic fungi; soil C:N ratio
• Online Access: http://www.mdpi.com/1424-2818/4/2/196

In forest ecosystems, fungal mats are functionally important in nutrient and water uptake in litter and wood decomposition processes, in carbon resource allocation, soil weathering and in cycling of soil resources. Fungal mats can occur abundantly in forests and are widely distributed globally. We sampled ponderosa pine/white fir and mountain hemlock/noble fir communities at Crater Lake National Park for mat-forming soil fungi. Fungus collections were identified by DNA sequencing. Thirty-eight mat-forming genotypes were identified; members of the five most common genera (<em>Gautieria</em>,<em> Lepiota,</em> <em>Piloderma, Ramaria,</em> and <em>Rhizopogon</em>) comprised 67% of all collections. The mycorrhizal genera <em>Alpova</em> and <em>Lactarius</em> are newly identified as ectomycorrhizal mat-forming taxa, as are the saprotrophic genera <em>Flavoscypha, Gastropila</em>, <em>Lepiota </em>and <em>Xenasmatella</em>. Twelve typical mat forms are illustrated, representing both ectomycorrhizal and saprotrophic fungi that were found. Abundance of fungal mats was correlated with higher soil carbon to nitrogen ratios, fine woody debris and needle litter mass in both forest ecotypes. Definitions of fungal mats are discussed, along with some of the challenges in defining what comprises a fungal “mat”.