Effects of prior decomposition of beech leaf litter by phyllosphere fungi on substrate utilization by fungal decomposers

Abstract

Changes in litter quality resulting from pretreatment of leaf litter by phyllosphere fungi may affect its subsequent decomposition by succeeding fungi. The purpose of this study is to clarify the effect of prior decomposition of leaf litter by two phyllosphere fungi of beech, Xylaria sp. and Ascochyta sp., on substrate utilization of 12 fungal species in the Basidiomycota, the Ascomycota, and the Zygomycota, in a laboratory experiment. Mycena sp. caused significantly higher weight loss in litter previously partly decomposed by Xylaria sp. than in control litter without fungal inoculation and litter previously partly decomposed by Ascochyta sp., whereas prior decomposition retarded litter decomposition or had no significant effect on 11 other species. Prior decomposition by phyllosphere fungi affected the substrate utilization patterns of two Mycena species in the Basidiomycota, shifting from simultaneous removal of lignin and carbohydrates to selective delignification.