Species-specific effects of grazing invertebrates on mycelial emergence and growth from woody resources into soil

Abstract

Extensive studies on the grazing of young basidiomycete mycelial systems by invertebrates have revealed effects on extension rate, hyphal coverage and fractal geometry. To date, no studies have compared the grazing effects of different invertebrates on the ability of fungi to emerge from wood and establish mycelial systems in soil. Here, the effects of six soil invertebrate taxa on mycelial emergence and subsequent development of six basidiomycetes were compared. Woodlouse (Oniscus asellus), millipede (Blaniulus guttulatus), oribatid mite (Euzetes globulus), collembola (Folsomia candida), enchytraeid (Enchytraeus crypticus) and nematode (Panagrellus redivivus) populations were allowed to graze Phanerochaete velutina, Resinicium bicolor, Phallus impudicus and three different isolates of Hypholoma fasciculare mycelia as they emerged from beech (Fagus sylvatica) wood-inocula in 2-dimensional soil-tray microcosms. Impacts varied between invertebrate taxa, ranging from woodlice which affected mycelial development of all fungal isolates and completely prevented mycelial growth in two fungal species, to mites and enchytraeids which had no discernable effect on any of the fungi. Grazing impacts also varied between and within fungal species. Wood decay rates were affected with implications for nutrient mineralisation and decomposition.