Species-area curve and distance-decay relationship indicate habitat thresholds of ectomycorrhizal fungi in an old-growth Pseudotsuga menziesii landscape

Aim: Ectomycorrhizal fungi (EMF) are a diverse and essential biota of forests that are vulnerable to species loss through reductions in late-seral habitat. We examined how the spatial ecology of this biota, particularly distance-decay and species-area relationships, could better inform habitat thresholds for EMF conservation planning. Location: Southeast Vancouver Island near Victoria, British Columbia, Canada.
Methods: Using a stratified sampling design, 11 plots (0.15 ha in size) were established at 0.05 to 17.5 km apart across 2800 ha of mesic old-growth Pseudotsuga menziesii var. menziesii and Tsuga heterophylla forests. EMF communities were compiled through molecular analysis of root tips and sporocarps. Results: The EMF community was comprised of many Cortinarius, Piloderma, Russula and Tricholoma species typical of mesotrophic habitat. A total of 238 EMF species were observed, of which 86 species were detected only once. The ratio of average species richness per plot (84 t...