Abstract:
Most conservation efforts in seasonally dry tropical forests have overlooked less obvious targets for
conservation, such as mycorrhizal fungi, that are critical to plant growth and ecosystem structure.We
documented the diversity of ectomycorrhizal (EMF) and arbuscular mycorrhizal (AMF) fungal
communities in Quercus oleoides (Fagaceae) in Guanacaste province, Costa Rica. Soil cores and
sporocarps were collected from regenerating Q. oleoides plots differing in stand age (early vs late
regeneration) during the wet season. Sequencing of the nuclear ribosomal ITS region inEMF root tips
and sporocarps identified 37 taxa in the Basidiomycota; EMFAscomycota were uncommon. TheEMF
community was dominated by one species (Thelephora sp. 1; 70% of soil cores), more than half of all
EMFspecies were found only once in an individual soil core, and there were few conspecific taxa. Most
EMFtaxa were also restricted to either Early or Late plots. Levels ofEMFspecies richness and diversity,
andAMFroot colonization were similar between plots. Our results highlight the need for
comprehensive spatiotemporal samplings ofEMFcommunities in Q. oleoides to identify and prioritize
rareEMFfor conservation, and document their genetic and functional diversity.