Macrofungal diversity of holm-oak forests at the northern limit of their distribution range in the Iberian Peninsula

Given the current gap in knowledge concerning the macrofungal diversity of holm-oak forests at the northern limit of their distribution range and in the Basque Country, a mycocoenological study was conducted by sampling 23 randomly selected permanent plots from 6 holm-oak forests. To obtain a better understanding of the macrofungal diversity distribution pattern on a regional scale, forests from both the temperate and Mediterranean-type climate regions of the Basque Country were selected, covering all their phytocoenological variation. After 4 years of sampling, a total of 377 macrofungal species were collected: 209 ectomycorrhizal species, 86 humicolous saprotrophs, 40 saprotrophs on litter, 36 lignicolous saprotrophs, 3 coprophilous saprotrophs and 3 parasitic species. Species considered characteristic of this kind of forest, such as Cortinarius aurilicis, Cortinarius callochrous, Cortinarius ionochlorus, Hygrophorus leucophaeo-ilicis, Hygrophorus persoonii, Hygrophorus russula, Lactarius atlanticus, Lactarius ilicis, Leccinellum lepidum, were recorded all over the territory, but Mediterranean forests were richer in species and more productive in sporocarps than temperate ones. Species assemblage was found to change gradually at local scale from temperate to Mediterranean climate zones, and was distinct to each phytocoenological association with all species, with ectomycorrhizal species and with saprotrophs.