Testing sampling effort and relative abundance descriptors of belowground ectomycorrhizal fungi in a UK planted scots pine woodland.

The native Caledonian pinewoods of Scotland, UK contain a unique and unexplored biodiversity of below-ground ectomycorrhizal fungi which may constitute a valuable source of microbial genetics resources for woodland restoration. In this study we test the sampling effort, taxa detection (ectomycorrhiza morpho-anatotyping) and relative abundance measurements (ectomycorrhizal root tip number vs. dry weight) of below-ground ectomycorrhizal fungal communities in a planted Pinus sylvestris Caledonian woodland. A total of 18 replicated sampling points were set up at differential distance along a 125 m transect, in a 50-yr-old, stem exclusion: thicket phase, Pinus sylvestris pinewood stand. A total of 11 ectomycorrhizal morpho-anatotypes were detected from 6689 ectomycorrhizal root tips counted and weighing 992.6 mg dry weight. The major ectomycorrhizal taxa were Meliniomyces bicolor and Cortinarius spp. accounting ~50% of total pine roots. A highly significant relationship (r2  = 0.16, p < 0.000) was found between Sørensen dissimilarity in soil cores and distance apart. In this study, the spatial arrangement of samples indicated that over short distances the dissimilarity was lower in contrast with the longer distances along the transect.

Interaction between an isolate from the Hymenoscyphus ericae aggregate and roots of Pinus and Vaccinium.

• A fungal isolate was obtained from Piceirhiza bicolorata-like ectomycorrhizas on Pinus sylvestris in a 160-yr-old natural woodland. • The fungus was identified by sequencing the PCR-amplified rDNA ITS regions. The sequence was compared with similar known taxa and grouped with Cadophora finlandia in the Hymenoscyphus ericae aggregate. • The fungus formed P. bicolorata-like ectomycorrhizas in aseptic synthesis with P. sylvestris seedlings. When seedlings of Vaccinium myrtillus were exposed to mycelium arising from these ectomycorrhizas, or to mycelium in pure culture, the hyphae entered the cells of the hair roots and formed coils characteristic of ericoid mycorrhizas. The presence of the fungus stimulated Vaccinium root growth and altered root architecture. • This is the first full report of the ability of a fungus from the H. ericae aggregate simultaneously to form both ectomycorrhizas and what appear to be ericoid mycorrhizas.

Fungal biogeography. Global diversity and geography of soil fungi.

Fungi play major roles in ecosystem processes, but the determinants of fungal diversity and biogeographic patterns remain poorly understood. Using DNA metabarcoding data from hundreds of globally distributed soil samples, we demonstrate that fungal richness is decoupled from plant diversity. The plant-to-fungus richness ratio declines exponentially toward the poles. Climatic factors, followed by edaphic and spatial variables, constitute the best predictors of fungal richness and community composition at the global scale. Fungi show similar latitudinal diversity gradients to other organisms, with several notable exceptions. These findings advance our understanding of global fungal diversity patterns and permit integration of fungi into a general macroecological framework.