Conservation
Fungal richness does not track plant richness
Global soil metabarcoding showed that fungal diversity follows its own rules, and that climate predicts it better than anything else.
Biodiversity conservation is usually planned from plants: they are easier to count and range maps have existed for a long time. The silent assumption is that where the flora is rich, the rest is rich too. The paper by Leho Tedersoo's team, published in Science in 2014, undermined that assumption.
The authors used DNA metabarcoding on hundreds of soil samples distributed worldwide. The basic result: fungal species richness is decoupled from plant diversity. The plant-to-fungus richness ratio declines exponentially towards the poles, so one does not stand in for the other as an indicator.
Climatic factors turned out to be the best predictors of fungal richness and community composition, followed by edaphic and spatial variables. Fungi show a latitudinal diversity gradient similar to other organisms, with several notable exceptions — and for conservation planning the exceptions are the interesting part.
The practical significance is direct. A protected-area network designed around plants is not automatically a network that protects fungi, because the maxima of the two do not coincide in any predictable way. Checking that requires soil data — and taking a soil sample is cheaper than surveying fruiting bodies, and does not depend on whether the season went well.
The limitation is equally clear, and the authors do not hide it: metabarcoding measures the presence of sequences, not the abundance or condition of organisms, and the samples come from the upper soil layer. It is a map of diversity, not a census.
Decoupling depends on scale and method
Tedersoo and colleagues sampled soil at 365 sites, pooling 40 cores per site and metabarcoding ITS. Soil-fungal richness did not track plant richness, while the plant-to-fungus ratio declined toward the poles. Climate, followed by edaphic and spatial variables, best predicted richness and composition. A newer full-length ITS analysis of more than 4,000 samples likewise found precipitation–temperature interactions strongly shaping local richness. “Decoupled” does not mean plants are irrelevant or that no relationship exists locally: these studies measured soil DNA, not all funga; sequence units are imperfect species proxies; and primers miss some lineages. Taxon richness is also not equivalent to conservation value—rare specialists and common generalists count equally in a simple total.
Written by MykoRadar from the source indicated. Informational only — it does not replace advice from an expert.