Estimated mature individuals < 250, continuing decline and largest subpopulation < 50.
Cortinarius nivalis is one of the truffle-like species in the genus. It is pure white and slimy and readily recognised. The species is sequence barcoded (type sequence) and phylogenetically well classified. This group of fungi has been extensively surveys in New Zealand for at least 50 years.
Why suggested for a Global Red List Assessment?
Very uncommon snow-white truffle potentially under threat from decline/loss of dispersal agents.
Preliminary Category: Endangered. B2 AOO <500km2, or Critically Endangered C1, or Critically Endangered D1
Population and Trends
The species is known from 4 records in 3 locations over a 50 year period. We infer the presence of 4 genotyopes, x 3 to account for undetected colonies, x 5 to convert to an estimate of 40 mature individuals. The decline and loss of associated dispersal agents will impact on populations.
Habitat and Ecology
This truffle-like species is associated with southern beech forests (Nothofagaceae). Like many New Zealand truffle species, it is visibly noticeable and grows on the surface of the soil layer. These characters are thought to be adaptations to dispersal by animal vectors (the spores do not naturally disperse). Elsewhere truffles are buried, dull-coloured and dispersed by mammals. In New Zealand, without any native mammals (except 2 species of bat) the role is thought to be take by ground-dwelling birds, which are either extinct (Moa) or in serious decline (Kiwi, Kakapo etc).
It is likely the natural dispersal agent for this species is either extinct or in decline and thus the current populations are limited and sensitive to change.
The potential role of replacement dispersal agents (e.g. introduced rats, possums etc) is unknown. The long-term survival of current populations without active dispersal is unknown.
Population size, distribution & trendsLife history & ecology