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  • Under Assessment
  • Preliminary Assessed
  • LCAssessed
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Butyriboletus abieticola (Thiers) D. Arora & J.L. Frank

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Scientific name
Butyriboletus abieticola
Author
(Thiers) D. Arora & J.L. Frank
Common names
Mountain Butter Bolete
IUCN Specialist Group
Mushroom, Bracket and Puffball
Kingdom
Fungi
Phylum
Basidiomycota
Class
Agaricomycetes
Order
Boletales
Family
Boletaceae
Assessment status
Assessed
Preliminary Category
LC
Proposed by
Noah Siegel
Assessors
Noah Siegel
Comments etc.
James Westrip
Reviewers
Gregory Mueller

Assessment Notes

Justification

Butyriboletus abieticola is a locally common species, often growing with true firs in high elevation forests in the Sierra Nevada of California, north into Washington in the Cascade Range.  The species is fairly widespread and appears stable, but hotter, stand replacing fires (rather than patchwork and understory burns) throughout much of its range are commonplace, altering appropriate habitat drastically, and making its habitat ill-suited.
Not enough data are available to assess how this decline in habitat quality is impacting its population size. Based on current data, the species is assessed as LC, but its population should be monitored as is likely experiencing decline, and the rate of decline will likely increase without appropriate habitat management.


Taxonomic notes

Described as Boletus abieticola (Thiers 1975) from a California, USA collection; later transferred to the genus Butyriboletus (Arora & Frank 2014).


Why suggested for a Global Red List Assessment?

Butyriboletus abieticola is a locally common species, often growing with true firs in high elevation forests in the Sierra Nevada of California, north into Washington in the Cascade Range.


Geographic range

Most records for this species are from high elevation fir (Abies spp) forests in the Sierra Nevada, Siskiyou and Cascade Range of California, and the Cascade Rang in Oregon and Washington (iNaturalist 2020, Arora & Frank 2014). It is also occasionally seen on the Northern Californian and Oregon coast (Siegel & Schwarz 2016).


Population and Trends

The species is fairly widespread and appears stable, but not enough data are available to assess how increases in fire frequency and intensity in the high elevation habitats where it grows is impacting its population size.

Population Trend: Uncertain


Habitat and Ecology

The species is ectomycorrhizal, associated with Abies sp. especially Red Fir (Abies magnifica) in high elevation forests of the Sierra Nevada and Cascade Range.  It is occasional to rare in coastal forest in northern California and Oregon with Grand Fir (Abies grandis). It produces sporocarps in the summer and early fall.

Temperate Forest

Threats

Prolonged droughts and decades of fire suppression have drastically altered the high sierra forest, leading to thicker, denser, Abies dominated forest. As a result, hotter, stand replacing fires (rather than patchwork and understory burns) are commonplace, altering appropriate habitat drastically, and making it ill-suited for this species.

Increase in fire frequency/intensityDroughts

Conservation Actions

Enhanced forest management is needed to reduce fuel load in mid to high elevation Abies forests.

Habitat & natural process restorationHarvest management

Research needed

More data on populations and trends of this species is needed to document impact of changing habitat conditions due to increase in fire frequency and intensity.

Population size, distribution & trends

Use and Trade

This species is edible, and is often collected for food.

Food - human

Bibliography

Arora, D. & Frank, J.L. 2014. Clarifying the butter Boletes: a new genus, Butyriboletus, is established to accommodate Boletus sect. Appendiculati, and six new species are described. Mycologia 106(3): 464-480.

Siegel, N. and Schwarz, C. 2016. Mushrooms of the Redwood Coast. Ten Speed Press: Berkeley, CA. 601 p.

Thiers, H.D. 1975. California Mushrooms—A Field Guide to the Boletes. Hafner Press: New York, NY. 261 p
Wood, M.G. and Stevens, F.A. 2020. MykoWeb; California Fungi. https://www.mykoweb.com/CAF/species/Butyriboletus_abieticola.html


Country occurrence

Regional Population and Trends

Country Trend Redlisted