vs Polar bear

Clitocybe diatreta compared with Ursus maritimus

Key Differences

is Least Concern while Polar bear is Vulnerable.

Taxonomic Classification

Rank		Polar bear
Kingdom	Fungi (菌界)	Animalia (動物)
Phylum	Basidiomycota (担子菌門)	Chordata (脊索動物)
Class	Agaricomycetes (真正担子菌綱)	Mammalia (哺乳類)
Order	Agaricales (ハラタケ目)	Carnivora (ネコ目)
Family	Tricholomataceae	Ursidae (Bears)
Genus	Clitocybe	Ursus (Bears)
Species	Clitocybe diatreta	Ursus maritimus

Conservation Status

LC — Least Concern

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute		Polar bear
Diet	—	Carnivore
Average Lifespan	—	25 years
Average Length	—	2.4 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

Habitat

Typically found in forest floors, decomposing wood, and soil ecosystems.

Range

Distributed across Belgium, Denmark, Norway, Sweden, and United States.

Polar bear

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and boreal forests and taiga, among 4 distinct biome types within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Found in Norway. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Clitocybe diatreta is a saprotrophic agaric fungus belonging to the family Tricholomataceae, found across temperate European forests and woodland habitats from Scandinavia southward through Central Europe. It typically fruits in autumn among leaf litter of deciduous and mixed forests, favoring moist, humus-rich soils beneath beech, oak, and conifer stands. The cap is convex to depressed, pale greyish-buff or whitish, with the decurrent gills and funnel-shaped profile characteristic of the genus Clitocybe. Microscopic examination reveals ellipsoid spores with smooth walls, confirming identity in this difficult taxonomic group. The diatreta species complex has been subject to taxonomic revision as molecular techniques clarify boundaries between morphologically similar taxa. As a decomposer of forest litter, C. diatreta contributes to the breakdown of cellulose and lignin in temperate forest floors, releasing nutrients back into the soil ecosystem. Its presence indicates structurally diverse, undisturbed forest conditions preferred by many specialist saprotrophic fungi in European woodland communities.

Polar bear

地球上で最大の陸上肉食動物であるホッキョクグマは700kgを超えることがあり、カナダからロシアまでの北極海氷域全体に分布する。ワモンアザラシとヒゲアザラシを狩るために海氷に依存する高度に特化した海洋哺乳類である。広大な距離を泳ぐことができる優れた泳者でもある。脆弱種に指定されており、気候変動による急激な北極海氷の消失で個体群が深刻な圧力を受けている。