Cliff Scalewort vs Polar bear

Porella cordaeana compared with Ursus maritimus

Key Differences

Cliff Scalewort is Least Concern while Polar bear is Vulnerable.

Taxonomic Classification

Rank	Cliff Scalewort	Polar bear
Kingdom	Plantae (植物)	Animalia (動物)
Phylum	Marchantiophyta (苔類)	Chordata (脊索動物)
Class	Jungermanniopsida (Jungermanniopsida)	Mammalia (哺乳類)
Order	Porellales (Porellales)	Carnivora (ネコ目)
Family	Porellaceae	Ursidae (Bears)
Genus	Porella	Ursus (Bears)
Species	Porella cordaeana	Ursus maritimus

Conservation Status

Cliff Scalewort

LC — Least Concern

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

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

Habitat & Geographic Range

Cliff Scalewort

Habitat

Native to Europe and North America, inhabiting ecosystems characteristic of the region.

Range

Found across Europe (6 countries) and North America (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.

Cliff Scalewort

Cliff Scalewort, Porella obtusata, is a leafy liverwort in the family Porellaceae found on cliff faces, shaded rock surfaces, and the bark of trees in moist, humid environments across Europe and North America. Porella is one of the most diverse and widely distributed leafy liverwort genera, with species adapted to a range of substrates from bark and rock to soil in forests and coastal habitats. Cliff Scalewort forms flat, overlapping mats of small, scale-like leaves arranged in two lateral rows and a row of smaller underleaves, creating a texture that gives the plant its common name. The green to brownish-green plants are tightly appressed to the surface, extracting moisture from rainfall and condensation. Liverworts in this family reproduce sexually when conditions are favorable, producing small capsules on delicate setae, as well as vegetatively through fragmentation. Porella species on cliff faces are sensitive to air pollution, particularly sulfur dioxide, and have declined in many industrial regions of Europe, recovering more recently as air quality has improved. They serve as indicators of habitat continuity and air quality in ecological assessments. Cliff Scalewort is not globally threatened but may be locally rare in heavily polluted or drought-prone areas.

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。