The forest

What grows on Ryuoo Ski Park

Mostly deciduous: broadleaf woods and larch. They stand bare through the winter, so you can see a long way into them.

Read from the national vegetation survey. The survey records the cut pistes as open ground, so the ski area shows up on its own.

Plan view of the forest around Ryuoo Ski Park. Bare deciduous woods pale, evergreen conifer dark, open ground lightest.
Plan view, about 7.8 km across, faintly shaded by the mountain's own relief. The pale threads are the pistes, which the survey records as open ground.
Darker ink is denser forest: evergreen conifer that stays closed through the winter. Paler ink is deciduous forest, bare from November, which you can see a long way into. The palest ink is ground with no forest on it. Every bar below uses the same three inks.
Forest cover
89%
of the ground this map covers
Bare in winter
79%
of that forest loses its leaves in winter
Planted stands
26%
of the classified ground, planted in rows of one age
Natural forest
22%
of the classified ground, level 9 of 10 on the survey’s naturalness scale
Most open at
1,177–1,316m
the height you can see furthest into the trees at
Commonest stand
ブナ-ミズナラ群落
29% of the ground the survey classified
Plant communities
35
distinct types on this mountain
Surveyed
2013
fieldwork years, not the 2024 edition

Where this mountain sits among the others on JapowDB

least bare 35%94% most bare

Its forest stands barer in winter than 18 of the 49 mountains on JapowDB.

01

Sight range, level by level

This is the mountain seen from the side. How far you can see into the trees changes with height.

Height What you can see through Bare
1,875–2,014 m
13%
1,735–1,874 m
31%
1,596–1,735 m
81%
1,456–1,595 m
96%
1,317–1,456 m
96%
1,177–1,316 m
96%
1,038–1,177 m
91%
898–1,037 m
77%
759–898 m
66%
619–758 m
75%
closed 50% 100%
A section through the mountain, base to summit.

Each reading is a share of that band's own forest, not of the mountain, and a band holding too little forest to state one is left blank. The pale bar behind the section is how much ground sits at that height, so a swing over a sliver of mountain does not read as a headline. No treeline is drawn — the survey describes stands, not a line.

02

What stands beside each run

Each run is scored on the band 35 to 90 m either side of its centre line, which is the forest you look at from the piste. Runs are ordered by how much of that band you can see through in winter.

Run The band either side See-through
Kiotoshi Bowl a (ar) 454 m 100%
Kiotoshi Bowl a (al) 1,349 m 87%
Kiotoshi Bowl b 1,177 m 65%
Base Gelande 978 m 31%
Green Gelande 619 m 24%
Mid Gelande 1,003 m 11%
Crystal Course 635 m 8%
Red Gelande 564 m 4%
The other 3 runs
Run The band either side See-through
A Course 1,115 m 2%
B Course 1,028 m 0%
C Course 447 m 0%

Each figure is a share of the surveyed ground in a band 35–90 m either side of the run. The run itself and the rest of the mountain are outside it. The survey resolves about 18 m on the ground and the band is only a few cells wide, so the figure covers what the band is made of and cannot single out one tree, gap or line of sight. Runs the survey barely covers are left out. The survey has no treeline and no stem-density data.

03

What actually grows here

The survey sorts every polygon into one of its vegetation zones, then names the stand within it. A mountain usually falls into five or six zones, each holding many named stands.

Vegetation zone Share of classified ground Share
Beech-zone regrowth ブナクラス域代償植生 42%
Plantation and farmland 植林地・耕作地植生 31%
Natural subalpine conifer forest コケモモ-トウヒクラス域自然植生 13%
Natural beech-zone forest ブナクラス域自然植生 10%
Other その他 3%
Subalpine conifer-zone regrowth コケモモ-トウヒクラス域代償植生 1%
Riverside, wetland, salt marsh and dune 河辺・湿原・塩沼地・砂丘植生 0%
Alpine natural vegetation 高山帯自然植生域 0%

The named stands underneath

The survey’s own community names, largest first. These are proper names for stand types, and the survey publishes them only in Japanese.

  • ブナ-ミズナラ群落 29%
  • カラマツ植林 18%
  • オオシラビソ群集 11%
  • チシマザサ-ブナ群団 9%
  • スギ・ヒノキ・サワラ植林 8%
  • レンゲツツジ-シラカンバ群集 7%
The other 29 communities
  • オオバクロモジ-ミズナラ群集 3%
  • 水田雑草群落 3%
  • 市街地 2%
  • ススキ群団(V) 2%
  • 牧草地 2%
  • ダケカンバ群落(III) 1%
  • 畑雑草群落 1%
  • オクチョウジザクラ-コナラ群集 1%
  • ササ群落(II) 1%
  • ジュウモンジシダ-サワグルミ群集 1%
  • ササ-ダケカンバ群落 1%
  • コメツガ群落 0%
  • ヒメヤシャブシ-タニウツギ群落 0%
  • ササ群落(III) 0%
  • 路傍・空地雑草群落 0%
  • ツルコケモモ-ミズゴケクラス 0%
  • ヤナギ高木群落(IV) 0%
  • アカミノイヌツゲ-クロベ群集 0%
  • 開放水域 0%
  • ブナ二次林 0%
  • ミドリユキザサ-ダケカンバ群団 0%
  • アカマツ植林 0%
  • オギ群集 0%
  • 果樹園 0%
  • 自然裸地 0%
  • コケモモ-ハイマツ群集 0%
  • ササ群落(V) 0%
  • ヌマガヤオーダー 0%
  • 造成地 0%

Every share is of the ground the survey classified on this mountain, which is more than the forest and more than the ski area. The zones are the survey’s own; the English is a gloss and the Japanese is the source term. Zones are ordered by area, and area has no bearing on how well a zone skis.

04

How natural this vegetation is

The survey grades every polygon on a ten-point scale of how little people have changed it. Level 1 is made ground with almost nothing growing on it; level 10 is natural grassland and alpine heath. The scale measures human interference only. Natural fir sits at 9 and is a wall you cannot see through; a larch plantation sits at 6, evenly spaced and good to ski.

Level Share of classified ground Share
10 Natural grassland and alpine heath 1%
9 Natural forest 22%
8 Regrowth close to natural forest 30%
7 Secondary forest 11%
6 Plantation 26%
5 Tall secondary grassland 2%
4 Short secondary grassland 0%
3 Orchard, tea and mulberry field 0%
2 Farmland and green residential land 5%
1 Built-up and made ground 2%

A fraction of a percent of the classified ground carries a code outside the ten levels. It is left out of the rows above.

Every share is of the ground the survey classified on this mountain. The scale records human interference only; a higher level does not mean better skiing. Levels this mountain does not have are left out.

National vegetation survey, 2024 edition, Biodiversity Center, Ministry of the Environment, Japan. Processed by JapowDB; the Ministry did not produce this version.

This mountain's polygons were walked in 2013. The edition is dated 2024; the fieldwork is older.

Each cell is about 18 m across, roughly the size of a small clearing.