The forest
What grows on Okushiga Kogen
This mountain has both, in separate patches. The deciduous stands drop their leaves and open up for the winter; the conifer stands stay closed.
Read from the national vegetation survey. The survey records the cut pistes as open ground, so the ski area shows up on its own.
Where this mountain sits among the others on JapowDB
Its forest stands barer in winter than 9 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 |
|---|---|---|
| 2,105–2,201 m | | 0% |
| 2,008–2,104 m | | 1% |
| 1,912–2,008 m | | 22% |
| 1,815–1,911 m | | 21% |
| 1,719–1,815 m | | 50% |
| 1,622–1,718 m | | 73% |
| 1,526–1,622 m | | 88% |
| 1,430–1,526 m | | 98% |
| 1,333–1,429 m | | 99% |
| 1,237–1,333 m | | 97% |
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 |
|---|---|---|
| Downhill Course Lower 319 m | 95% | |
| Hillside Course Mid 779 m | 79% | |
| Course No.1 867 m | 69% | |
| Hillside Course Lower 446 m | 68% | |
| Kids Forest Course 758 m | 63% | |
| Expert 697 m | 59% | |
| Course No.6 1,535 m | 52% | |
| Kuma-Otoshi Course 325 m | 52% |
The other 5 runs
| Run | The band either side | See-through |
|---|---|---|
| Course No.3 570 m | 52% | |
| Rinkan Course 1,208 m | 50% | |
| Downhill Course Upper 854 m | 36% | |
| Hillside Course Upper 417 m | 32% | |
| Course No.4 402 m | 24% |
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 16 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 | 38% | |
| Natural subalpine conifer forest コケモモ－トウヒクラス域自然植生 | 36% | |
| Natural beech-zone forest ブナクラス域自然植生 | 9% | |
| Plantation and farmland 植林地・耕作地植生 | 8% | |
| Subalpine conifer-zone regrowth コケモモ－トウヒクラス域代償植生 | 7% | |
| Other その他 | 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.
- レンゲツツジ－シラカンバ群集 20%
- オオシラビソ群集 18%
- オオバクロモジ－ミズナラ群集 10%
- ササ－ダケカンバ群落 9%
- ダケカンバ群落（III） 7%
- チシマザサ－ブナ群団 7%
The other 22 communities
- コメツガ群落 7%
- ブナ－ミズナラ群落 7%
- カラマツ植林 5%
- 牧草地 3%
- ササ群落（II） 2%
- ササ群落（V） 1%
- 市街地 1%
- ススキ群団（V） 1%
- ジュウモンジシダ－サワグルミ群集 1%
- ヤナギ高木群落（IV） 1%
- 緑の多い住宅地 1%
- アカミノイヌツゲ－クロベ群集 0%
- ササ群落（III） 0%
- ヒメヤシャブシ－タニウツギ群落 0%
- ゴルフ場・芝地 0%
- ヨシクラス 0%
- スギ・ヒノキ・サワラ植林 0%
- 路傍・空地雑草群落 0%
- 自然裸地 0%
- ツルコケモモ－ミズゴケクラス 0%
- 開放水域 0%
- コケモモ－ハイマツ群集 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 | 2% |
| 9 | Natural forest | 43% |
| 8 | Regrowth close to natural forest | 13% |
| 7 | Secondary forest | 30% |
| 6 | Plantation | 5% |
| 5 | Tall secondary grassland | 2% |
| 4 | Short secondary grassland | 0% |
| 2 | Farmland and green residential land | 4% |
| 1 | Built-up and made ground | 1% |
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 16 m across, roughly the size of a small clearing.