The forest
What grows on Zao Onsen Ski Resort
Both kinds, in patches. Some stands drop their leaves and open up for the winter; others are evergreen conifer and stay closed.
Read off the national vegetation survey. Where the pistes are cut the survey records open ground, so the ski area draws itself.
Where that sits among the mountains we publish
Its forest goes bare more readily than 4 of the 29 mountains we publish.
01
Sight range, level by level
The mountain seen side-on. How far you can see into the trees changes with height, and each band is drawn level with its own row.
| Height | What you can see through | Bare |
|---|---|---|
| 1,706–1,840 m | | 10% |
| 1,572–1,706 m | | 10% |
| 1,437–1,571 m | | 27% |
| 1,303–1,437 m | | 63% |
| 1,169–1,303 m | | 97% |
| 1,035–1,169 m | | 96% |
| 900–1,034 m | | 82% |
| 766–900 m | | 65% |
| 632–766 m | | 59% |
| 498–632 m | | 64% |
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
A band 35 to 90 m either side of each run’s centre line: outside the groomed piste, inside what you look at from it. Ordered by how much of that band is forest you can see through in winter.
| Run | The band either side | See-through |
|---|---|---|
| Nakamori Course 1 276 m | 89% | |
| Chuo Course 2 321 m | 88% | |
| Chuo Course 1 649 m | 86% | |
| Kurohime Connect Course 764 m | 78% | |
| Kurohime Course 2 1,020 m | 77% | |
| Sunrise Course 1 400 m | 77% | |
| Ohira Course 2,249 m | 76% | |
| Chuo Course 6 358 m | 75% |
The other 46 runs
| Run | The band either side | See-through |
|---|---|---|
| Kurohime Super Giant Course 1,630 m | 72% | |
| Mikaeri Course 253 m | 70% | |
| Ohmori no Kabe 30° 309 m | 69% | |
| B course 435 m | 68% | |
| Katakai Triple 430 m | 68% | |
| Hyakumanin Course 3 413 m | 66% | |
| Chuo Course 5 459 m | 62% | |
| Ohmori Course 1,753 m | 61% | |
| Chuo Course 7 535 m | 61% | |
| Takatori Course 699 m | 61% | |
| Hyakumanin Course 1 1,728 m | 60% | |
| Diamond Valley 1 589 m | 59% | |
| Chuo Course 3 444 m | 58% | |
| Yokokurano Wall 38° 358 m | 57% | |
| Nakamori Course 2 599 m | 56% | |
| Chuo Course 8 348 m | 56% | |
| Diamond Valley 3 662 m | 56% | |
| Diamond Valley 2 336 m | 53% | |
| Hahnenkamm A Course 532 m | 53% | |
| Hahnenkamm C Course 721 m | 51% | |
| Sunrise Course 3 557 m | 50% | |
| Yokokurano Course 4 570 m | 49% | |
| Chuo Course 4 381 m | 47% | |
| Ryuzan Course 3 634 m | 44% | |
| Uwanodai Course 2 519 m | 44% | |
| Hyakumanin Course 2 401 m | 43% | |
| Utopia Course 5 241 m | 43% | |
| Renraku Course 974 m | 39% | |
| Omori Course 1 656 m | 38% | |
| Sailor Course 470 m | 37% | |
| Omori Course 2 340 m | 33% | |
| Utopia Course 4 283 m | 33% | |
| Shobunuma Course 366 m | 31% | |
| Uwanodai Course 1 985 m | 31% | |
| Yokokurano Course 2 903 m | 30% | |
| Sunrise Course 2 354 m | 30% | |
| Ryuzan Course 1 308 m | 30% | |
| Utopia Course 3 437 m | 30% | |
| Paradies Course Detour 819 m | 29% | |
| Ryuzan Course 2 630 m | 28% | |
| Yokokurano Course 1 1,120 m | 23% | |
| Yokokurano Course 3 380 m | 8% | |
| Zangezaka Johyogen Course 1,539 m | 2% | |
| Utopia Course 1 653 m | 1% | |
| Uwanodai Course 3 336 m | 0% | |
| Utopia Course 2 260 m | 0% |
Each figure is a share of the surveyed ground in a band 35–90 m either side of that run — not of the run, and not of the mountain. The survey resolves about 21 m on the ground and the band is a few cells wide, so this says what the band is made of, never what one tree, one gap or one line of sight is like. A run the survey barely covers is left out rather than stated from a handful of cells. No treeline and no stem density: the survey records stands, not either of those.
03
What actually grows here
The survey sorts every polygon into one of its own vegetation zones before it gives a stand a name. Five or six zones describe a mountain; the named stands underneath them run to dozens.
| Vegetation zone | Share of classified ground | Share |
|---|---|---|
| Beech-zone regrowth ブナクラス域代償植生 | 38% | |
| Plantation and farmland 植林地・耕作地植生 | 23% | |
| Natural beech-zone forest ブナクラス域自然植生 | 17% | |
| Natural subalpine conifer forest コケモモ－トウヒクラス域自然植生 | 10% | |
| Alpine natural vegetation 高山帯自然植生域 | 8% | |
| Other その他 | 2% | |
| Riverside, wetland, salt marsh and dune 河辺・湿原・塩沼地・砂丘植生 | 2% | |
| Subalpine conifer-zone regrowth コケモモ－トウヒクラス域代償植生 | 0% |
The named stands underneath
The survey’s own community names, largest first. They are proper names for stand types and the survey publishes no English for them, so they stand in Japanese here rather than as a translation we invented.
- オオバクロモジ－ミズナラ群集 20%
- チシマザサ－ブナ群団 13%
- スギ・ヒノキ・サワラ植林 12%
- ブナ－ミズナラ群落 8%
- オオシラビソ群集 7%
- カラマツ植林 5%
The other 51 communities
- コケモモ－ハイマツ群集 5%
- 牧草地 3%
- オクチョウジザクラ－コナラ群集 3%
- ススキ群団（V） 3%
- 火山荒原植生 1%
- 高山ハイデ及び風衝草原 1%
- ナナカマド－ミネカエデ群落 1%
- 伐採跡地群落（V） 1%
- 緑の多い住宅地 1%
- ヒメヤシャブシ－タニウツギ群落 1%
- アカマツ群落（V） 1%
- チシマザサ－クマイザサ群落 1%
- 畑雑草群落 1%
- ウラジロヨウラク－ミヤマナラ群団 1%
- 高山低木群落 1%
- アカマツ植林 1%
- ササ－ダケカンバ群落 1%
- オニグルミ群落（V） 1%
- 開放水域 1%
- アカマツ群落（IV） 1%
- 水田雑草群落 0%
- 硫気孔原植生 0%
- イタドリ－コメススキ群落 0%
- クロベ－キタゴヨウ群落 0%
- ミヤマハンノキ群落 0%
- ジュウモンジシダ－サワグルミ群集 0%
- 市街地 0%
- 放棄水田雑草群落 0%
- 放棄畑雑草群落 0%
- ウダイカンバ群落 0%
- コマクサ－イワツメクサクラス 0%
- 雪田草原 0%
- ニセアカシア群落 0%
- 自然裸地 0%
- 路傍・空地雑草群落 0%
- 造成地 0%
- ツルコケモモ－ミズゴケクラス 0%
- ケヤキ群落（IV） 0%
- コメツガ群落 0%
- タニウツギ－ノリウツギ群落 0%
- ササ群落（II） 0%
- ヨシクラス 0%
- オオヨモギ－オオイタドリ群団 0%
- モミ植林 0%
- ヤナギ低木群落（IV） 0%
- 工場地帯 0%
- ササ群落（III） 0%
- ハンノキ群落（IV） 0%
- ヒルムシロクラス 0%
- ミヤマナラ群落 0%
- 河辺一年生草本群落（タウコギクラス等） 0%
Every share is of the ground the survey classified on this mountain — not of the forest, and not of the ski area. The zones are the survey’s own; the English beside each one is our gloss and the Japanese is what the source says. Ordering is by area, and says nothing about what skis well.
04
How natural this vegetation is
The survey places every polygon on a ten-point scale of how little people changed it: 1 is made ground with almost nothing growing on it, 10 is natural grassland and alpine heath. It measures interference and nothing else — natural fir sits at 9 and is a wall you cannot see through, a larch plantation sits at 6 and is evenly spaced and lovely to ski.
| Level | Share of classified ground | Share |
|---|---|---|
| 10 | Natural grassland and alpine heath | 4% |
| 9 | Natural forest | 32% |
| 8 | Regrowth close to natural forest | 8% |
| 7 | Secondary forest | 25% |
| 6 | Plantation | 18% |
| 5 | Tall secondary grassland | 4% |
| 4 | Short secondary grassland | 2% |
| 3 | Orchard, tea and mulberry field | 0% |
| 2 | Farmland and green residential land | 6% |
| 1 | Built-up and made ground | 0% |
1% of the classified ground carries a code that is not one of the ten levels. It is left out of the rows above rather than counted as a level.
Every share is of the ground the survey classified on this mountain. The scale records how little people interfered and nothing else: it is not a ranking, and a higher level is not a better place to ski. Levels this mountain does not carry are absent rather than drawn as zero.
National vegetation survey, 2024 edition — Biodiversity Center, Ministry of the Environment, Japan. Modified data, not produced by the Ministry.
This mountain's polygons were surveyed in 2000 and 2015: the edition is 2024, the looking is older.
About 21 m per cell — fine enough to describe a hillside, never an individual gap between two trees.