前言 / 第2章
多摩的林業
東京的森林約有七成位於都西部的多摩地區,面積約5萬3千公頃。[1] 多摩的私有林中有六成是柳杉、扁柏等人工林,其中大多是在昭和30〜40年代種植的。[1]
多摩森林的現在
大量種植的年代,與不再種植的年代
造林面積在昭和35年超過每年1,500公頃。其後急遽減少,到平成15年已降至6公頃。[1] 以齡級來看,山上盡是同一世代的樹木,幾乎沒有年輕的林子。
| 年度 | 新植面積 | 狀況 |
|---|---|---|
| 昭和35年 | 超過 1,500 ha | 擴大造林的鼎盛期 |
| 平成15年 | 6 ha | 最少的時期 |
| 令和4年度 | 48 ha | 伐採後重新造林的事業持續進行 |
出處:東京都《林業・木材產業循環成長對策 變更事業構想》[1]
不被砍伐的原因
由於木材價格長期低迷加上人事費上漲,林業變得無利可圖,已長到可用粗細的50年生以上柳杉、扁柏的伐採因此停擺。[3] 再加上地形陡峻、作業成本高,以及都內林業經營體規模小、利潤率低等因素。[1]
以花粉的形式來到城市
未被砍伐而留下的柳杉,也影響著城市生活。根據平成29年的調查,都內柳杉花粉症的盛行率推估為48.8%。平成18年度的調查則是28.2%。[3] 東京都農林水產振興財團正推動砍伐柳杉、改植少花粉品種的事業。從平成18年度到令和2年度,這項事業累計出貨了25萬7千立方公尺的木材。[3]
天然林與國有林
八王子市的高尾山國有林中,日本冷杉的天然林被指定為植物群落保護林。此地位於冷溫帶與暖溫帶的交界,天然林中可見日本水青岡(イヌブナ)、枹櫟、日本冷杉、日本鐵杉等。[4]
Across Japan as a whole, vegetation left in its natural state is not common. An exhibit panel I saw at a museum in Ueno Park showed that while forests cover more than 70% of Japan, most of them are satoyama coppice woodland or plantations of sugi, hinoki, larch and the like, and that "natural vegetation"—natural forest and natural grassland combined—makes up 19%. The panel cites the Ministry of the Environment's National Survey on the Natural Environment as its source.
Protection forests: woods you cannot fell freely
Protection forests (hoan-rin) are forests whose public functions, such as storing water, preventing landslides or breaking the wind, are especially important. Under the Forest Act, the Minister of Agriculture, Forestry and Fisheries or a prefectural governor designates them. There are 17 types by purpose, including water-source conservation and erosion control. Once designated, felling trees and changing the shape of the land are regulated[5]. At the end of FY2023 Japan had 12.29 million ha of protection forest: 49.1% of its forests and 32.5% of its land area[6].
The system goes back to the Meiji era. After the great floods of 1896, the Forest Act was enacted in 1897. After the war, the Temporary Measures Act for Protection Forest Improvement of 1954 drove designations forward, renewed every ten years[7].
| Restrictions after designation | Benefits in return |
|---|---|
| Felling requires a permit or notification | Exempt from fixed property tax, real estate acquisition tax and special land holding tax |
| No conversion to other uses such as housing | For inheritance and gift tax, the valuation is reduced by 30–80% depending on how strict the felling limits are |
| Changing the land, for example building work roads, requires a permit | |
| Felled areas must in principle be replanted |
Source: Saitama Prefecture, "About protection forests"[8]. The system rests on the nationwide Forest Act.
In Tokyo, the area of the Tokyo Metropolitan Forestry Office, covering 15 Tama municipalities, held 14,838 ha of protection forest as of 31 March 2019. Of this, 12,478 ha, about 84%, is water-source conservation forest. National forest accounts for 935 ha and non-national forest for 13,903 ha[9].
| 類別 | 國有林 | Non-national forest | 合計 |
|---|---|---|---|
| Water-source conservation | 485 | 11,993 | 12,478 |
| Erosion control | 296 | 1,316 | 1,612 |
| Landslide prevention | 0 | 51 | 51 |
| Windbreak | 0 | 1 | 1 |
| Drought prevention | 0 | 7 | 7 |
| Rockfall prevention | 0 | 35 | 35 |
| Public health (recreation) | 154 | 429 | 583 |
| Scenic | 0 | 71 | 71 |
| Total | 935 | 13,903 | 14,838 |
Unit: ha. As of 31 March 2019. A further 10 ha of non-national fire-prevention forest and 2,293 ha of forest designated for two purposes at once are excluded from the totals. Source: Tokyo Metropolitan Forestry Office, "Business overview, 2019 edition"[9].
Forests in the same area total 52,867 ha (as of 1 April 2019), so protection forest is about 28% of the forest[9]. That is lower than the national 49.1%, but the dates and scope differ, so treat it as a rough comparison.
In FY2018 the Forestry Office handled 9 felling permits (30.4 ha), 37 work permits and 92 thinning notifications (112.8 ha). Inquiries about whether a given plot lies in protection forest numbered 379, covering 4,023 parcels[9]. The metropolitan government manages 10 metro-owned public-health protection forests, 239.4 ha in all, in Hachioji, Akiruno and Hinohara[9].
The water-source forests managed by the Tokyo Waterworks Bureau are also protection forest. They cover 25,666 ha across Okutama and, in Yamanashi, Koshu, Tabayama and Kosuge; Tokyo Prefecture took them over from the imperial forests and began managing them in 1901. They are designated as water-source conservation, erosion control and public-health protection forest[10]. The Yamanashi part is not in the Tama table above.
The Tokyo figures come from the 2019 business overview; the latest areas have not been confirmed. Protection forests on the islands and in the 23 wards have not been researched here.
林業的從業人員與收支
林業從業人員：全國4.4萬人
全國的林業從業人員長期持續減少，2020年約為4.4萬人。65歲以上的比例（高齡化率）為25%，高於全產業的15%。另一方面，未滿35歲的比例（年輕人比率）自1990年以後逐漸上升，達到17%。[11]
新進入林業的人數，在國家「綠色雇用」計畫開始前平均每年約2,000人，開始後增加到每年約3,200人。[11] 一邊在現場接受研修一邊開始工作的機制，讓新進人員增加了。
東京林業的現場
東京都調查都內林業事業體的報告書（54個事業體回覆）顯示，現場工作人員的平均年齡為45.7歲，34歲以下的比例約為27%。2024年度（令和6年度）新進人員21人、離職人員19人，一年的留任率為91.8%。經驗15年以下的人占57.3%。[12]
薪資以「400萬～未滿450萬日圓」最多，占26.2%；未滿400萬日圓的約占46%。受調查的事業體中約有四分之三比前一年調高了薪資。[12]
危險與待遇
林業至今仍是危險性很高的工作。每1,000名勞工一年的死傷人數（死傷千人率），2022年（令和4年）林業為23.5，全產業為2.3，約為10倍。年平均薪資林業為361萬日圓，全產業為458萬日圓。[13]
工作方式正在改變。一年工作210天以上的人的比例，從1985年度（昭和60年度）的9%上升到約七成；月薪制的人的比例從2%上升到約三成。[13] 雇用形態正逐漸接近可以全年工作的穩定形式。
機械化：高性能林業機械
伐木、去枝、截成固定長度、運出。過去靠人力、鏈鋸與鋼索進行的作業，如今改由專用機械承擔。全國的高性能林業機械在2024年度（令和6年度）為16,431台，比前一年增加1,365台，約為10年前（2014年度，平成26年度）7,089台的2.3倍。[14]
| 機械 | 用途 | 台數（2024年度） |
|---|---|---|
| 集材車 | 把截好的原木裝上載貨台運出 | 5,186[14] |
| 造材機 | 為伐倒的樹木去枝，並截成固定長度 | 2,348[14] |
| 伐木造材機 | 伐倒立木，並完成去枝與截段 | 2,272[14] |
| 擺動式集材機 | 以鋼索從斜坡下方或上方拉近原木 | 1,151[14] |
機械功能的說明為一般性內容。台數為全國合計，都內的台數尚未確認。
林業能賺錢嗎
根據林野廳的試算，砍伐1公頃50年生的柳杉人工林，原木銷售額為398萬日圓。然而扣除伐採與搬運費用後，山林所有者的收入（山元立木價格）只有137萬日圓。之後種植苗木、開始培育的費用需要275萬日圓，超過了這筆收入。光是砍伐再重新種植就會虧損。[15]
林野廳試算，結合機械化與造林省力化的「新林業」，以目前可行的做法可達到71萬日圓的盈餘，導入新技術則可達113萬日圓的盈餘。[15] 山林所有者的收入與過去相比減少了多少，整理在附錄的「過去的木材價格」中。
每公頃的金額為林野廳以全國為對象的試算，並非僅限於東京山林的數字。
如何確保人才
確保人才的支柱，是像國家「綠色雇用」計畫這類附研修的就業支援，以及改善薪資、全年雇用等待遇。[11][13] 在東京，多數事業體已著手調薪，新進人員與離職人員的人數大致持平。[12] 在都內從事林業工作的相關資訊，以及以志工身分參與森林整備的窗口，整理在附錄的連結集中。
Forests, wood and taxes
Forest environment tax: ¥1,000 a year from Tokyo residents too
Taxes are also used to care for forests. Since fiscal 2024, a "forest environment tax" of ¥1,000 a year has been collected from each person who pays resident tax. Some 60 million people pay it, and revenue is expected to be about ¥60 billion a year.[16]
The tax is distributed to municipalities and prefectures as the "forest environment transfer tax," which began ahead of it in fiscal 2019. It is allocated by three criteria: the area of privately owned planted forest, the number of forestry workers, and population. Criticism that the large population weight sends much of it to urban areas with few forests led to a revision from fiscal 2024 to 55% planted forest area, 20% forestry workers and 25% population.[16]
| Allocation criterion | Until FY2023 | From FY2024 |
|---|---|---|
| Private planted forest area | 50% | 55% |
| Forestry workers | 20% | 20% |
| Population | 30% | 25% |
Source: Dai-ichi Life Research Institute (December 6, 2024)[16]
Even the 23 wards, which have almost no forest, receive this transfer tax. They can spend it either on using wood within their own ward or on helping regions that have forests. In fiscal 2023, for example, Suginami Ward used it for school rebuilding, chairs and shelves for childcare facilities and repairs to wooden playground equipment in parks, as well as a carbon offset project in partnership with another municipality and thinning experiences for children.[17]
Rules for using wood in public buildings
In 2010 the national government enacted the Act on Promotion of Use of Wood in Public Buildings, setting a policy of using wood in national and local government buildings. A revision in October 2021 renamed it the Act on Promotion of Use of Wood in Buildings to Contribute to Realizing a Decarbonized Society, and extended it to all buildings, including private ones.[18] The share of public buildings built of wood, 8.3% when the law was enacted, reached 15.9% in fiscal 2024; for low-rise public buildings of three stories or fewer it was 33.4%.[19] That also means more than half are still not built of wood.
Subsidies for using local wood: Tokyo Metropolis and Minato Ward
Through its "Tama Timber Use Promotion Project," the Tokyo Metropolitan Government subsidizes facilities that wards, cities, towns and villages build or improve using Tama timber—timber construction, wood interiors, wooden playground equipment, and wooden furniture and exterior structures. The subsidy covers half the cost, up to ¥30 million per municipality (as of the fiscal 2023 revision).[20]
There are also systems in which a ward requires the use of wood. Minato Ward's "Minato Model CO2 Fixation Certification System" asks developers building structures of 5,000 m² or more of total floor area in the ward to use 0.001 m³ of domestic timber per square meter of floor area. It also encourages the use of wood from regional municipalities that have signed agreements with the ward ("agreement timber"). It began in October 2011.[21] It is a mechanism by which a central-city ward with no forests channels money to regional forests through its buildings.
I have not confirmed the latest conditions of the Tokyo subsidy, the amounts of the forest environment transfer tax distributed to the 23 wards as a whole or to Tokyo and the Tama municipalities, or the wood-construction rate of public buildings in Tokyo.
出處
- 東京都産業労働局「林業・木材産業循環成長対策 変更事業構想」 PDF
- 東京都「森づくり推進プラン」表1-1(原典:令和2年版 東京の森林・林業) PDF
- 公益財団法人東京都農林水産振興財団 説明資料 PDF
- 林野庁関東森林管理局「多摩森林計画区の概要」 PDF
- 林野庁「保安林制度」(水源林の保全) 連結
- 林野庁「令和6年度 森林・林業白書」第1部第3章第1節 連結
- 林野庁 資料「保安林制度の沿革」 連結
- 埼玉県「保安林について」 連結
- 東京都森林事務所「事業概要 令和元年版」 連結
- 林野庁「水源の森百選 東京都水道水源林」 連結
- 林野庁「林業労働力の動向」 連結
- 東京都森林事務所『林業関係労働力実態分析報告書』(令和7年度、令和8年3月) PDF
- 林野庁「一目でわかる林業労働(データ編)」 PDF
- 林野庁「高性能林業機械の保有状況」 連結
- 林野庁『令和5年度 森林・林業白書』第2章(林業経営の効率化) 連結
- 第一生命経済研究所「6,000万人が納税する森林環境税」(2024年12月6日) 連結
- 杉並区「森林環境譲与税の使途」(令和5年度決算) PDF
- 林野庁「公共建築物等木材利用促進法」 連結
- 林野庁「公共建築物の木造率について」(令和8年3月30日更新) 連結
- 東京都産業労働局「公共施設における多摩産材使用事例集 ver.6」 PDF
- 港区「みなとモデル二酸化炭素固定認証制度実施要綱」 PDF