Inherited Forest Land Without Clear Boundaries — Negative Assets and the Making of Owner-Unknown Land
A family in Imari, Saga inherited about 4,300 square meters of forest whose boundary survives only by word of mouth; timber is worth less than surveying, yet disaster liability stays with the owner. Owner-unknown land reached about 4.1 million hectares in 2016 (exceeding Kyushu's main island) and a projected 7.2 million by 2040, while the cadastral survey sits near 53%. This reads how the four faces of one piece of land—ownership, boundary, benefit, and liability—split apart while registration, cadastral survey, forest management, the environment tax, and treasury absorption each pursue them separately, and points to redesigning ownership.
TL;DR
- Inherited forest keeps its boundary only by word of mouth; timber is worth less than surveying, yet disaster liability stays with the owner
- Owner-unknown land was about 4.1 million hectares in 2016 (exceeding Kyushu's main island) and a projected 7.2 million by 2040, with forest land at its center
- Ownership, boundary, benefit, and liability split apart while registration, cadastral survey, forest management, the environment tax, and treasury absorption each run on their own; the base of unfixed boundaries and unclear liability does not mesh
Ownership, boundary, benefit, and liability are different faces of a single piece of land. Inheritance neglect splits them apart, and each is pursued by a separate system on its own timeline: the cadastral survey stuck near 53% (MLIT), mandatory registration from 2024, the Forest Management System from 2019, the Forest Environment Tax from 2024. Because benefit from the timber has vanished, the Forest Management System and the Forest Environment Tax socialize the carriers and the funding rather than restore the owner's profit. Liability alone stays with the owner, with little system to absorb it.
What Is Happening
Inherited forest keeps its boundary only by word of mouth; timber is worth less than surveying, yet disaster liability stays with the owner
In Imari, Saga Prefecture, a family holds about 4,300 square meters of mountain forest they inherited. As FIRST-HAND Local reports from the field, a mountain the previous generation bought for one million yen in the hope of hot-spring development is now a negative asset. Cut and sell the timber, and it does not cover the cost of surveying to fix the boundary. Yet if heavy rain brings a landslide, the liability stays with the owner.
What stands out is not the price of the mountain. It is that no one knows the boundary. Where the family's forest begins and ends, the head of the house cannot say precisely. The boundary survives only by word of mouth, and the stones once used as markers no longer serve: the trees have grown over them, and no one quite remembers which stone marked what. The next generation inherits only the liability for damage, without once having seen the mountain.
This is not Imari's misfortune alone. Land whose owner cannot be readily identified from the registry after inheritance goes unregistered, or whose owner is known but cannot be reached, is called owner-unknown land. By the estimate of the Owner-Unknown Land Problem Study Group, such land amounted, as of 2016, to about 4.1 million hectares nationwide, roughly 20% of the land, exceeding the area of Kyushu's main island. Without countermeasures, it was projected to expand to about 7.2 million hectares by 2040, approaching the area of Hokkaido. Forest land sits at the center of that feeder pool.
Background & Context
Postwar planting stalled, forestry declined, inheritance went unregistered; the cadastral survey sits near 53% as boundaries and titles blur
Why did the mountain turn into a negative asset? After the war, cedar was planted all at once under national policy. On the Imari mountains too, that cedar is now 30 to 50 years old, past the right time to cut. Yet timber prices stayed low for years, and the cost of cutting and hauling increasingly exceeded the sale price. Where the numbers do not work, no hand enters the mountain. The people who carried forestry vanished from the region. Only the untended mountain remains.
On the ownership side, neglect breeds neglect. According to the Ministry of Land, Infrastructure, Transport and Tourism's account, when inheritance repeats without dividing the estate, the number of owners to trace multiplies. Heirs across several generations line up on the title, and without everyone's consent the land can be neither sold nor lent. A mountain left unmanaged can harm its surroundings through the outflow of earth and the collapse of slopes. Even so, the administration is cautious about preventive spending on private land. The liability stays with the owner.
The boundary problem runs deeper still. The cadastral survey that officially fixes land boundaries has been completed for only about 53% of the country. And it lags especially in urban areas and in the forest land of mountain villages. A mountain with no public record of its boundary, resting on word of mouth alone, is not unique to Imari.
On registration, the system has begun to move. In April 2024, applying for inheritance registration became mandatory. Fail to register within three years of learning of the acquisition, and without a legitimate reason you become subject to a fine of up to 100,000 yen. It applies retroactively to inheritances before the effective date, requiring registration by the end of March 2027. The pressure to align titles with reality has, at last, grown stronger.
Reading the Structure
Ownership, boundary, benefit, and liability split apart, each chased by a separate system, and only liability stays with the owner
Seen as a single line, the trouble with inheriting forest land is that four faces of one piece of land—ownership, boundary, benefit, and liability—pass to the next generation still split apart. Whose land it is stays unclear. Where the boundary lies is unknown. There is no income from the trees, and yet the liability for management and disaster clings to the owner alone.
The systems chase these four separately. For tracing titles, the mandatory inheritance registration. For fixing boundaries, the cadastral survey. For carriers of upkeep, the Forest Management System, in which municipalities take management from owners, began in 2019. The municipality confirms the owner's intent and, once entrusted, connects the forest to a forestry operator or manages it itself. As its funding, the Forest Environment Tax has been levied since FY2024 at 1,000 yen per person a year and distributed to municipalities. For owners who want to let go, the system for relinquishing inherited land to the treasury opened an exit in April 2023. For forest, the fee is calculated according to area.
The systems have multiplied. But the design that ties the four faces together is thin. If the boundary is not fixed, neither the treasury-absorption review nor the management entrustment can easily proceed. That the cadastral survey has stopped at half shakes the footing of these systems that presuppose a fixed boundary. And of the four, only liability has no system to absorb it head-on. Even for an unmanaged mountain, the primary liability for disaster stays with the owner.
ISVD's question stands here. How far can the premise hold that a mountain is a private asset to be carried by an individual to the very end? Who draws the boundary, who takes the benefit, who bears the liability? Could that allocation be reassembled at the community scale? We posed the same question for farm machinery. We wrote about the structure in which each household holds machines that run only days a year, as a question of separating ownership from use. Forest land, too, lies on the same line as an object for unbundling the design of ownership.
The number of people inheriting mountains whose boundaries are unknown will keep growing. The neglect of inheritance is not one person's mistake in judgment. It is the consequence of systems that treat ownership, boundary, benefit, and liability separately, and of the thin base that should tie them together. Deciding who draws the boundary is the very practice of a social vision: how to design public assets.
Further Reading
- 人口減少時代の土地問題 (Land Problems in an Era of Population Decline) (Shoko Yoshihara, Chuko Shinsho, 2017) — the first book to address owner-unknown land head-on, tracing why inheritance is left unregistered from the side of the registration system. (In Japanese.)
- 絶望の林業 (Forestry in Despair) (Atsuo Tanaka, Shinsensha, 2019) — refuses to romanticize forestry as a growth industry and coolly exposes the structure of subsidies and thin returns. (In Japanese.)
References
Owner-Unknown Land Problem Study Group, Final Report (Summary) — Owner-Unknown Land Problem Study Group. Japan Land Planning Association
Owner-Unknown Land Guidebook: To Prevent Lost Land — Ministry of Land, Infrastructure, Transport and Tourism. Ministry of Land, Infrastructure, Transport and Tourism
On the Mandatory Application for Inheritance Registration — Ministry of Justice, Civil Affairs Bureau. Ministry of Justice
On the Forest Management System (Forest Management Act) — Forestry Agency. Forestry Agency
Forest Environment Tax and Forest Environment Transfer Tax — Ministry of Internal Affairs and Communications. Ministry of Internal Affairs and Communications
