Japan’s Forestry Agency has confirmed an abundant beech flowering across 145 monitoring sites in five Tohoku prefectures, signalling that the autumn nut harvest is on track to exceed 2025’s extreme collapse and could keep bears inside the forest after a year of attacks that pushed the animals into residential streets and farmland across north-eastern Japan.
That is according to the Tohoku Regional Forest Office, which released its 21 April flowering survey from a national forest in the city of Akita, as Mainichi journalist Akira Kudo reported from the Akita Bureau, with foresters examining canopies at sites spread across Aomori, Iwate, Miyagi, Akita and Yamagata.
“Last year, when the crop was extremely poor, there were hardly any flowers, but this year’s flowering is more abundant,” a Tohoku Regional Forest Office officer told Mainichi after surveying canopies at the Nibetsu national forest in Akita, where male and female flowers were visible at the tips of branches.
Wood Central understands that the survey covers 145 sites across the five Tohoku prefectures, with 55 in Akita alone, and that the office will return in autumn to weigh actual nut production against the spring-flowering signal.
Beech mast cycles in Tohoku have run on a punishing every-other-year rhythm in recent years, with the autumn harvest averaging or falling to poor in 2022, extremely poor in 2023, abundant or average in 2024, and extremely poor again in 2025. In the lean years, reported bear sightings and human injuries have climbed sharply across the region.
Beech nuts are the primary autumn food source for Japanese black bears, and poor mast years drive animals out of the forest in search of calories before winter, often into the residential and urban fringes of Tohoku towns, where encounters with humans have resulted in fatalities and serious injuries in successive poor years.
Beech is a masting species, Fagus crenata in Japan, with trees synchronising heavy seed production in occasional mast years between lean ones, and the Tohoku Regional Forest Office monitors this cycle from spring flowering to autumn yield across its five-prefecture jurisdiction.
Forestry officers inspected the upper canopy through binoculars from the roadside in the Nibetsu national forest, scanning for the male and female flower clusters that emerge at the tips of beech branches in late April and serve as the most reliable spring indicator of autumn yield.
The Tohoku Regional Forest Office will return to the same 145 sites in autumn to count actual nut production, the second leg of the seasonal monitoring routine that flagged the 2025 mast collapse months before bears began appearing in residential streets across the five-prefecture region.
