Japan Plans to Cut Sugi Tree Plantations by 20 Percent to Reduce Pollen

Japan is addressing widespread seasonal allergies linked to large-scale tree planting that began after World War Two. Government data show that 43 percent of the population experiences medium to severe hay fever symptoms each spring, compared with 26 percent in the UK and 12-18 percent in the US.

After wartime fuel shortages led to widespread deforestation, officials planted only Japanese cedar, known as sugi, and Japanese cypress, known as hinoki, across roughly 10 million hectares. These fast-growing species now cover one-fifth of the country's land area and release large volumes of lightweight pollen that drifts into urban areas.

The trees matured around 30 years ago and now produce more pollen each spring. 6 billion per day at the height of the season.

2023 the central government declared allergies a national social problem and set a target of reducing pollen levels by 50 percent within 30 years. The first step calls for cutting sugi plantation area by 20 percent while replacing removed trees to prevent soil erosion.

Local projects are already underway. Kobe city has selectively cleared more than 180 hectares of plantation forest and reports increased sightings of badgers, pond turtles, frogs and insects. The town of Nishiawakura has converted hinoki and sugi wood into heating fuel for eel farms and other products.

Officials say the work also supports goals to expand protected natural areas and reduce landslide risks linked to climate change.