As the Japanese countryside is emptied, the wildlife disappears.
The Japanese population is declining, but the downward trend is particularly pronounced in rural areas. Loss of people may lead to a resurgence of wildlife. But paradoxically, where farms are abandoned, wildlife also disappears.
Researchers say small farms in the Japanese foothills have created mosaic landscapes with rice paddies, open pastures and scattered woodlands that provide homes for many types of wildlife. Where humans cut down trees for firewood and collected leaves for fertilizer, they made way for orchids and azaleas, Nature reports. Where farmers dug up rice fields, they made a home for rice fish and haiki fireflies. By and large, many species found on farms co-evolved with humans, scientists say.
A 2025 study from Japan found that biodiversity was only stable in places where the human population was also stable. In areas where the population has declined, researchers have recorded a decrease in the abundance of butterflies, fireflies, frogs, birds and native plants.
The trends in Japan mirror those in many other countries, from Spain to China, where rural areas are being emptied as people move to cities in search of work. Landscapes shaped by people are being reclaimed by nature, but often to the detriment of species that were dependent on human care.
A recent study of the Lake Constance region in the European Alps found that plant diversity peaked in the medieval era, when small farms created patches of fields, pastures and forests that supported a greater variety of plants than the closed forests that preceded it or the industrial farms that did.
"The broader lesson is that in modern conservation, the choice is not just between agriculture and biodiversity," said lead author Adam Spitzig, a PhD candidate at Stanford University.