The departure of people from rural areas does not always allow Nature to recover. In Japan and parts of Europe, studies have found that biodiversity can decline when communities shrink and traditional land management stops, challenging the assumption that abandoned landscapes inevitably benefit wildlife.
A study led by ecologist Kei Uchida of Tokyo City University examined records for 464 bird, butterfly, firefly and frog species, along with nearly 3,000 plant species, across Japanese landscapes. The data covered periods of five to 17 years beginning in 2004. Biodiversity fell in places undergoing development or more intensive agriculture, but researchers also found declines where people had left.
In landscapes around Mount Tenran, volunteers help maintain forests, rice paddies and meadows. These activities support habitats for species including the Eurasian harvest mouse and two kinds of firefly. For centuries, people in the region cut trees and cleared fallen leaves, keeping woodland relatively open. Without that activity, forests can become denser and lose conditions that benefit some plants and insects.
The loss of people can also bring practical changes to habitats. When irrigation stops, amphibians and many insects may lose the conditions they need to reproduce. Abandoned land can become dry and fragmented, making it harder for species to return. Similar patterns have been reported in Albania, Bulgaria, Croatia and Greece, where rural abandonment was associated with negative effects on bird communities, particularly farmland species.
Other examples show how wildlife relies on landscapes shaped by people. In Sweden, semi-natural grasslands maintained by livestock provide habitat for many threatened species, but their area has fallen sharply in some regions as rural land use changed. In Spain, declining livestock numbers can reduce food for vultures and other scavengers, while the removal of field borders and dry-stone walls can eliminate shelter for wildlife.
Researchers say the effects depend on the species and the place. Some benefit from rice fields, grazing, mowing or forest edges, and many rely on a varied landscape maintained by occasional, low-intensity activity. But there is no universal rule: top predators such as wolves may fare better where people are absent, and in tropical regions habitat loss remains a more urgent concern than depopulation.
The findings point to a conservation challenge in countries where rural populations are falling. Researchers have proposed supporting small-scale farming and maintaining habitats through local stewardship, alongside approaches that allow nature to develop with less intervention. In some ecosystems, conservation may depend not only on protecting land, but also on sustaining the people and practices that have helped shape it.
Sources: Nature.