Restored forests and wetlands often lack tiny but vital species
Research shows that while trees and wildlife return to regenerated forests and wetlands, many small organisms such as mosses, lichens, algae and fungi remain absent for decades.
A new study published in Nature Sustainability reveals that restored habitats often look healthy while their smallest inhabitants lag behind. In boreal forests, birch and aspen stands typically bounce back within 25 years, yet conifer forests may take 85 years or longer for understory plants such as lichens, mosses and liverworts to return, and some sites show no recovery over a century of data. Parallel investigations of reclaimed wetlands in southern Germany found abundant birds and insects but a stark loss of desmid algae diversity.
Researchers describe this hidden loss as "dark diversity," where species vanish from local sites without being globally extinct. The missing micro-organisms play crucial ecological roles, influencing oxygen production and nutrient cycles, and their absence can ripple through ecosystems. Findings suggest that forest management should favor partial or selective logging and that landscape-scale restoration is needed to sustain these subtle yet essential species.
Why it matters
Small organisms underpin ecosystem health, so their loss can undermine the benefits of forest and wetland restoration.
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