New tool helps forest restoration schemes include overlooked plants vital to biodiversity
New study from the University of Birmingham suggests that by planting trees alone, we are leaving out a vast and fragile slice of the world's biodiversity
Image by Kanenori from Pixabay
When forests are restored, the focus tends to fall on trees. But a new study from the University of Birmingham suggests that by planting trees alone, we are leaving out a vast and fragile slice of the world's biodiversity.
Vascular epiphytes - plants such as orchids, bromeliads and ferns that grow on other plants rather than in soil - account for around nine per cent of all vascular plant species on Earth. In tropical forests they can make up more than a third of local species. Yet they are almost never included in restoration schemes, and until now, there has been little guidance on how to reintroduce them successfully.
The research, published in the Journal of Applied Ecology, used three-dimensional virtual forests to simulate how epiphyte communities develop under different restoration conditions - testing variables like the age of the host forest and the size and age of the plant populations being introduced. Rather than waiting years for real-world trial results, the team could run thousands of virtual scenarios and identify what works.
The headline finding is that introducing adult plants into older forests - those aged 20 to 40 years - retains the most species overall. But the research also found that different types of epiphytes need different strategies. Faster-growing, light-loving species do better when planted at high densities in younger forests of five to ten years old, while slow-growing, heavy species fare best in more mature stands.
These plants are a vital part of tropical forest ecosystems, but they are almost invisible in current restoration frameworks. This research gives practitioners practical, evidence-based guidance for including them.
The findings matter beyond the lab. Global targets under the Kunming-Montreal Global Biodiversity Framework and the Bonn Challenge are calling for hundreds of millions of hectares of forest to be restored by 2030. If epiphytes continue to be left out, the world risks rebuilding the structure of a forest without recovering its full biodiversity.
The study was led by PhD researcher Zachary Chu from the University of Birmingham's School of Biosciences, in partnership with the Royal Botanic Gardens, Kew. The team also included researchers from the University of Birmingham's Advanced Research Computing centre, the School of Geography, Earth and Environmental Science, the International Institute for Applied Systems Analysis (Austria), and the University of Bonn.
The research was funded by the Natural Environment Research Council (NERC), the Royal Botanic Gardens, Kew, and the Swedish Research Council.