Research shows: Degraded rainforests retain considerable value

The findings challenge the common perception of these forests as ecological wastelands. Instead, they reveal clear thresholds at which proactive and reactive conservation efforts can be most effective.

The research involved scientists from 85 organizations around the world, including several staff and students from the School of Biological and Behavioural Sciences at Queen Mary University of London. Data were analyzed on over 1,600 species from 86 taxonomic orders and 126 functional groups in a rainforest in Malaysian Borneo that had been deforested to varying degrees.

The study revealed a surprising value of forests that have experienced little deforestation. Even areas that have lost up to 30% of their trees still have impressive biodiversity and function ecologically, suggesting that these areas could be an immensely valuable addition to conservation efforts.

Research has also highlighted two critical points for targeting conservation strategies. When less than 30% of biomass is lost, proactive measures such as creating protected areas prove most effective. However, for areas that have suffered greater losses, i.e. more than 68% biomass loss, a change in approach is needed. This is where restoration measures such as planting new trees and controlling invasive species become more important.

Dr Pavel Kratina, Senior Lecturer in Ecology, explained: “Our group investigated how the foraging interactions of bat predators change across the gradient of rainforest degradation. The data on bat communities that we contributed to the study provided an important piece of the puzzle in understanding how deforestation affects entire food webs. One of the findings of the study is that foraging specialists are disproportionately more affected by selective deforestation than generalist predators.”

Professor Stephen Rossiter, whose PhD students conducted fieldwork on site, added: “By providing data on population densities of leeches, arthropods and bats, our results have helped to reveal a complex picture of contrasting responses to forest degradation and complement the overall findings of the study.”

Dr Tom Fayle, Senior Lecturer in Ecology, explains their contribution: “Ants are an ecologically important group in tropical forests. They dig up the soil, form mutualisms with some species and eat others. We have been studying how ant communities respond to habitat degradation. Bringing together data on different species groups from so many different research groups makes this study particularly exciting and is something that has not been attempted on this scale before.”

All these contributions from different research groups show that although degraded forests cannot be compared to pristine primary forests, they still have considerable value for nature conservation.

The study calls for a change in the perception and management of these forests. By recognizing their remaining value and implementing targeted protection strategies, we can ensure the health and functionality of these vital ecosystems for years to come.