Noncertified logging concessions in Gabon have much quieter soundscapes, a proxy for vocalizing wildlife, than either national parks or sustainably logged concessions, according to a recent study. However, forests that have never been logged are home to the highest diversity of vocalizing wildlife, researchers found.
“Therefore, conserving these increasingly rare never logged forests, in combination with forest certification, is vital to effectively protect wildlife in the Congo Basin,” study lead author Natalie Yoh, a postdoctoral researcher at the University of Kent, U.K., told Mongabay in an email.
Roughly 90% of Gabon is covered in forest, making it one of the most forested countries in the world. It has a network of protected areas and logging concessions, some of which are certified by schemes like the Forest Stewardship Council (FSC), which aim to encourage logging practices that reduce harms to biodiversity compared to noncertified concessions.
To find out how wildlife respond to logging, the researchers decided to listen to animals in different forest types. They deployed acoustic recorders at 110 sites across three national parks and six selective logging concessions (three FSC-certified and three noncertified). Additionally, they placed recorders in a proposed community reserve located in an unlogged part of a noncertified concession. The community area is managed by the Kota community of Massaha.
At each site, the scientists measured the soundscape saturation, with 100% indicating the site is full of sounds and has a high diversity of vocalizing animals, and 0% meaning the forest is silent, Yoh said.
The study found that noncertified concessions had the lowest soundscape saturation among all the forest types.
“This is certainly an interesting, if not surprising, finding, which can help promote the wider use of certified logging concessions in Central Africa,” Christos Astaras, a wildlife researcher at the Forest Research Institute in Greece, who wasn’t involved in the study, told Mongabay.
However, Astaras cautioned that the study had deployed recorders in a relatively small number of certified and noncertified logging concessions, three each. Every logging concession follows certification regulations to a different extent, so “it would be great if the study is expanded to a larger subset of logging concessions,” he said.
Gabon’s national parks have some logging history too. Most were established in retired concessions last logged 20 to 40 years ago, the authors write. The study found that these parks had greater soundscape saturation compared to recently logged concessions, suggesting that animal communities can recover once logging stops. But the parks were still quieter than the few never-logged, old-growth sites within the proposed community reserve. In effect, forests that have been “resting” for decades still do not sound quite the same as forests that have never been industrially logged, Yoh said.
This suggests that logging activity has a “lasting legacy” on the soundscape, the researchers write.
Banner image of western lowland gorilla by Rhett A. Butler/Mongabay.