The most comprehensive study of its kind has shown the biodiversity and ecological functions of tropical forests are generally resilient to selective logging but vulnerable if the sites are converted to oil palm plantations.
A team of scientists led by the University of Oxford and also including the UK Centre for Ecology & Hydrology (UKCEH) looked at more than 80 metrics relating to forest structure, biodiversity and ecosystem functioning – from soil nutrients and carbon storage, to photosynthesis rates and numbers of bird and bat species.
Previous research has tended to focus on a limited number of factors, making the overall impact on the whole ecosystem difficult to assess.
The new study of a range of sites in Sabah, Malaysian Borneo, found that even low levels of logging alter the ecosystem. For example, when older, larger trees are removed for timber production, this creates gaps in the canopy, enabling rapid-growing species to emerge that have very different characteristics, including less dense wood and thinner leaves that are more vulnerable to herbivores.
However, the researchers were surprised to find such a huge variability in how different parts of the ecosystem responded to deforestation, with a mixture of increases, decreases and no changes in biodiversity.
Generally, ecosystems were shown to be resilient to selective logging but converting logged forests to oil palm plantations has greater impacts on biodiversity, with larger reductions in the abundance and diversity of birds, bats, dung beetles, trees, vines and soil microorganisms. This is likely due in part to the major changes in plant food resources and the shift to hotter and drier microclimates under the single layer of oil palm that follows conversion from logged forest.
UKCEH soil biogeochemists Dr Samuel Robinson and Dr Dafydd Elias were among the co-authors of the study, published in Science,
Dr Robinson said: “It is essential that we recognise the ecological consequences of rapid forest loss in Southeast Asia due to the production of palm oil, a product widely consumed in the Western world.
“Understanding the impacts of land use change in the tropics is important for identifying priority habitats for conservation and restoration, as well as informing decisions on whether a logged forest should be protected or restored rather than converted into a plantation."
The results of the study demonstrate that logging and conversion have significantly different and cumulative environmental impacts.
The researchers point out a key message of their work is that intact well-established forests are unique, but logged forests can retain much of their biodiversity, and should not be automatically ‘written off’ and converted to plantations.
Paper information
Marsh et al. 2025. Tropical forest clearance impacts biodiversity and function whereas logging changes structure. Science. DOI: 10.1126/science.adf9856