Two thirds of Key Biodiversity Areas (KBAs) in tropical forests are experiencing new temperature conditions as our climate changes, research co-authored by David Edwards from the Department of Plant Sciences shows.
KBAs identify the most important places on Earth for species and their habitats.
The new study – by Exeter, Manchester Metropolitan and Cambridge universities – assessed 30 years of temperature conditions below the forest canopy in KBAs in tropical forests worldwide.
The paper, 'Identifying climate-smart tropical Key Biodiversity Areas for protection in response to widespread temperature novelty', was published in the journal Conservation Letters on 15 October.
It found that 66% of KBAs in tropical forests have recently transitioned to new "temperature regimes" with more than 40% of temperature measurements being outside the range previously recorded there.
The remaining 34% are not yet seeing new temperature regimes and the researchers suggest these places may be vital refuges for biodiversity.
Key Biodiversity Areas the most important places for tropical biodiversity conservation
"Key Biodiversity Areas are the most important places for tropical biodiversity conservation, yet just one third retain unchanged temperature regimes," said David Edwards, Professor of Plant Ecology at the University of Cambridge.
"Over half of these 'climate refugia' are unprotected, pointing to the urgent need for enhanced delimitation of protected areas to ensure climate resilience in tropical forests."
The paper is published ahead of the United Nations Biodiversity Conference (COP16) in Colombia, which begins on 21 October.
“Beneath the canopy of tropical forests, a wealth of biodiversity exists in a very stable climate,” said Dr Brittany Trew, from the Environment and Sustainability Institute at the University of Exeter.
“As such, species there are at particularly high risk from new annual temperature regimes because they have evolved under a narrow range of conditions. They may only be able to tolerate a small margin of warming above what they’re used to.”
The Post-2020 Global Biodiversity Framework includes a draft target that at least 30% of land area globally is conserved by 2030 – and specifically identifies KBAs as a core priority for this.
KBAs do not automatically receive formal protection. This is decided by national governments in the areas identified.
The paper highlights that – of the 34% of tropical forest KBAs not seeing new temperature regimes – more than half are not currently protected.
'Climate-smart' policies needed to protect remaining refuges
“We need ‘climate-smart’ policies that protect these vital refuges,” Dr Trew said.
The researchers used temperature measurements, satellite data and a microclimate model to assess near-ground hourly temperatures across the world’s tropical KBAs.
The proportion of KBAs in Africa and Latin America with new temperature regimes was particularly high (72% and 59%), while fewer KBAs across Asia and Oceania shifted to new temperatures (49%).
Some KBAs across Latin America (2.9%) – and a small number in Asia and Oceania (0.4%) – have recently transitioned to almost entirely new temperature regimes (more than 80% of temperature measurements outside the previous range.
In Latin America, these KBAs were all located in Ecuador, Colombia, Venezuela or Panama, with the tropical Andes particularly affected.
Reference: Brittany T. Trew et al., ‘Identifying climate-smart tropical Key Biodiversity Areas for protection in response to widespread temperature novelty’. Conservation Letters (2024). DOI: 10.1111/conl.13050
Image: 66% of tropical forests have transitioned to novel temperature regimes, including hyperdiverse cloudforests in the Colombian Andes. Photo by David Edwards.
Adapted from a press release by the University of Exeter.