New temperature conditions discovered in two-thirds of major tropical forests

According to research, two-thirds of key biodiversity areas (KBAs) in tropical forests are experiencing new temperature conditions as our climate changes.

KBAs identify the places on Earth that are most important for species and their habitats.

The study, carried out by the universities of Exeter, Manchester Metropolitan and Cambridge, assessed 30 years of temperature conditions under the forest canopy in KBAs in tropical forests around the world.

It found that 66% of tropical forest KBAs have recently shifted to new “temperature regimes” (with more than 40% of temperature measurements being outside the previously recorded range).

The remaining 34% are not yet experiencing new temperature regimes – and researchers suggest these places could provide vital refuges for biodiversity.

The article, published in the journal Conservation lettersis titled “Identifying key climate-smart tropical biodiversity areas to protect in response to widespread temperature change.” » It is published ahead of the United Nations Conference on Biodiversity (COP16) in Colombia, which begins on October 21.

“Beneath the canopy of rainforests, a wealth of biodiversity exists in a very stable climate,” said Dr Brittany Trew, from the Institute of Environment and Sustainability at the Penryn campus in Exeter, Cornwall.

“As such, the species are at particularly high risk from new annual temperature regimes because they have evolved within a narrow range of conditions. They may only be able to tolerate a small margin of warming above what they are used to.”

The Post-2020 Global Biodiversity Framework includes a draft target that at least 30% of the world’s land area will be conserved by 2030 – and specifically identifies KBAs as a key priority in this regard.

Dr Alexander Lees, Reader in Biodiversity at Manchester Metropolitan University, said: “The amount of political and economic capital devoted to safeguarding biodiversity is woefully insufficient.

“Our results show that the painful process of conservation triage – selecting new protected areas – must therefore take into account the impact of ongoing climate change on these sites in prioritization assessments.”

KBAs do not automatically benefit from formal protection – this is decided by national governments in identified areas.

The document highlights that, of the 34% of tropical forest KBAs that are not experiencing new temperature regimes, more than half are not currently protected.

“We need ‘climate smart’ policies that protect these vital refuges,” said Dr Trew.

The researchers used temperature measurements, satellite data and a microclimate model to assess hourly near-ground temperatures in 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 in Asia and Oceania adopted new temperatures (49%).

Some KBAs in Latin America (2.9%) – and a small number in Asia and Oceania (0.4%) – have recently migrated to almost entirely new temperature regimes (more than 80% of temperature measurements fall within outside the previous range).

In Latin America, these KBAs were all located in Ecuador, Colombia, Venezuela or Panama, with the tropical Andes particularly affected.