Posted by Ted Feldpausch
1 March 2025Our new study published in the journal Science reveals a concerning trend, that tropical forests across the Americas are changing their composition and function too slowly to keep up with the pace of climate change. This mismatch puts these important ecosystems, biodiversity hotspots, and carbon sinks at significant risk.
The study was led by Dr. Jesús Aguirre-Gutiérrez and included researchers from the University of Exeter, and a large network of over 100 researchers from the UK and local partners. Using long-term ecological dataset spanning decades from 415 permanent forest plots, we assessed the rate of change in tree communities and forest traits in more than 250,000 trees across diverse tropical forests from South America to Mexico. We compared this ecological change rate to the climate change rate in these regions, focusing on factors such as temperature and rainfall patterns.
The study’s findings indicate a significant disconnect, where forests are not shifting their species composition or functional traits (characteristics that influence tree growth, survival, and ecosystem processes) quickly enough to track the rapid changes in climate. This slow pace of adaptation means that many tree species may be unable to thrive under future climate conditions, potentially leading to forest decline, loss of biodiversity, and reduced carbon sequestration capacity.
“We have shown from previous research that tropical forests are resilient to impacts—if the disturbance is not persistent and forests are given time to recover. But our current study shows they are not adapting quickly enough to the unprecedented recent rate of climate change in terms of shifting their key functional traits affecting plant physiology,” explains Dr. Ted Feldpausch, Professor of Tropical Ecology and Global Change at the University of Exeter and co-author on the study. “These traits have changed at only 8% of the pace needed to keep pace with climate change over the past four decades. The slow rate of adaptation has serious consequences for biodiversity and the role these forests play in global carbon cycling and storage. Urgent action is needed to protect these irreplaceable ecosystems.”
Figure: Mechanisms driving changes in community trait composition and climate tracking.
The research emphasise that the consequences of this slow adaptation are far-reaching. Tropical forests play a key role in regulating global climate by absorbing large amounts of carbon dioxide from the atmosphere. If these forests are unable to adapt and thrive, their capacity to store carbon could be compromised, potentially accelerating climate change. Furthermore, the loss of tree species and changes in forest composition will have effects throughout the food web, threatening the high biodiversity of the tropical forests.
The study highlights the urgent need to develop conservation strategies that go beyond simply preventing deforestation. This requires a shift towards proactive management approaches that consider climate adaptation, including strategies to maintain forest connectivity, and reduce other stressors like habitat fragmentation and wildfires.
Our research implies that the fate of these tropical forests is linked to global efforts to mitigate climate change. Reductions in greenhouse gas emissions are essential to slow the rate of climate change and give tropical rainforests time to adapt.
Reference
Jesús Aguirre-Gutiérrez et al., Tropical forests in the Americas are changing too slowly to track climate change. Science. 387, (2025). DOI:10.1126/science.adl5414. https://www.science.org/doi/10.1126/science.adl5414