A new study published in
Journal of Animal Ecology, conducted by researchers from the University of Oxford (UK), in collaboration with the Federal University of Tocantins (UFT), and the University of Brasília (UnB), shows how three species of lizards from the Brazilian Cerrado savannahs—one of the world's most biodiverse regions—are responding to variations in fire regimes, providing insight into mitigating human-induced environmental changes.
The Cerrado, often referred to as the "cradle of waters" in Brazil, is facing increasing wildfires (uncontrolled burns) due to deforestation and prolonged droughts caused by the global climate crisis. The study examined the ability of populations of endemic lizard species to withstand, recover, and adjust to these environmental disturbances.
The researchers analysed a remarkable 14 years of monthly monitoring data, using a sophisticated modelling approach to understand how climate and fire regimes affect key demographic processes (such as survival, growth, and reproduction) of three lizard species in the Cerrado: Copeoglossum nigropunctatum, Micrablepharus atticolus and Tropidurus itambere.
Despite having very different life strategies, these species share the same habitats, which allowed the researchers to compare and contrast how they react to fire regimes and vegetation changes caused by fire, depending on their preferences for specific microclimates and habitats.
The IBGE Ecological Reserve (RECOR), located in Brasília, was chosen for the study as it is a rare and extremely valuable example of a long-term natural experiment. Initiated in 1989, this project was designed to study the impacts of fire in the Cerrado, the most biodiverse and threatened savanna in the world. Before that, between 1972 and 1990, the area was completely protected from fires, which provided scientists with a solid foundation for understanding how ecosystems respond to different fire regimes.
The experiment, which covers 10 hectares, subjected divided plots to different prescribed fire regimes (controlled burns) that occur at specific times (early, mid, or late dry season) and with varied frequencies (every two or four years). Senior author Roberto Salguero-Gómez, Associate Professor in Ecology at Oxford Biology, says:
''Using an unprecedented dataset of monthly records on demographic rates of three lizard species with distinct life histories, and based on a quantitative framework of demographic resilience we have developed in my research group, we show how increases in fire frequency, the general trend projected for this region and many more around the world, will shape the resilience and viability of these three key lizard species''
The data investigated in this study revealed that, while lizards are more resistant in severe fire scenarios, their ability to compensate by increasing reproduction and recover to stabilised populations decreases drastically. The research suggests that intermediate fire regimes may be more beneficial for long-term resilience.
Heitor Sousa, currently a researcher from the Department of Zoology at the Institute of Biology, University of Brasília, who led the study developed at Oxford Biology as part of his PhD, added:
''In a period of intensifying environmental crises, our results highlight the importance of promoting heterogeneity in fire management, avoiding severe regimes, such as large wildfires, which homogenize the environment and harm fauna recovery."
These findings are relevant for environmental management and public policy formulation, as uncontrolled fire regimes not only threaten biodiversity but also the ecological stability of key regions like the Cerrado. Rob Salguero-Gómez added “Studying fire ecology in the Brazilian Cerrado is not merely a scientific pursuit; it is essential for understanding the ecological dynamics of one of the most biodiverse savannahs on Earth. Fire plays a pivotal role in shaping its landscapes, driving both evolutionary processes and ecosystem resilience, making its study indispensable for conservation efforts and climate change mitigation.’’ Heitor Sousa concludes
“These findings and future related works will be increasingly relevant for us to mitigate human-induced environmental changes.”
In times of unprecedented environmental challenges, scientific evidence points to the need for a new perspective on fire management and combating climate change in Brazil, as ways to ensure the survival of our biodiversity and the preservation of our most precious ecosystems.
To read more about this research, published in Journal of Animal Ecology, visit: Severe fire regimes decrease resilience of ectothermic populations - Sousa - Journal of Animal Ecology - Wiley Online Library
