08.07.2025 | Luiz Felipe Fernandes, Universidade Federal de Goiás | WSL News
A study published in Science and led by the Swiss Federal Research Institute WSL shows a clear link between energy availability in ecosystems and the biodiversity of terrestrial vertebrates. This provides a more solid basis for predicting how biodiversity might respond to climate change.
An international team of scientists led by the Swiss Federal Research Institute WSL has found new answers to one of the most fundamental questions in ecology: Why do some regions harbour more species than others? The study, which has just been published in the journal Science, shows that there is a clear link between the availability of energy in the environment (such as temperature and precipitation) and biodiversity, especially when these factors are analysed independently of geography.
For decades, ecologists have assumed that warmer, more humid environments tend to harbour more species because they are more productive. However, empirical data does not always confirm this idea, and the results vary greatly depending on the region and organism group.
The researchers therefore proposed a new approach: Instead of comparing neighbouring regions on the map, they grouped together areas with similar climates, even if they are on different continents. "Instead of analysing the Earth as a conventional map with latitudes and longitudes, we began to depict it on the basis of climate, for example with temperature and precipitation as the main axes," explains WSL researcher Marco Túlio Pacheco Coelho, first author of the article.
This means that distant locations with the same climate type - for example, hot and humid - are now analysed together. The Amazon, Congo, Madagascar and Papua New Guinea, although located on different continents, have similar climates and are considered as a single environmental type in this new model. "This new method has finally allowed us to isolate the pure effects of climate, such as temperature and precipitation, on biodiversity. Now the patterns are no longer confusing," adds Marco Túlio Pacheco Coelho.
The results show that in similar climates there is a direct correlation between the available energy and the number of species, especially in ectothermic animals such as reptiles and amphibians, which are more dependent on the ambient temperature. In this context, the research also confirmed one of the most important predictions of the metabolic theory of ecology (MTE), according to which species diversity increases with temperature in proportion to the available metabolic energy.
The research collected data on more than 30,000 species of terrestrial vertebrates (birds, mammals, amphibians and reptiles) and involved institutions from Brazil, Switzerland, Sweden, the United Kingdom, the United States and the Czech Republic.
The role of precipitation ¶
In addition to temperature, the researchers also included other factors in the model, encompassing precipitation, primary productivity and spatial characteristics of climate zones, such as their extent on the planet and their degree of isolation. The analysis revealed that while precipitation is fundamental to the productivity of ecosystems, excess precipitation can have a negative impact on diversity by favouring more competitive species. "This can reduce coexistence and consequently diversity," say the researchers.
Another important finding of the study is that warm climate zones tend to occupy larger areas, while humid and highly productive climate zones occur less frequently. This difference has a direct impact on diversity. "The area and isolation of the individual climate types explain how many species manage to evolve, disperse or survive in these environments," emphasises Marco Túlio Pacheco Coelho.
According to the authors, the study provides a more precise basis for predicting how biodiversity might respond to climate change. Controlling for geographical effects allows researchers to more clearly recognize the role of energy availability in shaping life on Earth.
Contact ¶
Publication ¶
Marco Túlio P. Coelho et al., Consistent energy-diversity relationships in terrestrial vertebrates. Science 389, 53-57 (2025). DOI:10.1126/science.adu2590
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