New tool maps hidden roles and risks in ecosystems

[Vienna, July 10, 2025] – Do you think you know which species are most vulnerable in an ecosystem? A novel analytical method developed by Italian physicists at the Complexity Science Hub (CSH) suggests there's more to discover. In their recent study, they found out how species like lizards and rabbits in South Florida's cypress wetlands are among their ecosystem's most at-risk species, pointing to vulnerabilities that aren't always obvious.

The study, published in Chaos, Solitons & Fractals, introduces an innovative tool to map and measure species' ecological roles and vulnerabilities. Compared to traditional models, it performs similarly or better, especially in identifying species at the most significant risk of extinction.

“We were able to reconstruct ecological roles entirely through network data, without requiring any biological knowledge on our part,” notes first author Emanuele Calò. “This makes the method particularly promising for large-scale biodiversity assessments and ecosystem management, especially in regions where ecological expertise or detailed field studies are limited,” adds Calò, from IMT School for Advanced Studies Lucca.

As a visiting student at CSH, Calò developed the new method with CSH researcher Vito D. P. Servedio and CSH junior fellow Giordano De Marzo.

A Data-Driven Approach

As ecosystems worldwide face mounting pressures from climate change, habitat loss, and overexploitation, conservationists urgently need better tools to prioritize species protection, point out the researchers. “Our data-driven approach provides a valuable, complementary, and cost-effective layer of insight.”

For instance, by pinpointing keystone species—those whose loss risks triggering wider coextinctions—the new approach might enable conservationists to direct limited resources and protective measures where they can make the most difference.

Dual Role: Predator and Prey

“With our method, we wanted to disentangle the dual role that every species plays, both as predator and prey,” explains De Marzo, also a postdoctoral researcher at the University of Konstanz. “The existing measures tend to compress these interactions into a single number, but ecosystems are more complex than that. Our approach captures both directions in the food web, allowing us to understand which species are keystone and most vulnerable.”

Using real-world data from six ecosystems, including the Florida Bay cypress and Coachella desert ecosystems, their method assigns every species two scores: importance, which captures how many others depend on a species as a food source; and robustness, which reflects how likely a species is to survive based on how flexible and successful it is at finding food.

Phytoplankton, Lizards, Rabbits, and Alligators

This bidimensional mapping revealed hidden vulnerabilities and keystone species with remarkable clarity. In the example of the Florida Bay cypress food web, it pinpointed high-importance species, such as phytoplankton, which often trigger widespread co-extinctions if removed, and high-robust species, including alligators, which tend to survive longer through ecosystem collapse due to diverse diets and low vulnerability to predation. 

In addition, the new framework identifies low-robustness species, such as lizards and rabbits. Even if marginal to the food web, these are still at significant risk of extinction, pointing to hidden vulnerabilities often overlooked in conservation planning.

Interdisciplinarity

"What we found particularly striking in our research was how economic complexity methods could be directly applied to ecological systems. When you mention using economic tools to study ecology, people often raise their eyebrows: these seem entirely unrelated. But that's precisely what makes complex systems science so powerful,” says Servedio.

“The mathematical frameworks we use to understand how countries develop competitive advantages in global trade networks can reveal how species interact and coexist within ecosystems,” explains the CSH researcher. This demonstrates that complex systems often share these underlying structural patterns, whether about economies or ecosystems. So while the context is different—in the new study, the researchers are looking at species instead of industries, habitats instead of markets —, the fundamental network dynamics are remarkably similar.

“This kind of methodological transfer is becoming increasingly important in our field. Some of our most significant insights come from borrowing tools from seemingly unrelated disciplines and discovering these unexpected connections," concludes Servedio.
 

About the Study

The paper “Species vulnerability and ecosystem fragility: A dual perspective in food webs,” by Emanuele Calò, Giordano De Marzo, and Vito D. P. Servedio was published in Chaos, Solitons & Fractals and is available online (https://doi.org/10.1016/j.chaos.2025.116741).

About CSH

The Complexity Science Hub (CSH) is Europe’s research center for the study of complex systems. We derive meaning from data from a range of disciplines – economics, medicine, ecology, and the social sciences – as a basis for actionable solutions for a better world. CSH members are Austrian Institute of Technology (AIT), BOKU University, Central European University (CEU), Graz University of Technology, Interdisciplinary Transformation University Austria (IT:U), Medical University of Vienna, TU Wien, University of Continuing Education Krems, Vetmeduni Vienna, Vienna University of Economics and Business, and Austrian Economic Chambers (WKO).