Inside Biodiversity

In this episode, Prof. Marten Scheffer from Wageningen University & Research explains critical transitions and tipping points, from shallow lakes and coral reefs to tropical rainforests. Together with host Dr. Volker Hahn, he explores whether local tipping points can be scaled up to a biospheric planetary boundary, and how uncertainty shapes our understanding and communication. Scheffer explains why he believes the concept of tipping points remains relevant for policy and management—even when we do not know where they lie.

Related links:

Marten Scheffer on Wikipedia:

“Critical Transitions in Nature and Society”, Marten Scheffer’s influential book from 2009: https://www.degruyterbrill.com/document/doi/10.1515/9781400833276/html

Two influential planetary boundary papers co-authored by Marten Scheffer

“Tipping out of Trouble”, Marten Scheffer’s new book: https://www.cambridge.org/tc/universitypress/subjects/history/global-history/tipping-out-trouble-how-societies-transformed-and-how-we-can-do-so-again

Host: Dr. Volker Hahn, Head of Media and Communications at iDiv

Are there tipping points in ecosystems — and if so, can we detect them before the system tips? In this episode of Inside Biodiversity, host Volker Hahn talks with Helmut Hillebrand, professor at the University of Oldenburg and the Helmholtz Institute for Functional Marine Biodiversity, about the science and the politics behind thresholds, regime shifts, and planetary boundaries.

Hillebrand explains why predicting tipping points in ecosystems is so difficult, what his global meta-analysis revealed about abrupt versus gradual change, and why applying “safe operating spaces” to biodiversity might do more harm than good. Together, Hillebrand and Hahn explore what this means for environmental policy — and for how we think about the resilience and value of life on Earth.

“Thinking about biodiversity in binary ways—about below and above the threshold—is the wrong way of thinking about how biodiversity works and how we rely on it”, says Hillebrand.

Related links:

Helmut Hillebrand at the University of Oldenburg:

Hillebrand’s meta-meta-analysis discussed in this episode: “Thresholds for ecological responses to global change do not emerge from empirical data”

Essay paper – mentioned in this episode – which conceptualises Hillebrand’s criticism of the tipping narrative: “Thresholds and tipping points are tempting but not necessarily suitable concepts to address anthropogenic biodiversity change—an intervention”

Paper, which introduced Human Appropriation of Net Primary Productivity (HANPP) as the control variable for the Functional Biosphere Integrity Planetary Boundary – discussed in this episode: “Earth beyond six of nine planetary boundaries”

Host: Dr. Volker Hahn, Head of Media and Communications at iDiv

Not every species introduced by humans becomes a problem – but some do, especially on islands. In this episode of Inside Biodiversity, invasion biologist Marten Winter (iDiv and Leipzig University) explains how we define alien vs. invasive alien species, why the raccoon is a management challenge for Europe, and why management is particularly tricky in places like Australia. We also discuss the ethical dilemmas of controlling species such as the red fox – and whether it is possible to identify non-native species without knowing their origin.

Related links:

Dr Marten Winter on the iDiv website:

“How we move (alien) species around the world” – TEDx talk:

“Don't judge species on their origins” – This comment in the journal Nature sparked several contesting replies:

IPBES Invasive Alien Species Assessment: Summary for Policymakers:

Host: Dr. Volker Hahn, Head of Media and Communications at iDiv

What should we really aim for in nature conservation—and who gets to decide?

Related links:

Emma Marris’s popular science books

Perspective paper “Ecosystem integrity is neither real nor valuable” (2021)

Media article “Inevitable Planetary Doom Has Been Exaggerated“ (2021)

Media article “Nature Doesn’t Care Where a Species Is From“ (2024)

Host: Dr. Volker Hahn, Head of Media and Communications at iDiv

Why has biodiversity decreased over the past 20 million years? Why did large mammals, such as giant sloths, tapirs, and mammoths, go extinct at the end of the last ice age, some 50,000 to 10,000 years ago? Why are there many fewer mammal species today than there “should be”?

In this episode, we speak with Prof. Susanne Fritz, research group head at iDiv and the Friedrich Schiller University Jena, about biodiversity change over very long time scales. She shares insights into how past extinction events shaped today’s ecosystems — and what that might mean for the future.

“Maybe we’re still in kind of the recovery from this extinction, maybe there is speciation ongoing, if we let it run for long enough, there would be large mammals again”, says Prof. Fritz.

Join us for a fascinating conversation about evolutionary history and biodiversity change over very long time scales, and what lessons we might be able to draw from the past and apply when looking at biodiversity today.

Related links:

Prof. Dr. Susanne Fritz at iDiv:

Paper on mammalian diversity change:

Paper on past mammalian body size change:

Paper on bird migration:

Paper on future bird diversity change:

Host: Dr. Volker Hahn, Head of Media and Communications at iDiv

While some biodiversity change trends are deeply worrying, such as the decline of common bird species in North America, others offer hope, such as the recovery of rare birds: “I've seen in my lifetime species that were locally extinct come back, and rivers that were dead come back to life,” says Inside Biodiversity guest Henrique Pereira. “And that's because there's been so much positive development from environmental policy in Europe and in other countries in the world.”

In this episode, we explore why biodiversity change isn’t a single story of loss and why it is important to understand the complexity of the issue for science, communication, and policy.

Other topics we cover:

Join us as we discuss these issues with Professor Henrique Pereira, research group leader at iDiv and the Martin Luther University Halle-Wittenberg.

Links:

Prof. Dr. Henrique M. Pereira at iDiv:

Science paper on biodiversity trends and scenarios:

Public talk about rewilding European landscapes:

Host: Dr. Volker Hahn, Head of Media and Communications at iDiv

Is biodiversity loss always bad? What if cutting down an old-growth forest actually increases the number of species? According to biodiversity researcher Jonathan Chase, “You can have huge levels of biodiversity in habitats that are strongly degraded by people.”

In this episode, we explore how biodiversity changes can be counterintuitive, and why measuring it is more complicated than just counting species. If biodiversity isn't inherently good or bad, then what do we—as individuals and as a society—value about nature? We discuss these questions in this episode of Inside Biodiversity with Jonathan Chase, professor at iDiv and the Martin Luther University Halle-Wittenberg.

Other topics discussed include:

Links:

Professor Jonathan Chase at iDiv:

Paper on “detection and attribution” in biodiversity research, discussed in this episode:

TEDx talk by Jonathan Chase, “Biodiversity scientists as honest brokers or advocates?”:

Host: Dr. Volker Hahn, Head of Media and Communications at iDiv

In this episode of Inside Biodiversity, we talk to Andrew Gonzalez about how biodiversity is changing – and how humans are driving this process. Gonzalez discusses shifts in species composition, critiques conclusions drawn from time-series analyses we covered in episode one, and calls for better data to link changes to human impacts. Drawing on climate science, he proposes a “detection and attribution” approach and urges scientists to focus on solutions. A thought-provoking look at the science and communication of biodiversity change.

Links:

Professor Andrew Gonzalez’s profile at McGill University: https://www.thegonzalezlab.org/about-andrew-gonzalez

Paper critiquing analyses of time-series data, which have suggested biodiversity is not declining at local scales:

Paper on “detection and attribution” in biodiversity research, discussed in this episode:

Episode summary:

Andy Gonzalez, a biodiversity scientist at McGill University, explores the complexity of biodiversity change and urges caution against oversimplified narratives of biodiversity decline. He acknowledges that while extinction is real and alarming, biodiversity is not uniformly decreasing — many local communities are experiencing reorganization rather than outright loss, with changing species compositions and shifting abundances.

Gonzalez critiques time-series data analyses we discussed in episode one for their geographic and taxonomic biases and argues that we lack a truly global, representative understanding of biodiversity trends.

Drawing inspiration from climate science, he promotes a “detection and attribution” framework to better link observed biodiversity changes to human drivers.

Gonzalez stresses the need for standardized, long-term data collection and a focus on causal understanding. Gonzalez also highlights the importance of shifting communication from loss to actionable solutions, suggesting that focusing solely on negative trends risks alienating the public. Instead, he calls for a balanced, evidence-based narrative that recognizes both the challenges and potential of biodiversity conservation.

Host: Volker Hahn

In this episode of Inside Biodiversity, we look at one of the most controversial questions in biodiversity research: How ubiquitous is biodiversity loss? Our guest, Maria Dornelas, has challenged overly simplistic narratives of how biodiversity is changing. We discuss the current state of knowledge and how best to communicate it. Whether you are a sceptic or an advocate of biodiversity conservation, this conversation will give you new insights into the fascination and complexity of biodiversity change.

Maria Dornelas is a Professor at the University of St Andrews and the University of Lisbon, specializing in global biodiversity patterns, species diversity, and ecological change. Her research challenges common assumptions about biodiversity loss, using long-term data to reveal complex trends.

Links:

Maria Dornelas’s profile at the University of St Andrews: https://www.st-andrews.ac.uk/biology/people/maadd

Controversial paper discussed in this podcast episode: Assemblage Time Series Reveal Biodiversity Change but Not Systematic Loss https://www.science.org/doi/10.1126/science.1248484

Recent review paper: Looking Back on Biodiversity Change: Lessons for the Road Ahead https://royalsocietypublishing.org/doi/full/10.1098/rstb.2022.0199

Episode summary:

Maria Dornelas, a macroecologist at the University of St. Andrews and the University of Lisbon, challenges the common view that biodiversity is uniformly declining. Her research, based on the BioTIME database, reveals a more complex picture, with biodiversity trends varying by location—some areas remaining stable or even seeing increases in species diversity.

She discusses the "biodiversity conservation paradox," where human activities alter ecosystems, yet biodiversity declines are not universal. While biodiversity loss is real, it is part of a broader story that includes species turnover and recovery. Dornelas advocates shifting the focus from "biodiversity loss" to "biodiversity change."

Addressing criticisms, she acknowledges limitations like short analysis timeframes and regional biases in monitoring but emphasizes that her findings remain valuable. She calls for a more nuanced conservation approach, highlighting successes alongside challenges. Overly simplistic narratives, she warns, risk disengaging the public—echoing mistakes made in climate communication. Instead, she urges balanced messaging and expanded global biodiversity monitoring efforts.

Host: Volker Hahn

Inside Biodiversity is hosted by the German Centre for Integrative Biodiversity Research (iDiv).