Nature may have fewer backup plans than we thought, leaving our food supply and climate more exposed when species disappear.
The largest global study of its kind suggests that losing species can steadily erode the benefits ecosystems provide, including pollination, clean water, carbon storage, and natural pest control. Led by King’s College London and Imperial College London, the research challenges the assumption that many species are interchangeable and that a few losses make little difference.
Working with the Natural History Museum and the Alan Turing Institute, the researchers combined 423 published studies and 222,829 data points from land, freshwater, marine, and estuarine ecosystems. Published in Nature Ecology & Evolution, their analysis produced a database more than twice the size of the largest previous effort.
Across 23 categories of ecosystem services and functions, most benefits kept increasing as biodiversity rose. They generally did not level off once a small collection of species was present, suggesting that ecosystems have less spare capacity than scientists previously assumed.
Why Losing Species Matters
The findings call into question the extent of “functional redundancy,” the idea that different species can perform similar jobs and compensate when one disappears. If that backup were widespread, additional species would eventually contribute little to a particular service. Instead, the study found that greater diversity usually continued to bring benefits.
Dr. Emma Moffett, the study’s lead author and a geography lecturer at King’s College London, said, “Our findings challenge the comfortable assumption has been that ecosystems carry plenty of backup, so losing a species here and there doesn’t change much. Across most of the benefits ecosystems provide that we looked at, the data doesn’t support that. The ecological benefits keep climbing as diversity rises, which means it is falling as we lose species.”
There were exceptions. Protection against coastal flooding, erosion, and similar hazards showed relatively little sensitivity to biodiversity overall. These functions often depend heavily on a few foundational species, such as shrubs whose roots stabilize sand dunes.
Conservation needs to account for both overall biodiversity and the outsized contributions of certain species. Protecting a wide range of species helps sustain many ecosystem benefits, while safeguarding foundational species preserves functions that others may be unable to replace.
Ocean Carbon Storage Stands Out
The strongest relationship between biodiversity and any measured service involved marine carbon sequestration, the capture and storage of atmospheric carbon dioxide (CO₂) in ocean waters and sediments. This suggests that species losses could have especially important consequences for the ocean’s contribution to climate protection.
Marine life helps move carbon through the ocean, from phytoplankton near the surface to microbial food webs involved in transferring it into deeper water. The findings point to the importance of diverse communities for blue carbon sinks in the ocean and coastal environments, including mangroves and salt marshes.
However, the striking ocean result came from only a small number of datasets. The researchers identify this shortage of evidence as an urgent research gap, so the finding warrants further investigation.
Dr. Moffett said, “The ocean result stopped us in our tracks. Carbon capture at sea responded to biodiversity more strongly than anything else we measured, and yet it’s one of the least studied areas we found. If the world is counting on blue carbon to help with climate change, marine life can’t be an afterthought.”
A Warning for Future Food Production
The team also explored how these benefits could change by connecting its database to biodiversity projections under the socioeconomic scenarios used by the Intergovernmental Panel on Climate Change. One focus was natural pest control on farmland, where predators and other enemies of crop pests provide a service farmers receive for free.
The model predicts that this protection would weaken under development driven by fossil fuels compared with a pathway less dependent on them. Countries experiencing rapid population growth and lower levels of development would face the sharpest losses.
Dr. Will Pearse, an associate professor in evolutionary ecology in Imperial College London’s Department of Life Sciences, said, “We’ve known that biodiversity supports humanity by providing us with food, clean water, clean air, and so many other ecosystem services. But what this model gives us is a precise, global picture: we can now predict the benefits biodiversity provides anywhere, making it even easier to recognize and take advantage of those benefits.”
The database and forecasts for all 23 categories are publicly available to support policy and planning.
Reference: “Biodiversity safeguards ecosystem services and functions worldwide” by Emma R. Moffett, Joel H. Gayford, Lexi Chen, Olivia F. Morris, Yuming Shi, Lucy Somekh, Nicole Stasik, Andy Purvis, Guy Woodward and William D. Pearse, 6 October 2026, Nature Ecology & Evolution.
DOI: 10.1038/s41559-026-03200-4
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