Mapping global biodiversity change

Thursday 17 October 2019

Sea life

New international research reveals different rates of biodiversity change across the globe.

The research, led by scientists from the Universities of St Andrews and Edinburgh, the German Centre for Integrative Biodiversity Research (iDiv), Martin Luther University Halle-Wittenberg, and published in Science (Wednesday 17 October), focussed on mapping biodiversity change in marine and land environments. The findings reveal negative and positive changes in ecosystems across the world, but also that changes in marine systems outpace those on land, with loss of biodiversity most prevalent in the tropics.

At the sDiv synthesis centre of the German Centre for Integrative Biodiversity Research (iDiv), the group of researchers from leading universities across Europe, the USA and Canada aimed to reach a consensus about variation in biodiversity change. The study reveals that although on average the numbers of species that live in each place are not changing, many regions are gaining or losing species.

Underwater coral and fishThe international team of scientists examined longitudinal variation in species richness and composition by piecing together and mapping over 50,000 biodiversity time series from studies across the planet using the biodiversity database BioTIME, hosted at the University of St Andrews, to establish clear geographic variation in biodiversity change.

Scientists were then able to dissect variation in biodiversity trends to identify the places and types of organisms that are changing most rapidly. Detecting geographic variation in biodiversity trends will not only improve understanding of how global biodiversity is changing but also inform conservation priorities by identifying which regions to protect and which regions to help recover.

Lead researcher Dr Maria Dornelas, from the School of Biology at the University of St Andrews, said: “Our study shows biodiversity is changing everywhere, but we are not losing biodiversity everywhere. Some places are recovering and adapting.

“When biodiversity is in the news these days, it is often because the Amazon is on fire, or there is a global mass mortality event in coral reefs, and rightly so, because these are terrifying news. However, there is a lot of recovery also taking place silently in the background, and many places where not much is happening. Our study puts these things on the map and shows they are not contradictory.

“We knew that biodiversity is affected by many different human actions, with different timings and effects, but we didn’t have a clear understanding of what were the net effects of these actions across the planet.”

“Our study shows how biodiversity change varies geographically. The species that make up local assemblages are changing everywhere, but these changes are happening faster in marine compared to terrestrial assemblages,” said Shane Blowes, from the German Centre for Integrative Biodiversity Research (iDiv) and Martin Luther University Halle-Wittenberg (MLU).

Sarah Supp, from Denison University in Ohio and joint first author of the paper, added: “Biodiversity change is complex to understand because it can be measured in many different ways, including the number of unique species, and the identities of those species. Our study shows that while some locations have experienced decreases in the numbers of species, others show increases, or little change at all. More consistently, however, the identities of species appear to be changing at nearly all sites – this kind of change is critical to planning conservation and management strategies, particularly for sites exhibiting rapid turnover.

“Our study provides an important description of biodiversity change across the planet, and highlights the value of monitoring biodiversity through time. Further, it provides motivation to increase our data sharing and establish new long-term field sites to include greater geographic coverage – for example, more tropical and freshwater systems.”

The paper The geography of biodiversity change in marine and terrestrial assemblages is published in Science and is available online.

Please ensure that the paper’s DOI (doi/10.1126/science.aaw1620) is included in all online stories and that Science is credited as the source.

The German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig is a DFG research centre with about 400 employees and members based primarily in Halle, Jena and Leipzig. Researchers from 30 nations establish the scientific basis for the sustainable management of our planet’s biodiversity.

Issued by the University of St Andrews Communications Office.

Category Research

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