Periodic Reporting for period 1 - DECRYPT (Drivers of Ecosystem Collapse and RecoverY across the Permo-Triassic)
Reporting period: 2021-03-01 to 2023-02-28
Growing evidence suggests that volcanic eruptions and the high emission of gases and ash, although lasting only a few days, can impact the climate for years. One important effect is a disruption of the earth's radiative balance when the aerosol clouds created by the particulate matter absorb terrestrial radiation and scatter incoming solar radiation. Volcanic eruptions have now been linked to the Permo–Triassic mass extinction approximately 250 million years ago, when up to 90 % of marine species and 75 % of terrestrial vertebrates disappeared forever. The EU-funded DECRYPT project is studying ultraviolet (UV)-B-absorbing compounds in the fossil remains of pollen for evidence of elevated UV-B radiation that may be related to this near-annihilation of life on Earth. Enhanced understanding could be important to addressing the challenges of climate change facing us today.
The Permo–Triassic mass extinction (PTME) was the most catastrophic extinction in the last 541 million years. There is now a robust temporal link between the PTME and Siberian Traps volcanism, which injected massive amounts of greenhouse gases and hydrothermal organohalogens into the atmosphere. This likely caused acute disruption of the stratospheric ozone balance, resulting in elevated harmful ultraviolet radiation (UV-B, 280–315 nm), but to date this possible key driver of the near-annihilation of life remains unquantified. A growing body of research demonstrates that UV-B absorbing compounds (UACs) contained within fossil pollen act as a reliable, independent proxy for changes in solar irradiance.
In this project I will develop a cutting-edge interdisciplinary framework that integrates high-resolution palaeoecological, stratigraphic, and palaeobiological data with new biogeochemical signatures from Permo–Triassic pollen and spores. This project will deliver a case study for proof-of-concept to address my key research objective: understanding the drivers of terrestrial ecosystem collapse across the PTME. As this ancient extinction is similar in many respects to current, anthropogenically-forced global changes, improving our understanding of ecological breakdown in the past is crucial to address a major societal challenge facing humanity today: accurately contextualising the rate and magnitude of modern species losses, in order to best direct conservation efforts and preserve essential ecosystem services.
The Permo–Triassic mass extinction (PTME) was the most catastrophic extinction in the last 541 million years. There is now a robust temporal link between the PTME and Siberian Traps volcanism, which injected massive amounts of greenhouse gases and hydrothermal organohalogens into the atmosphere. This likely caused acute disruption of the stratospheric ozone balance, resulting in elevated harmful ultraviolet radiation (UV-B, 280–315 nm), but to date this possible key driver of the near-annihilation of life remains unquantified. A growing body of research demonstrates that UV-B absorbing compounds (UACs) contained within fossil pollen act as a reliable, independent proxy for changes in solar irradiance.
In this project I will develop a cutting-edge interdisciplinary framework that integrates high-resolution palaeoecological, stratigraphic, and palaeobiological data with new biogeochemical signatures from Permo–Triassic pollen and spores. This project will deliver a case study for proof-of-concept to address my key research objective: understanding the drivers of terrestrial ecosystem collapse across the PTME. As this ancient extinction is similar in many respects to current, anthropogenically-forced global changes, improving our understanding of ecological breakdown in the past is crucial to address a major societal challenge facing humanity today: accurately contextualising the rate and magnitude of modern species losses, in order to best direct conservation efforts and preserve essential ecosystem services.
1. Chemical spectra of modern pollen grains from the genus Ephedra (Gnetales) have been generated using Fourier-transform infrared spectroscopy (FTIR) and Thermally Assisted Hydrolysis and Methylation with pyrolysis Gas-Chromatography Mass-Spectrometry (THM-GC/MS). Spectra have been analysed with the R packages MALDIquant and vegan. They are used as a modern training set for fossil grains, as well as to develop a chemical framework for determining plant pollination mode from (modern) pollen grains alone (Publication 1).
2. Fossil pollen grains from the lead-up to the PTME have been chemically prepared and individually picked out of samples in order to generate THM-GC/MS chemical spectra. These spectra will provide UV reconstructions spanning the PTME from southern (Australia) and northern (Greenland) high latitudes (Publication 2). This will enable a new assessment of extinction magnitudes of plants and ecosystem recovery related to patterns of ozone depletion (Publication 3).
All publications will be disseminated as preprints followed by open access publications and promoted via press releases, newspapers, and social media. Outreach via school visits and the Pint of Science event will tie in with the release of publications.
2. Fossil pollen grains from the lead-up to the PTME have been chemically prepared and individually picked out of samples in order to generate THM-GC/MS chemical spectra. These spectra will provide UV reconstructions spanning the PTME from southern (Australia) and northern (Greenland) high latitudes (Publication 2). This will enable a new assessment of extinction magnitudes of plants and ecosystem recovery related to patterns of ozone depletion (Publication 3).
All publications will be disseminated as preprints followed by open access publications and promoted via press releases, newspapers, and social media. Outreach via school visits and the Pint of Science event will tie in with the release of publications.
This project comprises a highly interdisciplinary study at the intersection of palaeobiology, geochemistry, palaeoecology, and atmospheric research. This ground-breaking research will provide a proof-of-concept for chemical palynology to be applied throughout the fossil record, going beyond the state of the art in a rapidly growing field with extra-disciplinal impacts in a wide variety of earth science and biological research themes.
In the long term, the work carried out contributes to the EU policies of aiming to protect the environment and biodiversity, minimising risks to human health, and protecting the ozone layer. The project addresses the drivers of massive ozone depletion during a past period of Earth’s history, the ensuing consequences for biodiversity, and time taken for the ozone layer to recover. While the geological record can never be a perfect analogue for today, it provides us with the only directly observable precedent for future scenarios that are relevant for modern-day policy making. The results are thus transferable to international assessment bodies for global atmospheric health and restoration (e.g. World Meteorological Organization, United Nations Environment Programme, European Environment Agency) and to inform future policies on regulation of ozone-depleting substances (ODSs).
In the long term, the work carried out contributes to the EU policies of aiming to protect the environment and biodiversity, minimising risks to human health, and protecting the ozone layer. The project addresses the drivers of massive ozone depletion during a past period of Earth’s history, the ensuing consequences for biodiversity, and time taken for the ozone layer to recover. While the geological record can never be a perfect analogue for today, it provides us with the only directly observable precedent for future scenarios that are relevant for modern-day policy making. The results are thus transferable to international assessment bodies for global atmospheric health and restoration (e.g. World Meteorological Organization, United Nations Environment Programme, European Environment Agency) and to inform future policies on regulation of ozone-depleting substances (ODSs).