̽��ֱ�� of Cambridge - ̽��ֱ�� of Michigan

Drier savannas and grasslands store more climate-buffering carbon than previously thought

jg533 — Sat, 30 Sep 2023 16:17:53 +0000

̽��ֱ��study estimates that soils in savanna-grassland regions worldwide have gained 640 million metric tons of stored carbon over the past two decades.

This is because over the last 20 years, fire suppression has led to smaller wildfires, and less burned area in drier savannas and grasslands.

When soil microbes break down fallen leaves, dead plant matter and roots, the carbon in this plant biomass is released and can associate with minerals in the soil to become very stable. But the energy of an intense fire can burn it back off, releasing carbon dioxide into the atmosphere.

Fires are being suppressed because of population expansion, and landscape fragmentation caused by the introduction of roads, croplands and pastures in savannas and grasslands.

̽��ֱ��study, published today in the journal Nature Climate Change, is based on a reanalysis of datasets from 53 long-term fire-manipulation experiments worldwide, as well as field-sampling at six of those sites.

“We found that the potential - at very high fire frequencies - to release soil carbon into the atmosphere as carbon dioxide is greatest in dry areas. ̽��ֱ��potential to store carbon in soil when fires are less frequent is also the greatest in these dry areas,” said Dr Adam Pellegrini in the Department of Plant Sciences at the ̽��ֱ�� of Cambridge, and lead author of the study.

̽��ֱ��reduction in the size and frequency of wildfires in dryland savannas has led to an estimated 23% increase in carbon stored in topsoil. This increase was not foreseen by most of the state-of-the-art ecosystem models used by climate researchers. As a result, the researchers say, the climate-buffering impacts of dryland savannas are likely to have been underestimated.

Soil contains at least three times more organic carbon than the atmosphere or terrestrial plants, making it an important global carbon pool.

"Our findings show that because drier savannas are more sensitive to changes in fires, the decreases in burned area in those ecosystems has resulted in soils storing more carbon than they are releasing,” said Pellegrini.

He added: “Many of the ecosystem models that are used in simulating the effects of global change on carbon cycling are unlikely to have captured these dynamics."

̽��ֱ��study involved twenty researchers from institutions around the globe, who looked at recent changes in burned area and fire frequency in savannas, other grasslands, seasonal woodlands and forests.

Across 888,000 square miles (2.3 million square kilometers) of dryland savanna-grasslands, where fire frequency and burned area declined over the past two decades, soil carbon rose by an estimated 23%.

But in more humid savanna-grassland regions covering 533,000 square miles (1.38 million square kilometers), more frequent wildfires and increased burned area resulted in an estimated 25% loss in soil carbon over the past two decades.

̽��ֱ��net change during that time was a gain of 0.64 petagrams, or 640 million metric tons, of soil carbon.

“In the past couple of decades, global savannas and grasslands have slowed climate warming more than they have accelerated it, despite fires. But there is absolutely no guarantee that this will continue in the future,” said Peter Reich, Director of the Institute for Global Change Biology at the ̽��ֱ�� of Michigan, who was also involved in the study.

“No single region – from the Amazon rainforest, to the US Great Plains grasslands to Canada’s boreal forest - can alone store sufficient carbon to make a large contribution to slowing climate change. But together, they can,” said Pellegrini.

He added: “There are several savanna and grassland regions where soil carbon-credit projects are being developed, so understanding their capacity to sequester carbon is relevant to those regions.”

This research was funded by the U.S. Department of Agriculture, United Kingdom Research and Innovation (UKRI), the Gordon and Betty Moore Foundation, and the US Department of Energy.

Learn more about Adam Pellegrini’s work.

Reference: Pellegrini, A.F.A, et al.: 'Soil carbon storage capacity of drylands under altered fire regimes.’ Nature Climate Change, October 2023. DOI: 10.1038/s41558-023-01800-7

Adapted from a press release by the ̽��ֱ�� of Michigan.

Savannas and grasslands in drier climates around the world store more carbon than scientists previously thought and are helping to slow the rate of climate warming, according to a new study.

Because drier savannas are more sensitive to changes in fires, the decreases in burned area in those ecosystems has resulted in soils storing more carbon than they are releasing

Adam Pellegrini

Fire in oak savannah

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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International collaboration between Cambridge and Michigan built on ‘Powerful’ foundations

sc604 — Tue, 05 Mar 2019 03:31:42 +0000

̽��ֱ��Michigan-Cambridge Research Initiative (MCRI) is supporting collaborative research projects at both universities, including engineering solutions to prevent head injuries in sport, improved battery reliability, and new approaches to metals recycling. This is the second year of the programme, which brings together engineers and scientists at all stages of their careers, enabling the exchange of ideas at all levels.

̽��ֱ��MCRI is built on the foundations of the Power Exchange Scholarship Programme, which supported more than 50 students from Cambridge and Michigan over three decades starting in the late 1960s, fostering a culture of collaboration between the two universities.

̽��ֱ��Programme was supported by Eugene Power, an entrepreneur, philanthropist, Honorary Fellow of Magdalene College and alumnus of both universities. Former Power Scholars include Lord Howard Flight, former Deputy Chairman of the Conservative Party, and Lord Mark Malloch-Brown, former United Nations Deputy Secretary-General.

Now, through the MCRI, Cambridge and Michigan are incorporating the type of collaboration and exchange exemplified by the Power Scholars Programme into their current relationship. ̽��ֱ��MCRI provides a formal mechanism and funding to encourage collaborations between the two universities, as well as support to develop partnerships and share expertise.

Richard Prager, Head of Cambridge ̽��ֱ�� Engineering Department, has been involved in the MCRI initiative since 2017. He said “collaborative links like this contribute to our strengths in both research and education. Genuine partnerships between universities can have a transformational effect on students’ lives and open up new, important fields of innovation and discovery.”

As the MCRI develops, both universities hope to create a Research Scholarship Programme to enable doctoral student exchange between the two institutions in key research areas, primarily in engineering and computer science, amongst other initiatives.

“We are pleased to reinvigorate this transatlantic relationship between two of the world's leading universities and the Power Scholars programme,” said Alec D. Gallimore, the Robert J. Vlasic Dean of the College of Engineering at the ̽��ֱ�� of Michigan.

“Eugene Power was an innovator and entrepreneur and this Michigan-Cambridge Research Initiative carries on the legacy of the Power Scholars. It develops a practical platform for collaborative efforts between our students, faculty, and external partners for transformative solutions to problems with global impact.”

Earlier this year, nine of the Power Scholars returned to Cambridge for a dinner at Magdalene College, which hosted many of the students from the original Power Exchange Scholarship Programme. Attendees heard from senior academics from both universities about the partnership, and two Power Scholars, Lord Howard Flight and Dr Christine Martin, spoke to celebrate the renewal of the collaboration between Michigan and Cambridge.

“I was most fortunate to be selected as a Power Scholar attending the Michigan Business School in 1969-71, and my MBA has stood me in good stead throughout my career,” said Lord Flight. “I am most grateful to Eugene Power for financing the Power Scholarship and pleased to be able to make the first capital contribution to the new Cambridge - Michigan programme.”

A programme of research collaboration between the ̽��ֱ�� of Cambridge and the ̽��ֱ�� of Michigan – which grew out of a scholarship programme founded in the 1960s between Magdalene College and Michigan – was celebrated at a recent event in Cambridge.

Genuine partnerships between universities can have a transformational effect on students’ lives and open up new, important fields of innovation and discovery

Richard Prager

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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