̽��ֱ�� of Cambridge - David Coomes

Return to the wild

jg533 — Fri, 11 Oct 2024 23:00:00 +0000

Ambitious collaborations are bringing biodiversity back to the Scottish Highlands.

Offset markets: new approach could help save tropical forests by restoring faith in carbon credits

jg533 — Mon, 30 Oct 2023 16:15:05 +0000

A new approach to valuing the carbon storage potential of natural habitats aims to help restore faith in offset schemes, by enabling investors to directly compare carbon credit pricing across a wide range of projects.

Current valuation methods for forest conservation projects have come under heavy scrutiny, leading to a crisis of confidence in carbon markets. This is hampering efforts to offset unavoidable carbon footprints, mitigate climate change, and scale up urgently needed investment in tropical forest conservation.

Measuring the value of carbon storage is not easy. Recent research revealed that as little as 6% of carbon credits from voluntary REDD+ schemes result in preserved forests. And the length of time these forests are preserved is critical to the climate benefits achieved.

Now, a team led by scientists at the ̽��ֱ�� of Cambridge has invented a more reliable and transparent way of estimating the benefit of carbon stored because of forest conservation.

̽��ֱ��method is published today in the journal Nature Climate Change. In it, the researchers argue that saving tropical forests is not only vital for biodiversity, but also a much less expensive way of balancing emissions than most of the current carbon capture and storage technologies.

̽��ֱ��new approach works a bit like a lease agreement: carbon credits are issued to tropical forest projects that store carbon for a predicted amount of time. ̽��ֱ��valuation is front-loaded, because more trees protected now means less carbon released to the atmosphere straight away.

̽��ֱ��technique involves deliberately pessimistic predictions of when stored carbon might be released, so that the number of credits issued is conservative. But because forests can now be monitored by remote sensing, if projects do better than predicted – which they usually will – they can be rewarded through the issue of further credits.

̽��ֱ��payments encourage local people to protect forests: the carbon finance they receive can help provide alternative livelihoods that don’t involve cutting down trees.

And by allowing for future payments, the new method generates incentives for safeguarding forests long after credits have been issued. This contrasts with the current approach, which passes on a burden for conservation to future generations without compensation for lost livelihoods.

̽��ֱ��approach also allows different types of conservation projects to be compared in a like-for-like manner.

“Until now there hasn’t been a satisfactory way of directly comparing technological solutions with nature-based solutions for carbon capture. This has caused a lack of enthusiasm for investing in carbon credits linked to tropical forest protection,” said Dr Tom Swinfield, a researcher in the ̽��ֱ�� of Cambridge’s Department of Zoology and senior author of the study.

He added: “Tropical forests are being cleared so quickly that if we don’t protect them now, we’re not going to make the vital progress we need towards net-zero. Buying carbon credits linked to their protection is one of the best ways to do this.”

Tropical forests play a key role in taking carbon dioxide out of the atmosphere, helping to reduce global warming and avert climate catastrophe. But the carbon they capture is not taken out of the atmosphere permanently: forests can be destroyed by pests, floods, fire, wind – and by human clearance.

This impermanence, and therefore the difficulty of reliably measuring the long-term climate benefit of tropical forest protection, has made it an unattractive proposition for investors wanting to offset their carbon emissions.

And this is despite it being a far cheaper investment than more permanent, technology-based methods of carbon capture and storage.

Protection of tropical forests, a nature-based solution to climate change, comes with additional benefits: helping to conserve biodiversity, and supporting the livelihoods of people living near the forests.

“Nature-based carbon solutions are highly undervalued right now because the market doesn’t know how to account for the fact that forests aren’t a permanent carbon storage solution. Our method takes away a lot of the uncertainties,” said Anil Madhavapeddy, a Professor in the ̽��ֱ�� of Cambridge’s Department of Computer Science and Technology, who was involved in the study.

̽��ֱ��new method, developed by scientists at the Universities of Cambridge and Exeter and the London School of Economics, is called ‘Permanent Additional Carbon Tonne' (PACT) accounting, and can be used to value a wide range of nature-based solutions.

“Carbon finance is a way for us – the carbon emitters of the richer world – to direct funds towards rural communities in the tropics so they can get more out of the land they have, without cutting down more trees,” said Andrew Balmford, Professor of Conservation Science at the ̽��ֱ�� of Cambridge and first author of the paper.

Co-author Srinivasan Keshav, Robert Sansom Professor of Computer Science at Cambridge added: “Our new approach has the potential to address market concerns around nature-based solutions to carbon offsetting, and lead to desperately needed investment.”

Conversion of tropical forest to agricultural land results in vast carbon emissions. Around 30% of all progress towards the ambitious net-zero commitments made at COP26 is reliant on better management of carbon in nature.

Other carbon credit investment options include technologies that remove carbon dioxide from the atmosphere and lock it deep in the Earth for hundreds of years. These permanent storage options may currently be easier to value, say the researchers, but they typically cost substantially more than nature-based solutions and do nothing to protect natural habitats that are vital in regulating the global climate and mitigating the extinction crisis.

̽��ֱ��research was funded primarily by the Tezos Foundation. It was conducted by researchers at the Cambridge Centre for Carbon Credits.

Reference: Balmford, A et al.: ‘Realising the social value of impermanent carbon credits.’ Nature Climate Change, October 2023. DOI: 10.1038/s41558-023-01815-0

Fixing the Fens

jg533 — Fri, 14 Apr 2023 08:20:08 +0000

Reconciling human activities with nature is never going to be easy, but a new Cambridge group is using everything it’s got to try and protect a vital part of the UK.

Cambridge researchers to tackle major threats to 'UK’s vegetable garden'

plc32 — Tue, 15 Feb 2022 07:00:00 +0000

Although covering less than 4% of England’s farmed area, the Fens produce more than 7% of England’s total agricultural production, worth £1.23 billion. But they are threatened by climate change and their ancient peat soils are drying out, releasing millions of tonnes of CO₂.
̽��ֱ��Cairngorms are home to over a quarter of the UK’s endangered species, from capercaillies to ospreys.
̽��ֱ��Lake District is a national treasure and a UNESCO World Heritage Site but future changes in agricultural subsidies present both challenges and opportunities for the landscape

̽��ֱ��Cambridge Centre for Landscape Regeneration project will work with farmers, local communities and conservation groups to tackle environmental threats in these areas. This major countryside regeneration project will be led by Cambridge Conservation Initiative (CCI), Cambridge Zero and the Royal Society for the Protection of Birds (RSPB), in partnership with the UK Centre for Ecology and Hydrology (CEH) and the Endangered Landscape Programme.

Professor Emily Shuckburgh OBE, Director of Cambridge Zero said: "We aim to make a demonstrable difference to the way landscape restoration is designed, implemented, scaled up and supported by policy, ensuring solutions are resilient, inclusive and sustainable."

Funding for the work with farmers, landowners, conservation groups and local communities to address ecological threats such as extinction, flooding, drought and pollution comes from the Natural Environment Research Council (NERC) as part of its £40 million 'Changing the Environment' programme.

̽��ֱ��UK’s vegetable garden

̽��ֱ��Fens contain almost half of the UK’s grade-1 agricultural land and support a farming industry worth around £3 billion across the food chain. Farming there directly employs over 10,000 people and supports around 80,000 jobs more widely.

̽��ֱ��area is the vegetable garden of UK horticulture with 33% of England's fresh vegetables grown here. More than a half of UK-grown lettuce and over 75% of UK-grown celery are produced in the Fens. Alongside salads, key vegetable crops such as carrots, leeks, potatoes, onions and beetroot are also extensively grown on the Fens.

Yet this fertile landscape faces a host of existential environmental challenges. It is estimated that only 1% of the original wetlands in the Fens remain intact and 30% of the peatlands have been lost – emitting millions of tonnes of carbon in the process.

Just as alarmingly, the region is projected to run out of water in five to 10 years, while simultaneously being threatened by rising sea levels.

Project researchers have been working closely with farmers in the region to find environmental solutions that work for them and their communities. Fourth-generation Fens farmer and Fenland SOIL steering committee member Tom Clarke said: "Farming in the Fens faces a triple threat – a climate challenge, a nature challenge, and a food security challenge. ̽��ֱ��best defence is for farming is to be less defensive about some of the problems it has contributed to. We farmers instead need to work in a positive and pragmatic way to find opportunities and solutions for the farmers of the future."

Agriculture in this eastern region of England is of vital importance not just to the whole UK, but also to local people who rely on it for a living. That is why simply rewilding the Fens to preserve and restore its ecosystem is not an option. ̽��ֱ��funding from NERC will support this work and will enable researchers to find the best ways of protecting the ecosystem and its farmers.

National treasures endangered

̽��ֱ��Cairngorms and the Lake District are both national treasures, but their ecology is severely imperiled. ̽��ֱ��beauty of these popular tourist destinations obscures significant degradation and wildlife loss.

̽��ֱ��Cairngorms are under particular threat from climate change, as well as deforestation, erosion and the loss of iconic species which cannot be found anywhere else in the UK.

Teams there are working to expand and restore ancient Caledonian pinewoods. These spectacular forests have suffered from a significant loss of biodiversity and the encroachment of non-native tree species.

Professor Stephen J Toope, Vice-Chancellor of the ̽��ֱ�� of Cambridge, said: " ̽��ֱ��interlinked extinction and climate crises pose a major threat to our future. Harnessing the full-breadth of expertise across Cambridge, this project will develop evidence-informed solutions and provide tools for government and stakeholders to regenerate landscapes for the benefit of climate, nature, the economy and society."

Whole-systems solutions

Professor David Coomes, Director of the Conservation Research Institute within CCI, said: " ̽��ֱ��emphasis of the Cambridge ̽��ֱ�� Centre for Landscape Regeneration project will be on whole-systems approaches, as these are critical to addressing the root challenges of landscape regeneration”. This means taking a holistic, long-term view that encompasses the whole ecology of a region.

One example is the work done by Cairngorms Connect – the UK’s biggest habitat restoration project, and a partnership of a private landowner, two government agencies and an NGO (the RSPB). Their focus is 130km² of biodiverse native pinewood habitats in the Cairngorms, Scotland. ̽��ֱ��partners’ 200-year vision will expand the forest to its natural limit, thereby doubling its area. Within the existing forest they are creating more natural character by pulling down trees to simulate naturally occurring deadwood – a vital feature of a healthy forest. This deadwood benefits a wide range of animals, from invertebrates, fungi and lichens, to bird species – many of which are rare elsewhere in the UK.

Professor Jeremy Wilson, RSPB Director of Science said: "As a partner in the Cambridge Conservation Initiative, we are excited by this opportunity to tackle the problem of restoring some of our most precious but fragile landscapes for the benefit of nature, people and the climate. As one of the largest nature conservation land managers in the UK, our nature reserves are at the heart of these landscapes and the insights from this cutting-edge research will underpin our restoration work for decades to come."

In the Fens, a group of farmers is experimenting with raising the water table to reduce greenhouse gas emissions. This offers a natural experiment to find out not only how such measures affect crop yields, but also its impact on the communities of insects and spiders on which bird populations and crop pollination depend.

In another example, farmers in the Fens are relaxing the usually drastic clearance of fen ditches and providing more farm reservoirs. This enables the storage of winter water for summer irrigation and also provides ideal habitats for fish and wetland birds such as herons and the Marsh Harrier – a species reduced almost to extinction in Britain in the 20th century.

Cambridge researchers will tackle environmental threats that could affect a third of England’s home-grown vegetables and more than a quarter of the UK's rare and endangered wild animals. Eco-friendly farming in the Fens, pine martens in the Cairngorms, and disappearing woodlands in the Lake District will all benefit from a £10 million countryside regeneration programme to safeguard the country’s most important agricultural land and beloved rural idylls.

̽��ֱ��emphasis of the Cambridge Centre for Landscape Regeneration project will be on whole-systems approaches, as these are critical to addressing the root challenges of landscape regeneration.

Professor David Coomes, Director of the Conservation Research Institute

J Garget via Pixabay

Wild horse on Wicken Fen

̽��ֱ��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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Cambridge-built carbon credit marketplace will support reforestation

sc604 — Wed, 10 Nov 2021 11:58:35 +0000

̽��ֱ��Cambridge Centre for Carbon Credits (4C) - based in the Department of Computer Science and Technology, and the ̽��ֱ�� of Cambridge Conservation Research Institute - has two primary goals: to support students and researchers in the relevant areas of computer science, environmental science, and economics; and to create a decentralised marketplace where purchasers of carbon credits can confidently and directly fund trusted nature-based projects.

̽��ֱ��Centre will build its decentralised marketplace on the energy-efficient Tezos blockchain because it operates sustainably and allows third parties to verify all transactions, in line with the Centre’s vision to support a sustainable future through technology. ̽��ֱ��goal of the marketplace is to exponentially increase the number of real nature-based conservation and restoration projects by channelling funding towards them via market-based instruments.

Nature-based solutions, particularly forests, have a vital role to play in mitigating the worst effects of climate change. Pressure is mounting from governments and the public to rapidly roll out a global programme of well-executed nature-based solutions (NbS) to sequester several gigatons of carbon each year and protect biodiversity. However, current NbS projects are hampered by chronic underfunding.

“Current accreditation systems that measure and report the value of carbon and related benefits like biodiversity conservation and poverty reduction rendered by NbS are costly, slow and inaccurate,” said Centre Director Dr Anil Madhavapeddy. “These systems have undermined trust in NbS carbon credits. What is needed is a decentralised marketplace where purchasers of carbon credits can confidently and directly fund trusted nature-based projects. And that’s the gap the Centre is aiming to fill.”

̽��ֱ��Centre will support 12 PhD students and postdoctoral fellows, and investment to prototype a scalable, trusted NbS marketplace. Researchers funded from the Centre will come from the Departments of Computer Science and Technology, Zoology, and Plant Sciences, as well as from the Centre for Doctoral Training in Artificial Intelligence for the study of Environment Risk.

Professor David Coomes, Director of the ̽��ֱ�� of Cambridge Conservation Research Institute, said: “Conservation strategies are increasingly broadening to include large datasets, remote sensing technologies and computational approaches. ̽��ֱ��Centre for Carbon Credits is a ground-breaking initiative that will bring together computer scientists and conservation scientists in a new way.”

Andrew Balmford, Professor of Zoology, said: “ ̽��ֱ��recent announcement at COP26 of the new commitment to halt and reverse forest loss and land degradation by 2030 demonstrates the crucial role forests play in carbon capture and the health of our planet. ̽��ֱ��new Centre has a significant role to play in supporting crucial research to develop new, trusted mechanisms to support reforestation projects.”

Speaking on the collaborative nature of the Centre, Professor Ann Copestake, Head of the Department of Computer Science and Technology, said: “In the last few years, we’ve been expanding our emphasis on the use of computer science techniques and technologies to help address the climate emergency and the crisis in biodiversity. We are delighted to be bringing our research strengths together with the expertise in environmental science across the ̽��ֱ�� of Cambridge. We hope the work resulting from this interdisciplinary collaboration will lay the foundation for tangible solutions to some of the environmental challenges facing the world.”

A new Cambridge centre will bring together computer scientists and conservation scientists to build a trusted marketplace for carbon credits and support global reforestation efforts, the first initiative of its kind in the UK.

What's needed is a decentralised marketplace where purchasers of carbon credits can confidently and directly fund trusted nature-based projects. And that’s the gap the Centre is aiming to fill

Anil Madhavapeddy

kazuend via Unsplash

View of forest

Yes

Nature has enormous potential to fight climate change and biodiversity loss in the UK - report

jg533 — Tue, 11 May 2021 23:01:00 +0000

Incorporating contributions from over 100 experts across academia, statutory agencies and NGOs, the comprehensive evaluation of the available evidence details the strengths, limitations and trade-offs of nature-based solutions in different UK habitats.

Professor Jane Memmott, President of the British Ecological Society, said: “ ̽��ֱ��Nature-based Solutions report offers a real basis for setting effective policies and incentives that will maximise the benefits of nature-based solutions in the UK for the climate and biodiversity.”

̽��ֱ��report finds that nature-based solutions can provide a valuable contribution to climate change mitigation and can simultaneously protect and enhance biodiversity, improve human wellbeing, bring economic benefit, and provide a wide range of ecosystem services.

Despite the huge range of benefits nature-based solutions have, the report makes clear that they should be seen as complementary to other climate and conservation actions, not as a replacement to them.

Restoration of the UK’s peatlands is a priority nature-based solution identified in the report. ̽��ֱ��UK’s 2.6 million hectares of peatland contain around 3 billion tonnes of carbon, but most are in a degraded state and are no longer actively sequestering carbon. Estimates suggest that they could be emitting the equivalent of 23 million tonnes of carbon dioxide annually, approximately half the amount released through the nation’s agricultural sector.

Restoring degraded peatlands through rewetting and revegetation can reduce and eventually halt these emissions as well as bring benefits in terms of biodiversity conservation and flood protection.

Restoring UK woodlands can also make a significant impact as a nature-based solution. Forests cover 13% of the UK and the report finds there is scope to expand this significantly to sequester more carbon, although the full benefits will not be felt before 2050. Reducing flood risk, providing shade and cooling, and biodiversity benefits from native woodland expansion are also highlighted as positive outcomes from woodlands as a nature-based solution.

Professor David Coomes at the ̽��ֱ�� of Cambridge, lead author of the Woodlands chapter of the report, said: “For large-scale tree planting to be effective in capturing carbon, we will need to avoid species-rich grasslands, peat and other organic soils. Our focus should be on areas of low-quality grassland. However, this will reduce the UK’s capacity to produce meat and dairy, meaning a shift in our diets would be needed to avoid importing more of these products and offshoring our carbon footprint elsewhere.”

Marine environments that surround the UK can also offer significant nature-based solutions thanks to the large size of habitats. Saltmarshes and seagrasses are important carbon sinks, and their restoration can contribute to climate mitigation. Saltmarshes also provide coastal protection from sea-level rise and storms and provide high-biodiversity coastal habitats, especially for bird species.

Professor Rick Stafford at Bournemouth ̽��ֱ�� and lead author of the Marine Chapter said: “In marine environments nature-based solutions changes are nearly always win-win. Investment in nature-based solutions that restore or protect coastal environments is an effective mechanism of achieving greater biodiversity, protection from storms and carbon capture with few trade-offs.”

̽��ֱ��implementation of nature-based solutions to help achieve net-zero commitments and tackle biodiversity loss will require shared knowledge, resources, and effective partnerships across different policy areas.

Long-term policies, goals and government commitments will be necessary to support long-term investment, research and monitoring of the solutions.

Although some habitats are highlighted as priorities, the report emphasises that all habitats covered can deliver nature-based solutions and play a role in addressing the climate and biodiversity crises.

Adapted from a press release by the British Ecological Society.

̽��ֱ��full report can be downloaded here: Nature-based Solutions for Climate Change in the UK: A Report by the British Ecological Society.

̽��ֱ��virtual launch event takes place from 10:00-11:30 on Wednesday, 12 May, hosted by Rt Hon Philip Dunne MP, Chair of the Environment Audit Committee of the House of Commons, and presented by broadcaster and journalist Tom Heap. It can be watched here.

A report launched today by the British Ecological Society, with contributions from the ̽��ֱ�� of Cambridge, offers the first complete assessment of the potential of nature-based solutions to mitigate climate change and benefit biodiversity in the UK.

For large-scale tree planting to be effective in capturing carbon...our focus should be on areas of low-quality grassland

David Coomes

Trees against blue sky

Yes

Cambridge researchers lead policy briefing on Nature-based Solutions for the climate and biodiversity crises

Anonymous — Fri, 30 Apr 2021 13:38:29 +0000

Nature-based Solutions (NbS) – solutions to societal challenges that involve working with nature – are such a solution. Examples include tree planting to sequester atmospheric carbon and restoring coastal habitats to mitigate floods.

Now, a group of researchers led by Professor David Coomes and Rogelio Luque-Lora from the ̽��ֱ�� of Cambridge Conservation Research Institute, have published a policy briefing outlining the underlying concepts of NbS as well a list of strategies and policy recommendations to take NbS to their full potential, in advance of the United Nations Climate Change Conference which will be held in Glasgow later this year.

̽��ֱ��briefing has been produced in association with the COP26 Universities Network, a group of UK-based universities and research institutes, including the ̽��ֱ�� of Cambridge and Cambridge Zero.

As explained by the authors, Nature-based Solutions can deliver both climate change mitigation and adaptation. Mitigation involves reducing the degree of climate change: planting trees to absorb carbon dioxide, for example. Adaptation is about reducing communities’ exposure and vulnerability to the negative effects of climate change, by providing flood protection, for example. And by enhancing biodiversity, NbS can also boost the resilience of ecosystems to changing climate conditions.

Nature-based Solutions often work by protecting existing ecosystems, which prevents further release of carbon into the atmosphere and safeguards the biological diversity attached to those ecosystems. They can also work by restoring habitats which have previously been degraded, improving the ability of these habitats to sequester carbon and host biodiversity. Both these strategies also have the potential to enhance the provision of ecosystem services, including water filtration and soil retention.

Other strategies include the sustainable management of working landscapes, such as agricultural land, and the creation of new habitats. ̽��ֱ��latter has also been referred to as ‘green engineering’ or ‘green infrastructure’, and can contribute to societal adaptation to climate change by cooling and cleaning the air in cities and providing physical and mental health benefits.

In the UK, NbS can support job creation and livelihoods, and can play a key role in ‘building back better’ after COVID-19 and can be more cost-effectively deployed than non-NbS approaches to mitigation and adaptation.

There is also scope for the UK use its presidency of COP26 to promote effective and fair NbS across the globe. In this context, the authors recommends that the UK promotes a broad range of NbS that go beyond the present emphasis on tree planting. In fact, while the authors acknowledge that commercial forestry plantations can be necessary to meet societal demand for timber and wood pulp, they caution that the promotion of afforestation with non-native species can have detrimental effects on biodiversity, for example when they replace species-rich grassland ecosystems. They can also lead to the release of carbon into the atmosphere, if carbon-rich habitats such as peatland are replaced by the shallower soils of plantations.

̽��ֱ��authors warn, too, that NbS can never be a substitute to the urgent and thorough decarbonisation of the economy. NbS can only contribute to meeting international climate targets if they act as a complement to the main task of transitioning away from fossil fuels. There is a risk that NbS could be used to justify ‘business as usual’, by conveying the illusion that emissions are being compensated for by deploying NbS.

NbS are most effective when they are strategically deployed to minimise trade-offs and deliver simultaneous wins. For example, restoring upland peat in the UK can help to protect communities from flooding and soil erosion while also storing carbon, providing recreational space and natural habitat for wildlife with negligible loss of agricultural potential on the national scale. In contrast, replacing highly productive agricultural land with natural habitats could make the UK more dependent on food imports.

Also, crucially, local communities must be involved in every stage of the planning and implementation processes. This is essential to ensure that local people do not overwhelmingly bear any costs associated with NbS, that they receive a just share of the benefits, and that they support the projects in the medium and long terms.

“I am excited by the opportunities that COP26 will provide to make the most of the potential of NbS to deliver climate change mitigation while benefitting biodiversity and livelihoods,” said Coomes.

Adapted from a story published on the UCCRI website.

As societies face the triple challenge of avoiding the worst effects of climate change, protecting remaining biodiversity and improving human wellbeing, there are calls to end siloed thinking and design solutions that address these problems simultaneously.

Rob Barnes under licence from AGEDI

Mangrove ready to be planted

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Local water availability is permanently reduced after planting forests

jg533 — Mon, 20 Jan 2020 00:01:00 +0000

“Reforestation is an important part of tackling climate change, but we need to carefully consider the best places for it. In some places, changes to water availability will completely change the local cost-benefits of tree-planting programmes,” said Laura Bentley, a plant scientist in the ̽��ֱ�� of Cambridge Conservation Research Institute, and first author of the report.

Planting large areas of trees has been suggested as one of the best ways of reducing atmospheric carbon dioxide levels, since trees absorb and store this greenhouse gas as they grow. While it has long been known that planting trees reduces the amount of water flowing into nearby rivers, there has previously been no understanding of how this effect changes as forests age.

̽��ֱ��study looked at 43 sites across the world where forests have been established, and used river flow as a measure of water availability in the region. It found that within five years of planting trees, river flow had reduced by an average of 25%. By 25 years, rivers had gone down by an average of 40% and in a few cases had dried up entirely. ̽��ֱ��biggest percentage reductions in water availability were in regions in Australia and South Africa.

“River flow does not recover after planting trees, even after many years, once disturbances in the catchment and the effects of climate are accounted for,” said Professor David Coomes, Director of the ̽��ֱ�� of Cambridge Conservation Research Institute, who led the study.

Published in the journal Global Change Biology, the research showed that the type of land where trees are planted determines the degree of impact they have on local water availability. Trees planted on natural grassland where the soil is healthy decrease river flow significantly. On land previously degraded by agriculture, establishing forest helps to repair the soil so it can hold more water and decreases nearby river flow by a lesser amount.

Counterintuitively, the effect of trees on river flow is smaller in drier years than wetter ones. When trees are drought-stressed they close the pores on their leaves to conserve water, and as a result draw up less water from the soil. In wet weather the trees use more water from the soil, and also catch the rainwater in their leaves.

“Climate change will affect water availability around the world,” said Bentley. “By studying how forestation affects water availability, we can work to minimise any local consequences for people and the environment.”

This research was funded by the International Union for the Conservation of Nature and the Natural Environment Research Council.

Reference

Bentley, L. et al: ‘Partial river flow recovery with forest age is rare in the decades following establishment.’ Global Change Biology, Jan 2020. DOI: 10.1111/gcb.14954

River flow is reduced in areas where forests have been planted and does not recover over time, a new study has shown. Rivers in some regions can completely disappear within a decade. This highlights the need to consider the impact on regional water availability, as well as the wider climate benefit, of tree-planting plans.

River flow does not recover after planting trees, even after many years.

David Coomes

Laura Bentley

Shallow river bed in Buderim Forest Park, Queensland, Australia.

Researcher profile: Laura Bentley

In the Mediterranean woodlands of Spain, trees have regrown naturally over the last 50 years. Laura Bentley is trying to understand how much carbon these trees are storing, and how this process is affecting water availability in the region.

“Previous research has shown how important restoring forest cover will be in combatting climate change,” says Bentley. “I want to inform how we use landscapes over the next century to meet environmental challenges. My goal is to help build a better understanding of what a world with increased forest cover will be like.”

Bentley developed an interest in the complex natural processes that support human needs while a masters student at Imperial College London. She subsequently moved to Cambridge for her PhD, where she is supervised by Professor David Coomes at the ̽��ֱ�� of Cambridge Conservation Research Institute.

Her research encompasses processing data from satellites and other remote sources, and visiting her collaborators in Madrid - a Spanish National Research Council team led by Professor Fernando Valladares - for fieldwork.

“My field sites in Spain’s Alto Tajo Natural Park are part of a truly beautiful landscape - but very punishing in the summer heat,” says Bentley. “ ̽��ֱ��most exciting part of my PhD so far was my first field season there. From driving through gorgeous remote landscapes, to getting caught in an intense hailstorm in the middle of summer, the experience will stay with me for a long time.”

Bentley’s interest in the natural world has led to a budding passion for photography, and she tries to capture new images whenever the opportunity arises. Her observations have convinced her that there is a way to make environment work for both people and nature in the long term. “I believe science can help us find that goldilocks zone.”

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