̽��ֱ�� of Cambridge - wetlands

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

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Casting light on the dark ages: Anglo-Saxon fenland is re-imagined

amb206 — Fri, 21 Jul 2017 08:00:00 +0000

̽��ֱ��East Anglian fens with their flat expanses and wide skies, a tract of some of the UK’s richest farmland, are invariably described as bleak – or worse. Turn the clock back 1,000 years to a time when the silt and peat wetlands were largely undrained, and it’s easy to imagine a place that defied rather than welcomed human occupation.

Historians have long argued that during the ‘dark’ ages (the period between the withdrawal of Roman administration in around 400 AD and the Norman Conquest in 1066) most settlements in the region were deserted, and the fens became an anarchic, sparsely inhabited, watery wilderness.

A new interdisciplinary study of the region by a leading landscape archaeologist not only rewrites its early history across those six centuries but also, for the first time anywhere in Europe, offers a detailed view of the settlement and agricultural management of early medieval wetland landscapes.

Susan Oosthuizen’s ̽��ֱ��Anglo-Saxon Fenland (published last month by Windgather Press) is a prequel to the geographer Clifford Darby’s definitive study of the medieval fen, published in 1940. She draws on her interest in the relationship between early communities and their landscapes – in particular their management of herds of cattle across extensive areas of shared grazing.

Oosthuizen suggests that, rather than undergoing dramatic change after 400 AD, communities continued to live around the fen edge and on ‘islands’ of higher ground rising above the peat wetlands just as their ancestors had. Her evidence lies in the recent boost in archaeological discovery.

A five-fold increase in excavations since new planning guidance was issued in 1990, and the introduction of the Portable Antiquities Scheme in 1997 for recording finds by the public, have transformed the volume of archaeological material across Britain – including the windswept fens.

As a result the ‘dark ages’, as the period was often described, with its connotations of backwardness, is now more commonly called ‘early medieval’ which suggests less of a disjuncture between eras that appear instead to have unfolded seamlessly.

In ̽��ֱ��Anglo-Saxon Fenland, Oosthuizen argues that this new evidence shows there is little to support the idea that the fenland was anything but continuously occupied by settled, stable communities during the period 400 to 900 AD.

Who were ‘the Anglo-Saxons’ and what do we know about the fens between 400 and 900? In her prologue Oosthuizen addresses these key questions with admirable clarity. Her answers set the stage for an exploration of a fertile wetland exploited for millennia by local communities and threaded through by a network of rivers that allowed incomers from across the North Sea to penetrate as far as the English midlands.

Since the early 19th century, it has been assumed that during the 5th and 6th centuries indigenous British communities were removed altogether or reduced to servitude by incomers arriving from north-west Europe – the Anglo-Saxons – who lived in separate settlements.

There is now, however, a growing realisation among archaeologists that it is impossible to identify ‘Romano-British’ and ‘Anglo-Saxon’ communities on the basis of material culture, the things that people used every day. “Settlements, fields and artifacts can be distinguished by status,” argues Oosthuizen, “but not by the cultural background of the people to whom they belonged.”

She writes: “ ̽��ֱ��evidence from fenland shows that newcomers were assimilated into late British communities; there was no displacement of populations nor establishment of separate communities.” ̽��ֱ��distribution, for example, of Old English, vernacular Latin and (to a lesser extent) British Celtic place-names across southern England suggests that most early medieval people were bi- or even tri-lingual. Fenland was no different.

As Oosthuizen points out, being able to speak several languages confers obvious advantages, widening opportunities for all manner of transactions. It’s highly probable that the inhabitants of Walsoken and Chatteris, to name just two fenland villages, would have spoken both Old English and another language, switching from one to the other according to interlocutor and topic.

Basing her arguments on pollen analysis, archaeological evidence, the longevity over almost 1,500 years of rights of common pasture in the fen, and the etymology of place names, (and the absence of evidence to the contrary), Oosthuizen proposes that new arrivals were assimilated within the indigenous Romano-British communities, sharing livelihoods within the same landscape, their various languages and cultures mingling and merging.

̽��ֱ��Anglo-Saxon Fenland paints a portrait of communities whose agricultural economies were based on common rights in shared wetland resources that belonged to the whole of the small territories among which they were divided. Arrangements by which the landscape’s bounty was apportioned took account of the needs of both local communities and the land itself, breathing life into the adage that the old ways are often the best ways, based on the wisdom that comes with practical experience and knowledge passed down from one’s elders.

Dairy cattle, for example, were allowed first access to spring pasture; as providers of milk their needs for optimum nutrition were greatest. On the other hand, cattle were barred from land at times when their hooves would damage the soil structure vital to its long-term health.

Oosthuizen writes: “Timetabling [grazing by the dairy herd] was focused on sub-dividing the fens to allow for their rotation for different uses in different months, whose objectives were to maintain the quality of the grazing, to sustain the health of the herd, to ensure equitable exploitation among right holders, to maximise production, and to assure the long term sustainability of fen pastures.”

A similar checklist of priorities, Oosthuizen points out, underpins modern conservation advice on floodplain water meadows, which are best maintained on a regime that includes annual mowing, use of livestock from August to keep the grass short, maintenance of boundaries, clearing of watercourses, and control of invasive weeds.

There is abundant evidence - in place names, ditches and banks, land- and water-management practices, and (once they began) records of agreements based on centuries-old tried-and-tested farming methods - that people managed the landscape not just to meet their immediate needs but to assure the long-term sustainability of the wetland resources on which their livelihoods depended.

Detail of a late 16th century copy of an earlier map, possibly medieval in origin. It shows the area around Four Gotes in Tydd St Giles, near Wisbech. (Courtesy of Wisbech & Fenland Museum)

Fen dwellers made incremental adjustments to the ways in which they collectively exploited and safeguarded the fenland’s natural resources, adapting to water levels that slowly rose as a result of climate change.

In the undrained fen, water was both friend and foe. Serious flooding was a destructive force. Yet periodic (but relatively brief) seasonal inundation of pasture land produces grass not just for grazing but also to make the nutritious hay on which cattle thrived during the winters. Perhaps as early as 650, fen communities were already digging ditches to redirect excess water away from their pastures.

In 1618, the commoners at Cottenham described how the right amount of flooding, at the right time, could produce the white fodder which the cattle like best and that “those grounds that lie lowest, and are oftenest and longest overflown in the winter season are the most fertile grounds and yield the best yearly value”.

Detailed knowledge of the varying characteristics that depended on the degree of wetness in each part of the fenland enabled fen-dwellers to maximise its productivity through seasons wet and dry, and makes the most of opportunities for hunting, trapping and fishing - wildfowl and eels for the pot.

With ̽��ֱ��Anglo-Saxon Fenland Oosthuizen reveals a society whose origins could be found in prehistoric Britain, which had evolved through the four centuries of Roman administrations, and continued to develop thereafter. ̽��ֱ��rich and complex history of the fen region shows, she argues, a traditional social order evolving, adapting and innovating in response to changing times.

In piecing together evidence from a wide range of sources, she illuminates how early medieval communities interacted with each other, with newcomers, and – especially – how those relationships were intertwined with their management of the pastoral landscapes on which their livelihoods depended.

̽��ֱ��Anglo-Saxon Fenland by Susan Oosthuizen is published by Windgather Press.

What was life in the fens like in the period known as the dark ages? Archaeologist Susan Oosthuizen revisits the history of an iconic wetland in the light of fresh evidence and paints a compelling portrait of communities in tune with their changeable environment. In doing so, she makes an important contribution to a wider understanding of early medieval landscapes.

̽��ֱ��evidence from fenland shows that newcomers were assimilated into late British communities; there was no displacement of populations nor establishment of separate communities.

Susan Oosthuizen

Cattle grazing in the River Ouse water meadows south of Ely

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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Up to four-fifths of wetlands worldwide could be at risk from sea level rise

sc604 — Wed, 24 Feb 2016 08:38:49 +0000

Using a new model to measure the possible effects on wetlands on a global scale, the researchers, from the UK and Germany, modelled the impacts of different scenarios for sea level rise to the end of this century.

They found that even in the event of ‘low’ global sea level rise (around 30 centimetres), much of the world’s wetlands, particularly on ‘micro-tidal’ coasts, are vulnerable. Around 70 percent of the world’s wetlands are found on micro-tidal coasts, where the range between high spring tide and low spring tide is less than two metres, such as in the Mediterranean and the Gulf of Mexico. ̽��ֱ��results are reported in the journal Global and Planetary Change.

Across the globe, wetlands cover more than 750,000 square kilometres, an area more than three times the size of the UK. Coastal wetlands, which include salt marshes, mangrove forests and mud flats, protect against erosion and flooding, provide habitat and food for wildlife, improve water quality, support commercial fisheries, and can store large amounts of carbon.

“Wetlands are particularly sensitive to environmental change, and are being lost worldwide due to human activity, such as conversion to agriculture, and through the effects of climate change, including rising sea levels,” said Dr Tom Spencer of the ̽��ֱ�� of Cambridge’s Department of Geography, the paper’s lead author.

According to the Intergovernmental Panel on Climate Change (IPCC), it is very likely that sea levels will rise during the 21^st century, but by how much depends on a variety of factors, including thermal expansion caused by ocean warming, loss of ice in glaciers and ice sheets, and the reduction of liquid water storage on land.

̽��ֱ��Wetland Global Extent Index, published in 2014, estimates that between 1970 and 2008, natural coastal wetlands declined by nearly 50 percent. A main reason for the high vulnerability of coastal wetlands to sea level rise is coastal ‘squeeze’, a consequence of long-term coastal protection strategies, such as dikes. While dikes provide flood defence to coastal populations and infrastructure, they prevent wetlands from moving landwards and upwards: dikes leave them with nowhere to go.

Wetlands such as salt marshes are made up of grasses and shrubs and are sensitive to environmental change, whereas wetlands such as mangrove forests, since they are trees, are far more resilient, at least in the short term.

Previous attempts to quantify the risk to wetlands posed by rising sea levels have focused on small areas, or have only looked at wetlands being lost through ‘drowning’ of the plants and shrubs, and not at how wetlands will ‘migrate’ inland.

̽��ֱ��model that Spencer and his collaborators from the ̽��ֱ�� of Southampton and Middlesex ̽��ֱ�� in the UK, and the Geographisches Institut and the Global Climate Forum in Germany, have developed assesses biophysical and socio-economic consequences of sea level rise and socio-economic development, taking into account coastal erosion, coastal flooding, wetland change and salinity intrusion.

̽��ֱ��researchers used their model to look at three different sea level rise scenarios (low, medium and high), combined with different scenarios for dike construction (no dikes, widespread dikes and maximum dikes), and assessed what the effect on coastal wetlands would be for each.

They found that if global sea levels rise by 100 centimetres combined with maximum dike construction, global wetland losses may reach 78 percent. For a rise of 50 centimetres, between 46 and 59 percent of coastal wetlands could be lost. For sea level rise around 30 centimetres, wetlands in micro-tidal regions are the most vulnerable.

“What our model does is provide better-informed projections about what might happen to wetlands over the coming century on a global scale,” said Spencer.

One of the issues which the researchers looked at was the use of dikes, seawalls, levees and other forms of coastal protection, and finding the balance between protecting cities and infrastructure from flooding, and protecting the wetlands which also play a key role in flood defences.

“One of the key things this project shows is that we need integrated management of wetlands and coastal protections on a national and international scale,” said Spencer. “Because if you don’t, in many cases if you protect one section of the coast, all you’re doing is moving the problem somewhere else.”

Countering these potential wetland losses will require both global responses such as climate mitigation to minimise sea level rise, and regional responses such as the maximisation of accommodation space and sediment supply on low-lying coasts.

̽��ֱ��researchers have already begun working on the next version of their model, which will also consider the effect that storms have on wetlands.

̽��ֱ��research was supported in part by the European Union.

Reference:
Thomas Spencer et. al. ‘Global coastal wetland change under sea-level rise and related stresses: ̽��ֱ��DIVA Wetland Change Model.’ Global and Planetary Change (2016). DOI: 10.1016/j.gloplacha.2015.12.018

Researchers have modelled how wetlands might respond to rising sea levels, and found that as much as four-fifths of wetlands worldwide could be lost by the end of the century if sea levels continue to rise.

We need integrated management of wetlands and coastal protections on a national and international scale.

Tom Spencer

By Anthony Bley, U.S. Army Corps of Engineers [Public domain], via Wikimedia Commons

Wetlands in Cape May, New Jersey, USA

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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