Beavers and river restoration boost resilience to drought, conservationists say

Yahoo

2 days ago

Restoring rivers to a natural state and introducing beavers can help make landscapes resilient to the increasing risk of drought, conservationists said.
The UK is facing increasing extremes such as drought and heavy downpours as the climate changes, with England weathering the driest spring for 132 years this year and two regions in the north of the country already in drought.
But in the South West of England, after the region saw around half the average rainfall in spring, river restoration work maintained lush vegetation and wetlands at the National Trust's Holnicote estate on Exmoor, Somerset.
The National Trust embarked on its 'riverlands' project on the estate in 2020, releasing beavers into two enclosures and working to restore the River Aller to a 'stage zero' state with multiple channels, pools and shallow riffles as it would have had before human interference.
The approach has been pioneered in Oregon in the US, and the UK's first attempt at scale on a main river landscape involved diggers moving more than 4,000 tonnes of earth to fill the river channel and laying hundreds of logs within the floodplain.
Thousands of wetland trees were planted and wildflower seeds sown to attract pollinators.
The project to give the river space and connect to its floodplain, completed just two years ago, has created a new natural landscape from once neat agricultural fields, with channels, pools, wetlands and marshes.
The wetlands are rich in plants, the young trees are starting to grow and meadows in the floodplain are full of wildflowers.
The landscape – along with the nearby beaver wet woodland – slows down the flow of water and holds it in the landscape to reduce flooding and counteract drought, as well as reducing pollution and loss of sediment, the Trust said.
The wetlands that have been created are habitat for water voles, as well as an array of birds, insects and fish including eels.
Ben Eardley, senior project manager for the National Trust in Somerset, said curbing flooding was a big part of the reason for the project, with communities downstream at Allerford and Bossington suffering from floods in the past.
'But then increasingly, you can see the impacts of hotter dry weather which I think are equally important in addressing,' he said.
While some restoration schemes only improve the river channel itself, the work at Holnicote makes the wider landscape more resilient, he suggested.
Even after the dry spring, the beaver enclosures, where the animals have created pools, dams and woodland clearings, were still 'brim full' of water, while the restored river catchment stays wet year-round, Mr Eardley said.
The denser vegetation acts like a blanket on the soil, holding moisture in and keeping the soil temperature more consistent, he added.
'It's a combination of different things that lead to more resilience.
'And it's not saying that you have to have all of those things everywhere, but if you've got more diverse landscape with a greater mosaic of different habitats. then just by default, you'll have greater resilience,' he said.
Farmers and landowners are among those who visit the 'exemplar' river restoration project, which comes amid intense debate over competing uses of land in the UK – for food security, energy production, climate action and to help restore nature and natural processes that can benefit people.
Mr Eardley argues that it does not have to be a binary choice between beavers or river restoration and agriculture, but land could be managed to provide both, with benefits for landscapes which are suffering more extreme weather throughout the year as the climate changes.
'You might need to sacrifice some small areas for beaver habitat or whatever.
'But then in that wider landscape you're going to have better, lusher grazing for longer, during those summer months, whereas before, everything would have burnt off,' he said.
'Because you've got higher groundwater levels, your soil and your vegetation are healthier.'
Stewart Clarke, senior national freshwater consultant at the National Trust said: 'Water is at the forefront of climate change impacts including flooding and drought, and after a very dry first six months of the year and with many UK regions either in or on the cusp of being in drought conditions, looking after the lifeblood of our landscapes is absolutely vital.'
He said that giving rivers more space could create 'nature-rich corridors' through towns and countryside, store water during floods and droughts and give rivers space to adapt to changing flows.
The riverlands project is one of a number of schemes the trust had undertaken to 'future proof' rivers, he said, adding: 'The new stage 0 wetland, and the beaver wetlands which it resembles, have created important stores of water and carbon to help in the fight against climate change.
'Over the coming years we aim to create and restore hundreds of such wetlands both for these benefits to people and for the rich wildlife they can support.'
And while the Holnicote beavers are currently in enclosures – though prone to escaping – following the Government's recent decision to allow licensed beaver releases into the wild in England, the National Trust is applying to be able to have wild beavers on the estate.
Then the beavers could link up with the stage 0 river landscape, and ultimately take over its management in their role as ecosystem engineers.