Blog post by UBoC scientists George Porton and Robyn Wrigley, who are based at the University of Leeds
The characteristic open landscapes of the uplands in England, such as the Lake District, Dartmoor and Yorkshire Dales, are loved by many. However, these are not natural landscapes and are often in poor ecological condition, with overgrazing by sheep a major factor.
Sheep have a narrow jaw, with curved incisors that allows them to be highly selective in their grazing behaviour. They will target specific plant species that contain the most nutrients, meaning the vegetation becomes less varied over time and dominated by less palatable grass species. On top of this, they are even able to consume specific parts of individual plants, such as flowers and young shoots, which can supress plant regeneration further accelerating the loss of plant diversity.
Reducing the intensity of sheep grazing is often seen as the solution, but their high selectivity means the benefit to biodiversity can be limited. Changing the grazing animal could be the answer instead.
Cattle graze in a very different way to sheep. Whilst cattle grazing at a high intensity will still have negative effects to biodiversity, low intensity grazing by cattle is likely to beneficial. Unlike sheep, they use their tongues to pull out taller patches of grass and herbs. This helps create more diverse habitats, with greater variety of species and vegetation structures, and smaller wildflowers have more space to thrive.
Cattle are expected to benefit biodiversity in other ways too. They are much heavier than sheep and so their trampling creates bare, disturbed soil, allowing new plants to colonise and seeds to germinate. They are also very effective at transporting seeds in their coats, hooves and dung.
It is widely accepted that moving from sheep to cattle will benefit biodiversity and many restoration projects have already made the switch. Although the mechanisms are well understood there is limited evidence that it actually works.
A UBoC case study: Wild Ingleborough
Wild Ingleborough is a landscape scale restoration project in the Yorkshire Dales National Park. Starting in 2021, it builds on decades of work by Natural England and Yorkshire Wildlife Trust on their nature reserves in the area. UBoC is a key partner within the project, collaborating with the University of Leeds to lead the scientific research happening on site.
One of the main changes in land management has been replacing low intensity sheep grazing with low intensity cattle grazing. Hardy native breeds like Red Polls, Shorthorns and Belted Galloways now roam large areas, a process started in 2004. But has this had the expected benefits to biodiversity? The evidence from long term monitoring suggests the answer is yes!
Firstly, the diversity of plant species and quality of habitats increased. After 18 years of cattle grazing, the number of species increased by over 40%. There was also an increase in the frequency of wildflower species, such as Eyebrights, Bird’s-foot trefoil and Fairy flax, indicating an increase in the quality of the habitat. The study took place on limestone grasslands, which are incredibly diverse habitats and important to biodiversity. In even as small an area as 4m² we were finding around an average of 30 different species!
Secondly, cattle grazing has allowed trees to start regenerating naturally – something that was not happening under sheep grazing. The arrival of trees to a site that was predominantly grassland is increasing the range of habitats available. It is hoped with time that Wild Ingleborough will be mosaic of habitats, ranging from woodlands to high quality grasslands and everything in between.
Lastly, cattle grazing supported five times the number of butterflies and twice as many species as sheep grazed sites. Butterflies are excellent indicators of ecosystem health as they require a diverse ecosystem for food, breeding and shelter. Restoration of vegetation has likely increased food plants for caterpillars and nectar sources for butterflies.
A way forward?
In the UK uplands, sheep farming is often pitted against rewilding projects, where livestock are often excluded. Low-intensity cattle grazing, like that at Wild Ingleborough, could provide a way for farming and nature restoration to coexist.
For farmers it importantly means food production can continue. The cattle at Wild Ingleborough produce high-quality meat and need little extra input, receiving feed only when snow covers the ground. It is an uncertain time for upland farmers and support needs to be in place to enable such a transition.
For nature restoration projects it highlights that grazing by large herbivores like cattle is a critical process in maintaining the diversity and quality of grasslands. Large herbivores are a natural part of our landscapes and have shaped habitats for thousands of years – the bones of the cattle’s wild ancestor, the Aurochs, have been found in caves in the region. The diversity of grasslands at the site would decline if livestock were removed altogether.
While the shift to cattle has been successful at Wild Ingleborough, it should not be considered a one-size-fits-all solution. A greater diversity of herbivores, such a ponies, are likely to benefit nature restoration even further. Historically, a wider range of grazing animals would have been present, creating diverse habitats across the landscape.
