Roselle Chapman - Community Ecologist & Camilla Burrow (CEO)
Trees are wondrous, no doubt about it. The ancient and veteran variety towering majestically above us, providing shelter and food to countless other species, securing soil with their network of roots, and communicating to other plants and symbiotic mycorrhizal fungi via chemical transfers. England has more large ancient Oaks than any other country in Europe; the Great Park of Oxfordshire’s Blenheim Palace alone has 143 oaks which are over6m in girth.
People are rightly passionate about protecting existing trees and planting new ones. In fact, many people see tree-planting as the answer to sucking up all the carbon we're releasing, a quick-fix letting us 'off the hook' from adopting a low-carbon economy. But there's tree planting and tree-planting...
The soils and worms of a woodland are just as important as the visible trees, as well as the midstory bushes and the low-growing flowers and fungi. All are essential components of the ecosystem, unique, and irreplaceable, having taken thousands of years to evolve and develop. So, planting saplings into an empty field will not result in the biodiversity or carbon-capture benefits some may imagine because the soil microorganisms and seed bed won't exist there.
In Oxfordshire we have many rare and valuable habitats which are in dire need of our efforts to conserve them. In a country that has lost 97% of its meadowland since the 1930s, Oxfordshire has some of the rarest and finest species-rich remaining grasslands, which are an intrinsic part of our natural and cultural heritage. Oxfordshire covers an area of 259,800 ha of which the key grassland habitats include floodplain grazing marsh (4503 ha), hay meadows (1220 ha), limestone and chalk grasslands (778 ha) and acid grasslands (48 ha). Similarly, our wetland habitats, such as lowland fens, reedbeds and ponds are declining in both area and quality. Both wetland and grassland habitats are not only fantastic habitats for biodiversity but provide multiple ecosystem services and are significant Carbon sinks. In the most comprehensive report to date on the impact of the nation’s landscape on carbon storage and sequestration, researchers found that peatlands and native woodlands are habitats which have the greatest capacity to store carbon, but traditionally managing habitats such as hedgerows, hay meadows, heathlands and old orchards is a very important way of preserving carbon stocks and wildlife that may have taken centuries to develop1.
Thames Valley Environmental Records Centre calculated that priority habitats in Berkshire and Oxfordshire store over 1.1 million tonnes of carbon and sequester at least 65,000 tonnes of carbon annually2. The Floodplain Meadows Partnership have produced an artistic graphic which depicts the root depth of typical meadow plants to demonstrate their underestimated importance for carbon storage3. Protecting, restoring and expanding these habitats will not just benefit biodiversity but will sequester carbon as well.
A recent study from the Oxfordshire based UK Centre for Ecology & Hydrology (UKCEH)provides direct empirical evidence that passive rewilding has the potential to expand native woodland habitat at very low cost and within relatively short timescales, potentially generating valuable successional habitats for biodiversity4. Passive rewilding can expand and buffer existing woods or create new woodland patches to diversify intensive farmland and act as sources for further expansion. Natural growth due to seed dispersal by birds, mammals and wind can produce biodiverse and resilient woodland, while avoiding the cost, management and plastic tubing involved in planting schemes5. There are opportunities to create new patches of habitat and hedgerows within farmed landscapes for biodiversity and carbon storage; check out our guidance on Hedgerow Heroes6. The Allerton Project is developing a Hedgerow Carbon Code7, which will encourage hedgerow habitat improvements and provide a tool to calculate the carbon capture potential of hedgerows.
So, what should we do?
For communities, land managers and farmers, it's essential to take a balanced and holistic approach, ensuring you are making informed decisions about what action to take. The best outcome is that Oxfordshire’s landscape is maintained and enhanced with a mosaic of habitats, including trees, grasslands and wetlands.
Consider what is already on your land by carrying out a survey and checking what data on species, habitats and designations is available from Thames Valley Environmental Records Centre8. Consider the wider landscape context - does the land fall into one of the three Area of Outstanding Natural Beauty in Oxfordshire? Which zone of the Nature Recovery Network is your land in9?
There are many actions which can be taken to maximise the biodiversity benefits of existing habitats. Existing hedgerows can have their gaps filled, be trimmed back less vigorously and frequently, allowing some hedgerow trees to grow taller. Existing woodland can be managed more proactively to increase biodiversity and protected from harm with buffers of grassland. And grasslands can be grazed less intensively, with different breeds, or cut for hay. Our Yellow Wagtail project is exploring how changes in land and livestock management such as reduced use of pesticides, herbicides and worming treatments can be massively beneficial too10. Streams, ditches, ponds and wetlands all contribute significantly to biodiversity and provide opportunities for flood mitigation; as demonstrated by the Evenlode Catchmentcase studies11.
If you are a community group, then our Community Ecologist Roselle12 will be able to help you with bespoke guidance and advice.
If you are within west Oxfordshire, then contact the Wychwood Forest Trust 13 who manage a number of nature reserves within the boundary of the former Wychwood Forest in west Oxfordshire. As well as various established habitats these include restoration sites where both considered tree planting and natural regeneration techniques are used. They can provide advice to parishes and landowners on appropriate habitat creation options, and also guidance on the ‘right tree in the right place’. They also offer conservation volunteering opportunities and regular hedge laying and dry-stone walling training courses.
If you are within any of the three Areas of Outstanding Natural Beauty, then they may also be able to help. The Chilterns14, North Wessex Downs15 and Cotswolds16 AONBs arecoordinating Farming in Protected Landscapes which help farmers and land managers to carry out projects that support nature’s recovery, mitigate the impacts of climate change, provide opportunities for people to discover, enjoy and understand the landscape and cultural heritage, or support nature-friendly, sustainable farm businesses.
If you are a landowner anywhere else in Berkshire, Oxfordshire or Buckinghamshire, then Thames Valley Environmental Record Centre's17 highly qualified and experienced ecologists can carry out ecological surveys and provide management advice for nature conservation purposes and Berks, Bucks and Oxon Land Advice Service18 can give advice to landowners and farmers about how trees and wildlife could be integrated into your land management. If you do decide to plant trees, then use the Wild Oxfordshire Guide for appropriate species, and our guidance on Hedgerows.
So, I would never say Don't Plant Trees (and I challenge anyone to resist hugging a gnarly beech or ancient oak!) but do consider all the options so you make the best choice for you, your land, and natures recovery.
1 R Gregg, J. L. Elias, I Alonso, I.E. Crosher and P Muto and M.D. Morecroft (2021) Carbon storage and sequestration by habitat: a review of the evidence (second edition) Natural England Research Report NERR094. Natural England, York.