On 14 April, the Woodland Trust released The State of the UK’s Woods and Trees 2021 – the first report into the state of trees and woodland in the UK.
This comprehensive report uses the best available data to give an overall picture of the extent and types of British woodland, the threats they currently face, and best practice for management going forward. The following highlights will be of particular interest to anybody involved in the NHS Forest or those considering whether and how to undertake tree planting at their healthcare sites.
Expanding tree cover in the UK is a priority for both environmental and social reasons. To meet the UK government’s ambitions for woodland creation, tree planting needs to take place at a rate of 33,000-50,000 hectares per year. However, the average rate for the past five years is under 10,000 ha per year. This means we need to quadruple this woodland creation rate, whilst following the fundamental guiding principle of the right tree, in the right place, for the right reason, and by the right method.
Accessible woodland and urban trees
In 2020, just 16.2% of the UK’s population had accessible woodland nearby (woodland of at least 2 ha within 500m of their homes), while two thirds had accessible woodland of at least 20 ha within 4km of their homes. Both these figures have fallen since 2016, due to factors such as the fencing off of previously accessible woodland. Increasing access rights would give another 37% of the UK’s population woodland access within 500m of their homes, and 22.8% within 4km of their homes. However, 41.8% of people have no woodland at all (whether public or private) within 500m of their homes, a figure which clearly underscores the need to increase tree cover in the most nature-deprived parts of the country.
In urban areas, the average tree canopy cover is around 16% but can be as low as 2%. An increase in planting urban trees would have a positive impact on air pollution, noise pollution, and wellbeing, amongst other issues. Annual financial benefits (carbon sequestration and storage, pollution removal, and avoided runoff) from urban trees have been calculated at over £33 million in Greater Manchester, or, at a smaller scale, £134,798 at the University of Leeds. These figures are from the measured benefits only; the public health impact in saved costs to the healthcare system would add even more!
Whilst quantification is complicated, this demonstrates that benefits even at a small scale are substantial – large hospital sites stand to gain much more from tree planting than they spend.
The Woodland Trust has been very successful in engaging schools, with their Green Schools Award, and with tree planting – 70%, 40% and 23% of all schools in the UK respectively. The NHS Forest can be inspired by this success rate, which demonstrates that amongst the public in all walks of life there is an appetite to learn about, engage with, and plant trees. Accessible green space, whether in school grounds or healthcare settings, inspires people to connect with nature and leads to a greater sense of responsibility for the natural environment, improving the health of people and planet simultaneously.
Ancient woodlands store a disproportionate amount of carbon. Despite comprising just 25% of woodland in Great Britain, they store 36% of woodland carbon in living trees, a total estimated at 77 million tonnes of carbon; their undisturbed soils could sequester even more. Native broadleaf woodlands are of key importance to support the whole spectrum of species richness beyond trees, in particular flowering plants. Locating newly planted native broadleaf trees adjacent to ancient woodland sites can encourage the spread of plants that thrive in ancient woodland environment, such as native British bluebells, wood anemones, primrose and sorrel.
One of the biggest threats identified in the report was inappropriate woodland management. This underscores the need for clear management plans and ongoing monitoring, and The Woodland Trust emphasises the use of citizen scientists to record species and monitor tree conditions throughout the document. This could be a great opportunity to encourage local community involvement and engagement in the care and protection of woodlands.
Trees outside woodland (TOWs) are given particular attention in the report. These have experienced a steep decline since the 1600s but they increase connectivity, provide habitats and contribute to a sense of place and personal relationship with individual trees that is important for wellbeing and cultural appreciation of trees.
Estimates suggest that 30-50% of all countryside TOWs have been lost in the past 150 years; a figure that will get worse with ash dieback. Individual or hedgerow trees have a great positive impact on biodiversity and the environment and can be landmarks that people connect with in the landscape; grounds containing such trees should have management plans in place for them.
This also applies to ancient and veteran trees in the landscape. The report highlights their particular importance, underlining the need to consider ‘the right tree in the right place’ when tree planting, and think in ‘tree time’ – tree planting is not a quick-fix that requires only thinking into the next ten years to ensure that trees won’t be cut down. The ecological, historical and social value of trees increases exponentially as they age, and they should be given every fair chance to do so. This includes ensuring they are not subject to undue grazing pressure, soil compaction, or over-shading by younger trees.
Imports of saplings have been one of the main ways that devastating tree diseases such as ash dieback have spread into the UK. Import controls are not sufficient to keep out known pests and diseases, and there is also a constant risk of importing unknown problems. The long-term ecological, cultural and environmental cost of ash dieback alone is predicted to be £15 billion. Therefore, biosecurity needs to be a key concern going forward.
Tree procurement should be of trees grown in the UK and use established assurance schemes such as UKISG (UK and Ireland Sourced and Grown), to ensure that no accidental import of tree pests and diseases can take place. Locally collected seeds are more likely to be adapted to locally prevalent pressures such as tree disease or drought. Plant Healthy, is a new, voluntary biosecurity standard in the plant health industry. Trees which are both UKSIG and Plant Healthy are preferred; if the seeds are locally collected, all the better, and this is the gold standard. Native tree seed supply is however a potential bottleneck as demand for UKSIG trees increases.
Of key importance in the future is consistent monitoring of the effect of tree planting on flood prevention. There is a national lack of metrics to assess this and if the evidence for nature-based flood management solutions is to be convincing, monitoring should take place. One case study in the south Lake District demonstrated that, after eight years, tree planting had markedly decreased the speed of water flow – it had also increased biodiversity of other plant and animal species at the site, demonstrating the multifaceted benefits gained from nature-based solutions.
NHS sites can use their role as an anchor institution to improve the future of their local community and environment by engaging in tree planting to mitigate flood risk and contribute to their target of Net Zero carbon emissions.
There are numerous issues threatening the health of British woods and trees, from grazing pressure to imported diseases and pests. However, public appetite for tree planting and understanding of the importance of trees for climatic, environmental, biodiversity and social wellbeing has never been higher.
Woodland creation and tree planting rates must increase to meet government targets for tree cover nationally. When considering woodland creation schemes, paying attention to the potential to expand the area of native woodland, create functional habitat connectivity across a landscape, and choose tree species that will provide interest and benefit to the local communities around them.