State of Nature 2023: What report tells us about UK trees and hedgerows
There is a lot of work to be done...
The landmark State of Nature Report 2023 is now available, and it makes for fairly disheartening reading. This fourth edition, following previous releases in 2013, 2016 and 2019, collates the work of more than 60 research and conservation organisations assessing the current status of the UK’s plants, animals and ecosystems.
The report paints a sobering picture.
Shockingly, it states that nearly one sixth of UK species are at risk of extinction (they are assessed as threatened by the IUCN Red List) and that, on average, monitored populations of UK species have declined by 19% since 1970. On the plus side, the report does showcase some more positive news, alongside conservation success stories, to demonstrate the power of coming together to act for nature.
What does the State of Nature Report 2023 mean for trees?
One of the key aspects of the report is understanding how the status of UK species has changed over time, with different monitoring programmes allowing different metrics to be calculated to demonstrate this.
Those relevant to trees include changes in vascular plant distribution, and in woodland cover. In terms of distribution change, vascular plants were found to have decreased by 16% on average between 1970 and 2019 – of the species monitored, 54% had decreased in distribution, 31% showed little change and 15% increased.
While this is a very broad taxonomic group and may not accurately reflect changes in tree distribution, the pressures mentioned as explanatory factors are also relevant to tree species: namely changes to agricultural practices, climate change and reductions in bogland and heathland habitats.
Woodland cover
With respect to woodland cover, the historical trend shows little change since 1998 – woodland cover in the UK has increased slightly from 12% in 1998 to 13% in 2022 (although it is worth noting that the 1998 baseline used here represents a highly deforested landscape). 2.5% of this 13% is ancient woodland cover, and the UK is estimated to have at least 123,000 ancient and veteran trees.
Alongside these historical trends, it is important to consider the current status of the UK’s ecosystems, as metrics such as ‘woodland cover’ measure only the quantity of woodland habitat, not the quality. To assess woodland health, the report refers to the Woodland Ecological Condition assessment carried out by Forest Research in 2020.
This assessment was based on different factors which influence woodland condition; such as number of veteran trees, diversity of tree species and structures and amount of deadwood. Woodland stands were scored based on these indicators and then categorised as either favourable, intermediate or unfavourable condition.
Unfortunately, only 7% of native woodland stands in Great Britain are in favourable condition, with 92% classed as intermediate and 1% in unfavourable. This demonstrates that despite increases in woodland cover, progress is needed to ensure these areas are ecologically viable, and issues of fragmentation, habitat degradation and lack of management need to be addressed to ensure woodland wildlife can thrive.
Trees outside woodlands
It was great to see the report recognise the value that trees outside of woodlands, and well managed hedgerows, can provide in this context. They are vital corridors between fragmented woodlands which can help movement of wildlife between these patches. These features are also important for biodiversity and tree cover in their own right but are frequently overlooked – something we’re trying to change here at The Tree Council!
Alongside some of the more concerning statistics, the State of Nature also provides some positive news in the form of conservation success stories. One of the focus areas is the importance of urban greenspaces and urban ecosystem restoration, with the example of the Tiny Forests project.
Again, it’s really great to see these initiatives getting recognition, as community tree planting projects are a valuable way of connecting people with nature; as well as providing benefits to biodiversity, clean air and climate change mitigation. In addition, they help contribute to Local Authority tree planting targets and the broader target to increase tree cover in England to 16.5% percent of total land area, as set out in the Environmental Improvement Plan (EIP) - and discussed by my Tree Council colleague, Jess Allan here.
The EIP and other updated agricultural and environmental policies that are being put in place post-Brexit provide important opportunities for progress, for example by encouraging nature-friendly farming through strategies like improved hedgerow management.
Importance of action
Overall, the report reflects the current struggle that nature in the UK is facing and the importance of taking action.
The focus on woodlands is a positive recognition of the importance of these treescapes to nature in the UK, but further focus on the value and status of hedgerows and trees outside of woodlands would have added dimension to these discussions and would be an important inclusion in future reports.
Finally, the report demonstrates the power of people acting together to protect nature, and the importance of the citizen science projects that contribute to the data collection that underpins these evaluations.
Charlotte Benham is The Tree Council’s Science and Research Projects Officer
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