Head of Wildlife Monitoring, Dr Vince Lea, gives his thoughts on how to ensure tree planting and woodland management gives the maximum benefit to wildlife and helps tackle the climate crisis.

There are many large-scale tree planting schemes popping up all over the country, most of which aim to solve two problems – the climate crisis and biodiversity loss. But quality as well as quantity matters when it comes to tree planting just as with hedgerows. We highlighted the latter point during our recent support of the CPRE’s campaign for 40 per cent more hedgerows to be planted across Britain by 2050.

Very little woodland wildlife uses young, healthy well-spaced trees. Many birds nest in the dense thicket provided by a woodland as it regenerates naturally – the spots where hundreds of tree seedlings compete to become that one tree that fills a gap after an old tree has fallen. Butterflies used to occur in coppiced woods, where a regular harvest of trees created clearings full of sunshine providing light for fast-growing ground plants – perfect food for caterpillars. The typical shady conditions of planted woods – often growing on ground with no woodland flora as the land has previously been used for other purposes – offers no opportunity for these species.

Tree cover in England is increasing. In its State of the UK’s Woods and Trees 2021 report, The Woodland Trust said that woodland now covers 13.2 per cent of the UK’s land surface (3.2 million hectares), up from 12 per cent cover in 1998. Yet the number of woodland specialist birds and butterflies continues to decline. This shows that biodiversity is affected by the quality, as well as quantity, of woodland. One of the biggest factors that impacts the quality of woodland habitat is the abundance and variety of deer, half of which are not native species and that have practically no natural predators to control their numbers. Another major issue is grey squirrels, which are far more abundant and destructive than native red squirrels and destroy tree seed crops, especially hazel, before the trees get a chance to propagate. A third problem is tree pests and disease, mainly brought to the UK by global trade in live trees and fresh wood.

A more natural means of creating tree-covered landscapes is to fix the problems that prevent natural regeneration, stand back and let trees grow naturally. Trees have a very different timescale to humans; we are too impatient. Planting large areas of two-year-old saplings in plastic tubes might create a tree-covered landscape in a couple of decades, but is this natural woodland where wildlife thrives? And why do we need the plastic tube? It’s because deer or rabbits are at such a high density that they prevent trees from growing. Reduce, exclude or remove the browsers and trees will set seed and grow without being planted or protected. The random nature of this process creates a far more diverse wildlife habitat.

Coppicing is key in using trees to help tackle the climate crisis

As trees grow, they absorb CO2 and turn it into wood, temporarily helping to reduce atmospheric CO2. But trees don’t live forever – they die, decay and release the CO2 back into the atmosphere. The most rapid absorption of CO2 by trees is in their early years of growth, while mature trees hold the greatest amount of carbon. Trees can play a much bigger role in tackling the climate crisis if we harvest and use them sensibly.

Most native broadleaved trees respond to being cutdown by growing back from the roots. This process, exploited by humans for thousands of years, is known as coppicing. Regenerated tree stems (coppice poles), cut on a regular rotation, used to be a mainstay of local fuel supplies, fencing and building material and could be once again. Burning coppice wood is effectively carbon neutral as the CO2 emitted by burning it is absorbed by the next generation of growing poles. It is how I heat my house.

When it comes to biodiversity, the gaps in the woodland canopy created by coppicing create the conditions required by much of our most rapidly declining woodland wildlife.

We also need to make better use of home-grown timber in England. Many of us are aware that we rely on food imports, but did you know that we produce just 10 per cent of the timber we consume? Using wood as a major component of building would greatly increase the locking away of carbon, reduce the use of energy-intensive manufacturing processes required for steel, brick and concrete in our buildings, and increase the value of a large standing crop of neglected timber. Using home-grown timber also reduces the risk of importing more tree pests and diseases.

By Dr Vince Lea, Head of Wildlife Monitoring

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We received these letters in response to this opinion piece by Dr Vince Lea:

At last! Thanks to The Lark I have at now found another proponent of coppice woodland as part of the mission to improve carbon sequestration. I take issue with Dr V Lea on just one point. His article reads " there are many large scale tree planting schemes...which aim to solve two problems- the climate crisis and biodiversity loss." In reality I think there is regrettably a third, often over riding, aim in too many of those schemes...namely political opportunism and our politicians "being seen" to be doing something.

Coppice woodland , much now sadly overstood, is already widespread in landscapes like those that surround the CRT's properties in Dorset ( I knew Beremarsh Farm v well under its previous ownership). If only it could be brought back into rotational harvesting it could indeed play a significant part in achieving climate change and biodiversity loss. The main barriers for doing so are primarily labour costs and lack of market for the harvested produce. Mechanisation can potentially help mitigate the first of those. Finding markets is harder. Maybe woodchip for heating systems? Regrettably there is limited demand for thatching spars ; wattle sheep hurdles; and bean rods these days!

Matthew Price, Dorset

 

What a great article on tree cover - and very well articulated. Vince makes great sense - am I right to look forward to his answer to the proliferation of rabbits and deer?

In our meadow and the local hedgerows myxomatosis is greatly reducing the enormous numbers of rabbits for the time being. But the deer increase  (a few muntjac now more visible around our part of West Sussex too.) We have more grey squirrels than ever too. What does Vince recommend?

Thanks for the great magazine - congratulations to all involved.

Chris Papworth, Cambridgeshire

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Dr Vince Lea, Head of Wildlife Monitoring, replies to letters from CRT Friends Matthew Price and Chris Papworth:

Many thanks to Matthew and Chris for their encouraging support in response to my article ‘See the wood for the trees’ in the spring edition of The Lark magazine.

The CRT has learnt about how to reduce populations of widespread invasive species from its American mink eradication programme, in partnership with Waterlife Recovery East. We carry out patchwork efforts at control of deer and grey squirrels on our properties. Co-ordinating these efforts, monitoring progress and maintaining effort once the population is in decline are all essential to success.

I am currently looking into whether the CRT can carry out more coordinated and widespread management of deer and grey squirrel numbers, funded by the sale of coppiced wood products from our farms.

The cost of producing small wood products through coppicing in the UK is higher than importing equivalent products from areas with more forest resource and lower wages, so both Matthew and Chris are correct in highlighting the biggest obstacles to achieving this vision. But the potential benefits to both biodiversity and climate challenges mean that, if this approach can be demonstrated as achievable, I believe there will be funding opportunities to support it.

A project like this will need support from neighbouring landowners, so that there are not pockets of woodland where the invasive species can maintain a presence. We’d also need volunteers to get involved and local people to buy the coppiced wood and game products.

Training and supporting people to get into sustainable woodland management is also vital. I have contacted local land management colleges to discuss recruiting apprentices and raised the subject with the landowner community surrounding Lark Rise Farm.

This idea is in the very early stages, but if we can prove the concept in and around one of our properties, I believe this is something that we could roll out to other farms and start a revolution in woodland management.