The UK is home to some of the most valued and treasured wildlife habitats in the world. Our woodlands, some dating back more than five centuries, contain ecosystems which are irreplaceable. The need for more tree planting, and to protect what we value, is high on the political agenda. And yet annual surveys over the past few years indicate a decline in the quality of these features. Is our management approach part of the problem, rather than the solution which is needed?
Nature is ready good at reclaiming abandoned sites devastated by heavy industry, and, as any gardener will vouch, ground left uncultivated is soon colonised by scrub and self-set saplings of Birch, Ash and Sycamore. When young trees are planted, whether in a large-scale forest setting or individually in a landscaped feature, they are often afforded little post-planting attention. The prevailing view for woodlands seems to be one of non-intervention being preferable, to let nature take the lead, and see what happens.
The principle behind this view would seem to be that the natural succession which occurs when a site is colonised will see a return to the original habitat. The problem with this view is that much of the landscape, in the UK at least, has been subject to human intervention for several millennia, and we often don’t know what the original feature was. The landscape that either we are seeking to restore, or to recreate, may not have the key original elements present. They may be very sensitive to change and profoundly difficult to recreate. If heavily shading species, such as Sycamore and Alder prevail, diversity can easily be lost.
Back in the 1980s, in the early days when the planning process was attempting to minimise the impact of developments on wildlife, a supermarket tried to move a meadow to a new location, lifting the surface turf, to a depth of 150mm. The problem was that the turf did not like the new home, and it was soon colonised by invasive weeds, the original feature being lost as a result.
Healthy woodland is not a static feature which remains unchanged over the centuries, nor is it one with trees and only trees. Other elements can actually be the more important. It should include open spaces, ideally a source of water and a healthy ground layer with shrubs and fauna habitation.
In centuries past, a woodland was actively managed as a source of forage and fuel. The autumn supply of acorns, known as panaage, was an important source of feed for pigs, which provided winter meat for the labourers. Indeed, woodland was measured in size by the number of pigs its pannage could support. 2017 marks the 800th anniversary of the Forest Charter, when the commoners were given access to this key resource, an occasion marked by the Woodland Trust’s Tree Charter.
Trees are important, but they are often not the pinnacle we think they may be. Heathland is a valuable habitat, especially for lepidoptera, but without active management, is easily encroached by scrubland. There seems to be genuine confusion regarding best practice regarding conservation management. On the edge of Ledbury in Herefordshire is a wooded area whose timber has sustained the town for centuries. Heathland is being encroached by scrub and attempts to clear a wooded ridge to encourage butterfly-friendly ground cover were abandoned after more time was spent explaining the work to numerous local visitors than clearing the ground. Felling trees seemed contrary to conservation.
Another part of this site contains young woodland, the tree population already too dense to allow sunlight to penetrate to the depths and spindly saplings, the trunks too thin to sustain mature growth, compete for space. The official policy is to only intervene when safety is an issue. Historic photography shows the site having been clear-felled for timber fifty years early, providing space for regeneration.
For conservation to be effective, we need to determine the aims. Few habitats remain unchanged, and sometimes the management is radical. For example, in order to maintain veteran trees, and provide them with the space they need, other trees may need to be felled. One site I am managing, with veteran Hornbeam, requires the removal of heavy Yew trees, which are crowding it. Natural regeneration can harm the ecosystem we are seeking to protect. The seedlings compete for site, water and nutrients, and unchecked, the soil can become dry and ill-equipped to sustain the trees that matter.
Conservation management needs careful thought and planning. To be effective, we need to determine the overall aim of the approach, and recognise site constraints. There can be historic elements which can easily be overlooked but are actually significant. For example, one woodland site used as a military training base since the Second World War developed significant, endangered species of fungi on the trees. The fungi was able to thrive due to the bark wounds caused by bullets used on training exercises. When the woodland was deemed surplus to military requirements, the army was soon being invited to return to ensure an on-going supply of bullet wounds was maintained.
There is an issue of lack of appreciation. Some estate managers speak with pride of the lack of intervention in woodland management, not appreciating the consequences of this inaction. Education is needed, as is demonstration and explanation of best practice. The 30th anniversary of the Great Storm has recently been marked. This event caused devastation to the landscape in large parts of the south-east. Yet our knowledge of trees developed considerably as the hollow specimens survived and many healthy trees blew over.
One unexpected element was how nature took advantage of clearings in woodlands. Fauna soon sprang up, enjoying the space. Many of these landscapes have recovered, as nature does what comes naturally. It would truly be a loss if the lessons of thirty years ago do not continue, and our habitats decline through lack of management.