Woodlands under threat

Climate change

We are in a climate emergency. Global warming – where the global average temperature rises – is happening at a scary rate, and experts agree that an increase of nearly 3-4^oC could be possible by 2100. The biggest culprit of this change is the greenhouse gas, carbon dioxide, emitted into the atmosphere through human activity like burning fossil fuels and cutting down trees.

Climate change not only affects our wildlife and habitats (our natural capital), but also affects many of our ecosystem services (the benefits we get from natural capital). Thus, it impacts every aspect of society, from disaster risk to food security, economy to health and well-being. In the Chilterns, it will have a major, but unpredictable, influence on the natural beauty and natural capital of the AONB; for example, shifts in the timing of seasonal events, will change how plants and animals live and thrive in our woodlands.

Deforestation is a major contributor to human-caused greenhouse gas emissions. This is because trees capture carbon dioxide from the atmosphere when growing, so deforestation removes an important carbon ‘sink’ that can offset carbon emissions.

Ancient woodlands are under threat from air pollution. Nitrogen pollution is mainly from transport and power stations, and ammonia comes from agriculture, particularly, livestock. As well as ravaging wild plants, woodlands and meadows, air pollution can also have a detrimental and direct effect on our health.

Nitrogen levels in the UK countryside are leading to an increase in nitrogen-tolerant plant species, which out-compete many characteristic native species. This can have a knock-on effect for other species like butterflies. Trees can also directly suffer as they are stripped of their protective lichens, and plants may be more susceptible to damage from drought, frost and diseases.

Lichens are powerful indicators of air pollution. They are sensitive and respond to pollution in short timeframes. Many woodland lichens evolved in naturally low levels of atmospheric nitrogen, so will disappear when faced with polluted air. Assessing the lichen communities of a woodland can provide an indication of its overall health.

Development, transport infrastructure and changes in land use fragment habitats. For trees and woodlands this can mean that hedgerows are severed, farmland monocultured, and ancient woodland sites lost, damaged or reduced. Wildlife habitats need to be big enough and well connected for wildlife to thrive. Species need corridors to move through the landscape in response to a changing environment.

A recent report highlighted that England’s wildlife sites are generally too small and too isolated, leading to a devastating loss of some of our most loved or iconic species. To combat this, we need better and more resilient ecological networks for plants and animals; we need more, bigger, better and joined habitats.

Over many years, there has been a decline in traditional land management, such as grazing, coppicing, the keeping of orchards, the exercise of common rights, and hedge-laying. This has led to the loss of many of our trees and woodlands. The demise of the Chilterns furniture industry has also reduced the need for local timber, so production has slowed right down. Some large estate woodlands have been split into small woods to sell, resulting in inconsistent management, pressure for fencing, access roads and buildings.

Woodland management is important to create the conditions in which wildlife can thrive. Actively managing our woods lets in light and creates different habitats, increasing the mix of tree ages and species in an area. This helps to ensure resilience to climate change, pests and disease.

There are plants and animals in our woods and countryside that have either been introduced from other countries, or spread from one area to another. Sometimes these species don’t cause too much trouble, but at other times, they can have terrible impacts on native wildlife. Examples include non-native muntjac deer and grey squirrels, but there are many more. Deer browse on the young shoots and leaves of trees, often damaging young saplings and creating a ‘browse line’ on mature trees. Grey squirrels can have a similar effect, stripping the bark of young trees, particularly beech and sycamore. They can also eat an entire crop of hazelnuts before they ripen.