The International Day of Forests on the 21st March focuses on the vital importance of the world’s forests. It provides an opportunity to reflect on the state of our trees and woodland.
Time to reflect
At some point we seem to have forgotten that we are both part of the natural world and reliant on it for all we need. We have lost sight of the critical interdependence between the health of ‘nature’ and the goods and services upon which we depend. But perhaps there are some sharp reminders of the importance of trees, woodland and other parts of the natural world as fundamental in underpinning our wellbeing – the decline in the number of bees and other pollinators which threatens pollination services with both economic and social consequences for food supply; the loss of forest and tree cover and the increased risk of flooding and soil erosion and release of more carbon in to the atmosphere; the loss and fragmentation of forests and other habitats leading to an accelerating loss of species; and the rapid increase in pests and diseases of trees and forests.
The vulnerability and threats to trees and forests is often highlighted through the unsustainable exploitation and deforestation of rainforests and boreal forests. Although in the UK we may not face this scale of loss, trees and woodland are vital to our wellbeing and to wildlife, and it is critical we protect and restore that which is left and expand tree cover and woodland where it can help deliver the vital services on which we depend.
Resilient wooded landscapes
These are all elements of creating resilient wooded landscapes – landscapes which provide the habitat networks for wildlife, but which also support sustainable productive agriculture, protect water resources, reduce the risk of flooding, and help make towns and cities places where we are pleased to live and work.
The idea of resilience is not new, but has found new importance in the face of climate change, the burgeoning demand for food, economic growth and development and the pressures on the worlds natural resources. How do we ensure that the natural systems can respond to and recover from the disturbances and pressures of change, while still maintaining the functions and diversity we value and on which we rely?
Two concepts emerge as particularly important for developing ecologically resilient systems; diversity and permeability or ecological connectivity.
Broadly speaking, systems with greater genetic, species and structural diversity are likely to be more resilient – more able to absorb and respond to change without losing function. It’s like the old adage of not putting all your eggs in one basket. As systems become simplified and narrowed the possible impact of single catastrophic events grows.
Linked to diversity is the permeability or connectivity in a landscape. Permeability relates to the ease or likelihood of gene flow – the movement of genetic material between populations of plants and animals. This is critical both for supporting genetic diversity upon which evolutionary adaptation is founded, and for supporting recovery from stochastic events, sudden and sometimes catastrophic impacts on individual populations.
Much of the habitat of the UK has become fragmented through habitat loss and developments in agriculture. Many landscapes have become simplified; hedges removed to make it easier for machinery, trees lost over time from fields and boundaries, species rich and unimproved grassland lost, and so on. Diversity and permeability have suffered.
What does all this mean in practice for trees and woodland and the wildlife they support?
Firstly it is vital to protect that which remains. Woodland and trees are the reservoir of woodland wildlife and diversity. It is critical we protect and restore those which we still have. Ancient woodland and ancient trees are critical and irreplaceable elements, but other woods and trees also play a crucial role in supporting wildlife and in adding to the permeability of the landscape.
Secondly we need to take opportunities to expand tree and woodland cover where it can strengthen and buffer existing tree and woodland habitat.
Thirdly we should increase permeability across the landscape through targeted woodland creation and tree planting, particularly where this can form part of other objectives for protecting water resources, reducing flood risk, supporting sustainable farming and developing timber and wood fuel resources.
This is not a hankering for the bucolic landscapes of pre-industrial Britain. We need landscapes which are productive and where we can grow food and the other products we all consume. But these things depend on having a healthy and robust ecosystem – they depend for their productive capacity and resilience on natural systems being themselves resilient.
As we consider the International Day of Forests this year we should think what we can do to reinvigorate our own trees and forests to make them resilient and fit for the challenges ahead.
Mike Townsend, Principle Advisor