The theme for World Environment Day 2021 is Ecosystem Restoration. This World Environment Day, we focus on Ancient Woodland. We all know that ecosystem destruction is occurring at an alarming rate and scale which means our attention is often focused on globally significant ecosystems such as mountains, coral reefs, peatlands, or rainforests. And rightly so, the need to save these ecosystems is urgent.
The World Environment Day organisers are keen to point out that many small actions – such as gardening for wildlife, planting trees and beach cleaning – can make a big difference too. As landscape architects working in the built environment, we are always looking for ways to implement these ‘small actions.’ We have a professional duty on any project to seek to enhance the natural environment (in fact it is the first standard in our Code of Conduct), ecology and ecosystem services are always a key consideration.
We are also fortunate enough to work on projects where ecosystem restoration is the focus. We took the opportunity this World Environment Day to revisit an old project, and an old ecosystem, that we are particularly fond of – Ancient Woodland.
What is Ancient Woodland?
Ancient woodland is an ecosystem distinct from other woodlands – owing to their age they have developed unique communities of plants, fungi and animals not found anywhere else. They are the most complex and rich terrestrial habitat in the UK, housing more threatened species than any other. Ancient woodland is woodland that has persisted since 1600 in England and 1750 in Scotland, it now covers just 2.5% of the UK.
Coldfall Wood, Haringey
Coldfall Wood is one of four ancient woods owned and managed by the London Borough of Haringey (the others being Highgate Wood, Queens Wood and Bluebell Wood.)
Working with Haringey Council’s landscape officer, our initial programme of works was to improve the water quality of one of the streams that flows through the wood, and to improve biodiversity and secure the wood’s long-term future by reintroducing the historic coppice cycle.
The stream through the wood was fed by a surface water drain in a nearby road. A number of misconnections had been made into this drain so that grey water from washing machines and dishwashers was entering the system producing a discoloured water course that was pungent in warm weather.
To resolve this we created a necklace of small ponds at the head of the stream, each planted with a range of emergent and marginal plant species to filter the water. The ponds cascade one into the next over a reinforced spillway that acted to oxygenate the water.
Coldfall Wood was historically managed as ‘coppice with standards’. This is a system that produces both standard trees – large timber trees that could be used for things like construction or ship-building – at a density of 12 trees per acre. These would be underplanted with a coppice species, cut on a short rotation to produce small size timber to be used, depending on the species, for things like chair making, besoms, charcoal making or firewood. The coppice species at Coldfall Wood is hornbeam.
The coppice had not been managed for a number of years, so the hornbeam had formed a dense under-storey, allowing very little light to the ground, leading to a bare woodland floor with very little planting and a dense layer of fallen leaves. Reintroducing the coppice cycle allowed light to be readmitted to the woodland floor and the seed bank of species, some of which will have been waiting for many years for an opportunity to germinate, burst into life providing a far greater range of species and habitats.
Coppicing is carried out in a number of small coupes yearly and only a small part of the wood is felled at any one time. There were also a number of tree species present that, if not removed, could start to colonise the newly opened up woodland. These include silver birch and Turkey oak.
Coldfall Wood also has a path system through it which crosses the stream several times. The final part of our involvement on the site was to create bridges and a boardwalk to allow easy circulation at all times of year.