Photographs of flooding on proposed housing development site – 17 Jan 2011.
Pollarding – An ancient art
Guest Article by Thibaud Madelin: Thibaud Madelin is the lengthperson for the National Trust River Wey and Godalming Navigations, based at Triggs Lock, Sutton Green. He looks after the section of river between Bowers Lock and Papercourt Lock and controls the flood alleviation weir structures.
There are 57 trees in a pollarding rotation along my length. Some of them have been planted this year and others have stood for over a 100 years. So why are those trees being pollarded?
Pollarding basically means coppicing at head height, to protect regrowth from grazing animals such as cattle or sheep. There are broadly two types of places where you can find pollarded trees. Traditional wood pastures, such as the National Trust’sHatfieldForest, where cattle graze amongst old pollarded trees such as Beech, Oak and Hornbeam, and river sides, where you often find pollarded Willows or Poplars, such as the River Wey Navigations.
First and foremost, pollarding trees doesn’t damage them, in fact quite the opposite. Done properly, pollarding extends the life of the trees, traditionally providing a sustainable supply of firewood or fodder (pollarded Ash and Birch in particular) and shade for livestock or weaving material in the case of willow. Beech and Oak were traditionally cut every 10 to 15 years and many of those trees remain standing and alive today thanks to that practice. The Willows along the navigations are cut on a 3-year rotation due to their astounding rate of regrowth.
Today we do not primarly pollard trees to collect firewood or fodder but to maintain the historic management of the navigations as well as creating valuable habitats for wildlife.
Pollards can live longer that trees that haven’t been pollarded. As a result, as they age they develop hollow, rotten stems, loose bark, sap runs and depressions where water collects. This is turns provide a myriad of opportunities for insects, animals, plants and fungi to thrive as well as the bird life that depend on them.
The pollarded Willows along Papercourt Lock are a prime example of this. Have a close look at the trunk and you’ll see aerial roots, decaying wood, holes and crevasses and yet the trees continue to shoot up at the same rate than those along the Triggs mooring line, which are probably three to four times younger!
The current rotation program along the length also takes into consideration the necessity to retain trees at varying stage of growth so each group of trees is cut over three years, meaning that at any one time you have group of trees at three different stages of regrowth.
If we didn’t continue to pollard those trees, the weight of the regrowth would soon topple the trees over, killing them in the process. Willows, in particular, are inherently designed to grow until they can fall and reshoot upwards from their laid main stem so the work is critical to maintaining the trees as living ecosystems.
Last year we used cuttings from pollarding to plant three new pollards above Triggs Lock Cottage. We made the decision after studying old pictures that showed a line of pollard in that location that had since disappeared. Having this variety of tree ages at different stages of pollarding rotation all along the length allows wildlife to make the most of this resource as well as demonstrates the healthiness of the process and the positive impact it has one the trees themselves. It may sound counterintuitive but the trees like nothing more than a short haircut during the winter! It also emphasize the historic and industrial heritage of the navigations. When a pollard dies, either due to age of other reasons, we always replace it. They are an integral part of a working waterways, a fantastic natural resource and when looked at closely, they provide an amazing diversity of life, from beetles to birds through to bats and fungi.
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