One Tree Hill
© Daniel James Greenwood 2013
Bramble (Rubus frusticosus) is a point of contention. This is a common plant in gardens, alongside railway lines, in woodland and parks. Through the summer and into autumn ripe blackberries are a delicious and easy feed for humans and animals alike, the only price you pay is the odd nip from a thorn or a scratch to the tummy reaching for the highest bunch of all. The gobbling of blackberries by animals and their ultimate evacuation is one of the main ways the plant colonises new ground. In my family we have a dense lot of bramble at the back of the garden which, traditionally, my mother picks for fruit and freezes through the winter. Blackberries work wonderfully in pies, their bloody juices swamping the mixture of apples and sugar, colouring the innards a fantastic pink.
In the open and wild landscape of woodland bramble can be invasive, encroaching on grassland, rides and glades until wildflowers are shaded-out. A happy medium can be drawn by the technique of ‘scalloping’ along pathways and rides or in glades. This can be achieved with a grass hook or slasher, or else with the petrol power of a brushcutter. By cutting messy semi-circles into the shrub layer the bramble is pushed back, but not completely, and hopefully wild flowers will thrive with the new light which reaches the soil. The biodiversity is improved all round. In the autumn we brushcut the woodland ride of Cox’s Walk in Sydenham Hill Wood and the next day I accidentally flushed a green woodpecker (Picus viridis) which was feeding on insects in the newly cut scallop.
In the summer months bramble is a good place to spot butterflies. Comma (Polygonia c-album) and red admiral (Vanessa atalanta) can lay their eggs on bramble, and speckled wood (Parage aegaria) is commonly seen sunning its brown wings on a bramble leaf. Last year on Cox’s Walk we found a dying purple hairstreak (Quercusia quercus) amongst bramble, a butterfly which is tied to oaks (hence its Latin name) and should really have been ferrying between the canopy above. Bramble is not a good sign for wildflowers in woodland because it points to nitrogen-rich soil which promotes common nettle (Urtica dioica) more than anything.
However, the problem with labelling plants as wholly good or bad was emphasised to me recently when a group of teenage volunteers were working in One Tree Hill to push back the bramble from the acid grassland patch. They did an excellent job and opened up a patch which will hopefully be reclaimed by a diverse array of acid grassland flora in the growing season. But as we enjoyed a break, we glimpsed a small mammal, possibly a wood mouse, but small enough to be a harvest mouse, climbing through the last line of bramble. The red bramble leaves were frost-covered. This beautiful mixture of ice and vibrant colouring, and the tiny creature escaping to safety made me wince at the thought: bramble, good or bad?
This was the first workday for the Friends of One Tree Hill (FrOTH). We coppiced 10 sycamore (Acer pseudoplatanus) trees and cut back the bramble (Rubus frusticosus) which is so dominant on the site. In the case of sycamore we were felling trees of some thirty-feet or more in height that were competing with the sessile oak trees (Quercus patrea). These oaks are regenerating on the slope of the south-facing hill and are slow growers compared to the highly successful sycamore. We felled the trees also to allow light in and let the herb layer regenerate. This is a technique which helps insects and butterflies in particular. PlantLife reports that by 2002 97% of British broadleaf woodland had become high forest. In 1951 that figure was at 51%. This means that most of our woodland is dark and overgrown generally because humans have stopped relying on woodland as a resource for firewood, furniture, grazing of livestock and so on. One of the great misconceptions about woodland is that felling a tree is somehow a bad thing when, on the contrary, wildlife flourishes when trees are cut down in moderation and sunlight can get in to bring life to the woodland floor.
One ancient tradition which has gone out of fashion is the art of coppicing. This is a process of cutting a tree down to its base, generally of hazel (Corylus avellana) or ash (Fraxinus excelsior), which means that the tree shoots new, straight growths. These poles were used for a variety of things, often as fencing. Sycamore is not a typical coppice tree, but the stumps we cut down to in One Tree Hill will shoot similar growths in the spring and summer. In the meantime the wood we have cut will be used either to make log piles for beetles and other bugs to inhabit, otherwise the material will be used to make handrails or deadhedges in the wood. The point of managing a wood in this way is to show that using the material, i.e. trees, is not a negative thing and can boost wildlife in the short term. The Pearl-bordered fritillary (Boloria euphrosyne) is one butterfly which saw a decline in numbers after the tradition of coppicing declined in the 20th century after we began to rely on gas to heat our homes and use wood imported from overseas. You can see that a tree has been coppiced if you spot thin shoots and the hairy green leaves of a hazel. This technique is renowned for its benefits for wildflowers such as wild primrose (Primula vulgaris) and bluebells (Hyacinthoides non-scripta) which can burst into life when the coppice is cut. These are plants indicative of ancient woodland and seeing as One Tree Hill is located in the area which was once part of London’s Great North Wood, we are hoping that some plants, in certain areas, could reappear one day, not to mention the wildlife which feeds from them. Sydenham Hill & Dulwich Woods and Dulwich Upper Wood are two fragments of the Great North Wood which have ancient woodland flora growing there, and have done for thousands of years. Perhaps one day One Tree Hill can be in a similar vein of health.
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