Trees not so common on the Common: Beech, Hornbeam, Alder

Trees not so common on the Common: Beech, Hornbeam, Alder

As we draw to the end of our series on trees and shrubs, there are three trees which are quite common across the country but currently rare on the Common. Next week we will look at shrubs and the last in our series will focus on a few unwelcome ‘Invasives’.

Beech belongs to the Fagaceae family that includes sweet chestnuts and oaks. The Common Beech, F. sylvatica is a native of England as well as being widely planted. Beech are often found growing over chalk or acidic sandy soils. They are notoriously shallow rooted and this accounts for their devasting loss during the storm of 1987. In a recently published paper, we hear that beech, along with spruce and pine, are the species most affected by climate change/drought in European woodlands. An interesting feature of beech (and Hornbeam mentioned later) is that, although deciduous, when clipped as a hedge, the dried leaves remain throughout winter, making it a good choice for garden hedging, as well as easy to identify all year.

Beech trees tend to be late arrivals in the woodland succession, and as such there are understandably no mature examples of this beautiful tree on Barnes Common.  There are a few young self-seeded saplings sheltering beneath the oaks in a few places, one slightly larger tree near Scarth Road.

Beech nuts are an important food source for wild animals.  Like most trees the quantity of nuts varies, with some exceptional mast years ensuring enough survive to germinate, since beech grows well from seed.  Beech wood does not last long outdoors but is good for furniture and other indoor uses. It lasts well under water, and has been used for piling, including under Winchester Cathedral and the old Waterloo Bridge.

A copper beech (F sylvatica f. purpurea) was quite recently, and to my mind inappropriately for a nature reserve, planted ‘in memoriam’ on the Common on Maisie’s Meadow. Apart from hawthorn, native oak, willow and ash, very few of the trees on that meadow are native, including the American red oak, Quercus rubra, that produces stunning autumnal colour. I get into trouble for calling the meadow an arboretum because of all the non-natives planted there over time.

Alder (Alnus glutinosa) and Hornbeam are both natives in the Betulaceae family, along with hazel and birch. Alder love having their feet wet and thrive near water. The roots have nodules in which nitrogen fixing bacteria grow, so they are useful trees in infertile soils.  The wood withstands constant wetting and drying so was useful for mill wheels, and lock gates… while its charcoal was apparently the best for gunpowder.

Common Alder is a frequent sight alongside streams, rivers and in damp places, often kept or planted to help prevent erosion.  It can self-seed in the right conditions, but mostly this is from floating seeds settling into muddy riverbanks, which are relatively infrequent these days.  Until a recent planting there were none on the Common.

The Grey Alder (A incana) on the Green is planted. This non-native was introduced to the U.K. some 200 years ago – the leaves are less round and are toothed while the fruit is larger and relatively smooth. There are also a few alders planted as street trees in Barnes that I believe to be Grey Alders, but need to take a closer look! Alder supports a wide range of invertebrates. Its wood is highly resistant to decay in water, so was extensively used for piling (notably in much of Venice), as well as for making clogs – Milner notes that most surviving alder coppice stands in the UK were formerly the haunt of ‘the cloggers’, as well as being used for charcoal.

Hornbeam (Carpinus betulus), as mentioned, is another native in the Betulaceae family. It is dominant is a few places such as Epping Forest.  The wood is one of the hardest and strongest of all native woods: the common name comes from its use for ox-yokes – literally the beam between the horns.  It was also used for wheel hubs, keys for pianos, cogs, pulleys, and at the heart of butchers chopping blocks.  The hornbeams on streets such as Woodlands Road are a more upright, cultivated species of C. betulus, known as ‘Fastigiata’. I am only aware of one hornbeam on the Common, and it is not clear if this is self-seeded (I like to think so, since they can be raised from seed) or planted.

Mike Hildesley. 20th July 2020

Banner Image: Andrew Wilson

 

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