Monthly Archives: November 2012

Do they know it’s winter?

It’s nearly December and I find myself back at Low Barns running a couple of winter tree  identification sessions. We’ve run these before and each time we change things a little, but everything revolves around a quiz and a walk around the reserve, and they are always good fun.

We start with an indoor session talking about the basic features useful for identifying trees in winter, then look at a bunch of samples, drink lots of tea, then go hunting…

Around the reserve there will be found lots of tagged trees; lots of numbers that have to be matched to the quiz. Although the theme was identifying trees in winter I no longer worry about concentrating entirely on winter features. There’s little point in being skilled at identifying a tree on buds alone if there are no buds to be found. In an arboretum, or park, the lower branches of many trees are raised and buds may not be accessible. You need to work with the material available to you: are there any leaves, dead or otherwise, still on the tree? In mild winters there often is, and oaks often obligingly hang on to their leaves deep into winter, which is very handy for distinguishing Sessile and English oak.

Common Alder
a single defiant Alder leaf clings on into winter

Another good clue is to look down. Sweet Chestnut, especially mature old trees, often have a fantastically expressive fissured bark. Combine that with the distinctive buds sitting on little shelves on the stout twigs, and it’s a straightforward id. The Sweet Chestnuts at Low Barns don’t tick any of these boxes. It seems to think it’s a hazel and sprawls haphazardly through the understory with a non-descript bark and hard-to-find buds. It does, however, carpet the ground with a dense layer of distinctive leaves making confirmation of the id easy.

Low Barns has a lot of ash trees (Fraxinus excelsior), at least, for the time being. With Ash Dieback being in the news it was a topic of some discussion. The obvious parallel is with Dutch Elm Disease. But with the Taxonomy of English Elm (Ulmus procera) still unclear and the possibility that many if not all English Elms were genetically identical, it remains to be seen whether a similar fate awaits the Common Ash. A prolific self-seeder, perhaps Ash has enough genetic diversity somewhere in its distribution to cope with the attack. If large numbers of ash succumb to the disease we shall see some big changes in our woodland. Lots of standing dead timber, a fantastic habitat, and lots of light hitting the woodland floor. Interesting times ahead.