Blowin’ in the Wind

Originally published September 2010

Hello everyone! I hope you have all survived the physical excesses of Summer (in particular the Tug ‘O’ War and of course, that last dance!) and are now bracing yourselves against the wind and rain that herald the onset of Autumn. The wind, as the more astute among you will have noticed, has a habit of blowing things around. Thus it plays a major role in plant ecology and woodland dynamics.

Every year the gales appear to leave a trail of destruction in nature reserves up and down the country, and more often than not we have to clear away a few of our Ladies of the Wood (Silver Birch) in their aftermath. Of course, just like the odd fire or flood, this is a perfectly natural occurance on the ecological scale of things and spaces left by fallen trees are very quickly colonised by a whole range of plants. This promotes the biodiversity of the site and we get to enjoy the sights and sounds of different insects and animals until the woodland canopy closes over again. The wind is not just a destructive force as far as trees are concerned. Many species, including our Ladies, rely on the wind for fertilisation of the female catkin with pollen, and later on for dispersing the seeds once they have been released by birds rumaging around in the branches.

A stroll through the Reserve at the moment will reveal a carpet of these tiny winged seeds and a number of distinctive Fleur-de-luc shaped scales called Bracts. The latter act as ‘spacers’ between the seeds on the gherkin-shaped fruiting catkin and are released alongside them to find their way on to spiders’ webs, car windscreens, other leaves and, occasionally, the fertile soil of the woodland floor. Calculations have shown the fertility rate for Silver Birch seed to be around 40%. However, the odds are stacked against a fertile seed growing into a tree as they require a timely cold spell to kickstart their biochemistry into action and then of course a suitable environment to develop in. Having said that, a mature tree can produce hundreds of viable seeds that will germinate, often where they are not wanted!

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This all leads me nicely onto the subject of our grand tree planting event. Talking to a number of people in the village led me to think that I came up with the bright idea a little late on in the year; especially as I made the point that, where possible, the trees should be grown from seed! In view of this, it makes more sense for us to hold the event in early Spring. This will give everyone a chance to have a go at producing seedlings from all those chestnuts, acorns, cob nuts, Holly berries, Hawthorn berries and yes even Birch seeds that are readily available at this end of the year.

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To finish off I must recount how lucky I was to take our Crowhurst School Foxes for their last jaunt through Quarry Wood before they broke up for the Summer Hols. As always, under the watchful eye of the redoubtable Mrs Wastell, we spent a pleasant couple of hours in the sun whilst looking at soil and rock structures. We also had the chance to witness first hand other trees spreading their seed with the aid of the light summer breeze. Both Aspen (Populas tremula) and Goat Willow (Salix caprea) produce seed encased in fluffy white down which flies for miles once it’s released. I ended up talking to the children in a veritable blizzard of arborial fertility! To see the Aspen leaves trembling in the wind and its seed forming spectre-like clouds over the pond you have to agree with Mr Ruskin with his description of this beautiful tree.

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“…it is with exquisite feeling that it is made afterwards the chief tree in the groves of Proserpine, its light and quivering leafage having exactly the melancholy expression of fragility, faintness, and inconstancy which the ancients attributed to the disembodied spirit.”
John Ruskin – Modern Painters (1856)

As always, put me right at pgcrow@yahoo.com

Paul Johnson

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Image 3: Ripening tassels by Marilylle Soveran, used under Creative Commons License 2.0


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