Originally published June 2011
Hello everyone! Here we are half-way through the year and we have barely needed to break out the oil skins and sou’westers! Met records show that less than 10% of normal rainfall fell in our patch during April. As I sit here looking through the window on, what is now, an uncharacteristically dull May day I can’t help but notice the deleterious effects of the prolonged dry spell on the local flora. Wild flowers have come and gone with un-nerving rapidity and many plants have taken on a world weary appearance as their leaves droop down abjectly to the parched ground.
School children up and down the land will be able to describe how plant cells need water to retain their rigid structure or, as biologists like to say, turgidity (from the Latin turgidus-to swell). Avid watchers of the likes of David Bellamy, Ray Mears and Rambo will know that a few well-aimed blows with a macheté will secure you a life-saving drink from a whole array of desert and jungle plants. However, if we rule out the unlikely event of canoe-building survivalists or muscle-bound ’Nam Veterans hacking the foliage to bits, we have to consider more natural causes of water loss in plants.
No doubt the younglings out there will be raising their hands and squirming in their seats whilst trying not to yell out the word “transpiration!” I wonder how many of them will associate this process with their parents telling them to get the washing on the line before breakfast as it is a perfect drying day! For those of you who dozed through biology classes (shame on you!), let us have a brief summary of plant physiology. Water and dissolved nutrients are taken up into the plant via the roots through vascular tissue called xylem (from Greek xylon-wood). The water fills the cells and provides the structure of the plant as it grows. Water is lost through a number of pores, mainly on the underside of leaves, called stomata. The stomata are opened to allow the diffusion of carbon dioxide gas from the air and thus start the green factory process, photosynthesis (see Building With Light – July ’09), and transpiration is the loss of water from the plants during this period. Water loss is considered to be the necessary ‘cost’ the plant has to pay for acquiring the raw materials for growth. The rate at which water is lost is analagous with how quickly washing dries on the line. The drier the air and the quicker the movement of damp air away from the surface of the leaf (or pair of jeans) the faster evaporation will take place. Water will also evaporate from the cuticle and young stems of plants. Clearly our rain-free, windy days have exacerbated the whole process without providing the ground-water needed to compensate for the loss.
The dry spell encouraged our very own school Foxes to venture forth and explore Quarry Wood. The day got off to an unexpectedly exciting start as a rather bewildered looking badger lolloped up the path to within a few yards of us, thought better of it and turned tail. It was certainly my first sighting of a live Brock in daylight hours and I feel compelled to do a little research into this rare occurance. Under the watchful eye of the stalwart Mrs Wastell the Foxlings spent an enjoyable morning strolling through the trees, peering in to our rapidly diminishing pond and sketching Fern fronds and the last few bedraggled Ramsons, Bluebells and Orchids. I look forward to seeing a display of all their hard work.
So there we have it, a month of flaccid foliage and budding biologists. Our little reserve may well be suffering the early effects of drought but it still has much to offer those in need of some of Ma Nature’s therapy.
Woods, meadows, hedge-rows,
corn-fields, all around
Much beauty intervenes,
Filling with harmony the ear and eye;
While o’er the mingling scenes
Far spreads the laughing sky.
John Clare 1835
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