Press Release
AUTUMN set to be a record
EXPERTS say the range and intensity of autumn colours this year is setting a new record. The brightest autumn colours are produced when dry, sunny days are followed by cool, dry nights. And this is exactly what the south of England experienced last month (September).
Bright sunshine and lower temperatures destroy the green chlorophyll and, if the temperatures stay above freezing the red pigments are promoted. Again everything went according to plan this year to produce an autumn ‘right off the scale’ at many gardens.
But this has not been the case everywhere as botanists at Kew have discovered. The dry weather in particular has meant that its country garden at Wakehurst Place (in Sussex) produced vivid autumn colour which was unseasonally ahead of Kew Gardens in London.
“Wakehurst Place has had the driest period from January to September since before the great storm of 1987,” according to its head Andy Jackson. “September in particular was very dry under half of the already lower than average rainfall at Kew Gardens, and this has made all the difference”, he adds.
The last spectacular year for Autumn colour in many parts of the country was 2003 which had a very dry September too.
So how does all this work in nature?
Well, the typical green colour of leaves is due to the compound chlorophyll which absorbs red and blue wavelengths of light.
Chlorophyll decomposes in bright sunlight but is
constantly replenished during the warm, sunny summer
months and the leaves stay green. In autumn other
chemicals remain in the leaves after the chlorophyll has
decomposed and when carotene is present it makes the
leaves appear bright yellow as it absorbs blue-green and
blue wavelengths of light.
So called anthocyanins, which are responsible for the red skins of apples and purple skins of grapes, are formed by a reaction between sugars and proteins. This reaction occurs when sugar concentration is high and sunlight is present. This is why one side of an apple is often red on the sunny side and green on the other.
If the leaf contains carotene it will change from green to bright yellow as the chlorophyll disappears. In some trees, as the concentration of sugar increase in the leaves to form anthocyanins then these pigments cause the yellowing leaves to turn red.
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FOR more information or images, please call the press office on 01444 894018.
For further Press information please contact:
|
Kew: Public Relations Tel: +44 (0)20 8332 5607/5619 |
Wakehurst Place: Public Relations Tel: +44 (0)1444 894018 |
