Nick Baker's Wildlife
Nick Baker is a professional ‘amateur naturalist’ who loves all things with a pulse (and quite a few things without!). He works as a TV broadcaster, author, photographer and wildlife tour guide. As the amaranthine and mauves of the heather moor slowly fade into the dark glooming green, another colour spectacular is underway. Autumn is a time of subtlety, but its palette is easily as worthy as any of the more ‘in your face’ gaudy seasons. This season sees the slow shutting down of what amounts to a light-processing factory. The hues of the famous autumnal backdrop preceding decomposition portray the last and final fling of pigments before they are reabsorbed or recycled by the system.
The greens that have shrouded the hills and filled the combes and valleys since the spring are a compound called chlorophyll. It resides within the tissues of plants and is crucial to that fundamental process of photosynthesis: the production of sugars from water, CO2 and sunlight. Because the production of chlorophyll is stimulated by light – and there are fewer hours of this now the days are getting shorter – the plant makes less and less of it until the green machine grinds to a complete halt. Any left in the leaf slowly fades out as it is broken down and recycled. What we notice now is the other pigments in the leaf. Many of these have been here all along, masked by the dominance of green.
A group of other compounds – carotenoids – produce colours as diverse as red and yellow. These do not need light to be produced and are relatively stable and long lived. Anthocyanins, another group of compounds, can be striking red or blue and purple, and because they need sugars for their production bright sunlight tends to make for brighter autumn colours. Other pigments such as tannins, especially in species such as Oak, produce those other seasonal deep browns.
This cocktail of chemicals is highly varied. Local weather and soil conditions – and whether you are seeing them in a stand of bracken, a beech wood or a bramble patch – determine what parts of the autumn palette are picked up.
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Dartmoor Wildlife
