The pine forest here at Abernethy is amazing. It's a truly magical place, housing trees that are hundreds of years old, regularly revealing new and previously unrecorded species and providing habitat for thousands of species of plants, animals and fungi. Scots pine trees are beautiful to behold - from the very upright youngsters, with their thin, straight trunks to the twisted and gnarled Granny pines, the OAP's of the forest who have been standing silently for decades. And all of them covered in bushy fingers of green needles contrasting delightfully with their reddish-brown trunks. A wander through the Caledonian pine forest is a magical and awe-inspiring experience.
But, at this time of year, the stars of the show at Abernethy aren't the pine trees (although we love them no less than usual). As autumn draws on we are treated to a spectacular display courtesy of the broad-leaved trees that are interspersed among the more abundant pines. These trees, including birch, rowan and willow are a vital part of the ecology of the Caledonian pine forest, providing nesting habitat for birds and mammals and acting as a vital food source for many insects. While, for most of the year, these trees are easily overlooked (there's almost a joke about not seeing the wood for the trees here but I can't quite get there...), in autumn their leaves undergo an incredible alteration from green, green and more green to a kaleidoscope of bright yellows, fierce oranges and, in some cases, deep reds. It's like hundreds of paint bombs have been set off along the trails, splattering the forest with mini explosions of colour.
"But what is the reason for this astonishing arboreal artistry", I hear you ask, "We know that leaves change colour in autumn but we want to know why". Well, despite your pushiness, which is quite uncalled for, I will do my best to explain this phenomenon. The classic green colour of leaves is due to the presence of chlorophyll. Chlorophyll is a special chemical that allows plants to turn sunlight into food, a process called photosynthesis (imagine that...if every time the sun shined, you could produce a three-course meal out of nothing! In Scotland, we'd all starve...).
During the spring and summer, when the days are long and sunlight is plentiful, trees and other plants put lots of energy into producing leaves filled with chlorophyll, ensuring they catch as much light as possible and are therefore as productive as they can be. Because of this abundance of chlorophyll, the other pigments in the leaves, important for many vital processes, are covered up by the green and therefore don't show their colours of yellow or orange (even though they are still there).
When autumn rolls around, as it tends to do, just after summer, the days begin to get shorter and darker. This stimulates the trees to ready themselves for the cold, dark winter ahead, when they spend months in a state known as "dormancy", a sort of hibernation where trees shut down and do pretty much nothing (like a Friday afternoon at work or school). This period is when sunlight is in short supply and any energy put into leaf production and maintenance would probably see little or no return. It's now that the tree starts to get rid of its existing leaves, however, before the leaves actually fall from the branches, we are treated to the magical colour change. All that chlorophyll which was so important in producing food is not really needed while the plant is dormant, and yet to let it simply fall to the ground along with the leaves would be incredibly wasteful - trees work hard to create that chlorophyll in the spring. So, instead, it is broken down into smaller molecules and reabsorbed by the tree, to be stored in the roots and re-used again next spring! Genius.
And because all of that greenness is now gone, the yellows, oranges and even reds start to shine out. Gradually, as the autumn becomes winter, the leaves will drop off the trees (itself an important process as nutrients then filter back into the ground) but not before we are treated to our Caledonian crescendo of colour.
And it isn't just trees that will change colour in autumn, many other plants will do the same.
While the leaves are busy changing colour, we have also been busy planning some events for the winter. I hope you are all coming along to the Goose Roost event tomorrow (Saturday 21st October)...our Community Ranger Alison has been busy counting the geese on the loch and although I won't reveal exactly how many she's seen (you'll have to find out for yourselves tomorrow...), it is much, much higher than the paltry 500 I thought there were! A spectacle not to be missed. We'll be on the loch shore from about 4pm so see you there.
We've also got an event planned for the Big Garden Birdwatch in January and a special "Show the Love" event around Valentines Day in February. Keep an eye on our website and Facebook page for more details coming soon. The events will be at or around the Osprey Centre, but why wait til then? The crested tits have been positively queuing up at the feeder over the past couple of weeks, jostling for position with red squirrels, coal tits, chaffinches and the occasional jay! Come and have a look for yourself...but don't forget, if you're tempted to attract the birds to your hand or to a certain perch, peanut butter isn't great - normal peanuts or a regular seed mix are much better. And, on that note, for any RSPB staff you happen to meet, chocolate cake is definitely the best...
See you soon!