Shocking green
The incredible green of fresh new oak and beech leaves every year is so intense that every year it comes as a bit of a shock to see it. Especially on days like today when the sunlight shines through the leaves and there is a bright blue sky behind, it is completely amazing. Later on, the leaves are thicker and darker, which is not only less spectacular, but also for a good reason. The first crop of leaves has very few tannins (bitter chemicals that make the leaves taste less good and more difficult to digest) and that coincides with the immense peak in caterpillar numbers at this time of the year. The evolutionary 'reasoning' seems to be that the caterpillars are going to eat many of those leaves anyway and so the tree makes disposable leaves first and only once they have been eaten does it invest in the leaves full of defensive chemicals to dissuade the caterpillars eating them. There is a whole web of life associated with this as the songbirds like blue tits and great tits rely on the plentiful supply of caterpillars to feed their offspring, and time their return from the winter migration accordingly. Global warming makes the leaves and caterpillars come earlier and earlier, and it is very much the question as to how long the birds can continue to adapt their migration patterns to that. Will we see a system that gets out of sync and collapses? But cycling through the woods this morning, it was all so stunningly beautiful that it was no problem to put those questions out of my mind.
