There is one other event that we can expect in life as well as death and taxation, and that is the changing of the seasons. It is nature’s alarm clock and it happens every year.
As the Spring temperature rises and the woods are bathed in sunlight, the countless plants and animals come to life. Once again the forest is reborn with colour, movement and life. For the oak this will be the season of most dramatic growth. After many months in a state of suspended animation the oak is beginning to come to life. The buds are finally starting to burst and the tree is about to undergo one of the most dramatic changes of the year. In the next few weeks the oak is going to have an epic growth spurt. As Winter ends and Spring takes hold, hundreds of thousands of individual leaves will emerge across the tree. It is a truly astonishing change. The remarkable change requires huge amounts of water. Hidden from the naked eye, at it’s peak the tree will be pumping up to fifteen gallons of water each hour out of the ground. Just behind the bark there are intricate pipes known as xylem vessels through which this huge amount of water gets moved about the tree. They carry water from the roots to the leaves, and as more and more leaves emerge so the tree takes up more and more water with the daily intake peaking at mid-day. With Spring the tree also produces it’s catkins which will ensure the future of the tree and the continuing success of the oak. This is the beginning of the reproductive cycle. The pollen from the male catkins takes to the sky, looking for a female flower on another tree. The pollen contains the unique D N A of the oak, and the pollen grains are scattered by the Spring breeze. The receptive female flower will take up passing pollen and become fertilized and over the next few months will combine it’s genetic material with the pollen to produce a tiny acorn. Oaks have been at Ashridge for some nine thousand years, since the last ice age, but there were no humans around at that time likely to appreciate them!
According to folklore the oak is a barometer for the forthcoming weather depending on when its leaves unfold. – Oak before Ash we’ re in for a splash, Ash before Oak we’ re in for a soak.
Our oak woods provide a habitat rich in biodiversity for they support more life forms than any other native trees. When Summer comes the leaf canopy hosts hundreds of species of insect, supplying many birds with an important food source. Flower and leaf buds of English oak are the foodplants of the caterpillars of the purple hairstreak butterfly, while down at ground level the silver-washed fritillary lays its eggs which hibernate in the oak bark. The exotic looking purple emperor dwells high in the tree tops in the domain of the birds – getting drunk on the oak sap giving rise to mid-air battles with birds and receptive females!
When you next take a walk in the woods, have a good look at the trees. You surely have time to stand and stare.