A spring clash with the ash

I WENT down to my little wood the other day to check up on the progress of spring. It was sunny and the birds were singing but the ground felt cold and some things were behind schedule.

Then I noticed something interesting. I was rummaging around in the leaf litter, taking advantage of the fact that the plants on the floor of the wood hadn’t yet got too tall, looking for naturally sown tree seedlings. I found a couple of sycamores about 20 centimetres tall. They were in full leaf, although the leaves still had that brick red flush that they have when they first open. But the interesting thing was that there were no leaves on the adult sycamores, just silver-grey buds.

Obviously the seedling trees had developed an adaptation that allowed them to come into leaf a couple of weeks before their parents. This is logical. It would give them a head start in the continual battle for light that is fundamental to woodland ecology. But I had never noticed it before. The interesting thing about looking for naturally regenerating seedling trees is that it gives you a notion of the way in which the wood wants to develop. The oldest trees have been there for a little over 30 years, which is a very short time in the life of a woodland. The wood as a whole is in a process of development, moving towards what biologists call “ecological climax”. If I don’t interfere it will make its own decisions about which species flourish and which don’t. So I continued exploring. It seemed to me that the wood had decided, at least for the time being, that it wanted to be composed of a mixture of sycamore, hawthorn and ash, because these were the commonest wild seedlings. There was a lot of hawthorn but it doesn’t develop into a very tall tree and it’s not very tolerant of shade. I imagine in time it will be restricted to the edges of the wood, though whether I’ll be around to seen this happen is debatable. The contest between the ash and the sycamore will be interesting. Ash can grow as quickly as sycamore on these lime-rich soils and is potentially a taller tree. But it is the last Irish deciduous tree to break bud in the spring and one of the first to lose its leaves in the autumn, so it suffers the competitive disadvantage of a short growing season.