It is fun to pick a tree and go back every week to check out what is called phenology or the seasonal budburst and leaf appearance on the tree, together with flowering plants below. This is for a project known as Trackatree which is a “citizens’ science” ecology scheme developed by a PhD student at University of Edinburgh.
As soon as I decided to register, the skies became gloomier and drizzle dulled our part of South Wales. The Valleys are full of forests and woods. On 21st March, I picked woodland – on the edge of Coed-y-Gedrys on the east side of the Garth – which I pass regularly with my horse. The woods lie over a footpath and are on both sides of the stream at the bottom of a horse field. It has lots of stunning beeches, silver birches and some oaks, a varied and fairly open wood. Many trees are covered with ivy.
I took a pack with camera, binoculars, tape measure, copy of the instructions … but no compass.
Here it is – the silver birch marked X chosen randomly out of four possibles. It is tall with no lower branches and, frankly, I couldn’t see the canopy clearly enough to know if there were catkins dangling or anything like a leaf. I had a peer at the photos at home and decided it was catkins, not budburst or anything exciting.
On this first visit, not having a compass, I didn’t do all measurements, except for the girth which was 125 cm.
The information about the site and tree get entered online, and observations are weekly. On 29th March, I took more photos, and this time decided there was some budburst.
By now, I was realising that these neat terms about budburst and leaf varied across the tree. Riding past, I would peer at the tree, waiting to see a tinge of that bright springtime green. Even on the southerly aspects of the forestry, some trees were coming into leaf next to others obstinately in bud. It is all very subtle as a landscape.
There are, on the banks, forest tracks and fields, loads of wood anemones which are having a good year like the celandines and primroses, as well as wild garlic, and I have seen the first violets. But none of these are near my silver birch tree.
On April 3rd, the sun shone and a green sheen could be seen over parts of my tree’s canopy – but not all. It seemed to have skipped completing its budburst all over and rushed into first leaf.
I was also able to complete some measures with my new gadget, with gives a precise location (“northings and eastings” in the jargon), elevation, and has a compass. I measured the size of the canopy to north, east, south and west to the nearest half metre (ie, by my stride). Given the ivy and saplings about, and my efforts not to crush too many bluebell leaves, I thought this accurate enough. The academic in me cringes a bit.
The Trackatree website defines phenology and its own aims: “Phenology is the study of recurring seasonal events in plants and animals, and the timing of these events in relation to weather and climate. In spring, phenological events include trees coming into leaf, the flowering of plants, nesting of birds and emergence of caterpillars. Track a Tree is a citizen ecology scheme that will record the spring phenology of individual woodland trees and the flowering plants that make up the ground flora beneath them.”