Trees and the way it use to be
Country sights and sounds
EVEN here, in the high hills at the head of the Erriff valley, there are signs of a prehistoric forest. Crooked stumps peek through the thin layer of blanket bog to show where trees once stood tall and proud, and along the stream beds the occasional timber protrudes from cut-away banks. It would appear that most of the woodland consisted of Scots pine. Or perhaps it is the resinous pine wood that has endured while that of birch, willow and other trees has decayed and vanished to leave us with a false impression?
A walk (more a daunting mixture of struggle and scramble) around the corrie lough of Glenawough gives us some insight into the past. Between the edge of the water and the tall, imposing cliffs that bound the lake on three sides, we find a little glimpse of prehistory in the form of a band of trees some few acres in extent. Mountain ash and alder are the dominant species. Both are valuable for wildlife, yet there are few birds and fewer animals to be seen. We might catch a rare glimpse of a mountain hare loping over the horizon or the hill fox searching for beetles in a rain washed gully, but that is about it. We can only imagine how these timbered slopes were with forest life, plants, birds and animals, teeming over them.
That they were far different than now is certain. Not only are the trees gone, so is the waist-deep heather that succeeded them; the sheep saw to that. Although the dense overstocking of recent times has happily passed into history the scars of careless subsidy remain. Many acres of hillside are still poor, almost destitute of vegetation. Yet, albeit slower than we would like it to be, the recovery is resolute. Now tough sedge grasses are moving in to reclaim the land which was previously shorn and apparently lifeless, and little pods of heather and other plants of high ground are appearing here and there. Given enough time these will attract a greater diversity of insects which will, in turn, draw a variety of birds.
How long must it be before the trees are back? It might be decades or even centuries from now. What we need is some way of adding a small amount of nutrient to the peaty ground while reducing the acidity of the bog and also drying it out. While this might sound like a tall and complex order, there is a way of fulfilling these requirements naturally.
Enter the humble willow, an often despised yet invaluable family of trees. The seeds of the willow are light enough to be carried by the wind and many enough to reforest the country on their own if given the chance. The willow is fittingly referred to as a Pioneer tree. Forget that woodland does not regenerate well on blanket bog: the willow will find foothold enough to make a start, and once a start is made the process of woodland succession is resolute.
Beneath the ground the roots of a willow seedling soon develop nodules that house special bacteria. These have the ability to take atmospheric nitrogen, which in its gaseous form is unavailable to plants, and ‘fix’ it in solid form into the ground where it can be absorbed by plant roots of various kinds, including those of the willow that helped to put it there.
As the willow tree grows it takes water from the ground and expels it through the leaves in a process called transpiration. Each winter the tree sheds its leaves, and these gradually add a layer of rich humus to the now drying ground, neutralising the natural acidity of the bog.
Willow supports numerous insect kinds. These attract birds and before long we have seeds of other trees like hawthorn and blackthorn excreted into nutrient rich soil conditioned for their growth. These so-called second-phase or secondary trees form thickets as they colonise an area, and with their growth a greater amount of leaf litter is added to the ground with each passing year.
Rooks and jays appear on the scene. These members of the crow family have special throat pouches within which they transport the seeds of larger trees, such as acorns from an oak. They have a habit of burying surplus food, perhaps with the intention of returning to it at a later date. Some of the seeds they plant will germinate and grow, and once more we will have hills covered with oak trees as they should be, with deer and badger and squirrel. It is not that simple. Still, we could do worse than plant the humble willow to give nature a head-start.