November beauty, contour felling and spidery thoughts

And that’s another November been and gone. A beautiful time in Strathglass, where we live. What little sunlight we get in November is amplified greatly by the orange-gold of silver birch and larch trees, against the russet of dying bracken and the orange-brown of the oaks. This time of year the local landscape never fails to stun me with its immense depth of colour. Even on a cloudy day the trees glow with their rich autumnal hues. When the sun catches the yellow leaves of the birch it is as if the trees themselves are radiating light. Autumn mists serve to increase the visual drama. On clear days the red glow of the setting afternoon sun on this landscape creates an amazing light, good for nourishing the senses. Later in the month the bright colours fade as the leaves fall. Two windy days towards the end of the month saw the end of most remaining leaves and larch needles, with winter forms and colours now apparent.

This must be my favourite time of year for working in the woods, and we are making steady, if slow, progress with felling the new track route. As the route is on a side-slope, contouring round the hillside, we are trying out a kind of ‘contour felling’ approach. Contour felling is something I read about, that was used back in the days of commercial hand cutting (i.e. before harvesters were used). Our approach is a variation on this.

We place a series of six- or nine-metre logs across the track line (perpendicular to the contour) to act as felling benches. The trees are felled along the contour, onto the benches, and are left attached to the stump to prevent them rolling down the slope. The benches keep the felled trees off the ground, making it easier to sned them (cut all the branches off). Once snedded, the tree is cut from the stump and rolled down the benches where it rests on high stumps left as stoppers. The tree is then out of the way of the next tree to be felled. We then use the winch to pull the full length tree trunks along the new track line to the existing track, where they are cross-cut and stacked. At some point we will reach the limit of the winch rope (100 m or so) and at this point the first section of track will be built, allowing access to extract the next section.

The felling of this corridor 10 – 12 m wide through the middle of the dense spruce stand has already made a difference. A twilight walk up to the felling site one evening earlier in the autumn revealed a bat using the newly opened route for its nightly hunting. The noisy flocks of little birds – long-tailed tits, blue tits, great tits, tree-creepers, goldcrests- that are often seen in autumn and winter flit along the edges of our corridor. Opening up the stand provides access and new spaces that can be used by various different creatures where previously there was just an expanse of closely spaced trees, dark and difficult to penetrate below the canopy level.

The track route skirts below several small areas of remnant native woodland – small openings or glades within the spruce stand where native trees and ground flora still prevail, though becoming increasingly shaded by the ever-growing spruce. We have reached a couple of these areas already, as we fell the trees along the route. Felling the trees immediately below (to the south) of these glades suddenly makes them feel more open. They are now less oppressed by the tall, dark spruce trees and have a bit of breathing space. Once the track is built we will be able to thin and clear further around these areas to protect the native woodland remnants against too much shading and help them expand outwards from their little islands. The track route will also link some of these islands so that certain creatures such as flying insects can potentially travel between them without the obstacle of a dense, dark stand of trees.

During my autumn exploits in the woodland I have been particularly noticing spiders. Their webs are very apparent on misty, dewy autumnal mornings, when spider silk adorns every plant from ground to tree-top. When felling trees I often notice disturbed spiders emerging from the trunk and running across the newly cut surface. This makes me wonder just how many spiders must be living in the woodland.

I did a little internet research into spider populations, which suggested that temperate and boreal forests have the greatest biomass of spiders for a given area compared with any other type of environment worldwide¹. Myffeler and Birkhofer cite Turnbull (1973)² who suggested that on average, globally, there are 131 spiders per square metre (on land), while densities could be up to 1000 per square metre in certain locations. Spiders are thought to be the most important predators of insects and are also important food for many species of birds as well as frogs, toads, newts, lizards, snakes, small rodents and bats. They are, therefore, an immensely important part of the food chain and the woodland ecosystem. They regulate insect numbers, helping to reduce numbers of insect pests that may otherwise damage trees and plants.

Thinking about the spiders highlighted to me just how complex the woodland ecosystem is, with creatures, plants and fungi all dependent on each other in a giant web of life. It seems important to me to help nurture this amazing community that has evolved over so long. Modern commercial forestry systems, in a drive for a certain type of efficiency, have simplified natural systems. They have a low diversity of plant species, habitats and the associated fungi and animal species compared with natural systems. They are more susceptible to pest attacks, where pests (e.g. pine weevils) can exploit the low numbers of natural predators and an abundance of a favourable plant or habitat, because the overall ecosystem has only a few components. By contrast, a natural woodland ecosystem has a much greater diversity of plants, animals and fungi and is therefore more resilient against pests and disease. The many different species within these types of ecosystem all have their own little part to play in the overall picture and make use of the full potential of the environment.

In a typical commercial plantation the trees are eventually harvested by machines in a clear-fell. A digger is then brought in to create mounds, into which new trees then have to be planted, sometimes with the addition of synthetic fertiliser. The newly planted trees are often sprayed with insecticide to prevent weevil attacks. This is a highly artificially managed system. In Comar Wood I would like to manage the woodland with much greater alignment to a natural ecosystem. This will mean: not clear-felling; using natural tree regeneration, including coppicing; having stands with a range of tree species mixed together; encouraging plants to grow on the woodland floor; having a mosaic of different ages and types of tree within the woodland. Hopefully this will create a woodland in which many different types of plant, animal and fungi can thrive. A woodland that can be resilient and adaptable to the challenges of the future, whilst also producing a range of useful products and not requiring large scale mechanical or chemical interventions. Hopefully it will create a woodland with an abundance of natural beauty and an abundance of spiders!

1. Myffeler M. and Birkhofer K., 2017, An estimated 400-800 million tons of prey are annually killed by the spider community, The Science of Nature 104
2. Turnbull AL., 1973, Ecology of the true spiders. (Araneomorphae) Annu Rev Entomol.18