In the last few weeks we have seen some unprecedented winds blowing across our patch. What does that mean for us? Well, for Wildlife Trust Officers it means worrying about the trees in our woodlands. Will they fall over? Which way will they fall and what will they fall on?
We do minimise this by doing tree safety surveys and then felling or removing limbs from “dangerous” trees. This work can cost a lot as specialists are often needed to climb these trees or use specialist equipment. However we can’t predict nature and it can be a perfectly healthy looking tree that falls over or drops a limb. This is why it is a good idea to stay out of the woods in windy weather.
Our reserves are zoned in high, medium and low risk areas depending on usage, paths, roads, houses etc. Trees in high risk areas are surveyed more often as they are likely to cause more damage. Low risk areas are those away from human activity and are surveyed less frequently.
So why don’t we fell all the potentially dangerous trees that are near areas of human activity? We’d have no woodlands left! Joking aside, trees are great for biodiversity; being the home or larder to many insects, fungi, birds, small mammals, bats… many on the decline or endangered.
Standing dead wood is home to a different set of creatures as it rots from the inside out rather than the outside in. Tree safety is always a balancing act: the beautiful, wildlife rich, old tree versus the public and access to the reserve. Sometimes a path can be diverted or that part of the reserve closed. Sometimes the tree has to be felled and that is always a sad day.
Sometimes the wind makes the decision for us: it blows a tree over. If it falls on a path, obviously it is cleared out of the way. If it falls away from the path it is often left where it lies and not just to save us a job!
Lying dead wood is a different habitat to standing dead wood or living trees. Sections cleared from the paths are often left in log piles or brash piles- a habitat pile, where many things live or hibernate: frogs, toads, hedgehogs, slugs and snails.
As the wood decays different insects and fungi move in. Habitat piles in sunny or shady spots will provide different conditions, however extremes are undesirable. Buried dead wood, e.g. roots or parts of fallen branches are also home to specific creatures. Furthermore, the decaying tree slowly puts nutrients back into the soil to benefit the trees of the future.
Another problem we face is trees falling on our fences. Not only does that mean the fence has to be mended but it could also mean that livestock can enter or get out of the reserve. Sheep especially can be a problem as they will eat new saplings, flowers and anything else available. And lost stock is never good.
When a tree falls over in the middle of a woodland it leaves a natural gap in the canopy. This lets the light down to the woodland floor allowing other woodland plants to flourish and new saplings to grow. So as well as the fallen tree being a home and larder it also helps create an age structure within the wood.
It is important to have trees of different ages for the continuity of the woodland in years to come and for the different habitats this provides. The new saplings will be the veteran (possibly “dangerous”) trees and standing dead wood of the future, but not in our life time.