Most woodland mammals are nocturnal, or if they are active during the day they prefer to avoid human contact and all we see of them is their droppings and tracks in the ground. The grey squirrel, an American import, is well known, destructive in removing bark from many species of tree and also accused of having driven out the native red squirrel. But research into the natural world is never static, and some people think that grey squirrels are a force for good, as natural replanters; out of the many hundreds of nuts stored by squirrels, many are forgotten in the Spring and these nuts start to grow into new trees.
Woodlands protect species from frost, drought and strong winds, but they also deprive them of light and so woodland plants must adapt to survive in the shade. Some plants like holly stay green all the year round, making use of the light that reaches them in Winter and Spring when other trees have no leaves. Many plants on the ground start growing befiore the trees have leaves: bluebells use the food stored in their leaves to produce leaves early in the year before they are shaded by trees. After flowering, the leaves send food back into the bulbs ready for the next year's spurt of growth.
Fungi live all the
year round as a mass of threads buried in the material on which they feed. Once a year, often in the Autumn,
fruiting bodies are formed and these are the structures we recognise as fungi. Some fungi are decomposers, breaking
down materials on the woodland floor and releasing them back into the soil as nutrients. Others are purely
destructive, such as the birch polypore which feeds on birch trees, giving nothing in return and
eventually killing them.
Trees offer a variety of food for hundreds of insect species, most of them well hidden and some of them too tiny to see. Some species including slugs and snails are natural recyclers, breaking down the material on the woodland floor when they eat it and then returning minerals to the soil to encourage further plant growth.
Small creatures make good meals for bigger ones, so many protect themselves from predators by looking like their surroundings. For example, caterpillars of the oak beauty moth look like oak twigs.
Lichens are in fact two organisms: Microscopic green algae and fungi, living together in a mutually dependent (or symbiotic) relationship. They are common in broadleaf woods, especially on trees with ridged bark, such as oak or ash. They absorb the minerals they need to survive from the rain and moist air.
A
variety of birds live in woodlands because there is plenty of food, and safe places to nest, shelter and hide from
predators. Many of the birds you see will be searching for food under leaves, tree bark or in leaf litter.
Woodpeckers chisel into decaying tree trunks to search for insects: they have long sticky tongues to lick insects
out of the holes they make.
Up to half the birds that nest in the wood nest in holes in dead or decaying trees. In new woods where there are few old trees with natural holes, nest boxes are often provided to encourage more birds to nest.
Bacteria in sheer numbers dominate the woodland system: more bacteria inhabit a handful of woodland soil than all the people who have ever lived on earth. Although bacteria are often associated with disease, the vast majority of them are essential to all other life. In woodlands certain bacteria return vital chemical elements to the environment by decomposing matter from dead organisms.