NATURE NOTES - Written by Dr Martyn Stenning

Nature Notes June 2022

Nothing is permanent in nature.  Even the surface of the planet is forever moving and changing with tectonic plate movements, usually too small to notice.  A forest is a climax community and if humans allow it, satellite images of forest will show no apparent change over a human lifetime.  However, most trees have an expected life span.  Birches live for about 60 years, beech for about 300, oaks for about 600 and yews over 1,000.

 

When an old tree dies and falls over, it forms a clearing.  Gradually, it will rot away and let the sunlight reach the floor.  From that time, there is a period of succession as the ground becomes recolonised.  The same happens within an abandoned field.  Incidentally, the word field is derived from ‘a felled area of forest’. On bare ground, the first visible organisms are the herbs, usually grasses and other seedlings.  Second come the larger plants such as nettles and brambles, following on from that come the woody saplings of shrubs and small trees such as heather, gorse, hawthorn and elder.  All these have a low maximum height so that eventually birch, beech, oak, yew and others can push through to the light and out-shade everything below that has gone before. 

 

If the canopy of the forest is not completely closed, parts of these layers can persist, and it is interesting to see how this succession happens every year concerning the leafing and flowering in some woodlands.  In a balanced ancient woodland, first the wood anemone leaves appear followed by their white flowers as the bluebell leaves push through and then flower, taking over from the anemones. After that, the hawthorn leaves and May blossom break bud with the honeysuckle and eventually the leaves in the giant trees burst and grow to form a shadowing canopy resulting in a decayed forest floor.  The insects follow this succession and pollinate the flowers in all these plants including the trees, which are sometimes also wind pollinated, and eventually form seeds through the summer and autumn.  They drop their seeds, then (if deciduous) their leaves and the cycle starts again.  Everything green in the plant world is a solar panel, converting carbon dioxide into oxygen and organic material.  It is lovely to see the breeze gently coaxing the mature fresh green leaves during May as I write these notes.


Dr Martyn Stenning


Nature Notes May 2022

 

As I write in April, I am in France and, surprisingly, dawn temperatures are several degrees below freezing.  We are here to manage our project of experiencing rural living in France and its natural history.  Our accommodation is a bergerie Landaise.  This is a 300 year old shepherds dwelling surrounded by fields and trees.  We live here with wildlife that you could expect in any good French nature reserve, including 3 species of owls (tawny, barn and little), a rare black-shouldered kite, stonechats, cirl buntings, European cranes flying over on migration, the occasional brown hare visiting our field, regular visits from the local stone marten (a kind of cat-sized weasel).  We constantly have wall lizards in and around the house, and occasionally see our resident giant green lizard called Lacerta viridis

 

One of my main jobs is to manage the grassland around the dwelling such that there is a diversity of habitats.  To this end we mow some of the herbage and let large patches rewild to support the many insects that use the wildflowers that like to grow tall such as black knapweed and ox-eye daisy.  The insects that we have here include praying mantids, and a range of large bush crickets and other singing insects that stridulate (sing) all night during the summer.  Butterflies such as swallowtails and scarce swallowtails fly in the garden on warm days and use the wild fennel plants to lay their eggs on and feed the hatching caterpillars.

 

We are regularly visited by the local western whip snake which is about 1 metre long and sometimes shelters in the house.  We had a peacock butterfly hibernating in our bedroom for the winter hanging underneath a large oak beam.  In 2019, a colony of honeybees moved into the attic but were apparently wiped out by hornets (Asian and European) leaving 14 kilos of honey and useful beeswax for us to harvest.  We also get visits from green patterned marbled newts and hear the tree frogs croaking.

 

Currently, as mentioned, we are experiencing an unusually cold spell, and most of the wild animals are still and silent.  However, the lizards occasionally emerge to warm up when the sun shines.  We have also seen carpenter bees collecting nectar from the few flowers in bloom.


Dr Martyn Stenning


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