The stony west bank of Pennard Pill

Sea Lavender on lichen covered stones of the river bank at Three Cliffs Bay Just before the Pennard Pill watercourse takes a dramatic swing to loop around the giant sand dune to get to the shore at Threecliff (Three Cliffs) Bay on the Gower Peninsula, the right hand or west bank is composed of rough stones and then transitions into a salt marsh. [The area lies on the opposite side of the river to a more substantial and higher shingle bank that can be reached via a set of concrete stepping stones].

The low shingle surface of the right bank is relatively stable. Despite regular tidal inundations of brackish water, life clings to the limestone. Last August it was particularly attractive, covered with bright patches of yellow and black lichens, and ground-hugging clumps of partially red-stemmed plants with clusters of small pink flowers. I will have to find out what these plants are the next time I visit. I didn’t take close-ups. I had thought they might be Sea Heath (Frankenia laevis) but apparently that does not grow in this area – although it likes the same kind of habitat.  I think Sea Sandwort was also present. However, the numerous flowering stems of Sea Lavender I did recognise; and these plants were found equally spread in stony ground and on the wetter salt marsh area.

Tracks and Trails on Whiteford Sands

Furrowed trails made by common winkles on wet beach sand

You don’t exactly have to keep your nose to the ground to see them but you do have to be a keen observer to notice all the different tracks and trails left on the soft wet sediments of the beach at low tide. Larger marks left by people and vehicles are the first ones you see. Bird footprints are every where. The birds are feeding on all sorts of invertebrate seashore creatures like worms, small crustacea and molluscs – all of which leave holes, burrows and furrows as they move in and out of the sand and across the surface. Some of the pictures shown here simply aim to give the general context for the area of Whiteford Sands that I was walking across. If you look closely the other images, you will see not only the ripples in the sand but also the intricate network of traces left by the virtually invisible organisms that inhabit this ecosystem. The larger furrows in photos 1, 12 and 13 are made by the common winkle (Littorina littorea Linnaeus). I cannot name each animal that is responsible for each of the other types of trace. However, I am sure that there will be some specialists out there who could, especially those researchers concerned with the interpretation of trace fossils (the ichnologists).

Click images to view full size.

View looking west towards the sea at Whiteford Sands

View looking north-east towards the dunes at Whiteford Point

Wet seashore sand with marine invertebrate and other tracks and traces

Wet seashore sand with marine invertebrate tracks and traces with bird footprints

View looking north-east over wet seashore sand ripples with marine invertebrate tracks and traces at Whiteford Sands

Wet seashore sand ripples with marine invertebrate tracks and traces

Wet seashore sand ripples with marine invertebrate tracks and traces

Wet seashore sand ripples with marine invertebrate tracks and traces

Wet seashore sand ripples with marine invertebrate tracks and traces

Wet seashore sand ripples with marine invertebrate tracks and traces

Furrowed trails made by common winkles on wet beach sand

Furrowed trails made by common winkles on wet beach sand

The Rise and Fall of Whiteford Sands

View looking towards the lighthouse at Whiteford on the Gower Peninsula showing rock strewn beach with patches of sand

The photographs in this post illustrate the way that vast quantities of wind- and wave-borne sand at Whiteford Sands on the Gower Peninsula move around the shore over time. I have taken one fixed object, a piece of ancient timber with an unmistakable shape that projects from the early to post Holocene deposits of peat and clay, and taken shots of it on every visit to the beach over the past ten years or so. The following images show how the sand level changes periodically to reveal or conceal the underlying layers with the surface scattering of rocks that were dumped by the melting ice during the last glacial event. Beaches like Whiteford are incredibly dynamic. Click on any image in the gallery below to view as a slideshow in chronological order.

 

Autumn Horse Chestnut Leaf Miners

Natural patterns caused by moth caterpillar infestation in leaves

These remarkable patterns on leaves of the Horse Chestnut tree (Aesculus hippocastanum) result from a combination of the natural changing of the leaf colour in autumn and the effects of infestation by tiny caterpillars of the Horse Chestnut Leaf Miner moth (Cameraria ohridella). This Spanish species has invaded Britain in recent years and is having a very noticeable impact on the appearance of this one type of tree but it does not seem to have an effect on the wood of the tree. I have noticed a decline in the numbers of conkers this year, which might have had something to do with the loss of photosynthetic capability in trees that have been bady affected, but could be attributed to a number of other causes as well.

The tiny caterpillars live in the shallow space between the upper and lower layers of the leaf, and eat away systematically between parallel veins, killing that area of the leaf and leaving narrow bands of dead tissue that cover the leaf in irregular stripes. These can be seen increasingly throughout the summer in infected leaves but in autumn, as the leaves change colour and naturally die back for the winter, the damage caused by the caterpillars becomes more pronounced. It looks almost as if some artist has been having fun decorating the foliage to celebrate Halloween.

Luminous Fungi

Fungus that causes decaying wood to glow in the dark

When you go out “trick or treating” this Halloween, not everything that glows in the dark will be a spectre, phantom, or ghost – or someone pretending to be one. By an incredible quirk of nature, one of the commonest of British fungi creates natural luminescence (Ramsbottom 1953). The Honey Tuft Fungus (Armillaria mellea) which grows on both living and decaying wood, has a vast hidden network of black fibres called hyphae that somehow or other make the wood glow in the dark.

This common fungus tends to grow most frequently on or near stumps of trees, with clusters of the fruiting bodies that can reach a metre across. The exact form that the Honey Tuft Fungus assumes can be extremely variable. It is the hidden parts of this fungus, the rhizomorph and mycelium, that are responsible for most of the luminous wood in Britain.

Luminous wood has been recognised since the time of Aristotle and Plato; and it may account for such phenomena as the burning bush that was not consumed by fire as seen by Moses in the Bible. Walter Raleigh in Elizabethan times is quoted as saying “Say to the Court it glowes and shines like rotten wood”. In 1667 Robert Boyle studied the luminescence of rotten wood – and that of decaying fish! However, the discovery of the fact that it was actually the infecting fungus in the rotten wood that was causing the luminescence was not established until the late 18th and early 19th centuries by people like Sowerby (1797), B. von Dershau (1822) and J F Heller (1843).

The fungus is known to widely infect wooden support structures in mines, and has been noted creeping across the floors of damp wine cellars. In the First World War soldiers placed small bits of luminous rotten wood on their gun sights and helmets to avoid collisions in the dark. In the Second World War the wood in a London timber yard is recorded as glowing so brightly on moonless nights that men on fire watch covered it with a tarpaulin in case it attracted enemy aircraft.

It makes me wonder whether many ghostly apparitions both indoors and out might be attributable to the hidden fibrous support networks of this common British fungus.

 REFERENCE

Ramsbottom, J 1953 Mushrooms and Toadstools, New Naturalist Series, Collins, London. Chapter 14 pp 154 -164, Sixth Impression 1972.

Fungus that causes decaying wood to glow in the dark

Fungus that causes decaying wood to glow in the dark