Wednesday, August 27, 2014

August Speakers' Reports

Report 1Fungi of the New Forest (UK). Talk by Diane Ball

In 1079 William the Conqueror declared a large tract of woodland and heath south of his Winchester Castle to be a royal hunting ground. This land would be subject to the considerably severe ‘Forest Law’ – hence the New Forest. The area actually consisted of some open forest, small farms, heath (a result of Bronze Age people clearing the woodland) and grazing land.
As the soil was quite poor and acidic and unsuitable for agriculture, the land has remained mostly undeveloped through the centuries and to this day. The New Forest was designated a National Park in 2004 and is 56,651 ha (566 sq miles) in area. It is Europe’s largest area of ancient pasture woodland with about 2,000 free roaming ponies as well as deer, donkeys, cows and in autumn, pigs. It attracts approximately 18 million visitors a year.
Orange birch bolete (Leccinum versipelle)
(Photo: Diane Ball)
About 2,700 species of fungus have been found in the Forest. Many of these have very descriptive common names. Photos were shown of many gilled fungi starting with the plentiful Amanita sp of which the well-known fly agaric Amanita muscari is one. Many of these, especially A.phalloides (death cap) and A.virosa (destroying angel), are extremely poisonous. Russula spp, the brittlegills, are often brightly coloured and these were prolific. Other gilled fungi included Lepiota sp – parasols, Collybia  sp – toughshanks, Lepista sp – blewits, Clitocybe sp – funnel caps, Laccaria sp – deceivers, Lactarius sp – milk caps, Mycena sp – bell caps, Hyphololoma sp – brick caps, Cystoderma sp – powdercaps and Gymnopilus sp – rustgills. A number of boletes were represented. Most of these have a distinct cap with pores instead of gills. Leccinum versipelle, the orange birch bolete is a particularly attractive one.
Dyer's polypore (Phaeolus schweintzi)
(Photo by Diane Ball)
Large numbers of bracket fungi are found in the wooded areas often in overlapping tiers, some quite large. Many cause diseases in their hosts – butt rot, white rot and heartwood rot among them. The fungi produce enzymes which can break down lignin and cellulose. Phaeolus schweintzii has several common names – fuzzy polypore/velvet-top/dyer’s polypore – this last because it is a source of green, yellow and brown dyes. The olive-brown pores run onto the stocky stem and become maze-like with age giving the fungus a striking appearance.

The last main group of fungi are the puffballs – Lycoperdon sp, Vascellum sp, and Scleroderma sp. These have very short or buried stems and tend to be globular. The talk finished with photos of some of the odd fungi which do not fall into major categories:- Clavulinopsis sp – the orange club, Sparassis crispa – cauliflower, Exuda glandulosa – witch’s butter and a slime mould Lycogala terrestre – wolf’s milk.
A marble quarry

Report 2: Geology of Greece. Talk by Bob Fuller
Long-time club member, Bob fuller gave a fascinating insight into some of the geology of Greece, following his recent trip there with his wife, Leanne. From their travels, and from his own research, Bob detailed connections between mining (of marble, lead, silver and gold) and the ancient history of Greece in particular on the Attica Peninsula, and on some of the islands in the Aegean Sea. 

"Greece's history and its geology are inseparable," said Bob.

Bob's photographs illustrated so much - mountainous landscapes, how marble is formed, marble quarries, how marble is transported, restoration work on ancient buildings and monuments, etc.

Bob explained three common reasons why archaeological sites had become covered: river silt (e.g. at Olympia), rock fall (e.g. at Delphi) and volcanic eruption (e.g. on the island of Santorini). Special features of Bob’s photo-graphs were details of Santorini, showing, for example - volcanic banding in the caldera, grapevines trained to a low-growing form as protection from strong winds and terraced houses built on steep slopes. Thank you Bob
(Report by Michael Rooke)

No comments: