Speaker: Nick Acheson
Reporter: Sue Gale
There was so much information packed in to the one and a bit hours of this riveting Zoom presentation that it is pretty much impossible to summarise. What can I leave out? Nick took us at breakneck speed through the 7 main landscape types found in Norfolk, telling us something of their history and evolution as well as describing the types of flora and fauna associated with each. And one of the 7 was subdivided into 3!
Woodland came first, because, well it did come first. Originally the county was covered by the Wildwood, although there was plenty of variability depending on soil, drainage and large animals like boars, lynx etc. There are indicator species for ancient woodland, like Wild Anemone and Dog’s Mercury. And although many common birds are woodland species there are some that are entirely dependent on woods to survive, like the Woodcock.
Coastal habitat is the subdivided habitat type. Very important nationally is the saltmarsh, found between the Wash and Cley and second only to Essex in extent. It has the lowest energy input of all, and develops behind spits or at the top of beaches where there is no wave action or tidal effect. Silts laid down are colonised by algae and then early plants like Glassworts, and eventually the Sueda. They provide homes for the Brent and Pink-footed Geese over winter, and breeding grounds for Redshanks etc in summer. Continuing round the coast we come to coastal vegetated shingle, as we all have seen at Cley and Salthouse, home to the Yellow Horned Poppy and Biting Stonecrop. It’s a very rare habitat and we most often visit in winter to find Snow Buntings. Then there are the sand dunes on the North and East coasts. The Northern ones are alkaline and have become heaths, the others are more acid. As dunes develop they become more complex once colonised, firstly by the pioneer plants like Sea Rocket, then by Couch and Marram grasses, until the older dunes have quite diverse flora. For example the Heath Dog Violet found in the East is food for the Dark Green Fritillary, so we need to go to the East coast to see this scarce butterfly, while in the north west the dune slacks are home to Natterjack toads. Sandwich and Little Terns nest on our beaches, Alongside Common and Grey Seals.
The habitat most associated with the county is the Broads, all of which flow out to sea via Yarmouth. They were man-made, having been dug out for peat and gravel, but they became very polluted by sewage and agricultural run-off, causing a rich nutrient environment that was too rich in algae. Several Broads have now been restored to their original productive state, with clear water and good diversity. Here we find the Norfolk form of the Fen Orchid, and of course the Swallowtail butterfly which lays its eggs on the Milk Parsley found only on alkaline fens. The female butterfly has to lay her eggs carefully as larger caterpillars will eat smaller ones that have hatched later. The reedbeds that surround many broads are dominated by Phragmites, and are important for the Bittern. Careful
management has increased the number of booming males from 7-9 to around 200 in the country. Marsh Harriers have also benefitted. These lovely raptors are a common sighting in Norfolk but in fact are scarcer than Golden Eagles! Other species of note in the area are favourites like the Bearded Tits, and more recently the Common Cranes.
The Fens are mostly in the West of the county, and huge areas have been drained for agriculture. Sometimes this has a positive effect, as with the overwintering Pink-footed Geese, which have increased from about 50,000 to around 530,000 each year, feeding on sugar beet and potatoes.
Other species like the Taiga Bean Geese and Bewick Swans are declining, but this is likely climate- related rather than land use. It’s possible that other species will also decline as the winter climate becomes less severe on the continent. The club has had an earlier presentation on the ‘headstarting’ of Black-tailed Godwits which is a good example of the conservation work to encourage more breeding waders.
Our fifth habitat is heathland. The largest areas are around Roydon and Grimstone Warren, but Salthouse and Kelling heaths are also significant. These are typified by Bell Heather and Gorse, and here we find Stonechats and Dartford Warblers, with Nightjars later in the summer. Insects special to the heaths include Green Tiger Beetles, Silver-studded Blue butterflies and Green Hairstreaks. The Black Darter dragonflies are only found in NW Norfolk, alongside Keeled Skimmers. The Raft Spider is only found at Roydon Common, although the Fen Raft Spider is being introduced in the more alkaline East. Adders are increasingly seen in April, with the males emerging first to guard their territories. These snakes can be easily separated from Grass Snakes by their slit pupils – Grass Snakes have round ones.
The Brecks are an ancient habitat of SW Norfolk, where Cretaceous chalk lies close to the surface under a top layer of sand. They are baked in the summer and very cold in winter. Rabbits are common and used to be farmed here. The poor, disturbed soil is good for rare species like the Stone Curlew. These strange looking birds are doing well, thanks to a partnership between local farmers and the conservation organisations. Ponies are used for conservation grazing, but for the Stone Curlews the very close grazing by rabbits is important. Around Thompson Common we find the man- made Thompson Water but also pingoes – small pools created in the ice age. There are 58 red-data species in the Brecks, including Scarce Emerald damselflies. Pool Frogs have been re-introduced here – a first in Britain.
Our last major habitat is farmland, which covers over 70% of the county. This is not as productive for wildlife as it was in more traditional times. The input of more chemicals and the reduction in ‘weed’ species has had an adverse effect, so we have almost lost species such as the Turtle Dove. These birds are site-faithful and so have died out when their usual places have lost small ponds with shallow edges for drinking and arable weeds for seeds. We do still have Grey Partridge in NW
Norfolk, although elsewhere it has been ousted by the introduced Red-legged variety.
I am sure that however experienced WVBS members may be they must all have learned something from this headlong race through the wild places of Norfolk. Perhaps we should ask Nick to talk about just one of those habitats next time. Meanwhile many thanks are due to him for an excellent presentation.