VC59 Flora Project - October 2004 Newsletter

NORTH WESTERN NATURALISTS' UNION

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VC59 Flora Project - October 2004 Newsletter

Recording for the Flora is scheduled to come to an end this autumn. We have reached a very satisfactory stage as far as Vascular plants are concerned, thanks to a burst of very hard work by the vascular plant recording team this summer (see the report by Dave Earl below). It is clear that the Flora will accurately reflect the distribution of Flowering Plants and Ferns in the vice-county. We shall very soon be beginning to write up the data and the format of the Flora will have to be irrevocably fixed. So this is your last chance to tell us your views about how the Flora should be presented (send them to the committeee via John Lowell).

For example

Your opinions and suggestions will be welcomed.

Bryophytes

While it is thought that we have a reasonable picture of the VC59 bryophytes it is clear that the data is not going to be complete. Even in "well recorded" regions a further visit always turns up more species! This is partly because of the difficulty in spotting all the colonies of these diminutive plants, but also because the flora is unquestionably changing: epiphytes like Metzgeria sp. and Orthotrichum pulchellum are rapidly colonising our area. For example, a recent NWNU visit to Borsdane Wood - a very well worked tetrad with 120 species recorded - yielded no less than nine new records! Some of these were colonising epiphytes and several others were ephemerals from a stubble field - a lucky encounter, as most fields in this area are ploughed and sown with overwintering Barley soon after harvest. One species, Microlejeunea ulcina, is a tiny plant probably overlooked previously; on this occasion, Alan Bamforth was deliberately searching for it. Other recent recording expeditions have turned up 3 to15 new species per tetrad. Happily, most of the new records of species were already recorded in neighbouring tetrads, which means they are not making much difference to our overall distribution picture. Most recent work has been concentrated on the West Pennine Moors and Cliviger/South Pennines, because it is important to assess the completeness of recording in these bryologically richer areas. The West of the county is undoubtedly under-recorded but we have enough data to be sure that the West is relatively species-poor.

John Lowell

Vascular Plant News

The main objective during the summer of 2004 was to target tetrads with totals of less than 200 species recorded. It was particularly important to visit areas at low altitude with low totals and to record the connecting valleys within the hill districts. We have now been able to demonstrate that over 90% of the South Lancashire tetrads have tetrad totals exceeding 200 species. The importance of the connecting valleys within the hill districts as corridors of diversity has also been shown. Note also that diversity is often enhanced by planting schemes in the upland areas particularly about reservoir complexes. In the valleys the presence of garden escapes also contributes to tetrad totals emphasising the significance of the 'mill village communities'. Exploration of important key habitats, especially the hill district cloughs is steadily producing results with extra records for notably species such as bog asphodel.

At the time of writing (September 2004) an estimated 9 tetrads remain for which totals might be increased beyond 200 species and all such tetrads will probably have been visited by the time that this article is published. The emphasis will thus change to that of i) targeting common species absent from tetrads which are thought to be present but have been overlooked during previous surveys, and ii) steadily increasing tetrad totals especially in the low altitude areas where a variety of habitats can be accessed.

For checking the presence or absence of the common species reference to the distribution maps on the flora CD will be the standard method. Steps are being taken to provide a method of producing tables which demonstrate the presence or absence of the top 100 species for any given 10km square and this facility should be available on upgrades of the flora CD in due course. This is a particularly important activity as we approach the final stages of recording for the forthcoming flora.

For general recording the standard tetrad totals map has been further modified to indicate which tetrads have totals of 200-209. The colour code red is used to indicate such tetrads. This works well and has already produced results. It is anticipated that steady progress will be made using this system. With time further increments will be made 210-219; 220-229 etc. and thus the areas of low diversity such as reclaimed 'mosslands' with limited access will become increasingly obvious as more and more species are recorded from the more species rich surrounding tetrads. This system of recording will be an ongoing activity beyond the cut off point for the flora. In fact 'The South Lancashire Flora' will no doubt be a constant source of reference as we analyse the results of our future natural history excursions within VC59.

Updates of the colour coded tetrad map are available on request.

Dave Earl