Nature Conservation. Peter Marren

butterflies, seem to occupy tiny patches of land, measured in metres rather than kilometres.

      The venerable Victorian tradition for recording the wild plants of a county has been given a new lease of life by computer-based mapping. Grid-mapping was used in most of the county floras published since 1960. Their compilation by dedicated amateur naturalists, sometimes working as a team, sometimes, especially in the more remote regions, representing a titanic solo effort, is one of the wonders of British natural history. The majority of English counties have a flora published during the past 20 years, generally mapped on a fine 2 x 2 kilometre scale. By tradition they also include an overview of the county’s natural vegetation, progress in conservation and potted biographies of local botanists. The recent Flora of Cornwall has an accompanying CD-Rom holding the entire database of records. Some, such as The Flora of Dorset, record mosses, lichens and even fungi, as well as vascular plants. Others, such as A Flora of Norfolk and A Flora of Cumbria use elaborate coloured maps to compare plant distribution with physical features, a valuable advance made possible by modern printing technology.

      Ten-kilometre square records of Arnoseris minima (lamb’s succory) plot the gradual decline to extinction in about 1970 of this once widespread ‘weed’. Hollow circles are records pre-1930, solid circles 1930-1970. (BSBI/CHE)

      There are a growing number of ‘county faunas’, mainly of birds or butterflies, but on occasion extending to other vertebrates and at least the more popular invertebrates. Surrey Wildlife Trust has published a wonderful series of local insect ‘faunas’, including hoverflies, dragonflies, ladybirds and grasshoppers. Local bird reports have reached a high state of elaboration. They are often produced annually, enabling the present year to be compared with the last and revealing population trends. By contrast, many fine wildlife journals have fallen by the wayside, victims of rising costs and falling subscriptions, such as the long-running Scottish Naturalist and Nature in Wales. Fortunately the magazine British Wildlife came in the nick of time to rescue serious naturalists, and includes valuable news reports on all the main groups of flora and fauna. There are welcome signs of a revival in regional or specialised publications, such as Natur Cymru, the new ‘review of wildlife in Wales’, and the lively magazine Atropos, which is devoted to moths, butterflies and dragonflies.

      Tetrad records of Danish scurvy-grass from A Flora of Norfolk reveal the plant’s fidelity to a natural habitat, coastal salt marshes, and its mimic, the moist, salty verges of main roads. (Alec Bull & Gillian Becket)

      A series of Red Data Books has been published on rare and vulnerable species, each one containing a great deal of ecological information on the eternally fascinating question of why some species are rare. The more recent ones include distribution maps. So far there are Red Data Books for Vascular Plants (first published 1977, 3rd edition 1999), Insects (1987), Birds (1990), Other Invertebrates (1991), Stoneworts (1992), Mammals (1993), Lichens (in part – 1996) and Mosses and Liverworts (2001). There is also Scarce Plants in Britain (1993), a kind of ‘Pink Data Book’ for wild flowers that live on the edge of conservation activity. Together they cover nearly 4,000 species, and undoubtedly many more would qualify, especially if we knew more about fungi, or soil and marine life. It is a daunting thought that perhaps a quarter of our wild plants and animals are rare enough to warrant conservation action – and, if our climate is truly changing, that this proportion will rise.

      Site registers and monitoring schemes

      To conserve species in a site-based system of nature conservation you need to link species to places. During the 1980s, the NCC embarked on a series of grand, nationwide habitat surveys, a kind of resource account of Britain’s wildlife. Cumulatively they produced a detailed documentation of Britain’s wild places as a factual basis for conservation decisions. The NCC drew on existing, scattered information, but the surveys also amounted to possibly the most ambitious programme of field survey there has ever been. First there were the habitat surveys: ancient woodland (‘the Ancient Woodland Inventories’), the coast (‘Sand-dune Survey’, ‘Estuaries Review’), peatlands (‘National Peatland Resource Inventory’) and rivers. Beyond the shoreline there was the Marine Conservation Review (q.v.), analogous to the Nature Conservation Review on land, which classifies maritime communities and documents the best sites. The Geological Conservation Review did the same for rock strata and special geological sites over 41 volumes. Then there were the species reviews. The Invertebrate Site Register documented the best sites of insects and other invertebrates. A Rare Plant Survey did the same for rare vascular plants. The long-running Seabirds at Sea project discovered where seabirds went and what they did once they were beyond the reach of land-based binoculars. These surveys formed a mass of raw material that could be tapped for SSSI notification, species protection, drawing up oil-spill contingency plans etc. The Geological and Marine Conservation Reviews were also major contributions to pure science. Most of this work remains unpublished, perhaps destined to remain forever in sagging, spiral-bound folders thronging the shelves of conservation offices or lodged somewhere in the labyrinth of cyberspace. It is almost unsung, this last, vast outpouring of British natural history. The NCC’s successor agencies continued some of it, and implemented smaller-scale surveys of their own, though generally for a particular, short-term purpose, but none of them had any interest in praising the work of their predecessor. All the same, it was a tremendous voyage of discovery with able captains. Those of its mariners that are not retired are now mostly in administrative conservation jobs, or working as consultants.

      Recording rare flowers: Barbara Jones, a trained climber, surveying the Snowdon lily, Lloydia serotina, (below) on Snowdon.

      There were also surveys that established a system of baseline monitoring to record how the natural world was changing. A basic ‘phase one’ survey that purported to map all Britain’s natural habitats started in the early 1980s, with the help of the county wildlife trusts. The NCC also started a National Countryside Monitoring Scheme, which compared present and past land use in selected parts of the countryside. A much finer tool for measuring change was handed to conservation workers with the publication, during the 1990s, of the five-volume British Plant Communities, compiled by John Rodwell of Lancaster University, the fruits of a 15-year project to classify all kinds of natural and semi-natural vegetation found in Britain. The vegetation of many SSSIs has been mapped using this National Vegetation Classification, thereby providing a baseline for monitoring change as well as for assessing how much of the different types of vegetation are on protected sites. The species that best lend themselves to detailed census work are birds and butterflies. Birds have long been monitored using the Common Bird Census (now the Breeding Bird Survey) organised by the British Trust for Ornithology (BTO), along with the regular counts of seabirds by the Seabird Group. The performance of rare birds is the responsibility of the Rare Breeding Birds Panel. For monitoring butterflies, a method was worked out in the 1970s by Ernest Pollard, which involved counting all the species seen along a regularly walked transect. The success of the scheme has meant that fluctuations in butterfly numbers can be recorded, as well as their distribution. Computer techniques have also made possible some novel ‘phenograms’ (see p. 28) combining numbers with dates of emergence. Further evidence of population changes in insects, especially moths, is provided by the ‘Rothamsted traps’ operated under standardised conditions across the country. There has also been a revival of phenology – timing the appearance of flowers or frog-spawn or migrant birds – in relation to climate change.

      ‘Abundance map’ of the kestrel from The New Atlas of Breeding Birds 1988-1991 showing relative numbers as well as distribution. (By permission, BTO)

      From data to action

      Surveys