The impact of sand extraction at Formby Point ... - Sefton Council

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16 adjacent habitats for a time. However, sand-dune ecosystems are known to recover quite quickly from major disturbances, a proportion of their characteristic biota being adapted to unstable conditions, including rapid colonising ability. The fact that large areas of undisturbed habitat remained between sand-quarries would have helped this process. Natterjack Toads, for example, may well have thrived in the open sandy conditions which followed sand extraction and which would have included abundant shallow pools in the quarry floors. There are circumstances in which large-scale disturbance to sand-dunes may be positively beneficial to wildlife. Thus, most larger dune systems in Britain, including the Sefton Coast, are over-stabilised due to lack of grazing, the introduction of non-native trees and shrubs and a recent preoccupation of land-managers with preventing sand-blow (Houston 1997). This encourages over-representation of mature successional stages with consequent threat to the many species that require younger, more open, habitats. Thus, it could be argued that sand-winning at Formby Point reversed, for a time, the trend towards more stable conditions and provided opportunities for the plants and animals of open dunes. However, the validity of this argument is reduced by the fact that, at the time when most sand-winning took place, the dune vegetation was more open and sandy than it has been in recent decades. While the sand quarries represent younger landscapes than would have been the case, they show plenty of evidence of having aged markedly since their creation. Thus, the eastern section of the Lifeboat Road quarry has become heavily wooded over the past 30 to 40 years, and trees and shrubs, many of which are non-native, are still spreading. Tall Creeping Willow, almost all of the coastal variety argentea, has overgrown the lowerlying parts of Ravenmeols and Cabin Hill, while larger willows have invaded some of the wetter basin sites. Several slacks, which were formed when excavation breached the water-table, have become dryer, probably due to increased evapotranspiration and accumulation of sediment. Not all these trends are wholly deleterious however. For example “fixed dune with Creeping Willow”, which is so extensive on quarry floors, is listed for conservation under Annex 1 of the EU Habitats Directive. The larger willows
are often accompanied by nationally rare hybrids and dune scrub is known to be important for breeding birds and invertebrates (Smith 1999). 17 Although we do not know whether important slacks were lost to sand-winning, the extracted landscape is nearer the water-table and therefore often wetter than might have been the case previously. Indeed, Smith (1978a) points out that natural wet-slacks at Formby Point were probably infilled for Asparagus cultivation during an earlier period. As is well-known, many of the Sefton Coast’s most charismatic species are associated with wet-slacks (Smith 1999) The topography of extracted sites is often less varied than before, several large dunes, such as Beacon Hill, Shorrock’s Hill and Cabin Hill having been removed. Undulating dune topography, notably lacking in most sand-quarries, is highly beneficial to biodiversity by creating a wide range of different micro-climates and habitats. For example, the plant communities on north-facing slopes of fixed dunes differ from those on south-facing slopes (Smith 1999). It can be inferred that animals are also influenced by such differences; for example the Northern Dune Tiger Beetle (Cicindela hybrida) is largely confined to localities with a southern exposure (Judd 2003), while Sand Lizards are also known to favour a southerly aspect. 4. Potential for habitat maintenance, restoration or creation 4.1. Smaller-scale Large parts of the three main sites are already subject to formal Management Plans (Sefton Coast Life Project 1996; English Nature 2004), which provide prescriptions for habitat and species management within areas previously extracted for sand. That for Cabin Hill NNR is especially detailed. It recommends, for example, reintroduction of summer grazing, including trials of ponies, to supplement winter sheep grazing, accepting that the current regime has been successful in controlling birch but not willow. Summer grazing was originally thought to be deleterious to Natterjacks through trampling and nutrient enrichment but these are no longer considered to be problems. Larger livestock should help to create more bare patches. Another suggestion is to encourage Rabbit-
Page 1 and 2: 1 The impact of sand extraction at
Page 3 and 4: • Rapid, up-to-date assessment of
Page 5 and 6: 5 jackii) with a smaller component
Page 7 and 8: grazed, fixed-dune grassland charac
Page 9 and 10: 9 The vegetation of the main quarry
Page 11 and 12: 11 on the Sefton Coast occur here b
Page 13 and 14: leaved Wintergreen (Pyrola rotundif
Page 15: 15 Slack 2 was progressively invade
Page 19 and 20: 19 by blown sand is mentioned; thes
Page 21 and 22: Creeping Willow nearby seems to be
Page 23 and 24: 6.3.1. Smaller-scale 23 • Cut bac
Page 25 and 26: Smith, P.H. (1978c). Cabin Hill - a

The impact of sand extraction at Formby Point ... - Sefton Council

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