The demand for aggregates (sand, gravel, crushed rock) in the UK shows no sign of abating as more and more roads, homes and other man-made creations claimed to be necessary for the ultimate profit as well as improvement and fulfilment of society are constructed.

For all the good intentions of the government-sponsored Aggregates Levy Sustainability Fund (ALSF) Partnership Grant Scheme, this extraction is placing ever greater pressure on the environment, often in areas which are vulnerable and possess significant biodiversity. Reigate Heath, a Site of Special Scientific Interest in Surrey, is just one example of a site which, until spring 2006, inexcusably was under threat from possible mineral extraction nearby.

Focusing on sandpits, when they are in full flow their varied and in many instances warm micro-climates offer perfect opportunities for invertebrates and, occasionally, for such birds as Sand Martins (Riparia riparia).

Once work in the pits is finished, though, it is all change – and rarely for the better in terms of continuity and balance. The pits can be left to their own devices, ending up covered in scrub due to lack of effective management, or, more often, they can be filled with water to provide sporting activities for people and, as a sop to environmentalists, a haven for birds, aquatic invertebrates and flora, and amphibians.

Of these, birds are seen as by far the most important, largely because of the overpowering influence their lobby has in the world of conservation and nature watching. If invertebrates – across the board, rather than just butterflies and dragonflies – had similar backing perhaps one or two disused sandpits might initially be left as they are, then managed to create a mosaic of habitats with sand dominant but with wet areas, woodland and controlled scrub also present. Benefits would accrue to a wide range of species, including mammals and birds as well as invertebrates.

The fact is, in any planning of a reserve or natural area, the initial focus should always be on invertebrates and flora – everything else ought to follow as a matter of course. Happily the RSPB, taking the holistic view as always, is furthering the cause of a varied approach to mineral sites after extraction has ended. The website www.afterminerals.com provides a fascinating and inspiring insight into what the future may hold for the 1,300 active mineral sites in England.

For a long time a small sandpit pictured on this page covering about two hectares and lying a stone’s throw from Canon UK’s headquarters in central Surrey provided less cause for optimism. Not used commercially for at least 40 years, it is now owned by Reigate & Banstead Borough Council and to the end of 2009 it had not been managed effectively, if at all. Despite being almost entirely covered in scrub, the remaining parcel of open sand, no more than 5 per cent of the total and probably less, is full of hymenoptera each summer. Remarkably, the site has at least nine Red Data Book species plus a number of nationally scarce ones and was the first location in Surrey to host the bee Colletes hederae, which nested in 2007. The colony has thrived since.

As a relevant point here, in 1991 Steven Falk pointed out for the Nature Conservancy Council that fragmentation of habitats can result in smaller sites having longer lists of invertebrate species than larger ones. However, most of the additional species may be immigrants from the surrounding countryside, or ones associated purely with edges. Despite appearances, this is not to the general good, since due to increased competition, predation and parasitism, the change does not usually benefit the original fauna.

Hymenoptera have peculiar and often subtle requirements, and the steady contraction of the open area at the sandpit, joined to general fragmentation in the wider area locally, was doing nothing to encourage the long-term survival of the habitat and its natural denizens.

However, early in 2010 the site was designated as a Site of Nature Conservation Importance, with the promise of management to assist the invertebrates in particular. With the pit in increasing danger of complete scrub encroachment this was splendid news. Local volunteers have done good work opening up banks for nesting and more is planned. There has been a reduction to the point of elimination of local youths digging the sand, turning sections of the locale into a cyclo-cross course and even lighting fires. A typically damaging piece of vandalism occurred in March 2007 when two large tyres were set fire to, making a significant portion of the open sand a temporary no-go area for fauna. A thing very much of the past one hopes.

A selection of the abundant bees and wasps found in the pit is shown under the headings below.

Images © Jeremy Early. All rights reserved.