Aim

To promote lichen conservation in cemeteries and churchyards managed by Chesterfield Borough Council.

Objective

To undertake sensitive management of stonework and masonry that support lichen.

What are lichens?

Many people are familiar with lichens, especially those found on tombstones and chapel and church masonry. This fascinating organism is not a conventional plant but is actually two plants in one. The outer layer is fungus whilst the inner body is made up of algae. The lichen grows by the algae using sunlight for nutrition in the same way as other green plants, and the fungal outer layer provides protection and structure. It reproduces by fruiting fugal spores finding a suitable algal partner on surfaces that are sufficiently stable and not too shaded or smooth. Each fungi (or group) is attracted to a distinctive algae which in turn is attracted to a diverse range of substrates such as stone, bark and soil.

Lichens in cemeteries and churchyards

Lichens are very slow growing, sometimes no more than half a millimetre a year, provided there is enough light and moisture. Individual lichens may be as old as the headstones upon which they live. They are highly sensitive to air pollution. The older stonework commonly found in cemeteries and churchyards provides a habitat in areas where often no other lichens would survive. This is particularly important in urban situations where old stonework is not retained.

The large variety of stone used in cemeteries and churchyards provides many distinct lichen communities. Of the 1,700 British species, over 300 have been found growing on churchyard stone in lowland England.

Lichens are not identified as a flagship species in the Greenprint for Chesterfield, but the UK Biodiversity Action Plan has identified lichens as a priority species group.

The older areas of Chesterfield's churchyards and cemeteries support several lichen species. A good covering of lichen actually protects the stone masonry. The conservation and enhancement of the lichens found in churchyards and cemeteries requires a few simple management guidelines.

• spraying with herbicides may damage existing lichen leading to staining of the stone, therefore weed removal at the base of tombstones should be done by hand
• grass cuttings should be promptly removed and not left to rot on low chest tombs and kerbs
• if lichen needs to be removed (for example, when an important inscription is obscured), plain water and a soft brush can clean the stone effectively
• if large scale cleaning is felt to be necessary, seek the advice of the Churchyard Co-ordinator of The British Lichen Society; the Society produces a Churchyard Lichens fact sheet, which gives information on lichens, the importance of churchyards and how people can help