Studies in the charophyte flora and ecology of some post-industrial water bodies in County Durham (v.c. 66)

Abstract

The reasons for the relatively small number of records for charophytes from County Durham (v.c. 66) in the 19th and 20th centuries are reviewed and the focus of recording on three specific areas is discussed. The augmentation of records is undertaken through four surveys of post-industrial water bodies in the period 2007–2013, specifically, of the Durham Magnesian Limestone Natural Area; Carboniferous Limestone quarries of Upper Weardale; lead mine reservoirs on the moorlands of the North Pennines Area of Outstanding Natural Beauty; lakes and ponds of the central Wear Valley. As a result of the surveys the charophyte database was more than doubled to 124 records for 16 taxa and 39 key sites identified from a total survey of 138 sites. The flora is compared with other local vice-county floras, the ecological and phytosociological aspects discussed and the prospects for conservation considered. Most of the sites were found to be relatively immune from the threat of eutrophication.

Keywords:

• Chara vulgaris
• Chara hispida
• Chara virgata
• Nitella
• phytosociology

Acknowledgements

Thanks are due to Clare O’Reilly for help with specific determinations and comments on the original manuscript; Nick Stewart for the original dataset for the Flora of North-east England database and for many confirmations of identification and much helpful guidance; Dr Quentin Groom for unrestricted access to the database and help with the production of distribution maps; Durham Biodiversity Partnership for funding Clare & John O’Reilly’s survey work (as Ptyxis Ecology) for the Durham Magnesian Limestone Fen Inventory Project; Professors Emeritus Brian Whitton of Durham University and David John of the Natural History Museum, London for information, guidance and enthusiasm for the project; Pascale Nicolet of the Freshwater Habitats Trust for survey information; Stuart Pudney of Northumbria Water Ltd for additional information; Russell Bell, Jill Essam, Dr Tom Mercer, Tom Osborne and Mick Martin for access permissions; Joe Ridley and Joe Shimwell for field assistance; and to the Reverend Gordon and Mrs Pat Graham for the inspirational gift of a grapnel.