The algal communities of colliery spoil heaps

A survey of the soil algae present on old coal mine spoil heaps at East Holywell, Tyne and Wear (O.S sheet NZ 37 ref. 313730 ) was carried out during 1979-1980. Samples were taken at monthly intervals from eight permanent quadratso The sites chosen provided a range of spoil types, including some devoid of higher plants and others where colonization was well developed. Algae were isolated and their density quantified using a dilution plate technique A limited flora was recorded at favourable sites on both shale (15 genera) and washeries waste (19 genera). The density of algae in the spoil at sites which were stable, moist and had a pH of about 7 was comparable to that reported for a range of natural soils Seasonal fluctuations in algal density were recorded with a general increase in spring and late summer and a decrease in autumn and winter. A marked decrease in mid-summer which coincided with a period of drought was recored at several sites. At five of the eight sites both a small number of algal species and low population densities were recorded. This was ascribed to the extreme nature of the physical and chemical environment. Evidence was however obtained that at one site the soil algae were acting as primary colonizers.