Macrophytes of the River Tweed

Abstract

An account is given of the 5 lichens, 76 bryophytes, 40 angiosperms and the ‘sewage-fungus’ community recorded from a survey of the River Tweed, Scotland, together with historical and environmental data. For most of its length the river water is relatively soft and low in key nutrients, although phosphate levels in the past were probably higher due to the effluents from wool mills. The presence or absence of each macrophyte was recorded for successive 0.5 km lengths of the river, and histograms are included which summarise the distribution of individual species. In addition, a subjective estimate of the relative abundance within each length was made for each species, and some of these data have been included in an ordination table. Some comparison is also made with data from the literature on rivers in North-east England.