River Macrophytes Database

The JNCC River Macrophytes Database (RMD) is a Microsoft Access database constructed to house data on the plant communities of rivers in Great Britain and Northern Ireland. An extract in Excel format is also provided. The RMD includes data from over 7,000 survey sites and is the most comprehensive database of its kind. Data have been collected from all over the UK between 1977 and the present day, following the methods of Holmes et al. (1999). The macrophyte survey method records aquatic and marginal plants in a 500 m-long survey section of river. Species from the river channel and the margins/base of the bank are recorded separately on a three-point scale of relative abundance and percentage cover. A standard check-list of species is used to aid recording. The field data can be used to classify the plant community as described by Holmes et al. (1999), and the database has a facility that allows keying-out of the community to sub-type level. This plant community classification has been used as the basis of river SSSI selection (see chapter 6 of Guidelines for Selection of Biological SSSIs). The database also holds a small amount of fish data. The RMD is an ‘active’ database (i.e. survey records can still be added). However, with a new standard method of river plant survey now being adopted by the UK conservation agencies (i.e. the LEAFPACS method), it is likely that less surveys will be added in future, and it may develop into more of a 'legacy' database. In 2011 the RMD was made available through the JNCC website with some restrictions on re-use. In June 2018, JNCC re-published the RMD as open data under the Open Government Licence. In November 2019 the invertebrate survey records were removed whilst some of these records underwent further validity checks. Background information on the classification system: Holmes, N.T, Boon, P.J., & Rowell, T.A. Vegetation communities of British rivers - a revised classification (1999) Link to the Vegetation communities of British rivers on the JNCC Resource hub: https://hub.jncc.gov.uk/assets/a974944a-3cd4-4574-9c1a-c977d482c0ed