A REVIEW OF THE IRISH RIVER MACROPHYTE DATABASE: INFORMING FUTURE RIVER MACROPHYTE SURVEYING

The study of river vegetation for the purposes of macrophyte community classification has often been neglected by vegetation scientists. There is little detail available on appropriate survey methods for classification of aquatic river communities and their suitability to the task in hand. There is great variation in river macrophyte surveying techniques within Ireland and abroad. Current methods relate mostly to water quality and status assessment; however, these methods are not always suitable for vegetation classification. We review survey methods utilised in European and Irish river vegetation studies. There is consensus on the optimum time of the year to survey and on the use of the most appropriate on-site recording techniques. The main challenges that need to be addressed are how best to select river survey sites and at what scale, then subsequently, selecting the most appropriate plot size within these sites, to capture existing vegetation community types accurately. Both issues are widely debated and little consensus exists. We discuss the practicalities of standardising survey procedures so that river vegetation studies can be compatible on a broad scale and suggest methods that will improve classification of river vegetation for the future. At least some standardisation in survey methodology would add to the quality and usability of future collected data, however, it is important that a level of flexibility remains so that different survey needs can be met. A thorough scientific assessment of techniques is not the purpose of this paper, but rather to present a proposed set of guidelines from lessons learnt while river macrophyte surveying and collating river vegetation data from different sources in to one central database, the Irish. River Macrophyte Database (RMD). Background information and summary statistics of the RMD are presented including limitations of the data in terms of classification and data quality.