Effects of drainage on the botanical richness of peat grassland.
Data on botanical composition from 3 studies involving drainage of peat grasslands in 1940-75 were reanalysed by means of analysis of variance using total number of plant species, number of quality-indicating species and a system in which species were weighted according to rarity and rate of decline. Alopecurus geniculatus, Glyceria fluitans and Phalaris arundinacea were used as moisture indicators, and Dactylis glomerata and Poa pratensis as drought indicators. On extensively exploited grasslands drainage alone had considerable adverse effects on species richness whereas on intensively managed grasslands the N supply had the dominant effect. Results indicated that there was little or no advantage to nature conservation in omitting drainage where grassland was intensively managed. (Abstract retrieved from CAB Abstracts by CABI’s permission)