Defining reference conditions for acidified waters using a modern analogue approach.
Analogue matching is a palaeolimnological technique that aims to find matches for fossil sediment samples from a set of modern surface sediment samples. Modern analogues were identified that closely matched the pre-disturbance conditions of eight of the UK Acid Waters Monitoring Network (AWMN) lakes using diatom- and cladoceran-based analogue matching. These analogue sites were assessed in terms of hydrochemistry, aquatic macrophytes and macro-invertebrates as to their suitability for defining wider hydrochemical and biological reference conditions for acidified sites within the AWMN. The analogues identified for individual AWMN sites show a close degree of similarity in terms of their hydrochemical characteristics, aquatic macrophytes and, to a lesser extent, macro-invertebrate fauna. The reference conditions of acidified AWMN sites are inferred to be less acidic than today and to support a wider range of acid-sensitive aquatic macrophyte and macro-invertebrate taxa than that recorded in the AWMN lakes over the period of monitoring since 1988.
Simpson
Gavin L
GL
Environmental Change Research Centre, University College London, 26 Bedford Way, London WC1H 0AP, UK. gavin.simpson@ucl.ac.uk
Shilland
Ewan M
EM
Winterbottom
Julie M
JM
Keay
Janey
J
D000818:Animals; D004784:Environmental Monitoring / Q000379:methods*; D005580:Fossils; D005618:Fresh Water; D019015:Geologic Sediments / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007448:Invertebrates; D012016:Reference Values; D014874:Water Pollutants, Chemical / Q000032:analysis*; D015048:Zooplankton
D014874:Water Pollutants, Chemical