title: Historical changes in arctic freshwater ecosystems.
abstract: Various types of ecosystem-based climate proxies have been used to assess past arctic change. Although lotic records are relatively poor because of the constant reworking of riverine material, high-quality lentic data have been assembled back to the end of the Pleistocene and deglaciation of the circumpolar Arctic. In general, climatic variations in the Holocene, partly due to changes in the shrinking effect of glacier coverage, produced significant temporal and spatial variations in arctic hydrology and freshwater ecosystems. Of particular note were the vast expansions of northern peatlands during major protracted periods of wetting. More recent lake biota and sedimentiological data reflect the general warming trend that has occurred over the last one to two centuries and indicate major changes to freshwater characteristics such as ice-cover duration and thermal stratification. Such data provide an excellent baseline against which future effects of climate change can be both projected and measured.
authors.affiliation: Water and Climate Impacts Research Centre, National Water Research Institute of Environment Canada, Department of Geography, University of Victoria, BC. terry.prowse@ec.gc.ca
authors.forename: Terry D
authors.initials: TD
authors.lastname: Prowse
authors.forename: Frederick J
authors.initials: FJ
authors.lastname: Wrona
authors.forename: James D
authors.initials: JD
authors.lastname: Reist
authors.forename: John J
authors.initials: JJ
authors.lastname: Gibson
authors.forename: John E
authors.initials: JE
authors.lastname: Hobbie
authors.forename: Lucie M J
authors.initials: LM
authors.lastname: Lévesque
authors.forename: Warwick F
authors.initials: WF
authors.lastname: Vincent
mesh_terms: D000818:Animals; D001110:Arctic Regions; D003081:Cold Climate; D017753:Ecosystem; D005618:Fresh Water; D017752:Greenhouse Effect; D049690:History, Ancient