title: Moss stable isotopes (carbon-13, oxygen-18) and testate amoebae reflect environmental inputs and microclimate along a latitudinal gradient on the Antarctic Peninsula.
abstract: The stable isotope compositions of moss tissue water (δ(2)H and δ(18)O) and cellulose (δ(13)C and δ(18)O), and testate amoebae populations were sampled from 61 contemporary surface samples along a 600-km latitudinal gradient of the Antarctic Peninsula (AP) to provide a spatial record of environmental change. The isotopic composition of moss tissue water represented an annually integrated precipitation signal with the expected isotopic depletion with increasing latitude. There was a weak, but significant, relationship between cellulose δ(18)O and latitude, with predicted source water inputs isotopically enriched compared to measured precipitation. Cellulose δ(13)C values were dependent on moss species and water content, and may reflect site exposure to strong winds. Testate amoebae assemblages were characterised by low concentrations and taxonomic diversity, with Corythion dubium and Microcorycia radiata types the most cosmopolitan taxa. The similarity between the intra- and inter-site ranges measured in all proxies suggests that microclimate and micro-topographical conditions around the moss surface were important determinants of proxy values. Isotope and testate amoebae analyses have proven value as palaeoclimatic, temporal proxies of climate change, whereas this study demonstrates that variations in isotopic and amoeboid proxies between microsites can be beyond the bounds of the current spatial variability in AP climate.
authors.affiliation: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK. jr328@cam.ac.uk.|Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK. jr328@cam.ac.uk.
authors.forename: Jessica
authors.initials: J
authors.lastname: Royles
authors.affiliation: Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4RJ, UK.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Amesbury
authors.affiliation: Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4RJ, UK.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Roland
authors.affiliation: Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK.
authors.forename: Glyn D
authors.initials: GD
authors.lastname: Jones
authors.affiliation: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Convey
authors.affiliation: Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK.
authors.forename: Howard
authors.initials: H
authors.lastname: Griffiths
authors.affiliation: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK.
authors.forename: Dominic A
authors.initials: DA
authors.lastname: Hodgson
authors.affiliation: Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4RJ, UK.
authors.forename: Dan J
authors.initials: DJ
authors.lastname: Charman
mesh_terms: D000656:Amoeba; D000864:Antarctic Regions; D002244:Carbon; D002247:Carbon Isotopes; D057231:Climate Change; D008834:Microclimate; D010100:Oxygen; D010103:Oxygen Isotopes
chemical_list: D002247:Carbon Isotopes; D010103:Oxygen Isotopes; D002244:Carbon; D010100:Oxygen
keywords: Assemblage; Climate change; Microtopography; Precipitation; Water line