Deepened winter snow increases stem growth and alters stem δ 13 C and δ 15 N in evergreen dwarf shrub Cassiope tetragona in high-arctic Svalbard tundra

Datos Bibliográficos

ID15550799
AutoresDaan Blok (0000-0003-2703-9303, University of Copenhagen, autor de correspondencia), Stef Weijers (0000-0003-3386-5417, University of Bonn), J M Welker (0000-0002-3865-4822, University of Alaska Anchorage), Eric J Cooper (0000-0002-0634-1282, UiT The Arctic University of Norway), Elisabeth J Cooper, Anders Michelsen (0000-0002-9541-8658, University of Copenhagen), Jörg Löffler (0000-0002-9320-6168, University of Bonn), Bo Elberling (0000-0002-6023-885X, University of Copenhagen)
Año2015
Volumen10
Número4
Páginas044008-044008
Fecha de publicación2015-04-01
Peer ReviewedSí
Open AccessSí
TipoARTICLE
RevistaEnvironmental Research Letters (JOURNAL)
Identificadores de la revistaISSN: 1748-9326 • E-ISSN: 1748-9326
EditorialIOP Publishing (PUBLISHER • GB)
DOI10.1088/1748-9326/10/4/044008
OpenAlexW2074916040
IdiomaEN
Citas recibidas4
Referencias citadas72

nDeeper winter snow is hypothesized to favor shrub growth and may partly explain the shrub expansion\nobserved in many parts of the arctic during the last decades, potentially triggering biophysical\nfeedbacks including regional warming and permafrost thawing.Weexperimentally tested the effects\nof winter snow depth on shrub growth and ecophysiology by measuring stem length and stem\nhydrogen (δ2H), carbon (δ13C), nitrogen (δ15N) and oxygen (δ18O) isotopic composition of the\ncircumarctic evergreen dwarf shrub Cassiope tetragona growing in high-arctic Svalbard, Norway.\nMeasurements were carried out on C. tetragona individuals sampled from three tundra sites, each\nrepresenting a distinct moisture regime (dry heath, meadow, moist meadow). Individuals were\nsampled along gradients of experimentally manipulated winter snow depths in a six-year old snow\nfence experiment: in ambient (c. 20 cm), medium (c. 100 cm), and deep snow (c. 150 cm) plots. The\ndeep-snow treatment consistently and significantly increased C. tetragona growth during the\n2008–2011 manipulation period compared to growth in ambient-snow plots. Stem δ15Nand stemN\nconcentration values were significantly higher in deep-snow individuals compared to individuals\ngrowing in ambient-snow plots during the course of the experiment, suggesting that soil N-availability\nwas increased in deep-snow plots as a result of increased soil winterNmineralization. Although interannual\ngrowing season-precipitation δ2Hand stem δ2Hrecords closely matched, snow depth did not\nchange stem δ2Hor δ18O, suggesting that water source usage by C. tetragona was unaltered. Instead,\nthe deep insulating snowpack may have protected C. tetragona shrubs against frost damage, potentially\ncompensating the detrimental effects of a shortened growing season and associated phenological delay\non growth. Our findings suggest that an increase in winter precipitation in the High Arctic, as\npredicted by climate models, has the potential to alter the growth and ecophysiology of evergreen\nshrub C. tetragona through changes in plant mineral nutrition and frost damage protection

Agronomy · Arctic · Atmospheric sciences · Biology · Evergreen · Geography · Geomorphology · Growing season · Permafrost · Physical geography · Shrub · Snow · Snowpack · Tundra · Climate change and permafrost · Cryospheric studies and observations · Environmental Science · Tree-ring climate responses · Ecology · Geology