ARTICLE SCIENTIFIQUE
Rapid decrease of the Labrador Sea’s influence on black spruce ecosystems with distance inland
AUTEUR.E.S
Julien Larose | Géographie UQAM, GEOTOP et CEN
Étienne Boucher | Géographie UQAM, GEOTOP et CEN
Anne de Vernal | Sciences de la Terre UQAM, GEOTOP et CEN
Ignacio Hermoso de Mendoza | Géographie UQAM, GEOTOP et CEN
Fabio Gennaretti | IRF et Groupe de recherche en Écologie - MRC Abitibi et UQAT
Aliénor Lavergne | Carbon Cycle Research Group, Space and Atmospheric Physics, Imperial College Royaume-Uni
Laia Andreu-Hayles | Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York
Robert D. Field | Department of Applied Physics and Applied Mathematics, NASA Goddard Institute for Space Studies, New York
Communications Earth & Environment | volume 5, Article number: 108 (2024)
Résumé (En anglais)
In eastern Canada, Black spruce (Picea mariana Mill. B.S.P.) grows in a wide variety of climates, from maritime-oceanic conditions near the Labrador Sea, to more continental climates, inland. Along this gradient, timing and provenance of heat and moisture that support growth are uncertain, weakening our capacity to predict the response of boreal ecosystems to climate variability. Here, we measured the stable oxygen isotopic composition of black spruce tree-ring cellulose at three sites in eastern Canada and provide evidence of a rapid decrease of Labrador Sea’s influence on adjacent ecosystems. Our results report a landwards decrease in the oxygen isotope composition of both tree-ring cellulose (δ18OTRC) and precipitation water (δ18Op). We also reveal a rapid landwards decoupling between δ18OTRC variability (1950-2013), maximum temperature and Sea Surface Temperature variations over the Northwest Atlantic. Thus, despite their apparent ecological homogeneity, eastern Canada’s black spruce ecosystems rely on heterogeneous sources of heat and moisture.