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TitreClimate cycles drive aquatic ecologic changes in the Fort McMurray Region of Northern Alberta, Canada
AuteurNeville, L A; Gammon, P; Patterson, T R; Swindles, G T
SourceProceedings of GeoConvention 2015, Geoscience New Horizons; 2015.
LiensOnline - En ligne
Séries alt.Secteur des sciences de la Terre, Contribution externe 20150269
ÉditeurCanadian Society of Petroleum Geologists (CSPG)
RéunionGeoConvention 2015, Geoscience New Horizons, Canadian Society of Petroleum Geologists (CSPG); Calgary Alberta; CA; mai 4-8, 2015
Mediapapier; en ligne; numérique
Sujetsécologie; effets climatiques; terres humides; Écosystème
ProgrammeDéveloppement durable des sables bitumineux, Géosciences environnementales
Résumé(Sommaire disponible en anglais seulement)
Understanding ecologic response to climate cycles will aid in defining current and future ecological changes associated with climate change and allow for a differentiation between climate-driven versus anthropogenic driven environmental stresses.
The paleoecological record from a northern Canadian lake located 40 km east of the Athabasca Oil Sands operation records a benthic stress-induced ecological response to climate cycles such as the El Niño Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO). Arcellacea (testate lobose amoebae) preserved in a freeze core obtained from "ALE", an upland lake in Northeastern Alberta, Canada, were used to reconstruct climate and associated benthic response since 1875 A.D. ALE is situated in a boreal wetland environment where inorganic sediment delivery is overwhelmingly dominated by surface overland flow transport during spring melt. Arcellacea are benthic protists that are excellent indicators of aquatic ecology. Relationships between arcellacean family groupings which represent either healthy or stressed environmental conditions were compared to instrumental climate indices. Modeling using wavelet analysis identified strong ENSO cycles in all arcellacean proxies and weaker PDO cycles in only the healthy ecosystem indicator. The ENSO phenomenon in the tropical Pacific Ocean drives the largest interannual variation in climate across western Canada, and in the study region has been associated with fluctuations in winter precipitation and temperature. The healthy ecosystem indicators decreased in response to positive El Niño and PDO conditions, which are characteristic of decreased precipitation and therefore nutrient input to boreal lakes.
The relationship between arcellaceans and climate anomalies shows that climate driven variations in nutrient input influence boreal aquatic ecology. The link between aquatic ecology and climate has significant implications on oil sands risk assessment and the determination of reclamation endpoints.
Résumé(Résumé en langage clair et simple, non publié)
Comprendre réponse écologique aux cycles climatiques aidera à définir les changements écologiques actuels et futurs liés au changement climatique et permettre une différenciation des stress environnementaux dus au climat de ceux dus à la pression anthropique. L'enregistrement paléoécologique d'un lac du Nord canadien situé à 40 km à l'est des opérations d'exploitation des sables bitumineux d'Athabasca enregistre une réponse benthique induite par le stress écologique aux cycles climatiques. La relation entre les anomalies écologiques et climatiques montre que les variations d'origines climatiques sur l'apport en nutriments influencent l'écologie boréale aquatique. Le lien entre écologie aquatique et climat à des répercussions importantes sur l'évaluation du risque quant aux sables bitumineux et à la détermination des paramètres de réhabilitation