|Title||Influence of the Pacific Decadal Oscillation and El Niño-Southern Oscillation on lacustrine hydroecologic cycling in Alberta|
|Author||Patterson, R T; Neville, L A; Gammon, P; Swindles, G T; Macumber, A L|
|Source||Proceedings of PACLIM 2015 - Droughts: Reconstructing the past, monitoring the present, modeling the future. Twenty-Seventh Pacific Climate Workshop; 2015.|
|Links||Online - En ligne|
|Alt Series||Earth Sciences Sector, Contribution Series 20150266|
|Meeting||PACLIM 2015: Droughts: Reconstructing the past, monitoring the present, modeling the future. Twenty-Seventh Pacific Climate Workshop; Pacific Grove, California; US; March 8-11, 2015|
|Area||Alberta Lake East|
|Subjects||climate effects; faunal assemblages; Cucurbitella triscuspis; El Niño-Southern Oscillation (ENSO); Pacific Decadal Oscillation (PDO); Atlantic Multidecadal Oscillation (AMO); Little Ice Age (LIA); C.
Tricuspis; Arcellaceans; eucaryotic microbes; paleolimnology; kettle lakes; difflugids; centropyxids|
|Program||Coal & Oil Resources Environmental Sustainability, Environmental Geoscience|
|Abstract||High-resolution (~ 1 yr resolution) temporal variation in Arcellinida (testate lobose amoebae) assemblages and grain-size data were documented in a freeze core record spanning the interval AD 1875-2010
that was collected from Alberta Lake East (ALE). Arcellinidans play a key role in aquatic ecosystems where they exert considerable predatory pressure on bacteria and smaller eucaryotic microbes and represent an important intermediary food web
component. In Alberta they respond to nutrient enrichment derived from sediment influxes from the catchment, and provide evidence that lakes in the region exhibit hydroecological responses to temporal variation in precipitation, including droughts.
They are thus useful indicators of paleolimnological and climatic change. Anthropogenic influence on this remote kettle lake has been minimal, as there are no roads or other infrastructure within the watershed. PeakFit analysis of the grain size data
indicates that the gyttja infill of the lake has not been significantly influenced by bioturbation, despite bottom waters being well oxygenated. Spectral time series analysis of individual arcellinidan taxa (e.g. Cucurbitella triscuspis, a
eutrophication indicator), as well as grouped difflugids (generally more sensitive to suboptimal conditions) and centropyxids (opportunistic generalists) resulted in identification of discontinuous cycles archived in the faunal assemblage data, which
correlate particularly well with the 2-7-year El Niño-Southern Oscillation (ENSO) and 15-25 and 50-70-year modes of the Pacific Decadal Oscillation (PDO), and to a lesser extent the 50-90-year Atlantic Multidecadal Oscillation (AMO). Wavelet time
series analysis of arcellacean assemblages indicate that the hydroecology of ALE changed significantly when the Polar Front retreated northward across the latitude of the lake as the Little Ice Age (LIA) drew to a close. Through the latter stages of
the LIA in the late 19th century centropyxids were ecologically dominant and responded strongly to the various climate drivers, particularly ENSO. As ALE warmed and productivity increased through the early 20th century first difflugids and then C.
Tricuspis began to out compete the centropyxids, and in turn began to cycle according to the various hydroecological influences of ENSO, PDO and AMO.|
|Summary||(Plain Language Summary, not published)|
Lakes in the Alberta Oil Sands region exhibit hydroecological responses to temporal variation in precipitation, including droughts. Changes in
hydroecological response correlate particularly well with the 2-7-year El Niño-Southern Oscillation (ENSO) and 15-25 and 50-70-year modes of the Pacific Decadal Oscillation (PDO), and to a lesser extent the 50-90-year Atlantic Multidecadal