Distribution and diversity of diatom assemblages in surficial sediments of shallow lakes in Wapusk National Park (Manitoba, Canada) region of the Hudson Bay Lowlands. Issue 13 (9th June 2016)

• Record Type: Journal Article
• Authors: Jacques, Olivier; Bouchard, Frédéric; MacDonald, Lauren A.; Hall, Roland I.; Wolfe, Brent B.; Pienitz, Reinhard
• Is Part Of: Ecology and evolution. Volume 6:Issue 13(2016:Jul.)
• Page Start: 4526
• Page End: 4540
• Publication Date: 2016-06-09
• Subjects: Diatoms -- Hudson Bay Lowlands -- Limnology -- Monitoring -- Shallow lakes -- Wapusk National Park; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.2179
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: The hydrology of shallow lakes (and ponds) located in the western Hudson Bay Lowlands (HBL) is sensitive to climate warming and associated permafrost thaw. However, their biological characteristics are poorly known, which hampers effective aquatic ecosystem monitoring. Located in northern Manitoba along the southwestern coast of Hudson Bay, Wapusk National Park (WNP) encompasses numerous shallow lakes representative of the subarctic zone. We analyzed the distribution and diversity of diatom (microscopic algae; class Bacillariophyceae) assemblages in surficial sediments of 33 lakes located in three different ecozones spanning a vegetation gradient, from NE to SW: the Coastal Fen (CF), the Interior Peat Plateau (IPP), and the Boreal Spruce Forest (BSF). We found significant differences ( P < 0.05) in diatom community composition between CF and IPP lakes, and CF and BSF lakes, but not between IPP and BSF lakes. These results are consistent with water chemistry measurements, which indicated distinct limnological conditions for CF lakes. Diatom communities in CF lakes were generally dominated by alkaliphilous taxa typical of waters with medium to high conductivity, such as Nitzschia denticula . In contrast, several IPP and BSF lakes were dominated by acidophilous and circumneutral diatom taxa with preference for low conductivity (e.g., Tabellaria flocculosa, Eunotia mucophila, E. necompacta var. vixcompacta ). This exploratory survey provides a first detailed inventory of the diatom assemblages in the WNP region needed for monitoring programs to detect changes in shallow lake ecosystems and ecozonal shifts in response to climate variations. Abstract : The biological characteristics of shallow lakes (and ponds) from Wapusk National Park are poorly known, which hampers effective aquatic ecosystem monitoring. We analyzed the distribution and diversity of diatom assemblages in surficial sediments of 33 lakes located in three different ecozones (Coastal Fen, Interior Peat Plateau, Boreal Spruce Forest) and found significant differences in community composition consistent with the prevailing limnological conditions among them. This exploratory survey provides a first detailed inventory of the diatom assemblages in the WNP region needed for monitoring programs to detect changes in shallow lake ecosystems and ecozonal shifts in response to climate variations.