Search

Université de Montréal Dataverse Logo
Sub-fossil crustacean zooplankton relative abundances from 101 lakes across Canada
Borealis
Paquette, Cindy; Griffiths, Katherine; Gregory-Eaves, Irene; Beisner, Beatrix E. — 2022-02-23 This data set contains cladoceran sub-fossil relative abundances for 101 lakes across Canada sampled as part of the NSERC Canadian Lake Pulse Network project. Lakes were sampled once, over three summers (2017-2018-2019). Cores were collected using a gravity corer in the deepest point of each lake and were sectioned on site with a vertical extruder. Each lake was sampled for a “top” sediment sample, represented by the first centimeter of the surface of the sediment core, and a “bottom” sediment sample, corresponding to the 1 cm of sediment located between 3 and 4 cm from the base of the core. Cladoceran extraction and preparation followed the protocol from Korhola and Rautio (2001). Cladocerans were identified using DM 2500 Leica compound inverted microscope under 200X-400X magnification with a minimal count size of 100 individuals. Identification at the species, genus, or species complex level followed Szeroczynska and Sarmaja-Korjonen (2007) and Korosi and Smol (2012a; b). Sites are identified with Lake ID number, followed by “T” for top samples and “B” for bottom samples. Lakes IDs with respective locations (longitude and latitude coordinates) and Continental Basin allocations can be found here: https://doi.org/10.5281/zenodo.4701262 References Korhola, A., and M. Rautio. 2001. Cladocera and other branchiopod crustaceans, p. 225–234. In J.P. Smol, H.J.B. Birks, and W.M. Last [eds.], Tracking Environmental Change Using Lake Sediments. Springer. Korosi, J. B., and J. P. Smol. 2012a. An illustrated guide to the identification of cladoceran subfossils from lake sediments in northeastern North America: Part 1-the Daphniidae, Leptodoridae, Bosminidae, Polyphemidae, Holopedidae, Sididae, and Macrothricidae. J. Paleolimnol. 48: 571–586. doi:10.1007/S10933-012-9632-3 Korosi, J. B., and J. P. Smol. 2012b. An illustrated guide to the identification of cladoceran subfossils from lake sediments in northeastern North America: Part 2-the Chydoridae. J. Paleolimnol. 48: 587–622. Szeroczyfiska, K., and K. Sarmaja-Korjonen. 2007. Atlas of Subfossil Cladocera from Central and Northern Europe, Friends of the Lower Vistula Society, Warsaw, Pol.
Dryad Logo
Data from: Ice-cover is the principal driver of ecological change in High Arctic lakes and ponds
Dryad
Griffiths, Katherine; Michelutti, Neal; Sugar, Madeline; Douglas, Marianne S.V.; Smol, John P.; Douglas, Marianne S. V. — 2017-03-30 Recent climate change has been especially pronounced in the High Arctic, however, the responses of aquatic biota, such as diatoms, can be modified by site-specific environmental characteristics. To assess if climate-mediated ice cover changes affect the diatom response to climate, we used paleolimnological techniques to examine shifts in diatom assemblages from ten High Arctic lakes and ponds from Ellesmere Island and nearby Pim Island (Nunavut, Canada). The sites were divided a priori into four groups (“warm”, “cool”, “cold”, and “oasis”) based on local elevation and microclimatic differences that result in differing lengths of the ice-free season, as well as about three decades of personal observations. We characterized the species changes as a shift from Condition 1 (i.e. a generally low diversity, predominantly epipelic and epilithic diatom assemblage) to Condition 2 (i.e. a typically more diverse and ecologically complex assemblage with an increasing proportion of epiphytic species). This shift from Condition 1 to Condition 2 was a consistent pattern recorded across the sites that experienced a change in ice cover with warming. The “warm” sites are amongst the first to lose their ice covers in summer and recorded the earliest and highest magnitude changes. The “cool” sites also exhibited a shift from Condition 1 to Condition 2, but, as predicted, the timing of the response lagged the “warm” sites. Meanwhile some of the “cold” sites, which until recently still retained an ice raft in summer, only exhibited this shift in the upper-most sediments. The warmer “oasis” ponds likely supported aquatic vegetation throughout their records. Consequently, the diatoms of the “oasis” sites were characterized as high-diversity, Condition 2 assemblages throughout the record. Our results support the hypothesis that the length of the ice-free season is the principal driver of diatom assemblage responses to climate in the High Arctic, largely driven by the establishment of new aquatic habitats, resulting in increased diversity and the emergence of novel growth forms and epiphytic species.
Zenodo Logo
Diatom relative abundances for LakePulse lakes (major taxa and full dataset) modern and pre-industrial samples
Zenodo
Griffiths, Katherine — 2024-04-29 Raw diatom relative abundance data and major species relative abundances used in: Griffiths K., Duda M. P., Antoniades D., Smol J. P., Gregory-Eaves I. 2024. Diatom species responses along gradients of dissolved inorganic carbon, total phosphorus, and lake depth from lakes across Canada. Journal of Phycology https://creativecommons.org/licenses/by/4.0/legalcode

Map search instructions

1.Turn on the map filter by clicking the “Limit by map area” toggle.
2.Move the map to display your area of interest. Holding the shift key and clicking to draw a box allows for zooming in on a specific area. Search results change as the map moves.
3.Access a record by clicking on an item in the search results or by clicking on a location pin and the linked record title.
Note: Clusters are intended to provide a visual preview of data location. Because there is a maximum of 50 records displayed on the map, they may not be a completely accurate reflection of the total number of search results.

(Author: Griffiths, Katherine)

Limit by:

Clear all

to