Effects of spatial variation in benthic phototrophs along a depth gradient on assessments of whole-lake processes
Date
2021-09-16
Authors
Gushulak, Cale A. C.
Haig, Heather A.
Kingsbury, Melanie V.
Wissel, Bjoern
Cumming, Brian F.
Leavitt, Peter R.
Journal Title
Journal ISSN
Volume Title
Publisher
Wiley
Abstract
- Phytobenthos are often underrepresented in both limnological and paleolimnological studies but may play key roles in whole-lake production and ecosystem processes including eutrophication, food-web dynamics, and ecosystem state changes.
- Photosynthetic pigments, stables isotopes, and diatoms were quantified from surface sediments (0-1 cm) collected across a depth transect of a small, DOC-rich, mesotrophic lake in boreal northwestern Ontario to assess spatial variation in phytobenthos abundance and production.
- Maximal concentrations of siliceous algae and cyanobacteria pigments occurred at ~2–6 m depth, with abundant tychoplanktonic diatoms, depleted sedimentary δ13C C values, and elevated 33 ratios of precursor chlorophyll a to product pheophytin a, all aligning well with the depths of the thermocline, epilimnetic mixing, and maximum light penetration.
- These patterns demonstrated the presence of three discrete community assemblages, with greatest mass accumulation occurring at intermediate depths where warm illuminated sediments provide habitat for tychoplanktonic diatoms and cyanobacteria between turbulent shallows and cold and dark depths.
- If widespread among boreal lakes, this tychoplanktonic zone may exert important effects on whole-lake production, carbon sequestration, benthic-pelagic food-web coupling, eutrophication, and ecosystem state change.
Description
This is the peer reviewed version of the following article: Gushulak, C. A. C., Haig, H. A., Kingsbury, M. V., Wissel, B., Cumming, B. F., & Leavitt, P. R. (2021). Effects of spatial variation in benthic phototrophs along a depth gradient on assessments of whole-lake processes. Freshwater Biology, 66, 2118– 2132, which has been published in final form at https://doi.org/10.1111/fwb.13820. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.
Keywords
phytobenthos, tychoplankton, pigment, diatom, stable isotope
Citation
Gushulak, C. A. C., Haig, H. A., Kingsbury, M. V., Wissel, B., Cumming, B. F., & Leavitt, P. R. (2021). Effects of spatial variation in benthic phototrophs along a depth gradient on assessments of whole-lake processes. Freshwater Biology, 66, 2118– 2132. https://doi.org/10.1111/fwb.13820