View Abstract

LONG-TERM RAINFALL CYCLES CONTROL LAKE PLANKTON DYNAMICS, DIVERSITY AND METABOLISM IN A LOW LATITUDE LAKE: AN ANALOG FOR FUTURE HIGH LATITUDE LAKES

The physicochemical dynamics that regulate biological properties among low latitude lakes have been shown to be less coherent than among higher latitude lakes. This difference has been partly attributed to higher spatio-temporal variance in precipitation that regulates fundamental features such as plankton dynamics, diversity and metabolism in low latitude lakes. We use a rare, long-term (35 year) record of physico-chemical, plankton and metabolic data from a precipitation-regulated subtropical lake to provide an empirical evaluation of the role of precipitation as a key driver of lake plankton dynamics. Years with high wet-season rainfall have fall and spring algal blooms dominated by mixotrophic algae capable of utilizing abundant dissolved organic matter in low light conditions, while blooms are muted in dry years of high transparency and reduced duration of winter mixing. Wet years are also associated with greater phytoplankton alpha and beta diversity, presumably due to increased vertical niche space offered by a more stratified water column, which is being tested in an intensive multi-lake field campaign. Finally, years with high rainfall appear to reduce phytoplankton-bacterial coupling and increase respiratory losses from the lake. Together these findings will populate, build, and evaluate a conceptual model that will inform expectations for lakes projected to receive more variable precipitation in the future.

Authors

Gaiser, E. E., Florida International University, USA, gaisere@fiu.edu

Corsi, I., Florida International University, USA, ileana.corsi@fiu.edu

Nodine, E., Rollins College, USA, ENODINE@rollins.edu

Swain, H. M., Archbold Biological Station, USA, HSwain@archbold-station.org

Details

Oral presentation

Session #:091
Date: 03/03/2017
Time: 10:15
Location: 308 A/B

Presentation is given by student: No