A trait-based approach to understanding the drivers of phytoplankton communities on agricultural landscapes

As phytoplankton form the base of aquatic food webs, their response to global change is of central importance to the healthy functioning of freshwater ecosystems. There are a myriad of internal and climatic factors that determine how communities are assembled, and freshwaters must also contend with anthropogenic changes across their broader catchments. For instance, runoff from agricultural lands can degrade downstream water quality, resulting in eutrophic conditions that impact algal growth. While organisms respond to these inputs in different ways, the phenotypic traits of phytoplankton offer critical insights into both how communities react to environmental changes and their functional ramifications. To better understand the biodiversity and functioning of phytoplankton communities on landscapes facing intensive agriculture, we leveraged data from the Iowa Ambient Lake Monitoring Program, which has collected water quality and phytoplankton samples from over 120 lakes and reservoirs since the year 2000. We applied a trait-based approach, combining environmental and compositional data with species traits to investigate the influence of water quality parameters, including nitrogen and phosphorus, on functional diversity. Our study of phytoplankton trait-environment relationships provides new insights into the consequences of shifting nutrients and other environmental conditions, such as the potential for harmful, toxin-producing blooms of cyanobacteria.

Primary Presenter: Grace Jackson, Iowa State University (ghj@iastate.edu)

Authors:

Grace Jackson, Iowa State University  (ghj@iastate.edu)

Charlie Loewen, Iowa State University  (cloewen@iastate.edu)