Award Date: 2017 

Climate change is expected to cause more intense and frequent extreme weather events, but we only have a basic understanding of how these events might alter freshwater systems. Storms are likely to impact lake systems through delivery of sediments from watersheds and mixing of the water column, both of which could have important consequences for phytoplankton. Phytoplankton are the base of the food web; their community configuration and how the community changes across seasons have large impacts on ecosystem processes such as energy flow, nutrient cycling, and carbon cycling. External disturbances may abruptly alter phytoplankton community dynamics and thus impact ecosystem function. The effects of storms on the physical structure of lakes and subsequent impacts for phytoplankton may depend on local feature such as lake size and shape, watershed connectivity, and the trophic status, or productivity, of lakes. Consequently, the degree to which storms will alter basic ecosystem processes is not well understood and requires a common framework applied across a gradient of lakes.

We will use long-term monitoring datasets and high-frequency data available through international networks to identify associations between abrupt shifts in phytoplankton community composition and extreme weather events across more than 20 lakes in Europe, the Middle East, East Asia, and North America. We will use multivariate time series analysis and meta analysis approaches to (1) identify conditions under which storm driven water column disturbances influence phytoplankton diversity and determine whether such conditions favor rapidly colonizing species over species more adapted to stable water columns and nutrient depleted euphotic zones; (2) characterize changes in phytoplankton community relative to metrics of lake physical states; and (3) identify mechanisms that lead to new phytoplankton assemblages or maintain community resilience. The study lakes represent a range of morphologies and productivity, providing a gradient on which to evaluate how phytoplankton communities respond to meteorological forcing. The work will be divided in four main tasks: data compilation; method development; data analyses; and interpretation, synthesis, and theoretical models of changes in communities.

Our international, interdisciplinary working group includes researchers who are specialized in meta-analysis and/or aquatic science, and consists of empiricists and theoreticians across the fields of math, physics, biology, and ecology. By bringing together physicists and biologists, we fill the gap between physical and biological sciences to better provide mechanistic understandings and theoretical frameworks of phytoplankton community response to storms. This project is co-funded by Centre for the Synthesis and Analysis of Biodiversity (CESAB) in Aix-en-Provence, France, and is part of the Global Lake Ecological Observatory Network (GLEON) project “Storm-Blitz”.

Photo credit: Lake Champlain Basin Program

ScienceBase Url: https://www.sciencebase.gov/catalog/item/57741fade4b07657d1a99150