Poster Australian Marine Sciences Association 2022

The role of belowground microbes in ameliorating climate change-induced heat stress in seagrasses. (#494)

Renske Jongen 1 , Ezequiel M. Marzinelli 1 , Paul E. Gribben 2
  1. The University of Sydney, Sydney, NSW, Australia
  2. University of New South Wales, Sydney, NSW, Australia

Across Australia, >275,000 ha of seagrass meadows and associated ecosystem services have been lost. Successful restoration requires detailed knowledge of the factors that foster recovery across a range of environmental conditions. To date, efforts to restore seagrass meadows have yielded limited success, possibly because they have focused solely on improving aboveground processes (e.g. water quality). In terrestrial systems, belowground microbes are known regulators of plant performance. Emerging evidence shows that seagrasses, having evolved from terrestrial plants, have similar ecological relationships with belowground microorganisms. Knowledge of microbe-mediated belowground processes in seagrasses is therefore critical for enhancing seagrass restoration efforts. However, the diversity and functioning of the seagrass belowground microbiome, and their role in seagrass functioning remains largely unexplored.

We aimed to determine the relative importance of microorganisms associated with the roots and the sediment for the performance of the seagrass species Zostera muelleri, and how the composition of those microorganisms changes in response to marine heatwaves. A manipulative mesocosm experiment was performed using novel experimental methods that directly connect microbe function to host functioning. Here, we present preliminary results that shed light on the role the microbiome plays on the performance of seagrasses under current and future environmental conditions.