What the study found
Ocean warming can change sediment microbial communities in ways that suppress seagrass performance. The authors report that sediment microbes may override the thermal history of the plant itself.
Why the authors say this matters
The study suggests that sediment microbial communities may act as hidden constraints on seagrass tolerance to warming. The findings indicate that belowground microbes can mediate how marine plants respond to thermal stress.
What the researchers tested
The researchers ran a common-garden field experiment at a long-term warmed site in Lake Macquarie, New South Wales, Australia, with more than 30 years of 1-3°C warming. They tested the effects of sediment origin, plant origin, and microbial disruption on the performance of seagrass (Zostera muelleri), including both rhizosphere microbes, which live around roots, and bulk sediment microbes.
What worked and what didn't
Both plant origins had lower aboveground biomass in intact warm-origin sediments. Warm-origin plants recovered when bulk sediment microbial communities were disrupted, which the authors interpret as evidence that warming-altered sediment microbes can suppress seagrass performance. Rhizosphere microbial disruption had no effect on plant performance, and in warm-origin sediments rhizosphere bacterial communities were similar across plant origins.
What to keep in mind
The summary does not describe broader limits beyond the specific field experiment and seagrass species studied. The findings are based on one warmed site and the conditions tested there.
Key points
- Warm-origin sediments were associated with lower aboveground biomass in seagrass.
- Disrupting bulk sediment microbial communities allowed warm-origin plants to recover.
- Rhizosphere microbial disruption did not affect plant performance.
- In warm-origin sediments, rhizosphere bacterial communities were similar across plant origins.
- The authors suggest sediment microbes can act as hidden constraints on warming tolerance.
Disclosure
- Research title:
- Ocean warming alters sediment microbes and lowers seagrass performance
- Image credit:
- Photo by Joe Holland on Unsplash
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