Skip to content
Ecological Intelligence

Ecological evidence.
Independent perspective.
Explore Wild Lands ↗

Ecological Intelligence / Subject

heat stress

Peer-reviewed

Coral-associated bacteria make steroids that influence their host's heat response

Evidence
Peer-reviewed
Geography
Saadiyat reef, Arabian Gulf near Abu Dhabi, UAE; laboratory isolates
System
Coral reef microbiomes / thermal stress

WHAT THE EVIDENCE SAYS

Combining sampling of Acropora pharaonis, multi-omics and lab work with three Endozoicomonas isolates, scientists demonstrated bacterial capacity to convert cholesterol to testosterone and progesterone. Immune response assays associated these hormones with pro-survival signaling and reduced inflammatory responses under heat stress.

WHY IT MATTERS / OUR READ

Microbial function may help explain why corals experiencing similar heat differ in their responses. It identifies a mechanistic hypothesis worth testing, not a field-ready remedy.

CAVEATS / UNCERTAINTY

Laboratory metabolism and host signaling results are not evidence that adding these bacteria restores or saves whole reefs.

SOURCE

Nature Microbiology — Mohamed et al. (2026)
View original evidence ↗

Coral Endozoicomonas bacteria were shown to produce steroid hormones and affect immune signaling in stress experiments.

Read the Wild Lands assessment →
Peer-reviewed North America

Coast-redwood leaves crossed a photosynthetic heat threshold before air temperature told the whole story

Evidence
Peer-reviewed
Geography
Garcia River Forest, Mendocino County, California, USA
System
Coast redwood forest

WHAT THE EVIDENCE SAYS

Repeated lower-canopy measurements from three young coast redwoods over two years showed leaf temperatures frequently exceeded air temperature during summer stress, with leaf-to-air differences reaching 10°C. Photosynthetic efficiency fell as leaves warmed, and controlled temperature-response curves showed net photosynthesis declining above about 30°C with steeper losses above 35°C. Internal CO₂ remained high during much of the decline, supporting a non-stomatal biochemical limitation rather than stomatal closure alone.

WHY IT MATTERS / OUR READ

Air temperature is an incomplete exposure metric when leaves can decouple from it. For redwood monitoring, leaf thermal status and water stress may reveal physiological limits that a weather station alone misses.

CAVEATS / UNCERTAINTY

The field physiology comes from three young trees, lower-canopy branches and one second-growth forest; temperature-response curves used detached, well-watered branches. Leaf-level responses do not directly quantify whole-tree growth, mortality or stand-level carbon sequestration.

SOURCE

JGR: Biogeosciences — primary study
View original evidence ↗

Two years of leaf physiology in Mendocino County found redwood leaves could run up to 10°C warmer than air, with photosynthesis declining above about 30°C and more steeply above 35°C.

Read the Wild Lands assessment →
Peer-reviewed

Coral probiotics may be changing more than the microbiome

Evidence
Peer-reviewed
Geography
Controlled coral experiment led at KAUST, Saudi Arabia
System
Pocillopora verrucosa coral holobiont under pathogen and heat stress

WHAT THE EVIDENCE SAYS

In Nature Communications, researchers inoculated Pocillopora verrucosa fragments with the pathogen Vibrio coralliilyticus, a putative probiotic Cobetia strain, both or neither, then exposed them to heat stress. Pathogen exposure produced distinct DNA-methylation changes; probiotic co-inoculation mitigated some of those changes, and those responses correlated with greater stress resilience and survival.

WHY IT MATTERS / OUR READ

If microbiome interventions can reproducibly alter host regulatory state, coral probiotics could eventually be more than short-lived microbial supplementation. That would widen the mechanism by which assisted resilience might operate—but this is exactly the kind of early mechanistic signal that needs replication before it becomes restoration practice.

CAVEATS / UNCERTAINTY

This was a controlled experiment on one coral species and specific bacterial strains. Epigenetic correlation does not establish durable transgenerational benefit, field effectiveness or ecological safety, and the authors note that many mechanistic questions remain unresolved.

SOURCE

Nature Communications
View original evidence ↗

A controlled experiment found that bacterial inoculation altered coral DNA methylation under heat stress, with a probiotic mitigating some pathogen-associated epigenetic changes and correlating with higher survival.

Read the Wild Lands assessment →

Keep exploring

Follow the systems. Find the connections.

WildlifeLandWaterOceansClimateCitiesOne HealthGovernanceMethods / Monitoring
Browse the archive →