Climate change: underwater forest decline

Smale D. A. & Wernberg T. (2013) Extreme climatic event drives range contraction of a habitat-forming species. Proceedings of the Royal Society B: Biological Sciences 280.

Aim: 
To document impacts of an extreme marine heat wave on the distribution and abundance of a forest-forming seaweed, and to assess potential long-term changes in reef communities
Type of Study: 
Natural experiment (before-after comparison)
Key Results: 
The marine heat wave eliminated Scytothalia dorycarpa at its warm distribution limit, causing a range contraction of approximately 100 km (approx. 5% of its global distribution). Seawater temperatures during the HW exceeded the seaweed’s physiological threshold and caused extirpation of marginal populations.
Treatments: 
Surveys before an after the marine heat wave at different geographical locations
Response: 
n/a
Models: 
n/a
Reviewer: 
Thomas Wernberg
Locations: 
Southwestern Australia, Jurien Bay
Response variable : 
Presence-absence and reef-scale percent cover of Scytothalia, percent cover of community components (benthic functional groups)
Replication: 
40 x 25m transects, 12 x 0.5m2 quadrats + variable sampling effort in historical surveys.
Ecosystem: 
Temperate reef
Full Reference: 
Smale D. A. & Wernberg T. (2013) Extreme climatic event drives range contraction of a habitat-forming species. Proceedings of the Royal Society B: Biological Sciences 280.