Substrate size mediates thermal stress in the rocky intertidal

• Published in: Ecology (Durham) 2011-03, Vol.92 (3), p.576-582
• Main Authors: Gedan, Keryn B, Bernhardt, Joanna, Bertness, Mark D, Leslie, Heather M
• Format: Article
• Language: English
• Subjects: abiotic factors; Abiotic stress; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Atlantic Ocean; barnacle; Bedrock; Biological and medical sciences; Body Temperature; climate; Climate change; Climate models; Climatology. Bioclimatology. Climate change; Cobbles; Conservation biology; Crustaceans; Earth, ocean, space; Ecological zones; Ecosystem; Environmental conservation; Exact sciences and technology; External geophysics; Fundamental and applied biological sciences. Psychology; General aspects; Habitats; heterogeneity; Hot Temperature; littoral zone; Marine ecology; Meteorology; Narragansett Bay; Rhode Island; Seawater; Semibalanus balanoides; Stress, Physiological - physiology; summer; Survival analysis; temperature; temperature thermal refuge; Thermal stress; Thoracica - physiology; USA; Water Movements; wind
• ISSN: 0012-9658; 1939-9170
• DOI: 10.1890/10-0717.1

Variation in physical factors, such as slope, orientation, and wind exposure, shapes thermal conditions. Variation in substrate size is common in many habitats, but its thermal consequences for organisms are not well characterized. Larger substrates should remain more thermally stable and act as thermal refuges for associated organisms during short, thermally stressful periods such as midday temperature peaks or tidal exposure. In observations and a transplant and thermal integration experiment, we found that larger rock substrates stayed cooler and facilitated greater survival of the barnacle Semibalanus balanoides in the high intertidal relative to small substrates during the hot summer months in southern New England, USA. However, in thermally benign northern New England, rock substrate size had no effect on barnacle distributions, indicating that the thermal effects of substrate size are mediated by regional climate.