Overall richness / diversityBruno, Stachowicz & Bertness
(2003)Trends in Ecology and Evolution 18: 119-125Scrosati &
Heaven (2007)Marine Ecology Progress Series 342: 1-14Richness of
secondary space holders (sessile and mobile associated
species)Richness of primary space holders
Vertical gradientDesiccation - TemperatureIrradiance - Osmotic
potentialHorizontal gradientWave exposure - Ice scourTest of ESM on
the NW Atlantic coast
Nova ScotiaNew England- Gulf of St. Lawrence coast- Atlantic
coastNova Scotia
Richness Sr of speciesDiversity (Simpson's index) 1 - D = 1 -
(pi) Evenness (Simpson's index) E = (D * S)-1MethodsRichness,
Diversity & Evenness Summer Abundance of all seaweeds and
invertebrates (% cover) 25 cm x 25 cm quadrats (n = 20 per
Elevation x Exposure combination)
38 seaweeds - 29 invertebratesResults
Gulf of St. LawrenceAtlantic2 = 41 %2 = 39 %Means
SEElevationResults - Richness across ElevationElevation
Wave - Ice ExposureWave Exposure2 = 10 %2 = 12 %Results -
Richness across ExposureGulf of St. LawrenceAtlanticMeans SE
Test of ESM on the NE Atlantic coast
Helgoland's elevation gradient(wave-sheltered shores)Test of ESM
on the NE Atlantic coast (Helgoland Island)
Overall richness and diversity (Helgoland Island)Zwerschke,
Bollen, Molis & Scrosati (2013)Helgoland Marine Research 67:
663-674
Environmental stress model (ESM)Menge & Sutherland (1987,
American Naturalist 130: 730-757)RICHNESSPredation
HypothesisIntermediate Disturbance HypothesisSESSILE
SPECIES(PRIMARY SPACE HOLDERS)
