Breaking Strength of Pelvetia compressa
[now Silvetia compressa (J. Agardh) Serrão, Cho, Boo et Brawley]
T his figure shows the cumulative probability of breakage at the three sites for a given breaking strength. A right-shifted curve indicates a stronger thallus material. Plants at Pt. Pinos are stronger than those at Hopkins since for a given breaking strength, Hopkins plants are more likely to break than those at Pt. Pinos. This is understandable since Pt. Pinos plants experience greater wave forces. Increasing the material strength of a thallus, therefore, may be one way of coping with wave forces.
T he plants at Lovers Point are anomalously weak. The curve for these plants is very much to the left of Hopkins and Pt. Pinos plants. Why these plants would be weaker than those at Hopkins when Lovers Point experiences greater wave exposure than Hopkins is unclear. Other factors, such as those related to demography or age structure, might be responsible.
© 1996 R. H. Lin