. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 118 J. A, KITZES AND M W. DENNY with wave environment, this difference may be due to a higher average drag for Carrington's samples. Carrington's study did not include drag values, however, so this hypoth- esis cannot be tested. There is no significant difference between the two means of stipe strength (Student's t test with unequal variances, P > ). Carrington found no differences among the mean stipe strength for her exposed, intermediate, and protected sites. However, our results sug- gest that within each of her s
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 118 J. A, KITZES AND M W. DENNY with wave environment, this difference may be due to a higher average drag for Carrington's samples. Carrington's study did not include drag values, however, so this hypoth- esis cannot be tested. There is no significant difference between the two means of stipe strength (Student's t test with unequal variances, P > ). Carrington found no differences among the mean stipe strength for her exposed, intermediate, and protected sites. However, our results sug- gest that within each of her sites she may have sampled across a variety of microhabitats, obscuring the relation- ships we found. Additional variation between our results and Carrington's could also be explained by the greater resolution of our measurements: we measured breaking force to the nearest N and cross-sectional diameter to the nearest 25 /am; Carrington measured these two quanti- ties to the nearest 1 N and 50 [im. respectively. Predictions of maximum attainable size Carrington found no significant relationship between cross-sectional area of the stipe and thallus planform area (P » ). and neither did we (r2 = , P = ). Operating under the assumption that equal stipe cross-sec- tional area implied equal breaking force across blade sizes, Denny and Wethey (2001) proposed that Carrington's data could be used to predict the maximum size a blade could attain at a given water velocity. Setting Equation 4 (the expression for measured drag at low velocities) equal to the mean breaking force of Carrington's sample ( N) and solving for planform area, they obtained the relationship: Smax = IT (6) Maximum blade area (and, therefore, maximum potential reproductive output) are predicted to decrease rapidly with increasing water velocity (Fig. 2). 90 80 • a £ 60 - E 50 • 1 40- E 30 - | 20- <o 10 -. 4 6 8 10 12 14 16 18 20 22 24 26 Water Velocity (mis) Figure 2. Prediction of
Size: 2149px × 1163px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
