Appendix D. Analysis of the number of transplanted adults lost over the course of the experiments (out of N = 80 at each site), and discussion of loss of biomass in surviving transplants.
Adult mortality/loss: Individuals lost over the course of the experiments include all that died in their new location, but also are likely to include some transplants that were still alive when they broke free of their anchor. I conducted iterative nominal logistic regressions were performed on the number of transplants lost at each site, with effect likelihood ratio tests used to assess whether mortality/loss varied significantly with transplant height, initial height, or their interaction (JMP v5.1.1). At Scott's Creek, the probability of loss was significantly greater when transplants were established outside (either above or below) S. compressa’s current distribution (P = 0.002); at the two other sites, the number of individuals lost was random with respect to transplant height, original height, and the interaction (P > 0.05 in all cases).
PIGEON POINT:
TO: Above |
Upper limit |
Lower limit |
Below |
|
FROM: |
||||
Upper limit |
5 |
4 |
4 |
1 |
Lower limit |
5 |
4 |
4 |
2 |
TOTAL |
10 |
8 |
8 |
3 |
GREYHOUND:
TO: Above |
Upper limit |
Lower limit |
Below |
|
FROM: |
||||
Upper limit |
7 |
3 |
4 |
5 |
Lower limit |
4 |
3 |
3 |
5 |
TOTAL |
11 |
6 |
7 |
10 |
TO: Above |
Upper limit |
Lower limit |
Below |
|
FROM: |
||||
Upper limit |
0 |
1 |
1 |
4 |
Lower limit |
0 |
1 |
0 |
3 |
TOTAL |
0 |
2 |
1 |
7 |
Discussion of loss of biomass in adult transplants: Most adult transplants declined in size over the course of the experiment, a function of season (late summer) rather than an effect of the treatment. On both transplanted and unmanipulated individuals, I observed tattering and necrosis of terminal branches, tissue damage associated with long daytime emersion periods in the summer (e.g., Haring et al. 2002; Wright et al. 2004), and the change in length of transplanted controls and unmanipulated controls were comparable (e.g., Greyhound: 0.37 ± 1.55 cm vs. -0.19 ± 2.11 cm). Adult transplants were conducted in summer (when plants are nonreproductive) to avoid accidentally altering natural patterns of gene flow. Given this seasonal decline, differences in size among treatment groups usually indicate an ability to retain biomass rather than a tendency to grow.
LITERATURE CITED
Haring, R. N., Dethier, M. N., and S. L. Williams. 2002. Dessication facilitates wave-induced mortality of the intertidal alga Fucus gardneri. Marine Ecology Progress Series 232: 75–82.
Wright, J. T., Williams, S. L., and M. N. Dethier. 2004. No zone is always greener: variation in the performance of Fucus gardneri embryos, juveniles and adults across tidal zone and season. Marine Biology 145(6): 1061–1073.