Unattached benthic algae are a common component of seagrass meadows and other benthic systems. I used a series of field experiments to investigate (1) whether competition by algal mats represents a disturbance force capable of opening gaps in the seagrass canopy, (2) the extent of associated indirect effects on mobile fauna, (3) the extent to which algal patches are isolated epifaunal islands, and (4) whether algal clumps serve as a dispersal mechanism for benthic animals. Algal mats proved to be a powerful disturbance mechanism which killed most of the above-ground and half of the below-ground biomass of seagrass underlying the algae. Total faunal abundance increased on experimental algal plots, although relative dominance of various taxa changed considerably. The algal mats, despite supporting large numbers of animals, should provide a poor substitute for seagrass because of algal ephemerality. In situ staining and mark-recapture techniques showed that algal clumps were not isolated islands; rather, there was extensive exchange of fauna between algal masses and the surrounding habitat, although there was greater insularity for are dispersed by tumbling benthic algae. Transport of animals by algae proved to be considerable, and observations of tagged algae indicated that clumps can tumble up to 0.5 kilometers per day. This dispersal mechanism should be particularly important for species with direct development or abbreviated larval phases and should entail lower risk than other adult dispersal stratagems such as vertical migration or rafting. The pattern of non-shifting mosaic disturbance and mobility present in this system result in unusual patch dynamics and provide some alternative views of plant-plant and plant-animal interactions in the benthos. / Source: Dissertation Abstracts International, Volume: 53-07, Section: B, page: 3267. / Major Professor: Robert J. Livingston. / Thesis (Ph.D.)--The Florida State University, 1992.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_76705 |
| Contributors | Holmquist, Jeffrey George., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 196 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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