Biological response to microhabitat formation by rocky shore intertidal benthic macroalgal canopies
Intertidal macroalgae modulate their biophysical environment by ameliorating physical conditions and creating habitats. Thereby, influencing the abundance and distribution of associated species, and altering ecosystem dynamics within their local environment. The modification ability of macroalgae an...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | México |
| Institución: | Centro de Investigación Científica y de Educación Superior de Ensenada |
| Repositorio: | Repositorio Institucional CICESE |
| Idioma: | inglés |
| OAI Identifier: | oai:cicese.repositorioinstitucional.mx:1007/1613 |
| Acceso en línea: | http://cicese.repositorioinstitucional.mx/jspui/handle/1007/1613 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/Autor/biofilm, density, environmental stress, macroalgae, macroinvertebrates, microphytobenthos, morphology, seaweeds info:eu-repo/classification/Autor/densidad, estrés ambiental, macroalgas, macroinvertebrados, microfitobenthos, morfotipo info:eu-repo/classification/cti/2 info:eu-repo/classification/cti/24 info:eu-repo/classification/cti/2417 info:eu-repo/classification/cti/241705 |
| Sumario: | Intertidal macroalgae modulate their biophysical environment by ameliorating physical conditions and creating habitats. Thereby, influencing the abundance and distribution of associated species, and altering ecosystem dynamics within their local environment. The modification ability of macroalgae and the relative importance of their bioengineering outcomes may change rapidly in response to shifting levels of environmental stress. Exploring how seaweed aggregations made up of distinct species at different densities modify their local environment may help explain the processes, patterns and mechanisms driving species distribution and community composition, and how the connections between these organisms are affected. Using Silvetia compressa, Halidrys dioica, Chondracanthus canaliculatus and Pyropia perforata, I constructed monocultures representing the leathery, corticated and foliose functional-forms, as well as a mixed tri-culture assemblage including the former three, at four different densities. Treatment quadrats were installed in the intertidal where I measured irradiance, temperature, particle retention, desiccation bulk water flow underneath the canopies. Additionally, I examined the response by the understory microphytobenthos and by a targeted group of macroinvertebrates. I found that the density per unit area and species composition influence the magnitude in which macroalgae modify extreme physical conditions in their local environment. Macroalgal aggregations of greater spatial complexity, showed a greater attenuation of understory bulk water flow, irradiance, temperature, particle transport and water loss. I also found that increasing the number of species within a patch do not always results in increased spatial complexity and therefore, did not necessarily cause greater ameliorated conditions. Moreover, I found that a further modulation on the microphytobenthos occurred, and that the response by macroinvertebrates differed based on the baseline conditions of the environment. Results indicate that the environmental modifications driven by these macroalgae as ecosystem engineers play a significant role in promoting distinct temporal and spatial patchiness of associated organisms. Consequently, affecting the biological dynamic pathways and influencing the local diversity at various scales and in turn, affecting the strength and nature of interspecific interactions. |
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