E-Thesis 181 views 124 downloads
Variation in the Morphological and Physiological Traits of a Foundational Macroalga along a 20-Degree Latitudinal Gradient / MARTYNA ZAWADZKA
Swansea University Author: MARTYNA ZAWADZKA
Abstract
Large brown macroalgal species are highly plastic primary producers that shape the intertidal zones of temperate regions. Their plasticity enables them to display a range of morphological traits, including variations in total length, blade thickness, and structural complexity, in response to environ...
| Published: |
Swansea University, Wales, UK
2025
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| Institution: | Swansea University |
| Degree level: | Master of Research |
| Degree name: | MRes |
| Supervisor: | Griffin, J., and Pimiento, C. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa69938 |
| Abstract: |
Large brown macroalgal species are highly plastic primary producers that shape the intertidal zones of temperate regions. Their plasticity enables them to display a range of morphological traits, including variations in total length, blade thickness, and structural complexity, in response to environmental factors. Using a trait-based approach allows us to examine the effects of biotic and abiotic factors on macroalgae, offering insights into the functioning of these ecosystems. Most current studies on macroalgal traits have primarily concentrated on a limited geographical range characterized by variable environmental factors such as temperature and salinity. In this study, the variation in traits of foundation macroalgae is examined across a 20-degree latitudinal gradient, extending from Portugal, through the central region of Wales, to the cooler range in Scotland. In response to the harsher climate and increased desiccation stress in southern regions, individuals were expected to exhibit reduced size and thicker blades.Similarly, increased temperatures in the south which are known to enhance metabolic rates, were expected to increase photosynthetic performance. In each region, morphological traits of individuals sampled from two shores were collected, and their photosynthetic parameters were measured in a mesocosm study – a controlled experiment assessing photosynthetic parameters.The size, as well as blade and stipe thickness, decreased towards the south. Although a decrease in blade thickness at lower latitudes was unexpected, the study found that the more acquisitive strategy of the southern population was reflected in its blade morphology. Photosynthetic performance was higher in Wales and Portugal than in Scotland, suggesting greater photosynthetic capacity of populations inhabiting lower latitudes. In contrast to our expectations, findings indicated that Wales, rather than the southernmost location (Portugal)was characterised by individuals exhibiting the highest photosynthetic performance and the most pronounced influence of morphological traits on the rate of photosynthesis. This observation may be attributed to the mid-range morphological traits of individuals compared to other populations, resulting from the region's temperate climate. |
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| Keywords: |
functional traits, macroalgae, Fucus serratus, latitudinal variation, photosynthesis, specific thallus area |
| College: |
Faculty of Science and Engineering |