Document Type
Dissertation
Degree
Doctor of Philosophy (PhD)
Major/Program
Biology
First Advisor's Name
Heather D. Bracken-Grissom
First Advisor's Committee Title
Committee chair
Second Advisor's Name
Ligia Collado-Vides
Second Advisor's Committee Title
Committee member
Third Advisor's Name
Laurel Collins
Third Advisor's Committee Title
Committee member
Fourth Advisor's Name
Suzanne Fredericq
Fourth Advisor's Committee Title
Committee member
Fifth Advisor's Name
Evelyn E. Gaiser
Fifth Advisor's Committee Title
Committee member
Keywords
life sciences, biology
Date of Defense
6-30-2023
Abstract
Chapter II presents the first global biogeography of marine benthic macroalgae at the species level, while updating the previous largest attempts to map global genus level diversity by twelve-fold the number of localities and 12 percent more genera included. A major finding is that a subset of just 69 algal genera is responsible for half of global algal species diversity, and that these particularly speciose and widespread genera appear to have diversified to a greater degree in tropical waters. Chapter III investigates global endemism patterns in marine benthic macroalgae using two techniques. Traditional measurements of endemism by counting species found only in a single locality (singletons) are compared with a range-restriction approach by mapping the proportion of range-restricted species per equal unit area. Range extensions for species were calculated by designing a global connectivity network for the marine benthic environment that accounted for the short dispersal capacity of algae, temperature gradients, and the geographical separation of oceanic basins. The results of chapter II found differences in algal biodiversity patterns depending upon taxonomic levels (class, genus, or species) and chapter III suggested that biodiversity differences also existed in different temperature zones and oceanic basins. Therefore, chapter IV investigated the role of temperature on biodiversity patterns for marine benthic algae while accounting for geographic area and oceanic basin effects. Together, these chapters reveal that algal biodiversity patterns differ depending upon taxonomic level (reflecting separate evolutionary life histories), broad temperature zones (tropical, subtropical, and temperate), and oceanic basins. Temperature is found to significantly positively correlate to species diversity in marine benthic macroalgae, though the correlation is stronger for the subset of 69 genera found to disproportionately contribute to global algal biodiversity. While most algal genera are found to be temperature generalists, some genera may have invaded the tropics and diversified to a larger extent once there. Thus, while overall algal biodiversity peaks in mid-latitude subtropical to temperate waters in both hemispheres, a subset of genera have higher diversity in tropical waters, with patterns more closely resembling some other coral reef associated organisms.
Identifier
FIDC011199
ORCID
0009-0001-8581-5668
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License
Recommended Citation
Tomasetti, Robert, "The Global Biogeography of Marine Benthic Macroalgae" (2023). FIU Electronic Theses and Dissertations. 5367.
https://digitalcommons.fiu.edu/etd/5367
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