Date of Award

Summer 8-19-2022

Level of Access Assigned by Author

Open-Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Ecology and Environmental Sciences

Advisor

Jasmine Saros

Second Committee Member

Hamish Greig

Third Committee Member

Amanda Klemmer

Additional Committee Members

Kirk Maasch

Jeffery Stone

Abstract

Algae supply over half of the Earth’s global primary production and form the base of almost all aquatic food networks. Thus, changes in algal productivity or composition will induce profound shifts in many ecosystems. This research is guided by two questions. Herein I ask if 3D models of algae can be created accurately enough to use for research applications? If they can be accurately created, then how can these models be used to advance our understanding of functional trait evolution and paleoecology? Herein, I develop 3D computer models for estimating the volume of individual algae and their parts. I also examine pressures that influence algae biomass, resource requirements, and trait evolution. Further, I apply these to an annually resolved sediment records to reveal paleontological applications that can be used to reconstruct past ecosystems and evolutionary events. This dissertation provides the means improve historical ecological reconstructions, advance predictions of ecological changes that will occur under global climate change and allow for evolutionary cost benefit analysis of traits of microscopic organisms. For this study I exploit the sedimentary record from Herd Lake Idaho USA (44.089428, -114.173921). because it contains large (~0.5 cm) annual layers. These layers are extraordinarily abundant in the remains of the diatom Stephanodiscus niagarae. These qualities present an ideal setting to produce accurate 3D computer models of a diatom that influences a large portion of the nutrient cycles in an aquatic system. The abundance of individuals provides ample data and diversity for strong statistical interpretations of the diatom populations while the annual resolution of the sediment provides a means to compare the novel methods to weather and climate data that inform us of the ecological significance of these new methods. The bounds of this study are within the years 1927 – 2011 and pertain to aquatic environments on Earth. Although these works are constrained to the recent past and local ecosystems, future applications are bound only by the geological time frame in which algae have existed and are limited in space to wherever algae are found in the universe.

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