Toward re-scaffolding the Phanerozoic :  an improved representation of plants in the Late Paleozoic Ice Age.

Matthaeus, William J., 1984-

Toward re-scaffolding the Phanerozoic : an improved representation of plants in the Late Paleozoic Ice Age.

dc.contributor.advisor	White, Joseph Daniel.
dc.creator	Matthaeus, William J., 1984-
dc.creator.orcid	0000-0002-0117-4059
dc.date.accessioned	2022-06-03T13:14:03Z
dc.date.available	2022-06-03T13:14:03Z
dc.date.created	2022-05
dc.date.issued	2022-03-04
dc.date.submitted	May 2022
dc.date.updated	2022-06-03T13:14:04Z
dc.description.abstract	Plants have served as the scaffolding of terrestrial ecosystems for hundreds of millions of years. Era-appropriate vegetation function and distribution are critical to resolve Earth’s natural history and potential future climates. However, plants have evolved and functioned differently across the Phanerozoic. This work aims to clarify plant function and ecosystem impacts in the Late Paleozoic Ice Age (LPIA, Pennsylvanian Subperiod), a representative time period and the most recent Icehouse before the present one. Pursuant to this aim I present: (Chapter Two) the first process-based global vegetation cover estimate for the LPIA, (Chapter Three) the first fossil-derived simulations of sapwood dysfunction in a paleo-ecosystem model, and (Chapter Four) an approach to stomatal pore measurement to allow resolution of lineage functional differences. In Chapter Two, I use GENESIS v3 global climate model data, and fossil-derived plant traits to parameterize the paleo-ecosystem model Paleo-BGC. Simulation results corroborate near-global vegetation cover based on leaf water balance. However, vegetation cover was limited by freezing temperatures, affecting surface runoff and mineral transport. Stem properties likely also limited Pennsylvanian plants. In Chapter Three, I expand Paleo-BGC to explore the importance of stem hydraulic properties of plants to ecosystem processes as an intersection of climate and natural selection associated with anatomical constraints on water supply. The limited ability of ancient plant stems to tolerate water stress suggests that even subhumid conditions certain plant types may have been water limited. These modeling approaches are based on incomplete plant physiological information due to open topics in that field regarding differences in stomatal function, which may have distinguished plant groups and their role in ecosystems for hundreds of millions of years. Toward the resolution of functional differences, I present (Chapter Four), an improved method for measuring stomatal pores in vivo that: 1) allows the characterization of additional pore dimensions (i.e., pore depth), 2) avoids artifacts of previously described methods, and 3) is applicable across a range of experimental conditions. Reconciling the details of extinct plant function by combining inferences from models, natural history, and Plant Physiology will allow improved predictions of future climate change impacts on ecosystems.
dc.format.mimetype	application/pdf
dc.identifier.uri	https://hdl.handle.net/2104/11908
dc.language.iso	en
dc.rights.accessrights	No access – contact librarywebmaster@baylor.edu
dc.subject	Modeling. Carboniferous. Freezing. Forest cover. Runoff. Sapwood. Leaves. Allometry. Cavitation. Xylem. Tracheids. Guard cells. Stomata. Scanning electron microscopy. Light microscopy. Imaging equipment.
dc.title	Toward re-scaffolding the Phanerozoic : an improved representation of plants in the Late Paleozoic Ice Age.
dc.type	Thesis
dc.type.material	text
local.embargo.lift	2024-05-01
local.embargo.terms	2024-05-01
thesis.degree.department	Baylor University. Dept. of Biology.
thesis.degree.grantor	Baylor University
thesis.degree.level	Doctoral
thesis.degree.name	Ph.D.