Live Fast, Die Young: Examining Hydraulic Conductivity Of The Extinct Lepidophloios And Extant Wollemia Nobilis
Date
2024
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Producer
Director
Performer
Choreographer
Costume Designer
Music
Videographer
Lighting Designer
Set Designer
Crew Member
Funder
Rehearsal Director
Concert Coordinator
Advisor
Moderator
Panelist
Alternative Title
Department
Bi-College (Haverford and Bryn Mawr Colleges). Department of Environmental Studies
Type
Thesis
Original Format
Running Time
File Format
Place of Publication
Date Span
Copyright Date
Award
Language
eng
Note
Table of Contents
Terms of Use
Rights Holder
Access Restrictions
Haverford users only
Terms of Use
Tripod URL
Identifier
Abstract
The climate is changing at a scale never before seen by humans, and it is impossible to anticipate with certainty how these changes will affect the planet. The best way to attempt to predict how species and ecosystems will respond to our ever-evolving climate is to look to the past. Paleobotany—the study of plant fossils—can inform us about the environment in deep time and how plants previously interacted with, responded to, and influenced a changing climate. The Carboniferous period is the most recent climate parallel we have to today. Although the world looked very different 300 million years ago, with the supercontinent Pangea and so-called “primitive” plants dominating the Earth, there were several similarities to the modern climate. Carboniferous CO 2 fluctuations were within the range anticipated for the twenty-first century and, like we are seeing today, these variations in atmospheric CO 2 were associated with large decreases in sea ice volume, rising sea levels, and the cyclical restructuring of the planet's most extensive tropical forests (Montañez et al., 2016). This was also the last time the planet had complete deglaciation, a phase that we are currently on the trajectory for, so Carboniferous floral transitions during its glacial-interglacial periods could provide insight for what is to come. Several Carboniferous plants are reviewed in relation to their hydraulic efficiency and safety, providing insight to their plant function and the environments they inhabited. An important factor in the hydraulic capacities of plant fossils is the size, shape, and porosity of their pit membranes: the permeable barrier separating xylem cells which water passes through. A larger, more porous pit membrane allows water to pass through the plant quickly while a smaller pit membrane better protects the plant from the entrance of gas and possible embolism. Arborescent lycophytes (lycopsids)—which dominated the first 20 million years of the Carboniferous—are analyzed in particular. Hydraulic elements from lycopsid fossils are measured and considered in the context of the biomes they occupied. The extant Wollemi pine is also measured to contrast with the extinct lycopsid. Consequences for plants with low hydraulic safety when the Carboniferous climate changed and implications for modern plants are discussed.