Response of Polytrichum strictum Plants to Regional Warming of the Antarctic Peninsula Using Geochemistry of Past and Modern and Fossil Plants

Date
2016
Authors
Yumol, Lauren
Contributor
Advisor
Beilman, David
Department
Oceanography
Global Environmental Science
Instructor
Depositor
Speaker
Researcher
Consultant
Interviewer
Annotator
Journal Title
Journal ISSN
Volume Title
Publisher
Volume
Number/Issue
Starting Page
Ending Page
Alternative Title
Abstract
Ecosystems of the western Antarctic Peninsula (AP) are currently experiencing one of the fastest rates of regional warming in the world. Aerobic moss-dominated peatbanks, which have the most flourishing vegetation in this ice-dominated region, were studied along the wAP to investigate plant growth conditions over space and time. Living plants of the dominant moss bank species, Polytrichum strictum, were collected from 13 populations along seven sites located between 6409' and 6735'S and a core was raised from a Polytrichum-dominated moss bank at 6514’S. Stable isotope ratios were measured in modern and fossil plant tissue. Modern plant δ 13C values varied from −31.7 to −27.0‰ and were influenced more by tissue type than geographic location. Modern plant δ 15N values ranged from −1.4 to +14.7‰ showing little tissue effect. In the core, radiocarbon-dated fossil leaf tissue showed plant growth began 2300 years ago (one of the oldest plant ages on the wAP), peat accumulation rates varied over time, and there is evidence for a hiatus between ~1600 and 800 years ago BP. Fossil leaves deposited during recent decades had δ13C values between −30.3 and −27.2‰ that were 2.0‰ more depleted than any time during the last 2300 years. Enriched δ15N values of +11.5 to +13.2‰ in fossil leaves deposited between 209 and 700 years before present (BP) suggest a period of more trophically-enriched animal inputs. Our results suggest P. strictum plants have experienced unprecedented growth conditions with recent rapid warming and that moss bank ecosystems may have changed nutrient sources over time.
Description
Keywords
antarctica, climate change, geochemistry
Citation
Extent
56 pages
Format
Geographic Location
Time Period
Related To
Table of Contents
Rights
All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.
Rights Holder
Local Contexts
Email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.