Monitoring climate change induced desertification of Antarctica using stable isotopic signaturesEntry ID: AAS_3129
Abstract: Metadata record for data from AAS (ASAC) project 3219.
We will use mosses to investigate the changing climate in Antarctica and the implications this has for terrestrial biodiversity. Mosses grow incrementally from the tip, thus shoot sections contain a record of atmospheric carbon corresponding to each growing season, in a similar fashion to tree rings. This method has been used ... to age East Antarctic mosses and indicates that some individuals are more than 60 years old. Analysing stable isotopes of carbon and oxygen in cell walls tells us how climate has changed around these mosses over time and allows us to determine which sites are drying and becoming inhospitable.
Our hypothesis is that the carbon and oxygen isotope composition of bryophytes can be used as a proxy for desertification, inundation and precipitation regimes in Antarctica.
We will determine whether stable isotopes of carbon and oxygen in plant tissues can be used as a surrogate for changes in effective growing season by determining whether they provide an accurate record of water availability to moss beds through time. To do this we will:
1) determine if long term water availability is accurately recorded in cell wall delta13C and delta18O signatures of moss, and if
2) short term, within/between season changes in moss submergence are reflected in the delta13C of sugars. In addition we will
3) measure instantaneous fractionation of carbon isotopes during photosynthesis in moss under different water availabilities.
Taken from the 2010-2011 Progress Report
Progress against objectives:
Moss, snow and water samples for Objectives 1 and 3 were collected in February 2011. These were from ASPA136 (Stevenson's Cove and a ridge site near Whitney Pt), on Bailey Peninsula (ASPA135, Science and Red Shed locations) and from Robinson Ridge
These samples have all been identified.
Objective 2 requires a longer season and was not possible in the time available at Casey.
These samples have all been identified at Wollongong
Stable isotope analysis is planned for September-October 2011 in Vienna (Bramley-Alves and Robinson).
An experiment to investigate the fractionation of mosses under different water availabilities is planned with some of the samples that were collected and transferred to ANU (Bramley-Alves, Robinson and Ball).
Jess Bramley-Alves has applied for a 2011 AINSE Postgraduate Research Award, which would provide research funding and access to radiocarbon dating facilities at ANSTO. This will allow us to date the samples and track stable isotope changes over time.
Transplant experiment will be conducted and additional samples will be collected in 2011/12
These will be analysed in 2012.
Progress to date is excellent given the short season at Casey.
(Click for Interactive Map)
Start Date: 2010-10-01Stop Date: 2013-03-31
BIOSPHERE > VEGETATION > FOREST COMPOSITION/VEGETATION STRUCTURE
BIOSPHERE > VEGETATION > VEGETATION COVER
BIOSPHERE > VEGETATION > VEGETATION INDEX
BIOSPHERE > VEGETATION > VEGETATION SPECIES
HUMAN DIMENSIONS > HABITAT CONVERSION/FRAGMENTATION > DESERTIFICATION
BIOLOGICAL CLASSIFICATION > PLANTS > MOSSES/HORNWORTS/LIVERWORTS
ATMOSPHERE > ATMOSPHERIC CHEMISTRY > CARBON AND HYDROCARBON COMPOUNDS
ATMOSPHERE > ATMOSPHERIC CHEMISTRY > OXYGEN COMPOUNDS
BIOSPHERE > VEGETATION > PLANT CHARACTERISTICS > VEGETATION WATER CONTENT
ISO Topic Category
Quality The values provided in temporal and spatial coverage are approximate only.
Taken from the 2010-2011 Progress Report
Difficulties affecting project:
Due to flight delays and short time available at Casey we did not collect all the samples we had hoped to and in particular we were not able to collect the full suite of species along water availabilities required. Hence there ... are some gaps in the sampling that we hope to fill next season. In addition work on Objective 2 was delayed until 2011/12 because it requires a longer season than the 3 weeks available. Given the short time available and the fact that the weather was not ideal at this late stage in the season, we nonetheless collected the bulk of the samples as planned.
We had planned that the transplant experiment in Objective 2 would run for 2 years. This will probably not be possible if the project has to end in 2012.
Samples were delayed for a long time on RTA and this is not ideal.
Access Constraints The full dataset for this project is not yet publicly available.
A copy of the species list collated during data collection is available for download from the provided URL.
Use Constraints This data set conforms to the PICCCBY Attribution License
Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=AAS_3129 when using these data.
Data Set Progress
Distribution Media: HTTP
Distribution Size: 17 kb
Distribution Format: Excel
Role: TECHNICAL CONTACT
Phone: +61 2 4221 5753
Fax: +61 2 4221 4135
Email: sharonr at uow.edu.au
Department of Biological Sciences University of Wollongong Northfields Ave
Province or State: New South Wales
Postal Code: 2522
Role: DIF AUTHOR
Phone: +61 3 6232 3244
Fax: +61 3 6232 3351
Email: dave.connell at aad.gov.au
Australian Antarctic Division 203 Channel Highway
Province or State: Tasmania
Postal Code: 7050
Creation and Review Dates
DIF Creation Date: 2011-04-29
Last DIF Revision Date: 2011-05-04