Moss desiccation experiments conducted at Casey 1998-99 and 1999-2000 by Jane Wasley

Brief description

This series of experiments were conducted in the Casey station laboratories, using field collected moss samples, during the 1999/2000 summer field season. The work is fully described in Wasley et al. 2006 and Chapter 5 of Wasley 2004 (pp. 118-152), full citation details are:
- Wasley J., Robinson S.A., Lovelock C.E., Popp M. (2006) Some like it wet — biological characteristics underpinning tolerance of extreme water stress events in Antarctic bryophytes, Functional Plant Biology 33. 443-455.
- Wasley J. (2004) The Effect of Climate Change on Antarctic Terrestrial Flora, Doctor of Philosophy, University of Wollongong 191pp.
In summary, three byrophyte species were investigated: Bryum pseudotriquetrum, Ceratodon purpureus and Grimmia antarctici (later taxonomically revised as Schistidium antarctici).
Samples of the three moss species were collected early, mid and late season (2/12/99, 24/1/00 and 27/2/00) from ASPA 135 on Bailey Peninsula. Additional samples of G. antarctici were also collected from the edge of the melt lake behind the Casey station accommodation building.
Selected samples were used to determine a range of biological traits for the three species, including:
- morphology (gametophyte density and width)
- physiological response to desiccation and subsequent recovery
- a range of plant biochemical characteristics (soluble carbohydrates, fatty acids, nitrogen and carbon contents and N and C stable isotope signatures)
These traits were used to assess the biological characteristics underpinning relative tolerance of desiccation in the three Antarctic bryophytes species. This work improves our understanding of how these three species survive extreme water stress events in the Antarctic environment.

The raw data associated with this work, in the form of laboratory notebook scans are available in Metadata record name: JWasley-LabBook-Casey-1999-2000 (http://data.aad.gov.au/metadata/records/JWasley-LabBook-Casey-1999-2000). Following is a description of these scanned data – which are arranged in three sections: 1. early-season, 2. mid-season and 3. late-season experiments.
1. The early-season experiment, using samples of moss collected from the field on 2 December 1999, is recorded on pages 5-22 of the laboratory notebook and uses filename "desiccation 991203". This batch of work, includes:
- Sub-sample weights for analysis of soluble sugars prior to desiccation; T0 sugars (p5)
- Key to randomised sample locations in 24 well tray (p6)
- Method description and notes (p7)
- Desiccation experiment data; Fv/Fm (photosynthetic efficiency) and sample mass (for calculation of relative water content). Starts T0 (5:30PM, 3/12/99) on p9 and continues to T12 (4PM, 6/12/99) on p12.
- Estimation of gametophyte densities; desiccated on 7/12/99 and rehydrated on 13/12/99. Includes methods notes (p14)
- Recovery from desiccation: planning notes and methods (p15-17); recovery data up to T11 at 24 hours (1440 min), with time since hydration recorded (min:sec) and corresponding Fv/Fm measured. Sample weight recorded at T0 when still desiccated and at 24 h since hydration. (p18-21)
- Sub-sample weights for analysis of soluble sugars after desiccation (T1 sugars) and after recovery from desiccation (T2 sugars) (p22)

2. The mid-season experiment, using samples of moss collected from the field on 21 January 2000, is recorded on pages 47-79 of the laboratory notebook and uses filename "desiccation 000125". This batch of work, includes:
- Sample collection and methods notes (p47)
- Key to randomised sample locations in 24 well tray (p48)
- Sub-sample weights for analysis of soluble sugars prior to desiccation; T0 sugars (p49)
- Desiccation experiment data; Fv/Fm (photosynthetic efficiency) and sample mass (for calculation of relative water content). Starts T0 12:30AM, 26/01/00) on p50 and continues to T22 (12PM, 03/02/00; 203.5 hours) on p59.
- Recovery from desiccation: up to T13 at ~24 hours, with time since hydration recorded (min:sec) and corresponding Fv/Fm measured. Sample weight recorded at T0 when still desiccated and at T9, T12 and T13 ~1,4 and 24 h since hydration (p62-65)
- Note: p66-69 are blank
- Sub-sample weights for analysis of organic content and method notes (p70)
- Sub-sample weights for analysis of soluble sugars prior to desiccation; T0 sugars (p71), after desiccation (T1 sugars) and after recovery from desiccation (T2 sugars) (p73-75), sugar sub-sample label details and notes (p79).
- Estimation of gametophyte densities; desiccated and rehydrated (p76-77) and methods notes (p78).

3. The late-season experiment, using samples of moss collected from the field on 27 February 2000, is recorded on pages 87-89 and 94-121 of the laboratory notebook and uses filename "desiccation 000228". This batch of work, includes:
- Sample collection and methods notes (p87)
- Key to randomised sample locations in 24 well tray (p88)
- Estimation of gametophyte densities; desiccated and rehydrated and methods notes (p89)
- Note: p90-93 are associated with a different experiment.
- Desiccation experiment data; Fv/Fm (photosynthetic efficiency) and sample mass (for calculation of relative water content). Starts T0 12:00AM (midnight), 28/02/00) on p94 and continues to T30 (11:30AM, 08/03/00) on p117. Note: p96-99 are associated with a different part of this same experiment (see below).
- Sub-sample weights for analysis of soluble sugars prior to desiccation; T0 sugars (p96-97), after desiccation (T1 sugars) and after recovery from desiccation (T2 sugars) (p98-99), sugar sub-sample label details and notes (p79).
- Recovery from desiccation: up to T19 at 20 hours, with time since hydration recorded (min:sec) and corresponding Fv/Fm measured. Sample weight recorded at T0 when still desiccated and at T9, T12 and T13 ~1,4 and 24 h since hydration (p62-65)

Data files, additional to laboratory notebook
Filename – description
- Desiccation_991203_updated2018.xlsx - early-season desiccation experiment, measurements primarily photosynthetic efficiency and water content

- Desiccation_000125_updated2018.xlsx – mid-season desiccation experiment, measurements primarily photosynthetic efficiency and water content

- Desiccation_000228_updated2018.xlsx – late-season desiccation experiment, measurements primarily photosynthetic efficiency and water content

- Desiccation_Suagars.xlsx – soluble carbohydrate (sugar) contents of moss samples collected in association with the three desiccation experiments

- Desiccation_Gametophyte Densities.xlsx – moss gametophyte densities measured for turf samples in association with the three desiccation experiments