Understanding the impact of change on Australia's World Heritage subantarctic islands
Entry ID:
ASAC_3095
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Summary
Abstract:
Metadata record for data from AAS (ASAC) Project 3095. Public Global warming and the impact of feral animals or weedy plant species are causing changes in terrestrial sub-Antarctic ecosystems. We are examining how sub-Antarctic organisms and ecosystems will respond to this change. In doing so we will contribute to the conservation of these remarkable ecosystems for which Australia has a large ... responsibility.
Project objectives:
Australia's unique sub-Antarctic World Heritage Areas are experiencing rapid climate change and their biodiversity is under threat from alien species invasion. Heard Island is experiencing some of the fastest climate change in our region, which is evidenced by extensive changes in vegetation communities. This change appears to be exacerbating the expansion of the alien grass species Poa annua. MacDonald Island has recently expanded in surface area due to volcanic activity. On Macquarie Island, as well as undergoing climate change, rabbit numbers have recently increased causing major ecosystem devastation. Furthermore, the AAD has begun remediation of some contaminated sites in the station vicinity. This project is designed to understand the impact of these changes to these rare island ecosystems.
Objective 1 Quantify change in terrestrial ecosystems at a range of spatial and temporal scales on Heard and McDonald Islands and Macquarie Island.
Objective 2 Examine the biology, life history strategy and distribution of the indigenous Azorella selago and Acaena magellanica, Rannunculus crassipes and the alien grass species Poa annua on Heard Island and indigenous Poa littorsa and Carex trifida on Macquarie Island.
Objective 3 Examine the impact of human induced perturbations (rabbit and rodents, petrochemical contamination and the rubbish tip) at varying spatial levels on Macquarie Island before and after management actions.
Objective 4 To contribute to furthering our understanding of subantarctic microbial diversity.
Taken from the 2008-2009 Progress Report:
Progress against objectives:
Objective 1: We have focussed on Macquarie Island this year. We have delivered a globally significant paper quantifying change in plant communities on the island since 2001. We also completed a major field season in which we revisited and examined sites established in 2001 with regard to change in plant and invertebrate communities and developed a new sampling method for the rapid collection of field data to train satellite image interpretation and terrain analysis of the distribution of plant communities. This included the design and construction of close-range aerial photography equipment, the classification of landforms on Macquarie Island, based on terrain characteristics and the Normalised Difference Vegetation Index (NDVI) and design of a stratified random sampling regime.
Objective 2: We focused on examining the extent of northern populations of Poa littorosa and Carex trifida and added an additional component of examining the health of Azorella maquariensis and genetci variation in Azorella spp, Acaena magellanica and Poa annua across the subantarctic region.
Objective 3: We focussed on the examination of the impact of rabbits, at a variety of scales across the island. We provided assistance to a sister project with regards to the impact of petrochemical contamination on invertebrate communities.
Objective 4: We collected microbial mat samples from selected sites in collaboration with the Belgium AMBIO project.
Taken from the 2009-2010 Progress Report:
Progress against objectives:
Objective 1: We have focussed on Macquarie Island this year. We have delivered a second globally significant paper concerning change in plant communities on the island since 2001. We also completed a major field season in which we revisited and examined sites established in 2001 and 2008/09 with regard to change in plant communities using the sampling method developed in 2008/09 for the rapid collection of field data to train satellite image interpretation and terrain analysis of the distribution of plant communities. This included assessing the results of the first field sampling season and the design of a follow-up stratified random sampling regime.
We have completed sample analysis of invertebrates collected last season and data analysis and ms preparation is underway.
Objective 2: We focused on the health of the endemic cushion, Azorella maquariensis. Last summer the CI of the project, Dr Bergstrom identified that A. macquariensis was undergoing rapid dieback. Substantial efforts during the year, both in the field and in the laboratory have been focused on this rapidly emerging issue.
Objective 3: We focussed on the examination of the impact of rabbits, at a variety of scales across the island. We provided assistance to a sister project with regards to the impact of petrochemical contamination on invertebrate communities.
Objective 4: Microbial mat analysis is under way with colleagues in Belgium. 
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Description:
Public information for ASAC project 3095
Description:
Citation reference for this metadata record and dataset
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Geographic Coverage
(Click for Interactive Map)
Spatial coordinates
Temporal Coverage
Start Date:
2008-09-30
Stop Date:
2012-03-31
Quality
The values provided in temporal and spatial coverage are approximate only.
Taken from the 2008-2009 Progress Report:
Variations to work plan or objectives:
During the summer, we noted widespread die-back in Azorella macquariensis. New field sampling protocols were established to to assess the distribution of the dieback and identify the cause. In ... January 2009 Cores of plant material were taken from 30 sites on the northern plateau and sent to Hobart for examination by DPIW plant pathologists. A further 40 cores were taken in March 2009 from cushions in the Mt Elder region across dieback fronts. In addition, visual and photographic assessments of the health of Azorella in 10 x 10 m plots was undertaken at 142 sites. These data will be used to investigate links between terrain features and the distribution of dieback.
Objective 2 - work on the biology, life history strategy and distribution of the indigenous Azorella Spp and Acaena magellanica, and the alien grass species Poa annua was expanded to Macquarie Island. Collaborative work has developed with South African, French and UK colleagues looking a genetic variation in these species.
Field work:
Objective 1: Plot scale: Fifty long-term vegetation sites ((5 x 5 m) established in 2001 and 2007) were revisited and surveyed during the summer to quantify changes in species composition and cover. In addition 43 long-term invertebrate sites were revisited and surveyed for change in invertebrate communities. Soil cores were collected (established in 2001) in nine different vegetation communities on three separate occasions during the summer. From these, invertebrates were extracted for analysis of changes in invertebrate communities during the past 8 years.
Mid Scale scale: 220 larger vegetation plots (10 x 10 m) were surveyed across the island using close range aerial photography, identified using stratified random sampling design locations across the island.
Plant and soil cores were taken from Azorella macquariensis at 37 sites for examination by plant pathologists at DPIW.
Objective 2: The populations of Poa litorosa and Carex trifida at Handspike Point were resurveyed using differential GPS (these populations were surveyed in 2003 and 2006). Leaf samples were collected from Azorella macquariensis (5 sites), Poa annua (4 sites) and Acaena magellanica (5) sites.
Visual/photographic health assessments were conducted on Azorella macquariensis cushions at 142 mostly randomly located sites (~65 of these sites were also used for other vegetation/invertebrate surveys).
Objective 3: Field work for this objective is detailed under objective 1.
Objective 4: At 19 sites, samples of microbial mats were taken, along with photographs and site descriptions. Samples were stored by three methods (cold, frozen and preserved in alcohol). Samples have been shipped to colleagues in Belgium for analysis.
Laboratory activity/analysis:
Invertebrate extraction and analyses: micro-invertebrates from soil cores (described in section 1.4, objective 1) were extracted using a high temperature gradient extractor.
Micro-invertebrate samples from 2001 are currently being processed. Each site has two replicate cores, to date the A replicate cores (141 samples) have been sorted and identified.
Analysis of change detected by satellite imagery has been progressing. This study implemented and applied a binary ensemble classifier for identification of grazed vegetation communities on Macquarie Island from very high resolution Quickbird imagery. The aim of this study was to identify the grazed areas from Quickbird imagery to map their spatial extent. Seven different soft classification algorithms were applied to classify the image into grazed vs. 'other' classes. The maximum likelihood classifier, supervised fuzzy c-means classifier (Euclidean distance, Mahalanobis distance, and k-nearest neighbour), and three support vector machine classifiers (SVM) were applied. An ensemble classifier based on the consensus rule was used to combine the seven classification results. A very high classification accuracy of 97% was achieved with the ensemble classifier, identifying grazed areas and providing an estimate of classification uncertainty. In addition we have generated a Wetness Index map for Macquarie Island, and using fuzzy c-means (FCM) IDL code to stratify the island based on topography and the Quickbird satellite image. This stratification was used to guide the field sampling design.
Difficulties affecting project:
The differential GPS base station at VJM (MAC1, maintained by Geoscience Australia) broke down in late February and was not fixed until the resupply voyage. This has reduced the quality of GPS surveys undertaken on 17 days in this time period. We are unable to indicate at this time what impact this will have in the long term. However we are hopeful of working around this problem.
Taken from the 2009-2010 Progress Report:
Field work:
Objective 1: 207 sites were surveyed across the island using close range aerial photography. Site were identified using a stratified random sampling design. Of these, 72 were revisits to sites established in 2008/09 for the purpose of quantifying vegetation change in coastal areas. Quick assessments (including site photographs and species lists) were undertaken at an additional 67 sites, of which 54 were revisits to sites established in 2008/09. At all sites containing Azorella macquariensis additional site photographs were taken and an estimate made of the health of Azorella and bryophytes.
The methods for each of the field protocols are outlined below:
Close range aerial photography:
Sites were subjected to the polecam treatment outlined in the 2009/10 permit application for AAS 3095 and in the permit report for 2008/09 for AAS 3095. A GPS location was recorded at the south-east corner of the site, and a 10 m x 10 m plot marked out with rope. Vertical photographs were taken of each corner of the site from a height of 2.5 m. Site photographs, soil depth measurements and a vascular plant species list were collected.
Quick assessment:
This assessment was undertaken at sites where it was deemed unnecessary to conduct a full polecam protocol. In coastal areas (including SMAs) this occurred on beaches with less than 1% vegetation, or where the slope made close range aerial photography dangerous. On the plateau, these were sites that had been visited in 2008/09 and were considered unlikely to have changed significantly. At these sites, the location was recorded, site photographs were taken and a note made of the dominant species present.
Opportunistic resurvey of established Pleurophyllum hookerii sites (under project 1015) were completed. This allows us to document impact of environmental change in this key species.
Objective 2:
Health Assessment:
Repeat visual/photographic health assessments were conducted on Azorella macquariensis and other vegetation at 144 sites, established in 2008/09.
Temperature logging:
At 10 selected sites, two ibutton temperature loggers were deployed October 2009 - March 2010. One logger was inserted 2 cm into the centre of an Azorella macquariensis cushion and the other was inserted 2 cm into soil next to the cushion.
Near-infra red repeat photography:
At 31 selected sites, a 1 m2 quadrat was photographed using a NIR sensitive camera and a visible light-sensitive (i.e. normal) camera Photograph occurred a 3 week interval frequency November 2009 to March 2010
Azorella cushion profiling and microtopography:
At selected sites, three cushions of varying health conditions were probed every 5 cm along its longest axis and along the axis perpendicular to that. The probing at each 5 cm interval measured the distance between the cushion surface and soil surface. Soil depths, slope and distance for which the slope was constant were also measured at each of the cardinal and intermediate directions for each cushion. Site locations were based on sites previously selected for close range aerial photography.
Physiological performance:
in situ and ex situ physiological measurements of Azorella performance was undertaken at selected sites. A short term watering experiment was also the establishment.
Objective 3: Field work for this objective is detailed under objective 1.
Objective 4: Field work for this objective was completed last season .
Laboratory activity/analysis:
Invertebrate analyses:
Micro-invertebrates from soil cores collected last year were processed, sorted and identified. Analysis and ms preparation is underway.
Vegetation Change:
Analysis of change detected by satellite imagery has been progressing. This year, there has been a focus on processing data acquired in the previous two field seasons and assessing the capacity of close range aerial photography to quantify plant species cover. Initial results of photograph interpretation are promising and a paper is in preparation comparing this method with plot scale methods that have been used as part of AAS3095 since in 2001. The large number of sites visited during the 2008/09 field season enabled us to increase the sample size. To do this we used a similar stratified random sampling method to the previous year.
Azorella dieback:
Data analysis of health assessments were completed with the finding that over 90% of all 144 sites had evidence of dieback and over 85% had evidence of dieback in mosses.
Material collected during October 2009 were used to investigate hydraulic properties of the species with findings that species is easily prone to water stress.
Access Constraints
The data are currently not publicly available.
Data Set Progress
IN WORK
Personnel
Role:
INVESTIGATOR
Role:
TECHNICAL CONTACT
Phone:
+61 3 6232 3209
Fax:
+61 3 6232 3351
Email:
dana.bergstrom at aad.gov.au
Contact Address:
Australian Antarctic Division
203 Channel Highway
City:
Kingston
Province or State:
Tasmania
Postal Code:
7050
Country:
Australia
Role:
DIF AUTHOR
Phone:
+61 3 6232 3244
Fax:
+61 3 6232 3351
Email:
dave.connell at aad.gov.au
Contact Address:
Australian Antarctic Division
203 Channel Highway
City:
Kingston
Province or State:
Tasmania
Postal Code:
7050
Country:
Australia
Publications/References
Adams, B., Arthern, R., Atkinson, A., Barbante, C., Bargagli, R., Bergstrom, D., Bertler, N., Bindschadler, R., Bockheim, J., Boutron, C., Bromwich, D., Chown, S., Comiso, J., Convey, P., Cook, A., di Prisco, G., Fahrbach, E., Fastook, J., Forcarda, J., Gili, J-M., Gugliemin, M., Gutt, J., Hellmer, H., Hennion, F., Heywood, K., Hodgson, D., Holland, D., Hong, S., Huiskes, A., Isla, E., Jacobs, S., ... Jones, A., Lenton, A., Marshall, G., Mayewski, P., Meredith, M., Metzl, N., Monaghan, A., Naveira-Garabato, A., Newsham, K., Orejas, C., Peck, L., Portner, H-O., Rintoul, S., Robinson, S., Roscoe, H., Rossi, S., Scambos, T., Shanklin, J., Smetacek, V., Speer, K., Stevens, M., Summerhayes, C., Trathan, P., Turner, J., van der Veen, K., Vaughan, D., Verde, C., Webb, D., Wiencke, C., Woodworth, P., Worby, T., Worland, R., Yamanouchi, T. (2009) Chapter 4, The Instrumental Period In: Turner, J., Bindschadler, R., Convey, P., di Prisco, G., Fahrbach, E., Gutt, J., Hodgson, D., Mayewski, P., Summerhayes, C. (ed.) Antarctic Climate Change and the Environment 183-298 Arbetter, T., Arthern, R., Barbante, C., Bargagli, R., Bergstrom, D., Bertler, N., Bindschadler, R., Bockheim, J., Boutron, C., Bromwich, D., Chown, S., Clarke, A., Comiso, J., Convey, P., Cook, A., di Prisco, G., Fahrbach, E., Fastook, J., Fleming, A., Gugliemin, M., Gutt, J., Hellmer, H., Hennion, F., Heywood, K., Holland, D., Huiskes, A., Jenkins, A., Jones, A., Lenton, A., Hodgson, D., Hong, ... S., Jacobs, S., Linse, K., Marshall, G., Mayewski, P., Meredith, M., Metzl, N., Monaghan, A., Naveira-Garabato, A., Rintoul, S., Roscoe, H., Shanklin, J., Scambos, T., Sparrow, M., Speer, K., Stevens, M., Summerhayes, C., Turner, J., van der Veen, K., Vaughan, D., Verde, C., Wang, Z., Webb, D., Woodworth, P., Worby, T., Worland, R., Yamanouchi, T. (2009) Chapter 2, Observations, Data Accuracy and Tools In: Turner, J., Bindschadler, R., Convey, P., di Prisco, G., Fahrbach, E., Gutt, J., Hodgson, D., Mayewski, P., Summerhayes, C. (ed.) Antarctic Climate Change and the Environment 33-114 Bergstrom D.M., Lucieer, A., Kiefer, K., Wasley, J., Belbin, L., Pedersen T.K. and Chown, S. (2009) Management implications of the Macquarie Island trophic cascade revisited: a reply to Dowding et al. (2009) Journal of Applied Ecology 46: 1133-1136..
Creation and Review Dates
DIF Creation Date:
2009-04-23
Last DIF Revision Date:
2010-04-21
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