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Seeds of twelve plant species were collected from Macquarie Island during January and February 2013. The seeds were used in a series of laboratory-based tests during 2013, at the University of Wollongong. Tests were conducted to determine species suitably for use in laboratory-based toxicity testing, using germination success and seedling growth (shoot and root length) as end points. Two soil types (containing low and high organic carbon contents) were used, to reflect the variable organic carbon content found in soils at Macquarie Island. Test soils were spiked with Special Antarctic Blend (SAB) diesel fuel and aged for 14 days to generate a concentration series of SAB-contaminated soils. Exposure doses were quantified as the concentration of total petroleum hydrocarbons (TPH, nC9-nC18) on a soil dry mass basis. Based on germination success in initial trials, four species (Colobanthus muscoides Hook.f., Deschampsia sp., Epilobium pendunculare A.Cunn. and Luzula crinita Hook.f.) were included in definitive toxicity tests. Description of files provided: - FILE: GabriellaMacoustra_Germination.xlsx Excel data file providing results of germination trials. Includes test development data (germination response of test species on test substrates without addition of fuel toxicants). - FILE: GabriellaMacoustra_Growth.xlsx Excel data file providing results of germination trials. Provides measurements from image analysis of roots and shoots of plants used in germination trials. - FILE: GabriellaMacoustra_Soil Characterisation.xlsx Excel data file providing soil characterisation data for the two soil substrates (sandy and peaty) used in the germination trials. Includes spiked fuel concentrations and a range of physicochemical properties. - FILE: Macoustra 2013_Thesis.pdf PDF file of University of Wollongong Honours thesis submitted by Gabriella Macoustra 2013. - FILES (Field and lab notebook scans): Notebook-Field_42420.pdf, Notebook-Field_42422.pdf, Notebook-Field_42398.pdf, Notebook-Lab_101036.pdf. Four scanned PDF files of field notes taken by Corrine de Mestre, related to seed collections on Macquarie Island during 2012/13.
This data set deals with embolism repair in two species of cushion plants (Colobanthus muscoides and Azorella macquariensis) which grow on Macquarie island and rely on protoxylem for water transport. Detailed description of each file can also be found in the readme.doc file. Index: Movies 1 and 2: Movies of in vitro embolism resorption in Colobanthus muscoides. 1 frame per 0.5s. Both movies have the same scale bar, shown on Movie 2. Images 1-13: Bright field time series of in vivo protoxylem embolism resorption in Colobanthus muscoides. Scale identical for all images and visible on Image_6. Images 14-17: Confocal images of protoxylem of Azorella macquariensis (Image_14 and Image_15) and Colobanthus muscoides (Image_16 and Image_17). Scale identical for all images and visible on Image_16 and Image_17. Images 18-23, 26: Cryo-SEM images of protoxylem of Azorella macquariensis (Image_18, Image_19 and Image_26) and Colobanthus muscoides (Image_20 to Image_23). Images 24-25: Bright field images of in vitro protoxylem embolisms in Colobanthus muscoides. Measurements.xls: Measurements on individual bubbles obtain from in vitro embolism resorption in Colobanthus muscoides. See the download file for a detailed description of the methods used in this project.
MICROINVERTEBRATE SAMPLING PROTOCOL Macquarie Island 01 October 2001 - 28 February 2002 A.HABITATS SAMPLED 8 habitats representative of the following vegetation types were chosen: 1.Azorella macquariensis - Open cushion areas 2.Acaena (magellanica and minor) herbfield 3.Colobanthus muscoides (coastal cushion plants) 4.Mires - Upland 5.Pleurophyllum hookerii dominated areas 6.Poa foliosa Tall tussock 7.Short grassland (incl. Agrostis magellanica/ Festuca contracta/ Luzula) 8.Stilbocarpa polaris dominated coastal herbfield B.HABITAT LOCALITIES 1.Range within which quadrats for a chosen habitat were located : a) Altitudinal limits- Lowland (coast to +/- 300 - 350m) b) Area- Spread over whole island c) Distance- i) 500m min. distance from the perimeter of the Base/logistic zone Viz. none in the logistic zone. - ii) 100m min. distance from an established hut - iii) 50m min. distance from an established path d) Aspect- East and west coasts 2.Types a) Homogeneous areas b) Least impacted areas (viz. Avoided heavily grazed Rabbit areas) (viz. Avoided Alien dominated areas) (viz. Avoided previously sampled or long term study sites) C.GENERAL SAMPLING STRATEGY FOR EACH HABITAT 1.For each habitat Five 2m x 2m quadrats were located (similar in vegetation structure) and marked 1-5. 2.From each quadrat two random samples were taken with the O'Connor split corer (as per sampling protocol D below). Viz: 10 cores from each habitat. 3.Each sample was retained separately (in it's core-tube placed in a plastic bag) and marked accordingly. Viz: A and B from 1 through to 5 (e.g.: Poa1A-B, Poa2A-B, etc to Poa5A-B). 4.On return from the field samples were immediately stored the in a cool, safe (rodent free) place (lab refrigerator) for processing. 5.Invertebrate extraction followed as per protocol E below. Sample numbers were retained throughout the sampling period, together with sampling date. 6.Each habitat was sampled on an average of once every five - six weeks. D.SAMPLING METHOD 1.Random numbers were obtained using a table of random numbers. 2.Numbers 1-100 are in top left quarter, progressing clockwise in the remaining three quarters for 101-200, 201-300 and 301-400. 3.If the position chosen for the first core had already been cored, the next random number and so on was used. 4.The core sample comprised a 70mm depth from ground level (viz. not including above ground vegetation growth and flowering parts). 5.Care was taken to disturb as little as possible of the vegetation in and around quadrat, as well as approach to site. 6.Sampling in or directly after heavy rain was avoided to prevent poor results (although it never rained hard or long enough for this situation to have occurred). 7.Samples were processed within 4 days (max) after return or safe / cool storage. 8.Before re-using any equipment (corer, cores, plastic bags, collecting jars and mesh cover etc), it was cleaned thoroughly to avoid contamination. E.EXTRACTION AND SORTING MESO-INVERTEBRATES : (These include all collembola and mites and enchytraeid earthworms). 1.In the collecting bottle of each sample placed in the HG extractor, an amount (+/- 2 cms high) of propylene * glycol was poured (*propylene glycol; CH3 CH(OH) CH2 OH = 76.10). 2.Core-samples were separated into litter-like top and about 5- 7 cm of soil. 3.Samples were retained in their respective core-rings, and where above ground vegetation biomass was more than could fit the depth of a ring, this was placed into additional rings. The veg (top)-side was covered with mesh or mutton cloth (approx. 1.5-2mm diam.) and secured with elastic bands (shock cord 3mm diam.). 4.The mesh covered side was placed facing down over the collection bottle in the HG extractor. The HG was left running for the first 2 days at 25 degrees C, and for the following two days (3rd and 4th days) at 30 degrees C. 5.Samples were transferred to 99% or 100% alcohol by draining off the propylene glycol through a 60 micron mesh, picking all the colembola and mites off it with a very fine paint-brush through the view of a good microscope, and placing these into labeled vials. 6.The filtered propylene glycol was re-used a couple of times. 7.Where time allowed, mites and colembola were separated for certain samples. 8.Sample details were noted in pencil on labels provided on the outside of each vial, and printed labels were inserted into each sample vial (see Macca Colembola and Mite labels 2001-02.doc). F.DATA ACQUISITION AND ARCHIVAL 1.Field data were captured in pencil using one A6 hard-cover note-book. 2.Data was transferred to spreadsheet and document and stored on CD-R discs with a back-up copy. This work was completed as part of the RiSCC project (Regional Sensitivity to Climate Change). The fields in this dataset are: Site name Habitat Location Latitude Longitude
The nitrogen fixing biota of Macquarie Island are dominated by cyanobacteria growing epiphytically or symbiotically with plants or lichens. Highest rates of acetylene reduction (N-fixation) were found in the leafy lichen Peltigera sp. Colonising herbfields and short grasslands, and in the coastal angiosperm Colobanthus muscoides. Significant rates of N-fixation were also associated with the liverwort Jamesoniella colorata commonly occurring in coastal and plateau mires, in a moss-bed of Dicranella cardotii colonising a land-slip face on the grassland slopes at 100m altitude, and within polsters of the mosses Ditrichum strictum and Andreaea sp. found in exposed localities on the plateau at 200-300m altitude. It was concluded that the common feature of plants supporting active N-fixation in dry habitats was the dense packing of stems and leaves, enabling water translocation to the cyanobacterial zone by wick action. Epiphytic cyanobacterial fixation in wet habitats was widespread and not restricted to plant species. This work was published in Polar Biology, 11: 601-606.
The dataset contains a series of anatomical images of plant specimens collected as part of AAS (ASAC) project 3095 at Macquarie Island during the summer of the 2011/2012 season. Species The four species examined were Azorella macquariensis, Colobanthus muscoides, Stilbocarpa polaris and Agrostis magellanica. Samples labelled 'South' were from Hurd point either near the hut (Colobanthus Stilbocarp and Agrostis) or from near the track at the top of the Hurd Point jump-up. The remaining plants were collected from the northern end of the island near the station. Anatomy and Leaf area The anatomy of the four species were investigated by taking hand cut sections and where necessary, staining with Toluidine Blue (0.05% in distilled water). Both transverse and longitudinal sections were taken. Photographic images were taken using Nikon Coolpic camera with eye tube adjustment. Images were accompanied with stage micrometre images. Two microscopes were used: a dissecting Leica MZ 8 and a Zeiss Axioscope. In some samples corresponding leaf surfaces were photographed of leaves removed from branches above the location of the transverse sections to calculate xylem surface area to leaf area ratios. Leaves were removed from the branches and places on graph paper under glass slides and photographed. Scales of the graph paper is 1 x 1 mm. Rehydration sequence Rehydration sequences of xylem vessels in both Colobanthus and Azorella samples were created by dissecting out xylem strands from longitudinal sections and drying on a glass slide. Water was then applied to rehydrate the cells and the sequence of embolism collapse was observed and photographed at defined time intervals. Interval measure had some non-measured margin of error as the shutter control on the camera was manually operated. Repeat drying and rehydration sequences were performed on the same sample. Two plants labelled Azorella macquariensis MC Ball experimental plant 1 and MC Ball Azorella no 2 Kleaf have associated physiological experimental data collected from them by Marilyn Ball.