Heard Island Vegetation Survey 1986-1987 and 1987-1988
Vegetation surveys were conducted on Heard Island during the 1986/87 and 1987/88 Australian National Antarctic Research Expeditions (ANARE). A stratified sampling approach was adopted. Given the limited time available for sampling, quadrats were placed to sample the bryophytic component of Hughes (1...
| Other Authors: | , , |
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| Format: | Dataset |
| Language: | unknown |
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Australian Antarctic Data Centre
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| Online Access: | https://researchdata.ands.org.au/heard-island-vegetation-1987-1988/701105 https://doi.org/10.4225/15/54B334FFA503B https://data.aad.gov.au/metadata/records/Heard_veg_survey_86-88 http://nla.gov.au/nla.party-617536 |
| Summary: | Vegetation surveys were conducted on Heard Island during the 1986/87 and 1987/88 Australian National Antarctic Research Expeditions (ANARE). A stratified sampling approach was adopted. Given the limited time available for sampling, quadrats were placed to sample the bryophytic component of Hughes (1987) six visually recognizable broad vascular plant community categories as well as sampling distinct landscape features such as coastal areas, moraines, scoria cones, and lava fields. Ideally, this stratification would have ensured that the major environmental gradients on the island were detected. A total of 475, 1 x 1 m quadrats were surveyed during the 8-wk 1986/87 field period. Two hundred and fifty quadrats were randomly selected within 25 (10 x 10 m) sites. One hundred and eighty quadrats were positioned on transects over distinct landscape features. The remaining 45 quadrats were randomly located in visually different areas in isolated localities. Access to Heard Island is logistically difficult. Field time for our survey was short. Travel by foot was slow due to rough terrain and the use of helicopters was restricted by unfavorable weather conditions. Field work was conducted in three major ice-free areas on the island: the northwest areas encompassing Laurens Peninsula, Azorella Peninsula, and Mt. Drygalski; the eastern Spit Bay area; and the southern Long Beach area. The number of quadrats in each area reflects the time available (Laurens Peninsula, 119; Azorella Peninsula, 40; Mt. Drygalski, 10; Spit Bay, 250; Long Beach, 45; other areas 11. In each quadrat the following habitat characteristics were noted: location (mapped); geomorphological features (sand, moraine, clinker lava, and lava flow), and general notes on topography; altitude; general slope of the quadrat (irregularities in clinker lava sites made slope difficult to assess); aspect; unconsolidated substrate depth to bedrock or a maximum of 100 cm, using a 1-cm-diameter metal probe (this may be an organic base such as peat or an inorganic substrate such as moraine); availability of water, rated on a subjective five-point exponential scale ranging from 1 (very dry) to 5 (surface free water); exposure to wind, rated on a subjective five-point scale ranging from 1 (very exposed) to 5 (very protected); availability of light, rated on a five-point subjective scale ranging from 1 (exposed to full light conditions) to 5 (deep shade). In each quadrat, cover values using the Braun-Blanquet (1932) scale were recorded for all vascular plants, bryophytes (as a collective unit), bare ground, and rock. Notes on individual cover values for major bryophyte taxa were taken, and samples of bryophyte taxa were collected for identification. This work now falls under the auspices of the RiSCC project (ASAC_1015). The fields in this dataset are: Region Site Formation Environ Altitude (m) Species |
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