Archive Web Document, 1993
[This article was originally prepared for the Australian Systematic Botany Society Newsletter]
A report on a short visit
J.R. Croft (email@example.com) and M.M. Richardson (firstname.lastname@example.org), Australian National Botanic Gardens
In mid November 1989, JRC visited Macquarie Island for four days during the turn-around of the summer resupply voyage and collected living plant material and herbarium voucher specimens from the northern quarter of the island.
The project, proposed and planned by MMR, was to collect live material of subantarctic plants from Macquarie Island, ship them back to Australian as quickly as possible, and attempt to establish them in cultivation. The driving reasons for this project were to make this material, which is not commonly seen by the botanical community, readily and easily available for research, both taxonomic and horticultural, for education in the form of public displays and formal education programs, and to investigate the possibilities of ex situ cultivation and conservation of the species.
In particular we hoped to collect and establish material of the most striking plants on the island, Stilbocarpa polaris, Pleurophyllum hookeri and the dominant tussock grass, Poa foliosa. We were particularly anxious to collect the world's southernmost orchid, a Corybas previously known as C. macranthus, but believed by David L. Jones to be an undescribed species.
That most of the species collected are still alive, and actively growing, in Canberra indicates that the exercise was successful. [see nursery propagation report.]
Macquarie Island is a subantarctic island lying just outside of the antarctic convergence (c. 54.5 deg S, 159 deg E), almost 1500 km SE of Hobart. It is an approximately N-S strip of land 34 km long and 5 km wide and 250-350 m high, vainly trying to interrupt the onslaught of the 'furious fifties'. It is a tectonically active area, the island rising at a rate of c. 5 mm per year.
The island was discovered in 1810 and its natural resources were intensively exploited by seekers of abundant animal fur and oil until well into second decade of this century. Tragically, the original populations of the fur seal were exterminated within 5 years of the discovery of the island. The introduction of vermin such as rats, cats and rabbits also had disastrous effects on the biota. Intensive scientific activity took place on the island with Australasian Anatarctic expedition of 1911-1914 led by Sir Douglas Mawson. Australian National Antarctic Research Expeditions (ANARE) have maintained a research and meteorological station on the island since 1948.
Politically and administratively the island is part of the state of Tasmania. The island itself is a Tasmanian Nature Reserve with Tasmanian park management and Tasmanian Rangers but the research station on a narrow isthmus at the northern end is maintained and run by the Commonwealth Antarctic Division. It is a successful example of Commonwealth-State co-operation.
The weather on Macquarie Island is both uniform and unpredicable, or uniform in its unpredictability. Rain can be expected on more than 300 days of the year (c. 900 mm/y) and the wind blows strongly and constantly from the west; the air temperature oscillates only a few degrees from 5 °C from day to day and throughout the year. While it is quite true to describe it as very windy, cold and wet, it is a common occurrence to experience all four seasons in one day.
As a geologically new island, and a subantarctic one at that, the flora of Macquarie is not particularly diverse. All vascular plants are herbs or prostrate sub-shrubs, 5 are pteridophytes and c. 45 are phanerogams; there are 5 introduced species and 2 endemics (the Azorella and the Corybas), both of which have very closely related sibling taxa on other southern islands. There are three times as many bryophyte species and over twice as many lichen species.
The vegetation cover on the island is rarely over 1 m tall and consists of tussock grasslands, herbfields, exposed feldmark, and wet and peaty fens and bogs.
The most striking feature of the island is of course its abundant bird and mammal fauna. Although exciting, walking and collecting near elephant seals has its problems.
Collecting plants on Macquarie is not a trivial exercise; one does not simply get on a boat or 'plane and drop down for the week end. First you need permission to go there and do things and then logistic support from ANARE. To gain this you have to submit a plausable research project at least 10 months in advance and have it examined by a series of committees. If it is approved, participants are subjected to a variety of medical examinations to ensure they are not likely to die on the island. Then you have to get your equipment together and ship it to the Antarctic Division in Hobart.
The Antarctic Division has stringent requirements on training. Five days in October were spent being kitted out with quality cold weather gear and being trained in techniques of survival, rope work, search and rescue, first aid and in induction to the administrative and management arrangements of the Macquarie Island station. The Antarctic Division maintains a well appointed training centre at Bernacchi in the central highlands of Tasmania for this purpose, complete with appropriately cold, wet and windy weather. This may seem a bit excessive for a four-day excursion, but it was a valuable and productive learning exercise that enabled participants to start productive and safe work almost immediately after landing on the island.
To the Island
After a day of training in lifeboat procedures, polar survival suits and survival at sea, the expedition left on the Polar Queen, a Norwegian ice-strengthened research vessel chartered by ANARE, on November 21 1989. On board were the replacement winter party for the 1990 season, the summer research and logistic personell, a handful of 'round-trippers', and an army team responsible for the LARCs (Light Amphibious Resupply Craft), the only means of getting people, equipment and supplies between the ship and the shore. The passage was fairly calm with tail winds and we arrived at Macquarie Island within three days, on the morning of Friday November 24.
On the IslandBecause of limited time on the island, Patricia Selkirk willingly offered her assistance to seek out and collect plant material. We were exempted from the usual duties associated with loading and unloading and were able to make collections from the afternoon of first day on the island.
The base is situated at the northern tip of the island and the limited time meant that our collecting was restricted to the northern quarter of the island (10 km). The main areas collected were Wireless Hill, Hasselborough Bay to the northern end of the 'Featherbed', Gadget Gulley and onto the plateau, Nuggets Point and Sandy Bay through to Bauer Bay and from Bauer Bay overland back to the station.
The 'Featherbed' was a deep spongy peat bog of low herbs and grasses and pockets of free water. Juvenile plants of Stilbocarpa and Pleurophyllum were collected here. It was easy, but not pleasant, to extract the plants from the cold soft wet peat. The silky-silver-leaved Pleurophyllum had a large swollen carrot-like tuber and long roots that descended deep into the peat.
The cryptic Corybas orchid was found in full flower in similarly wet peat conditions on the north side of Bauer Bay. It was difficult to find due to its size and the fact that the leaves looked not unlike a very young Pleurophyllum.
Pleurophyllum also occured high on the plateau in well drained sandy gravel. With this wide tolerance of altitude, exposure, soils and water levels it was anticipated that this species would be extremely hardy and easy to establish in cultivation. This was not to be the case.
Throughout the island, the Pleurophyllum especially and other species generally, were copiously in flower and there was no trouble finding fertile voucher specimens. Regular visitors to the island stated that often the flowering is poor or non-existant, so we were fortunate in this regard.
We were also fortunate in the weather which was mild by Macquarie standards allowing four days collecting with virtually no rain, moderate winds and hardly any mist or low cloud. Another advantage of summer field work on Macquarie Island are the very long daylight hours; you can work from 4 am to 9 pm in full daylight.
Herbarium voucher specimens were collected for each of the live samples. As there is no woody vegetation on Macquarie Island to speak of, most plants were collected as whole plants, clumps, or juvenile plants of the larger species. To satisfy quarantine regulations, soil was removed from the specimens and they were wrapped in moist newspaper and placed in plastic bags. Some specimens were potted directly in moist vermiculite, but this was a very time consuming process and was abandoned in the later stages.
Return to the Mainland
Departing Macquaruie Island on Wednesday 29 November, the return voyage was not quite so halcyon as the arrival, strong winds and 10-15 metre waves out of Macquaire Island making the dining roon an interesting experience for a couple of days. The return voyage took three days and we arrived in Hobart on the afternoon of Saturday 2 December. The ten boxes of specimens were inspected by Quarantine officials to minimize the risk of introducing pathogens from the island. The boxes were rushed by air-freight to Canberra; some specimens, especially the Pleurophyllum, were already showing signs of stress.
Back in the Gardens
When the specimens arrived in Canberra they were unpacked in the nursery of the Australian National Botanic Gardens and potted into a mixture of 6 parts composted pine-bark, four parts sharp quartz sand with slow release fertilizer. The collection was divided. Part was placed in an artificially illuminated cool room in the nursery and part was sent to the Australian National University where it was placed in two environmentally controlled growth cabinets.
The environmental control at the ANBG was by means of 2 evaporative coolers and maintained minimum air temperatures of 13.6-15.1 °C and maximum air temperatures of 20.6-22.7 °C over the summer months. The environmental cabinets at the ANU were set at 8 oC by day and 5 °C by night with a photoperiod of 16 hours. All watering was done by hand.
It was interesting to note that for those species in both the ANBG and the ANU a given regime did not favour all taxa, some doing better in the warmer conditions of the ANBG and others in the harsher conditions of the growth cabinets; subjectively, 6 taxa did better in warmer conditions, 6 in the cooler and 7 showed no differences.
The following species are currently being cultivated at the ANBG nursery:
Luzula crinita var. crinita
Coprosma perpusilla ssp. antarctica
Corybas sp. nov.
At the time of writing the Stilbocarpa polaris was growing extremely well in Canberra and had even flowered. Unfortunately the Pleurophyllum hookeri did not take kindly to being moved and nearly all plants have regressed and died; it is unlikely that the collections of this species will survive in captivity.
As many of the species are mat-forming, some plants will be grown in trays rather than in pots, both for cultivation and display purposes.
In spite of near perfect weather (by Macquarie standards), four days proved to be insufficient time for one person to adequately cover the area and process the material collected. Two weeks would have been ideal, but it was either 4 days or six weeks.
Many of the Macquarie Island plants had not previously been brought into cultivation; they are now available for study and display. By varying the cultivation regimes, we have shown that the plants can survive in conditions milder than those experienced in their native habitat.
A facility is to be constructed in the nursery to provide cool conditions for the collections sover the summer months and a permanent display of the Macquarie Island flora. Attempts will be made to have those taxa that did not establish well recollected by future expeditions to Maccquarie Island. The ANBG will be distributing those species that have been established and repropagated to other Australian and international botanic gardens with facilities to maintain alpine and subpolar plants.
This project would not have been possible without the support and endorsement of the Tasmanian Department of Parks, Wildlife and Heritage (DPWH) and the logistic support of Australian National Antarctic Research Expeditions (ANARE). In the field, Dr Patricia Selkirk of Macquarie University provided willing and daylong assistance; without her detailed knowledge of the island and its flora and vegetation, the field trip would not have been nearly as successful.
Dr Patricia Selkirk surounded by large plants of Stilbocarpa polaris, one of the most striking plants of Macquarie Island, south of the ANARE station.
Report on Nursery holdings 1989.