Extracts from QN News No243

Nullabor Plains Caves by David Lowry

General Meeting Report: May 20 2003 

David Lowry began his talk by telling us the Eucla Basin is the geologic term for the area of tertiary sedimentation that extends over the continental shelf at the  Great Australian Bight; Nullarbor is the name for the treeless stony plain.  Coloured maps showed the elevation of the various areas, the old Miocene shoreline and limestone plateau.
  David first went to this area in 1963, looking for a crater; this was the site of a cave system and he mapped the surface area for the WA government.  Slides illustrated the stony nature of the plain, coastal cliffs, relic sea scarp, with glimpses of such things as the old telegraph station and camel wagons.
   There are two types of caves: deep and shallow.  Cocklebiddy Cave is a good example of a deep cave, and a cross-section illustration showed its features that included a lake that lay in a long tube.  A team with diving equipment later swam  a distance of about 8 miles along this. In the cave were halites, and David’s explanation of the presence of these was that they were possibly caused by salt  water (spray across the land) seeping through into the caves and crystallising out when the water evaporated, extruding through cracks into these hair shapes.
  The shallow caves had ‘blowholes’ out of which very strong winds blew.  He felt that these blowholes were not caused  from rock pools that had corroded their way downwards, as had been assumed.  He decided they had come up from underneath, in domes that eventually broke through the surface.
  He noticed that the Cocklebiddy lake level changed during the day and that this change had a correlation with the air pressure – the rising pressure of air pushes the lake level down.
   In 1966 he found the cave that became known as the Thylacine Cave, as he found a very well preserved carcase of a thylacine there.  This cave is a typical example of a shallow cave, and it had a huge amount of skeletal material from animals that presumably had fallen down the hole.  It was a little surprising that there were more remains of carnivores than of herbivores, but perhaps the carnivores were attracted by the smell of trapped herbivores.  The thylacine was  taken to WA Museum and dated at 4600 years old, but stories from a local Aboriginal source seemed to suggest to David a much later date for the presence of thylacines (e.g. about 400 years).  The animal was a subspecies that was smaller than the Tasmanian thylacine and probably a female (from its size).
   Life in the caves was sparse.  There were bats, crickets and others that came in to shelter.  Two spiders and one centipede were blind and without pigment, suggesting that they had adapted entirely to life underground (perhaps not only in these caves, however).
  David was working only in the Western Australian stretch; here there were 20 odd deep caves and a lot of blowhole caves.  

EXCURSION REPORT: Jolly’s Lookout to Boombana, BFP, May 18 2002

The seven members who made it to this walk had a most enjoyable day.  Although easily accessible at any time, being a public walking track, the area has much of natural history to offer, and is rarely, if ever, host to a concentration of people.  To walk it as a Nats group was a huge bonus.  We encountered only two other couples fast-tracking past, so virtually had it all to ourselves.   
   We took time to look at the excellent display of the volcanic origins of Jolly’s Lookout and then went on the 4 kilometre track that heads out into the forest, staying on the one contour level all the way to Boombana.  It goes through both sclerophyll and rain forests, and we stopped many times to look at such things as the arrangement of spores on ferns (we passed eleven species),  the smooth trunks of Python wood (Austromyrtus bidwillii), Logrunners scratching in the litter, and small unidentifiable flowers shed on the path from somewhere up in the high canopy.  Not surprising then to reach the morning tea spot, about three quarters of the way along, at about 11.30.  Consequently, lunch was a divided affair, partaken partly here and the rest at Boombana a little later.  (Some people called this part of it ‘munch’.)
   After lunch, we did the circuit walk at Boombana, but the highlight was a view of a male Paradise Riflebird at lunch time.
  Having left one car at Boombana, we transported drivers back to their cars to avoid the walk back along the road, and had afternoon tea at our place down the range.  It was very pleasant indeed, made more so by the fact that it was all ours for the day and so close to Brisbane.           Helen Horton   

Book Review

    Stephens, K.M. & Dowling, R.M.: Wetland Plants of Queensland. A     field guide. 160 pp.   CSIRO Publishing. $39.95.

The book was originally planned ‘as a resource to assist those people involved in the construction and use of artificial wetlands used for the treatment of waste water’.  However, its value extends beyond that area; it is an attractively produced work and will be a useful source for naturalists interested in the flora of wet freshwater areas.
   There is a ‘Key to the Genera of Wetland Plants Occurring in Queensland’. This is clear and well-constructed and leads one mostly to a genus, in two cases to a family, and, where only one species of a genus is treated, to that species. In the families Cyperaceae and Poaceae and the genus Juncus the use is directed to previously published keys.  Otherwise, for each genus mentioned in the main key there follows a key to ‘species occurring in Queensland wetlands’. These keys contain numerous species which I should have thought of as being typically plants of other habitats. Examples of such species are Anagallis arvensis (Scarlet Pimpernel) and Cardamine hirsuta (Common Bittercress), both common weeds of gardens, and Hydrocotyle pedicellosa, usually occurring along rainforest tracks.  In the Introduction it is stated: ‘The key will also help you to identify closely related species’, but since the key headings state ‘species occurring in Queensland wetlands’ and there is no identifying of the ‘closely related species’ there is potential here for confusion.  Nearly 350 species are included in the keys.
   For ninety species, there is a page each with family name, scientific name, habit and description, flowering period and notes.  There is a map of Queensland showing distribution of the species and photographs, sometimes two, of the plant.  These illustrations, in the main, provide useful assistance in making a determination but a few, such as those of Hydrilla verticiallata and Utricularia stellaris are of doubtful value.
   The copy received for review lacked several pages at the end which included most of the Glossary, References and Index.        A.B. Cribb