Cunninghamia : A Journal of Plant Ecology for Eastern Australia, Volume 16 (2016)
Refine
Year of publication
- 2016 (8)
Document Type
- Article (8)
Language
- English (8)
Has Fulltext
- yes (8)
Is part of the Bibliography
- no (8)
Keywords
- Baron von Mueller (1)
- Camden Park (1)
- Chevert (1)
- Sir William Macleay (1)
- conservation (1)
- floodplain (1)
- floristics (1)
- mapping (1)
- mulga lands (1)
- wetlands (1)
Thomas Reedy (1842-1929), gardener from 1854-1926 at Camden Park, the family estate of the Macarthurs in western Sydney was sent by Sir William Macarthur on the Chevert Expedition to New Guinea in 1875. He collected plants on islands off the Queensland coast; Cape Grenville; around the Somerset outpost on the tip of Cape York; on islands in the Torres Strait; and around two locations on the mainland of southern Papua New Guinea. Reedy sent or brought back 800-1000 living plants, in addition to an unknown number of seeds, and at least 157 dried specimens, the latter sent to Baron Ferdinand von Mueller in Melbourne. This study is focused on locating the dried plant specimens now held in herbaria and highlighting their significance.
Reedy is something of an enigma with little ever written about him. His initial has been presented erroneously since 1875 and has gone through various morphs including J, P, M and T; searches for Reedy best use all these initials or
just his family name.
Melichrus urceolatus R.Br. (family Ericaceae) (Urn heath) is a small shrub endemic to eastern Australia found in open grassy woodlands and heath from southern Queensland to central Victoria. Very little is known of its ecology, particularly in relation to its pollination and reproductive strategies. Most Melichrus species are thought to be animal-pollinated, but some floral traits of Melichrus urceolatus suggest wind pollination. Here, I describe an observation of parasitic wasps (Diapriidae sp.) found inside Melichrus urceolatus flowers in a Box-Gum Grassy Woodland remnant in Albury, New South Wales and discuss the ecological significance of the observation.
A survey of the population of the parasitic herb Thesium australe R.Br. (family Santalaceae) in Booroolong Nature Reserve, northwest of Armidale, found it was restricted to an eastern facing lower slope on metasediments, within regenerating grassy woodland of Eucalyptus nova-anglica H.Deane & Maiden (New England Peppermint) and a predominantly Themeda triandra Forssk. (Kangaroo Grass) and Sorghum leiocladum (Hack.) C.E.Hubb. (Native Sorghum) understorey. The population is in two clusters over a total area approximately 260 m long by 40 m wide and was estimated to be about 800 individuals at the time of survey (May 2014). Current threats include a maintenance trail, erosion of creek bank, stray cattle and sheep, rabbits and Rubus anglocandicans A.Newton (Blackberry) invasion. It is recommended that further searches be conducted and that monitoring occur on a regular basis using the permanently marked sites and methodology used in this survey.
Naree and Yantabulla stations (31,990 ha) are found 60 km south-east of Hungerford and 112 km north-west of Bourke, New South Wales (lat. 29° 55'S; long. 150°37'N). The properties occur on the Cuttaburra Creek within the Mulga Lands Bioregion. We describe the vegetation assemblages found on these properties within three hierarchical levels (Group, Alliance & Association). Vegetation levels are defined based on flexible UPGMA analysis of coverabundance scores of all vascular plant taxa. These vegetation units are mapped based on extensive ground truthing, SPOT5 imagery interpretation and substrate. Three ‘Group’ level vegetation types are described: Mulga Complex, Shrublands Complex and Floodplain Wetlands Complex. Within these Groups nine ‘Alliances’ are described: Rat’s tail Couch – Lovegrass Grasslands, Canegrass Grasslands, Lignum – Glinus Shrublands, Coolibah – Black Box Woodlands, Turpentine – Button Grass – Windmill Grass Shrublands, Turpentine – Hop Bush – Kerosene Grass shrublands and Mulga Shrublands. Sixteen ‘Associations’ are described 1) Mulga – Poplar Box Shrubland, 2) Mulga – Poplar Box – Bastard Mulga Shrubland, 3) Turpentine – Hop Bush – Senna Shrubland, 4) Turpentine – Elegant Wattle – Boobialla Shrubland, 5) Turpentine – Hop Bush – Daisy Bush Shrubland, 5) Belah – Rosewood – Turpentine Bush Shrubland, 6) Belah – Rosewood – Turpentine Bush Shrubland, 7) Ironwood – Leopardwood – Supplejack Shrubland, 8) Yapunyah – Black Box – River Cooba Woodland, 9) Coolibah – River Cooba – Yapunyah Woodland, 10) Rat’s tail Couch – Lovegrass – Fairy Grass Grassland and Herbfield, 11) Rat’s tail Couch – Lovegrass – Purslane Grassland and Herbfield, 12) Darling Pratia – Rat’s tail Couch – Spike Rush Herbfield, 13) Canegrass Grassland, 14) Glinus – Groundsel – Lignum Herbfield, 15) Poplar Box – Mulga – Coolibah Woodland and 16) Black Box Woodland. In total 355 vascular plant taxa were found of which 6% were considered exotic in origin. A population of Dentella minutissima; a species listed as threatened (endangered) under the New South Wales Threatened Species Conservation Act 1995 was found. A summary of select structural and habitat attributes within Alliances is also presented.
The shrub Nematolepis ovatifolia (F. Muell.) Paul G. Wilson (family Rutaceae) is endemic to the alpine and subalpine areas of the Snowy Mountains, Australia, where it dominates large areas of heath. Mass dieback was observed in the spring/summer of 2012. Damage at first was confined to the tips of branches, a symptom that could be due to frost damage and/or pathogen-induced water stress. Subsequently, whole stems and shrubs died and new areas of chlorosis appeared on smaller shrubs. Surveys of 186 sites covering the geographical range of the shrub in the summers of 2013/14 and 2014/15 found that 59 populations were definitely dieback affected, 92 had early symptoms and 35 were healthy. Two possible causes were investigated: killing frost and pathogens, with insect attack being a further cause of defoliation. The root rot pathogen, Phytophthora cambivora was isolated from one washed root sample and from one of five soil/ root samples. In 2014/15, in five sites where symptomatic plants were monitored, most plants recovered to a condition where they were considered unaffected in March 2015. It is possible that symptomatic plants had in fact suffered frost damage. Hence populations with early symptoms were grouped with healthy populations for analysis of proximity to trails. Compared with these, dieback affected populations were significantly closer to trails. It could not be determined when the pathogen was introduced, as it could have been imported on earthmoving equipment or by subsequent users of trails. It was apparently well spread before spring of 2012 but infection of plants was not evident. Its sudden eruption in spring of 2012 may have been facilitated by two warm and wet La Nina years, with mean growing season soil temperature up to 1.5°C higher than the long term mean and growing season rainfall double the long term mean. Plant death occurred in the hottest year on record in Australia, with the average alpine treeline growing season soil temperature of 9.2°C in 2012/13 being >2.0°C above the long term mean.
The recently described shrub Epacris browniae (family Ericaceae) an endemic Blue Mountains species, occurs on treeless, dry, rocky, Sydney Montane Heath, on Narrabeen and Hawkesbury Sandstone in the upper Blue Mountains, 100 km west of Sydney, New South Wales, (c. 33° 40' S; 150° 22' E) at altitudes above 800 m, and within the 1300 mm Average Annual Rainfall isohyet. Based on our surveys in the Blue Mountains (incorporating 46 locations), the Area of Occurrence of the species is estimated at 525 square km, within which the Area of Occupation is 25 hectares. The northern limit is Mt Wilson, southern limit, Mt Solitary, western limit appears to lie between Clarence and Narrow Neck (Katoomba) and eastern limit is Lawson Ridge.
The species grows either on flat terrain or on gentle southern or western slopes, sometimes blending into escarpment complex, on soils of moderate acidity (pH 6.5–6.8) and good drainage, associated most commonly with Banksia ericifolia and, in descending order of abundance, with Leptospermum trinervium, Allocasuarina distyla, Kunzea capitata, Allocasuarina nana and Hakea dactyloides.
Epacris browniae flowers in November and seeds ripen in March. Seeds are shiny, brown, minutely warty, about 0.6 mm long, and weigh 0.038 mg.
Epacris browniae does not resprout after fire. Average stem diameters at three sites with known single fire histories correlate strongly with likely maximum age and confirm that the species is a facultative reseeder with a potential lifespan of up to 50 years.
Despite its relatively narrow habitat and area of occupancy Epacris browniae is well conserved within National Parks in the Blue Mountains but its susceptibility to Phytophthora, an exotic pathogen in the Blue Mountains is unknown.
Hunter Valley Weeping Myall Woodland is listed as a Critically Endangered Ecological Community (CEEC) under both the New South Wales Threatened Species Conservation (TSC) Act 1995 and the Commonwealth Environment Protection and Biodiversity Conservation (EPBC) Act 1999. Uncertainty regarding the provenance of Weeping Myall (Acacia pendula) in the Hunter has led to questioning of the place of Hunter Valley Weeping Myall Woodland CEEC in State and Commonwealth legislation. A recent publication has endorsed its legislative listing, largely based on the co-association of Weeping Myall with a range of other semi-arid species in some parts of the Hunter Valley. We counter this argument and show that the semi-arid species present in low rainfall areas on Permian sediments of the Hunter Valley floor are in fact more widespread than previously documented. Through examination of distributional records, we demonstrate that these species display no fidelity to purported Hunter Valley Weeping Myall Woodland, but instead occur in a range of other vegetation communities across much of the central and upper Hunter Valley. Habitat suitability modelling undertaken for Acacia pendula shows there to be nearly 900 times the 200 ha of pre-European extent, or 20 times the area of occupancy previously estimated for this community. We also revisit an earlier ordination analysis which showed a divergence in sample data potentially representative of Hunter Valley Weeping Myall Woodland. We add new samples and provide a revised classification of the purported community, which shows that sample plots from two forms of Hunter Valley Weeping Myall Woodland are floristically indistinguishable from comparative data in 20-25 year old mining rehabilitation forests of Eucalyptus cladocalyx, and native grasslands derived predominantly from landscapes of Eucalyptus crebra and Eucalyptus moluccana. Relevant legislation requires any threatened community to be identifiable based on a particular species assemblage and its area of occupancy. We question whether Hunter Valley Weeping Myall Woodland is recognisable with and without the presence of Acacia pendula. We argue that the identification of Hunter Valley Weeping Myall Woodland is unachievable without the visual cue of Acacia pendula, and note that for some time regional botanists have used this species’ presence as a de facto diagnostic tool to identify this community; in fact, there are no examples of the community having been identified as such in the absence of Acacia pendula. Finally, following from our ordination results, and the presence of key diagnostic species within more widespread grassy woodlands and derived native grasslands, we suggest that 200 years of anthropogenic disturbance across the Hunter Valley has sufficiently masked any distributional pattern of western semi-arid species that might have once occurred. We contend that there is little value in conserving a purported community that cannot be confidently delineated in numerical classifications, lacks a consistent and diagnostic suite of characteristic species, and for which there is uncertainty over the origins of its dominant, flagship species, Acacia pendula.
