Cunninghamia : A Journal of Plant Ecology for Eastern Australia, Volume 10, Issue 3 (2008)
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Between 1993 and 2005 I investigated the introduced plant species on the Newcastle foreshores at Stockton and Macquaries Pier (lat 32º 56’ S, long 151º 47’ E). At North Stockton in a rehabilitated area, cleared of *Chrysanthemoides monilifera subsp. rotundata, and planted with *Ammophila arenaria interspersed with native shrubs, mainly Acacia longifolia subsp. sophorae and Leptospermum laevigatum, is a rich flora of introduced species of which *Panicum racemosum and *Cyperus conglomeratus have gradually become dominant in the groundcover. Notwithstanding continuing maintenance, *Chrysanthemoides monilifera subsp. rotundata has re-established among the native shrubs, and together with Acacia longifolia subsp. sophorae, is important in sand stabilisation along the seaward edge of the dune terrace. The foredune of Little Park Beach, just inside the Northern Breakwater, is dominated by Spinifex sericeus and backed by Acacia longifolia subsp. sophorae-*Chrysanthemoides monilifera subsp. rotundata shrubbery. In places the shrubbery has given way to introduced species such as *Oenothera drummondii, *Tetragonia decumbens and especially *Heterotheca grandiflora. At Macquaries Pier *Chrysanthemoides monilifera subsp. rotundata forms an almost continuous fringe between the rocks that protect the pier against heavy southerlies. However, its presence on adjacent Nobbys Beach is localised and the general aspect of this beach is no different from any other along the coast as it is dominated by Spinifex sericeus. Many foreign plant species occur around the sandy foreshores at Port Hunter. Since the first coal exports in the 1850s the Newcastle wharves and ballast-ground at Stockton became points of entry for foreign species, either directly, or via stopovers at other Australian ports. Some of these, *Panicum racemosum, *Tetragonia decumbens, *Ursinia speciosa, *Hebenstretia dentata and until recently, *Heterotheca grandiflora, remained restricted to the Newcastle region, while others, e.g. *Chrysanthemum monilifera subsp. rotundata, *Hydrocotyle bonariensis, *Gladiolus gueinzii and *Oenothera drummondii, spread further afield, but only colonised their preferred coastal habitat. Many more species spread far and wide, their port of introduction no longer recognisable. Other species were introduced as garden plants, escaped and became naturalised. However, for most foreign, generally widespread, species their mode of entry can no longer be determined. 99 species were recorded in the six areas regularly visited, about 25% native to Australia, and 75% about evenly divided between species from Africa, Asia and Europe. More detailed information on 15 of the more notable introduced species is provided in an appendix. On the dune terrace vegetation of North Stockton, only about 20% of the 50 species are native to Australia, the only one of any prominence being Acacia longifolia subsp. sophorae. Nevertheless, on first impression this ‘multinational’ assemblage looks quite normal, and when one compares the ecological functioning of the 1930s vegetation with that of the present vegetation, it appears that, due to presence of more graminoids, and the fact that *Panicum racemosum produces a denser sward than Spinifex sericeus, the present vegetation is more effective in sand-catching and dune stabilisation than the vegetation in the 1930s would have been. However in view of the increasing influence of climate change, e.g. a rise in sea level and more extreme weather events, there is no indication that the present terrace, notwithstanding the increased density of the rhizomatous species and a sprawling shrubby vegetation along the crest, will endure such attacks any better than in the 1990s.
The vegetation of montane lagoons of the New England Tablelands Bioregion, New South Wales is examined using flexible UPGMA analysis of frequency scores on all vascular plant taxa, charophytes and one liverworts. Seven communities are described: 1. Hydrocotyle tripartita – Isotoma fluviatilis – Ranunculus inundatus – Lilaeopsis polyantha herbfield; 2. Eleocharis sphacelata – Potamogeton tricarinatus sedgeland; 3. Eleocharis sphacelata – Utricularia australis – Isolepis fluitans, herbfield; 4. Utricularia australis – Nitella sonderi herbfield; 5. Eleocharis sphacelata – Utricularia australis – Ricciocarpus natans sedgeland; 6. Carex gaudichaudiana – Holcus lanatus – Stellaria angustifolia sedgeland; 7. Cyperus sphaeroides – Eleocharis gracilis – Schoenus apogon – Carex gaudichaudiana sedgeland. 58 lagoons were located and identified, only 28% of which are considered to be intact and in good condition. Two threatened species (Aldovandra vesiculosa and Arthaxon hispidus) and three RoTAP-listed taxa were encountered during the survey.
The vegetation of Gibraltar Range National Park and adjoining parts of eastern Washpool National Park, 65 km east of Glen Innes (29° 31’S 152° 18’E) on the eastern escarpment of New South Wales is described. In total 124, 20m x 50m full vascular plant floristic sites were recorded and information from an additional 53 sites was collated. Thirteen vegetation assemblages are defined based on flexible UPGMA analysis of cover-abundance scores of all vascular plant taxa. Many of the vegetation communities are typical of what is found along the north eastern escarpment of NSW. Three communities are considered to be rare and two vulnerable. A total of 878 vascular plant taxa from 138 families were recorded, of which only 21 (2%) were of introduced origin and 81 (9%) were found to be of conservation significance. Pattern diversity, species density, species accumulation and average geographic range size, along with general measures of richness and diversity, were analysed for all communities. Each of the communities described varied considerably in the diversity attributes measured. Communities with a high number of shrubs had greater constancy between sites compared to those that contained a high number of closed forest species. The community from rock outcrops had the largest average geographical range size.
Tropical lowland plant communities in north-eastern Queensland remain under pressure from continuing clearing, fragmentation, exotic species invasion, inappropriate fire regimes, and altered hydrological patterns. Comparatively little scientific research has been conducted on the highly diverse and ecologically significant range of remnant vegetation types. Additionally, most plant communities remain very poorly represented in the existing conservation reserve system. Melaleuca viridiflora Sol. ex Gaertn. open woodlands were selected for investigation based on their relatively simple structure, compared to other lowland communities, and the large extent to which they have been affected by past clearing patterns. A detailed analysis of community structure and composition was conducted at 24 sites throughout the wet-tropics coastal region between Townsville and Cooktown. Surprisingly, a high diversity of structural and floristic types was recorded, with a total of 127 species documented across the 24 sites. Classification analyses of species composition data produced seven or eight main groups of sites (dependent on the statistical technique used), essentially related to a gradient of latitude and rainfall. These floristic groups were not well explained by either species richness, past fire frequencies or soil types. Structural classification analyses based upon DBH data identified six or seven main groups, the singularly most striking of which were sites with annual fire histories. Ordinations based on both the DBH and species composition data produced groupings that supported those detected by the classification techniques. On closer examination of sites with similar fire histories, soil moisture and soil type were both found to have significant effects on community structure and composition. Many of the woodland types recorded are not adequately included (some not at all) in the existing conservation reserve system.
A study was conducted on the Liverpool Plains (30o 43’–31o 44’S; 149o 40’–150o 41’E), North Western Slopes of NSW, to determine the original boundaries of the naturally-treeless grasslands, to determine reasons for the lack of woody vegetation on these areas, and to assess the status of Austrostipa aristiglumis (Plains Grass), a species that is today commonly dominant on the few remaining remnant grassland areas and is commonly assumed to characterise the original grassland community. The original tree line boundaries were reconstructed using NSW Lands Department survey portion plans and other historical records. The lack of woody vegetation was attributed primarily to a combination of fine-textured soil, climate and topography restricting the availability of water below the grass root zone, with waterlogging and deep soil cracking possibly playing minor roles. Published and anecdotal evidence and landholder experience indicate that the Austrostipa aristiglumis dominated remnants are probably a relatively recent anthropogenic feature, a consequence of post-settlement management practices. The pre-settlement grasslands appear to have been composed of a wide range of grasses, possibly dominated by species such as Themeda avenacea (Native Oatgrass) and Eulalia aurea (Silky Browntop), with a range of forbs occupying the interstitial spaces. Management implications are discussed.
Dry rainforests are those communities that have floristic and structural affinities to mesic rainforests and occur in parts of eastern and northern Australia where rainfall is comparatively low and often highly seasonal. The dry rainforests of the western slopes of New South Wales are poorly-understood compared to other dry rainforests in Australia, due to a lack of regional scale studies. This paper attempts to redress this by deriving a broad floristic and structural typology for this vegetation type. Phytogeographical analysis followed full floristic surveys conducted on 400 m2 plots located within dry rainforest across the western slopes of NSW. Cluster analysis and ordination of 208 plots identified six floristic groups. Unlike in some other regional studies of dry rainforest these groups were readily assigned to Webb structural types, based on leaf size classes, leaf retention classes and canopy height. Five community types were described using both floristic and structural data: 1) Ficus rubiginosa–Notelaea microcarpa notophyll vine thicket, 2) Ficus rubiginosa–Alectryon subcinereus–Notelaea microcarpa notophyll vine forest, 3) Elaeodendron australe–Notelaea microcarpa–Geijera parviflora notophyll vine thicket, 4) Notelaea microcarpa– Geijera parviflora–Ehretia membranifolia semi-evergreen vine thicket, and 5) Cadellia pentastylis low microphyll vine forest. Floristic groupings were consistent with those described by previous quantitative studies which examined smaller portions of this study area. There was also general agreement between the present analytical study and a previous intuitive classification of dry rainforest vegetation throughout the study area, but little concurrence with a continental scale floristic classification of rainforest.
Macrozamia johnsonii D. Jones & K. Hill is a locally endemic cycad (family Zamiaceae) with a restricted occurrence in north-eastern New South Wales and currently listed as Endangered. Based on recent field surveys, its mean population size is estimated as approximately 3.5 million mature plants, with the lower bound of the 95% confidence interval at 1.9 million mature plants. Thirty percent of the population occurs in a formal reserve. Macrozamia johnsonii occurs in grassy eucalypt forest, shrubby wet sclerophyll forest and in rainforest. It occurs most frequently on steeply sloping sites with high moisture index. There are no immediate significant threats to the species although timber harvesting is judged to be a potential longer term threat to part of the population. The conservation status of Macrozamia johnsonii is assessed using IUCN criteria and thresholds, using population size and extent data from this study and a plausible range of values based on available circumstantial evidence for parameters for which quantitative estimates are not available. Based on this assessment, we regard the conservation status of Macrozamia johnsonii to be in the category of Least Concern, and that its current listing as an Endangered species under the NSW Threatened Species Conservation Act (1995) needs to be revised.
Rare or threatened vascular plant species of Wollemi National Park, central eastern New South Wales
(2008)
Wollemi National Park (c. 32o 20’– 33o 30’S, 150o– 151oE), approximately 100 km north-west of Sydney, conserves over 500 000 ha of the Triassic sandstone environments of the Central Coast and Tablelands of New South Wales, and occupies approximately 25% of the Sydney Basin biogeographical region. 94 taxa of conservation significance have been recorded and Wollemi is recognised as an important reservoir of rare and uncommon plant taxa, conserving more than 20% of all listed threatened species for the Central Coast, Central Tablelands and Central Western Slopes botanical divisions. For a land area occupying only 0.05% of these divisions, Wollemi is of paramount importance in regional conservation. Surveys within Wollemi National Park over the last decade have recorded several new populations of significant vascular plant species, including some sizeable range extensions. This paper summarises the current status of all rare or threatened taxa, describes habitat and associated species for many of these and proposes IUCN (2001) codes for all, as well as suggesting revisions to current conservation risk codes for some species. For Wollemi National Park 37 species are currently listed as Endangered (15 species) or Vulnerable (22 species) under the New South Wales Threatened Species Conservation Act 1995. An additional 50 species are currently listed as nationally rare under the Briggs and Leigh (1996) classification, or have been suggested as such by various workers. Seven species are awaiting further taxonomic investigation, including Eucalyptus sp. ‘Howes Swamp Creek’ (Doherty 26), known from a single location within the park, and Pultenaea sp. (Olinda) from Dunns Swamp – both these species remain undescribed, but are listed as endangered species. After applying IUCN criteria to the 94 taxa, 2 are considered Critically Endangered; 11 are considered Endangered; 23 are considered Vulnerable; 3 are considered Near Threatened; 19 are considered Data Deficient; and 36 are considered of Least Concern. It is likely that additional highly restricted plant taxa await discovery in remote locations.
