Cunninghamia : A Journal of Plant Ecology for Eastern Australia, Volume 18 (2018)
Refine
Year of publication
- 2018 (8)
Document Type
- Article (8)
Language
- English (8)
Has Fulltext
- yes (8)
Is part of the Bibliography
- no (8)
Keywords
- Acacia pendula (1)
- Endocarp (1)
- Eucalyptus camphora (1)
- Greater Blue Mountains World Heritage Area (1)
- Hunter Valley (1)
- Lorien Wildlife Refuge (1)
- Myrtaceae (1)
- National Heritage (1)
- Petalura gigantea (1)
- Phoenix canariensis (1)
The current status of exotic freshwater vascular plants in Australia - a systematic description
(2018)
Freshwater systems are considered particularly vulnerable to human impact, through habitat modification, changes to water regimes and quality, invasion by exotic species and climate change. Using various records, we conducted a descriptive analysis of the naturalised freshwater plant species in Australia. There are 63 freshwater plant species belonging to 45 genera and 26 families naturalised in Australia with the dominant families being Cyperaceae, Poaceae and Plantaginaceae. More than 40% of these species are categorised as either invasive or declared weeds, the majority being perennial wetland marginal plants. They originated from all the inhabited continents with most of the species being native to Europe, South America and North America. The greatest number of species are currently found in New South Wales (90%), Queensland (68%) and Victoria (65%); the ornamental aquarium plant trade was identified as the main introduction pathway. Most species are clonal plants with flexible modes of reproduction and multiple dispersal vectors. We conclude that exotic plant species are now an important component of Australia’s freshwater systems and that ongoing monitoring of their status, distribution and impact should be a high priority in light of the increasing influence of anthropogenic factors including climate change.
The threatened Australian endemic rainforest tree Rhodomyrtus psidioides (Myrtaceae) is visited and pollinated by a taxonomically diverse assemblage of mainly small, ecologically unspecialised, insects. Flower structure suggests that it may also be adapted for wind-pollination. However, the recent (2010) invasion by the aggressive fungal pathogen Myrtle rust (Austropuccinia psidii) has resulted in the local extinction of both the floral resource and associated plant-insect relationships. Here I table observed insect visitors to the flowers of Rhodomyrtus psidioides made before the impact of Myrtle rust - no other records appear to have been published.
Washingtonia robusta (Mexican Fan palm) is endemic to the semi-arid zone of California and northern Mexico. Dispersed globally by the horticultural trade, the species has demonstrated its ability to successfully invade disturbed areas and urban landscapes in warm temperate climates. Once established, the plant is extremely hardy. This paper presents the first documented instance of the successful establishment and growth of Washingtonia robusta in a pond in continually flooded wetlands at Albury, the first record of it naturalising in New South Wales.
The Greater Blue Mountains World Heritage Area (GBMWHA), a natural area of about one million hectares immediately west of Sydney, Australia, is significant for its biodiversity, and particularly for its richness of eucalypt species (species of Eucalyptus, Angophora and Corymbia in the family Myrtaceae), numbered at 96 species in 2010. This paper describes the finding of a previously unlisted Angophora species in the GBMWHA, and makes a conservation assessment of the population. A population of the Broad-leaved Apple Angophora subvelutina F. Muell. occurs at Euroka Clearing south of Glenbrook just within the eastern edge of Blue Mountains National Park, one of the eight conservation reserves that make up the GBMWHA. The population numbers over 200 plants and there is evidence that the species has been present at the site since before European settlement. The population includes a mixture of age classes and is considered viable, although substantial intergradation is occurring with the closely related species Angophora floribunda. Elsewhere in the Sydney area, the species is relatively uncommon and has been extensively cleared from its relatively fertile habitats. The population in the GBMWHA noted here has conservation significance for its size and long history at the site, and for the unusual ecological conditions of the Euroka diatreme, which is an atypical habitat for the species.
Persoonia (family Proteaceae) is a diverse genus of 99 species, mainly of woody shrubs and small trees, that are endemic to Australia. The fleshy fruits that characterise these plants are an important resource in otherwise resource-depauperate ecological communities. However, this genus is highly under-represented in restoration and conservation programs, as its species are notoriously difficult to propagate and transplant in the wild. Understanding the mechanisms that control seed production, viability, dormancy and germination will hasten progress on Persoonia propagation. Here we review Persoonia studies to reveal the nature of, and variability within, the genus. We identify key factors that need to be addressed; specifically, those affecting fruit set, endocarp degradation and subsequent propagation of Persoonia. This synthesis of current knowledge provides important material to inform management of this taxon in the landscape, and outlines several important priorities for future seed biology research on the genus. We outline several important priorities for future seed biology research on the genus.
Mires or peat swamps have a restricted distribution in Australia and are limited to areas where hydrological inputs exceed evapotranspiration. In NSW, mires are restricted to the coast, adjacent ranges or tablelands, and along the Great Dividing Range; most are listed as threatened ecological communities under State or Commonwealth legislation. Due primarily to the relatively high rainfall and suitable geology, the Blue Mountains region includes a number of such threatened mire ecological communities. Most of these mire types are largely included within the Greater Blue Mountains World Heritage Area, although there are notable exceptions, such as the endangered Newnes Plateau Shrub Swamps.
This paper reports on a little-known group of diverse, relatively isolated and largely unprotected mires, in a relatively low rainfall area in the upper Cudgegong River catchment, east of Rylstone in the NSW Central Tablelands, and of their floristic, hydrogeomorphic and typological relationship with other mires of the Blue Mountains. They can be broadly divided into montane bogs, montane fens and hanging swamps. Particular attention is focussed on the largest and most diverse one, Rollen Creek swamp, which contains all three types. It is hoped that highlighting this hitherto unrecognised group of high conservation-value mires will contribute to their improved conservation and encourage further research into mires of eastern NSW.
A rare flowering event in a stand of Acacia pendula (Weeping Myall) (family Fabaceae, Mimosoideae) from the Hunter Valley of New South Wales is documented. This species flowers poorly in the region and (with the exception of horticultural specimens) has not been observed to fruit and develop viable seed for over a decade. One stand of this threatened Hunter Valley population of Acacia pendula was monitored over a seven month period (January to July 2018) to investigate this poor reproductive output. Despite copious bud production in January and February, the extent and condition of these, and all subsequent flowers rapidly declined, and none progressed to fruit.
Primary reasons for reproductive failure were postulated to be a combination of mass desiccation of capitula following extended dry conditions, infestation by native flower- and phyllode-galling midges and thrips (Asphondylia sp., Dasineura glomerata, Kladothrips rugosus), fungal galls (Uromycladium sp.), caterpillars (Ochrogaster lunifer), and mistletoe (Amyema quandang). Collectively, these stressors appear to be eliminating seed production from the study
population; survival is maintained only by the copious root-suckering observed around most plants, particularly after the pressure from stock grazing (cattle, sheep) has been removed. The age of trees studied, based on measures of girth and comparison with growth rates reported for other semi-arid Acacia, was inferred to be between 50 and 150 years. The level of Amyema quandang (mistletoe) infestation on Acacia trees was independent of tree size, and there was no evidence to suggest that mistletoe density alone influenced flowering progress.
Consequences of these observations on future management of Acacia pendula in the Hunter Valley are briefly discussed.
Classifying and mapping landscapes are tools to simplify complex systems into the discreet subsets widely used in landscape management. In 1999, the Queensland Government adopted a Regional Ecosystems approach as a state-wide landscape classification scheme. For the Cape York Peninsula bioregion in north-eastern Australia, Regional Ecosystems (RE) were initially recognised based on a pre-existing vegetation map and classification for the bioregion. The classification had been developed using expert-techniques based on extensive field plot data. Here, we use numerical analyses to classify the field plot data and identify savanna plant communities associated with two widespread landform groups in the bioregion (the old loamy and sandy plains (land zone 5) and the hills and lowlands on igneous rocks (land zone 12). Communities were identified at the plant association level, using species importance values calculated from foliage cover and vegetation height at each plot. We developed a descriptive-framework for each community using statistically based characterising species and biophysical attributes. We recognise 57 communities compared with 110 that had been previously identified using expert-techniques. This classification is used to recommend refined Regional Ecosystems under the government’s regulations. The descriptive-framework supported consistent descriptions of communities and assignment of new sites to the classification. We conclude that incorporating quantitative methods in classifying and describing plant communities will improve the robustness and defensibility of Regional Ecosystems and their use in landscape management across Queensland.
