Genetic diversity in the endangered Phebalium daviesii (Rutaceae) compared to that in two widespread congeners

Genetic diversity in the rare and endangered Phebalium daviesii was compared to that in P. squamulosum subsp. squamulosum and P. glandulosum subsp. glandulosum using allozyme analysis. Phebalium daviesii was once presumed extinct, but 43 adult plants have so far been rediscovered. Phebalium squamulosum subsp. squamulosum and P. glandulosum subsp. glandulosum are widespread in the south-eastern part of the Australian mainland. Morphologically, these two taxa are the closest relatives of P. daviesii and share a similarity with P. daviesii in their ecological habitat. The level of genetic diversity and deviations from Hardy-Weinberg equiibrium were investigated using allozyme data with 18 enzyme systems. Nei's total genetic diversity, the proportion of polymorphic loci and the average number of alleles per locus were all slightly lower in P. daviesii than in P. squamulosum subsp. squamulosum and P. glandulosum subsp. glandulosum. Deviations from expected Hardy-Weinberg equilibrium were present in all three taxa and were more frequent in P. glandulosum subsp. glandulosum. This suggests that inbreeding may be occurring in all three Phebalium taxa and that P. daviesii does not suffer from increased inbreeding due to rarity. Phebalium daviesii has a high level of genetic diversity (Ht = 0.30) for such a rare species and should be able to recover from its population bottleneck with appropriate management

Pattern and process in alpine vegetation and landforms at hill one, southern range, Tasmania

Hill One is a wind-exposed, alpine environment in southern Tasmania. The prevailing wind-stream is westerly. However, high intensity south-westerly winds associated with frost events appear to control the patterning of fjaeldmark. These winds cause necrosis of prostrate Richea scoparia and cushion plants on their south-western side and induce migration of individual plants in a north-easterly direction. Fjaeldmark is confined to the exposed mountain summit and terrace and step treads. Mosaic cushion heath occurs in more exposed and poorly drained areas than other heath communities. The horizontally bedded sediments of Hill One have been worked by erosional and depositional agents into a complex morphology. Large terraces and non-sorted steps are likely to have formed from altiplanation processes, that is, differential erosion of interbedded sediments, with accumulation of erosional debris at the foot of the risers. Depositional lobes and erosional washout features are actively forming in localised areas of concentrated drainage. The distribution of plant communities is closely associated with rockiness, wind exposure and drainage

The ecology, phytosociology and stand structure of an ancient endemic plant Lomatia tasmanica (Proteaceae) approaching extinction

Lomatia tasmanica W.M.Curtis is a nationally endangered shrub of the family Proteaceae. It is entirely restricted to one population extending over 1.2 km in southwestern Tasmania. The species occupies a variety of riparian vegetation types ranging from sclerophyll scrub to implicate rainforest. The population is dominated by ramets originating after fire in 1934, although the species regenerates in a continuous manner by root suckering. The ramets or stems may reach ages >300 years. The entire population may be composed of one genet and fruit production has never been observed. The extreme rarity of the species, its inability to reproduce sexually and its lack of genetic diversity suggest that L. tasmanica is heading inevitably towards extinction. One population appears to have disappeared since 1934. Threats such as too frequent firing and the root-rot fungus Phytophthora cinnamomi increase the likelihood of extinction of L. tasmanica in the short term to a very high level

Changes in alpine vegetation related to geomorphological processes and climatic change on Hill One, Southern Range, Tasmania, 1989-2000

Photographs of 84 plots in alpine vegetation, largely consisting of fjaeldmark and bolster heath, on Hill One, Southern Range, Tasmania, were taken in both 1989 and 2000 to compare cover characteristics. Between these two observations, vegetation cover declined in the fjaeldmark, largely as a result of erosion. Declines also occurred on the active depositional lobes, through burial of bolster heath. Within the parts of Hill One where vegetation cover was not lost, graminoids decreased and Pterygopappus lawrencei increased in the bolster heath and tall shrubs displaced bolster heath. Thirty-six per cent of the rocks visible in the 1989 photographs had moved by 2000, the mean area of the individual rocks that moved being 95 cm2. Larger rocks were moved on the exposed western slope than on the leeward eastern slope. Analyses of climatic data from nearby stations for 1979 - 2000 indicated a decline in both precipitation and temperatures and an increase in the frequency of the highest wind speeds, all of which are consistent with the nature of vegetation and geomorphological changes that occurred on the mountain, although a climatic cause is far from proven. Localised cooling and drying, in the two hottest and wettest decades recorded for the globe, emphasises the importance of local data in determining the possible impacts of climatic change on biota

The Tasmanian endemic shrub Acacia axillaris: Conservation ecology applied to the question of rarity or vulnerability

Acacia axillaris Benth. had been recommended for downgrading from a conservation status of vulnerable to one of rare in response to changed knowledge of its distribution. Ecological investigations of its phytosociology, stand structure, germination requirements, soil seed store and response to fire and disturbance indicate, however, that it is susceptible to elimination by fire regimes that allow the survival of most of its co-occurring species and most other Australian species of Acacia. The species is also vulnerable to land clearance and weed competition in the lowland part of its range, which is largely on private land.A. axillaris may be a refugial species, better suited to glacial Tasmania than to interglacial Tasmania. On ecological evidence, the species should retain its conservation status of vulnerable to extinction

Incorporating Indigenous values with 'Western' conservation values in sustainable biodiversity management

Biodiversity management in Australia is underlain by legislative mechanisms such as the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) and policies such as the national Strategy for the Conservation of Australia's Biological Diversity and the international Convention on Biological Diversity. \ud While these policy directives encompass a range of values and components of 'biodiversity', on-ground planning and development assessments often focus only on threatened species and ecosystems as defined in state and national legislation.In regions such as northern Cape York Peninsula, which is managed by the resident Aboriginal and Torres Strait Islander communities as Deed of Grant in Trust (DOGIT), planning for biodiversity management needs to acknowledge the high cultural values of such areas and to encompass Indigenous values and perspectives. \ud A recent study assessed the significant species and habitats of the greater Lockerbie Scrub – the northernmost extent of rainforest in Australia and a region with high species and ecosystem diversity. While it is acknowledged that research into the cultural values of the plant species is preliminary, the minimal overlap between lists of flora from Western (i.e. under legislative mechanisms) and Traditional Owner perspectives suggests that cultural differences in values and perceptions may result in differing conservation management priorities. \ud A more holistic, integrative approach to local and national biodiversity management planning could accommodate multiple perspectives and enable greater environmental and socio-cultural sustainability

Genetic evidence that Lomatia tasmanica (Proteaceae) is an ancient clone

Lomatia tasmanica W.M.Curtis is an endangered species with only one population. The population occurs over a distance of 1.2 km and consists of several hundred stems. Although it flowers occasionally, fruit production has never been observed, and it propagates vegetatively. The genetic diversity in L. tasmanica, and its relationship with the other species of this genus in Tasmania was investigated using allozyme analysis and chromosome counts. Sixteen isozyme loci were scored on 78 L. tasmanica plants collected from throughout the range of the species. No genetic diversity was found in L. tasmanica. Lomatia tinctoria possessed 22 (2n = 22) chromosomes, like other Lomatia species previously counted, while L. tasmanica had 33 to 29 chromosomes, which makes it an unstable triploid. The triploid nature of L. tasmanica would explain its lack of genetic diversity and its apparent sterility. This suggests that the entire species may be one genet, one of the largest plant clone ever found. Fossilised leaves identified as L. tasmanica by Jordan et al. (1991) and dated as at least 43 600 years old may indicate the minimum age of this genet. This clone maybe one the world’s oldest known living plant individual.