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Disturbance ecology of Tasmanian highland grassland — an overview and implications for conservation management
Full text linkActive manipulation of disturbances such as fire and grazing is often necessary to maintain or enhance biodiversity values in grasslands. However in many instances information is lacking on the disturbance regimes most likely to achieve conservation aims. This paper provides an overview of the effects of fire and grazing in Tasmanian highland grasslands, and the implications of these for conservation management of this vegetation. In Tasmania, highland grassland is defined as occurring above 600 m above sea level. The vegetation is typically dominated by species of Poa. Highland grassland is grazed by a suite of native herbivores and has a history of stock grazing, which continues at some sites of high biodiversity value. There is evidence that Indigenous Tasmanians regularly burnt highland grasslands and that Indigenous burning was instrumental in maintaining grassland at sites that otherwise would be forest. For highland grasslands below 1000 m asl, a reduction in the biomass of dominant grasses through disturbance is necessary in order to maintain plant species diversity. The use of periodic fire, together with native grazing, is likely to be beneficial in this regard. The combination of fire and grazing is also likely to prevent woody plant invasion and maintain vegetation structural heterogeneity. The near ubiquity of native grazing species means there is no ecological imperative for stock grazing. Low productivity of grasslands occurring above 1000 m means that competitive exclusion of interstitial species by grasses is unlikely and therefore active application of disturbance as a management tool will rarely, if ever be necessary. Disturbance management should be accompanied by a well-designed monitoring program and regular review of the management strateg
An irreplaceability map for Tasmanian priority plant species
Full text linkThere is a strong need to map the relative importance of areas for nature conservation both inside and outside reserves, given increasing development pressures and ongoing threats to biodiversity. Nature conservation importance has typically been established using iterative or optimising systems which select areas to achieve explicit targets. Irreplaceability has been a concept used in many of these analyses. We
calculated rarity-weighted richness values (irreplaceability scores) from reliable distributional data for all vascular plant species of conservation importance in one square kilometre grid cells covering the State of Tasmania, Australia. The spatial patterns of scores on the irreplaceability index were not strongly related to data collection intensity. Thus, our scores were reliable for most parts of the State, irrespective of survey effort, except where there were no or little survey data. Irreplaceability scores were high in places with concentrations of local endemics, on mountains with persistent snow cover, along the northern part of the coast and on the Bass Strait islands
Decadal-scale vegetation dynamics above the alpine treeline, Mount Rufus, Tasmania.
Full text linkAlpine areas by definition have summer temperatures too cool to support trees. Concerns have been raised that trees may invade these distinctive habitats where global climate change results in an increase in summer temperatures beyond the threshold limiting tree growth. In 2016, we investigated changes in the treeline and vegetation immediately above it by resampling quadrats and rephotographing from the set points established in the Alpine Treeline Ecotone Monitoring Program on Mount Rufus, Tasmania, in 2006. Within the study area, the only species with the potential to reach a tree height > 3 m is Eucalyptus coccifera Hook.f. The height, density, basal diameter and diameter at breast height were recorded for all E. coccifera within the study area, together with an estimate of percentage cover of each vascular plant species. No change was found in the location of the treeline over the 10-year period, although E. coccifera height and density above the treeline did increase. The vegetation on the north-facing slope shifted to a composition more closely related to the forest below the treeline, while on the south-facing slope forest species reduced in abundance and the vegetation became more dominated by alpine species. Historical aerial photographs suggest that there has been a minor and inconsistent establishment of E. coccifera plants at higher altitudes since 1953. The area was burned by bushfire in 1965, making it difficult to separate the effects of putative climate change and recovery after the fire event on vegetation changes, although data from Lake St Clair suggest a local constancy of mean growing season temperatures and rainfall
A new species of Oniscigastrid mayfly from Tasmania, Tasmanophlebia lotis, with comments on the Australian Oniscigastrid species.
Full text linkImagoes, sub-imagoes and nymphs of a new species of Tasmanian mayfly (Tasmanophlebia lotis sp.nov.) are described based on morphological, ecological and genetic differences between it, the only other known Tasmanian species in the genus (T. lacustris) and congeneric species on the Australian mainland. Tasmanophlebia lotis is widely distributed in rivers at low elevations across the island, in contrast to T. lacustris, which is found in high-altitude lentic habitats. The separation of mainland Australian and Tasmanian species of Tasmanophlebia is consistent with similar observations based on genetic analysis of other Australian mayflies, and suggests differentiation well prior to the flooding of Bass Strait during Holocene deglaciation
Settlement and Swift Parrots — historic and ongoing habitat loss for a critically endangered species (1788–2016)
Full text linkThe Swift Parrot, Lathamus discolor White, 1790, was among the first of Australia’s birds to be scientifically described and illustrated following European settlement in 1788. Within 60 years of settlement, key habitat throughout the species’ range was being lost. A unique compilation of historical and recent information on Swift Parrot habitat loss demonstrates how past events have rendered this species Critically Endangered. A crucial aspect of the loss of habitat is the speed and spatial extent over which it occurred. The most extensive loss happened during colonial times however, losses continue to this day due to various government land management policies and practices. Consequently, the Swift Parrot remains the subject of an ongoing national recovery program and its future is far from secure
Hans Hermann Behr (1818–1904): botanist, entomologist, anthropologist, humorist and dangerous?
Full text linkHans Hermann Behr arrived in Adelaide in late 1844 as a newly-graduated doctor interested more in botany, entomology and anthropology. After just one year, he returned to Germany with prolific samples and notes. He returned to Adelaide towards the end of 1848, again exploring and collecting extensively. Within a year he left for the Philippines and after another year had arrived in San Francisco where he firmly established his international reputation
Gustav Thureau, first Tasmanian Inspector of Mines and Government Mining Geologist.
Full text linkFrom humble origins as a rebellious student in Clausthal, Germany, Gustav Thureau became the first Tasmanian Inspector of Mines and Government Mining Geologist. He brought to these offices his experience in Germany, South Australia, Victoria and, briefly, America as a miner, mine manager, lecturer, mining inspector, mining reporter and mining consultant. His 50-year career in mining is interspersed with a number of controversies
Contributions to a catalogue of alien plants in Tasmania IV.
Full text linkThe status of four alien plant taxa in Tasmania is discussed. Mirabilis jalapa L., Phytolacca octandra L., Coleonema pulchellum I.William and Gomphocarpus fruticosus (L.) W.T.Aiton are ornamentals that are now recognised as naturalised in Tasmania. A description for each taxon is provided and distribution and habitat details are discussed. The status of two species that are recorded as naturalised in Tasmania but are not represented in the Tasmanian Herbarium collection was also investigated. Veronica peregrina L. is known from two collections from Tasmania whilst the name Silene longicaulis Pourr. ex. Lag. was found to be misapplied to Tasmanian specimens of Silene colorata Poir
Mt John Observatory: the first 50 years
Full text linkMt John Observatory at Lake Tekapo is New Zealand’s only professional research observatory. It was founded in 1965 as a joint institution of the universities of Pennsylvania and Canterbury, though the American participation disappeared after 1980. Some of the successes of the past 50 years and also the numerous problems that arose are described here. Four telescopes have been established at Mt John, including the 1.8-m MOA telescope in 2004, dedicated to microlensing. Astro-tourism has flourished in the past decade
Global Perspectives, Local Knowledge : address at the conference dinner
Full text linkThe 2015 biennial conference of the Australian and New Zealand Associations of Alexander von Humboldt Fellows offers an important opportunity for current and former Alexander von Humboldt Fellows, across both the Humanities and Sciences, to meet, to present and exchange ideas, and to learn more about the current and future activities of the Foundation. The German Embassy is pleased to be able to support this Humboldt conference, and to encourage continued and productive German-Australian and German-New Zealand research collaborations