Garden plants that invade native vegetation can be a threat to native ecosystems. The species composition of gardens near the bush in Hobart, Tasmania, Australia is shown to relate to environmental variation and the attitudes of gardeners to their recreation, to native plants and to the bush. Four types of gardens are discriminated: the species‐poor shrub garden; the local native garden; the woodland garden; and the gardenesque. A group of gardeners who valued functional gardens, and the hard work in creating a garden, largely produced gardenesque outcomes. A strongly conservationist group of gardeners had native, woodland or shrub gardens. A group of gardeners who valued romance and privacy largely had woodland gardens. A small group of gardeners who liked gardens to create themselves, and preferred to minimize the act of gardening, tended to the shrub garden outcome. Plant species that invade the bush are least frequent in the more manicured shrub and gardenesque styles of garden than in the more informal local native and woodland gardens, in a dissonance between expressed attitudes and outcomes. Most of the most invasive weeds in the bush are shown to be independent of their occurrence in adjacent gardens, suggesting that integrated control programs involving both all gardeners within dispersal range, and bush managers, are necessary. The existence of a small number of respondents who see benefits in environmental weeds in their gardens, suggests that such programs would be ineffective without regulation, a solution offered by no respondent. However, regulation might be ineffective without community understanding, the raising of which was the main solution suggested by the interviewed gardeners.

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Many small- and medium-sized mammals dig for their food. This activity potentially affects soil condition and fertility. Digging is well developed especially in Australian mammals, many of which have recently become rare or extinct. We measured the effects of digging by mammals on soil in a Tasmanian temperate dry sclerophyll forest with an intact mammal community. The density of diggings was 5812 ha−1, affecting 11% of the forest floor. Diggings were created at a rate of around 3113 diggings ha−1 yr−1, disturbing 6.5% of the forest floor and displacing 7.1 m3 ha−1 of soil annually. Most diggings were made by eastern bettongs (Bettongia gaimardi) and short-beaked echidnas (Tachyglossus aculeatus). Many (approx. 30%) fresh diggings consisted of re-excavations of old diggings. Novel diggings displaced 5 m3 ha yr−1 of soil. Diggings acted as traps for organic matter and sites for the formation of new soil, which had higher fertility and moisture content and lower hardness than undisturbed topsoil. These effects on soil fertility and structure were strongest in habitats with dry and poor soil. Creation of fine-scaled heterogeneity by mammals, and amelioration of dry and infertile soil, is a valuable ecosystem service that could be restored by reintroduction of digging mammals to habitats from which they have declined or gone extinct.

The Tasmanian Wilderness World Heritage Area (TWWHA) has globally significant natural and cultural values, some of which are dependent on the absence of fire or the presence of particular fire regimes. Planned burning is currently used to reduce the risk of loss of world heritage values from unplanned fires, but large and damaging fires still occur, with lightning as the primary ignition source. Lightning-caused fire was rare in the TWWHA before 2000. There has since been an increase in both the number of fires following lightning storms and the area burnt by these fires. In the absence of a direct measurement of lightning strike incidence, we tested whether changes in rainfall, soil dryness and fuel load were responsible for these changes in fire incidence and extent. There were no relationships between these variables and the incidence of fires associated with lightning, but the variability in the Soil Dryness Index and the mean of 25% of driest values did predict both the number and area of fires. Thus, it appears that an increase in the proportion of lightning strikes that occur in dry conditions has increased ignition efficiency. These changes have important implications for the management of the TWWHA’s values, as higher projected fuel loads and drier climates could result in a further increase in the number of fires associated with lightning.

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Pollen analysis of a core taken from a reed marsh in northeastern Tasmania near Bass Strait highlights the interplay between climatic changes, sea level rises and the effects of Aborigines during the Holocene. Prior to 10,000 BP the region formed part of the Bassian landbridge which connected Tasmania to the Australian mainland. Vegetation at that time was characterized by shrubby grasslands with a very sparse tree cover. After 9000 BP, Eucalyptus forests prospered until about 6000 BP. A combination of salt spray from a stabilizing mid-Holocene