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Urban trees provide social, economic, environmental and ecosystem services benefits that improve the liveability of cities and contribute to individual and community wellbeing. There is thus a need for effective mapping, monitoring and maintenance of urban trees. Remote sensing technologies can effectively map and monitor urban tree coverage and changes over time as an efficient and low-cost alternative to field-based measurements, which are time consuming and costly. Automatic extraction of urban land cover features with high accuracy is a challenging task, and it demands object based artificial intelligence workflows for efficiency and thematic accuracy. The aim of this research is to effectively map urban tree cover changes and model the relationship of such changes with socioeconomic variables. The object-based convolutional neural network (CNN) method is illustrated by mapping urban tree cover changes between 2005 and 2015/16 using satellite, Google Earth imageries and Light Detection and Ranging (LiDAR) datasets. The training sample for CNN model was generated by Object Based Image Analysis (OBIA) using thresholds in a Canopy Height Model (CHM) and the Normalised Difference Vegetation Index (NDVI). The tree heatmap produced from the CNN model was further refined using OBIA. Tree cover loss, gain and persistence was extracted, and multiple regression analysis was applied to model the relationship with socioeconomic variables. The overall accuracy and kappa coefficient of tree cover extraction was 96% and 0.77 for 2005 images and 98% and 0.93 for 2015/16 images, indicating that the object-based CNN technique can be effectively implemented for urban tree coverage mapping and monitoring. There was a decline in tree coverage in all suburbs. Mean parcel size and median household income were significantly related to tree cover loss (R2 = 58.5%). Tree cover gain and persistence had positive relationship with tertiary education, parcel size and ownership change (gain

Unplanned fire is a major control on the nature of terrestrial ecosystems and causes substantial losses of life and property. Given the substantial influence of climatic conditions on fire incidence, climate change is expected to substantially change fire regimes in many parts of the world. We wished to determine whether it was possible to develop a deep neural network process for accurately estimating continental fire incidence from publicly available climate data. We show that deep recurrent Elman neural network was the best performed out of ten artificial neural networks (ANN) based cognitive imaging systems for determining the relationship between fire incidence and climate. In a decennium data experiment using this ANN we show that it is possible to develop highly accurate estimations of fire incidence from monthly climatic data surfaces. Our estimations for the continent of Australia had over 90% global accuracy and a very low level of false negatives. The technique is thus appropriate for use in estimating the spatial consequences of climate scenarios on the monthly incidence of wildfire at the landscape scale.

While wool growing is an important component of the economy, few wool growers make a good return on capital from wool alone, relying more, where they can, on opium poppies, potatoes, prime lambs, wood chips, tourists and cattle. Potential investments in the productivity of the runs equal the somewhat risky potential returns. The runs are regarded as economically valuable for fodder, particularly for sheep producing premium fine micron wool, and shelter. They are managed in a wide variety of ways, partly reflecting the nature of properties, and partly as a matter of choice between alternative systems, based on perceptions of risks and returns. Rotational grazing and set stocking systems have different challenges and benefits, as do burning and not burning. There are different ways and degrees of controlling wild herbivores and weeds. There is no one right solution.

Most remnants of lowland grassland and grassy woodland in Tasmania are grazed by sheep. In some instances, grazed remnants have high conservation value, indicating that grazing and biodiversity conservation are not necessarily conflicting management goals. However, few data exist on the management practices most conducive to maintaining conservation values. The present study examined native grassland and grassy woodland subject to seven different sheep-grazing regimes in the Northern Midlands bioregion of Tasmania and sought to identify the effects of management and environmental factors on vegetation structure and composition. Structural and compositional differences between grassland and woodland, and herbivore scat counts, suggested that grazing disturbance was more intense in grassland than in woodland. Floristic differences within the vegetation appeared to be related to differences in grazing regime. Occurrence of species not commonly observed in grassy vegetation was associated with the resting of pastures in spring, while more intensely grazed sites contained assemblages of species typical of disturbed areas. Exotic invasion was greatest at sites that were not rested and/or had higher stocking rates, and at more eroded sites. Thus, resting and/or low stocking rates were associated with good condition in the grassland and grassy woodland. The nature of differences in vegetation attributes between woodland and grassland suggests that grazer habitat preference increases the differences between these vegetation types. Relatively minor variation in grazing regime was found to have resulted in distinct floristic outcomes, suggesting that the maintenance of a range of management regimes may be conducive to the maintenance of plant species diversity at a landscape scale.

Some species and genera of tall herbs that are widespread both in Tasmanian and in mainland Australian alpine vegetation are dominant or codominant over large areas in the Australian Alps, while being typically subordinate species in Tasmania. This difference has been attributed to the impact of vertebrate herbivores, which are abundant in the Tasmanian high country but rare in or absent from the higher altitudes in the Australian Alps. The present study tests the hypothesis that lack of dominance (>50% cover) of tall alpine herbs in Tasmanian alpine and subalpine areas could be at least partially caused by grazing of their reproductive parts. Both in experimental plots and a clipping experiment, tall herbs produced more flowering stems under lower grazing/clipping pressure. In the field, the greatest reduction in flowering occurred under a grazing regime of sheep plus rabbits plus native herbivores. There was no consistent difference in the number of flowering stems between rabbit-grazed and rabbit plus native-grazed areas. However, there was a significant negative relationship between the number of flower heads and wallaby scats and a non-significant positive relationship between the number of flower heads and rabbit scats, suggesting that wallabies, not rabbits, were largely responsible for flower head depletion. Many species had more flowering stems in rabbit plus native vertebrate-grazed areas than in ungrazed exclosures. Therefore, it seems possible that the effects of vertebrate herbivory on flowering may have contributed to the lack of tall alpine herbfields in Tasmania.

An important conservation question for grazed areas of lowland subhumid Tasmania is ‘what effects do different, practical disturbance regimes have on native vegetation?’ An experiment designed to determine the single and interactive effects of fire and sheep grazing was established at four sites with distinct vegetation types. There were significant interactive effects of fire and sheep grazing on vegetation attributes at all sites. An analysis of published and new data indicated that there were several vascular plant species that appeared dependent on sheep grazing for their persistence in the present landscape, while there were others that were intolerant of this disturbance but required other types of disturbance, such as mowing. However, most native species appeared to survive in a wide variety of disturbance regimes short of ploughing and fertilization. The implications of these results are that a variety of disturbance regimes is necessary to maintain biological diversity in this environment, and that the naturalness of the regime is not necessarily relevant to its use for conservation.

An examination of the relative breakdown rates of unused toilet paper, facial tissues and tampons was undertaken in nine different environments typical of Tasmanian natural areas. Bags of the paper products (toilet paper, facial tissues, tampons) were buried for periods of 6, 12 and 24 months at depths of 5 and 15 cm. A nutrient solution simulating human body wastes was added to half of the samples, to test the hypothesis that the addition of nutrients would enhance the breakdown of paper products buried in the soil. Mean annual rainfall was the most important measured variable determining mean breakdown in the nutrient addition treatment between sites, with high rainfall sites (mean annual rainfall of greater than 650 mm) recording less decayed products than the drier sites (mean annual rainfall of 500–650 mm). Temperature and soil organic content were important influences on the breakdown of the unfertilised products. Toilet paper and tissues decayed more readily than tampons. Nutrient addition enhanced decay for all products across all sites. Depth of burial was not important in determining the degree to which products decayed. In alpine environments, burial under rocks at the surface did not increase the speed of decay of any product. The Western Alpine site, typical of alpine sites in the Tasmanian Wilderness World Heritage Area, showed very little decay over the two-year period, even for nutrient enhanced products. Management prescriptions should be amended to dissuade people from depositing human toilet waste in the extreme (montane to alpine) environments in western Tasmania. Tampons should continue to be carried out as currently prescribed.

In many natural areas, changes in fire regimes since European settlement have resulted in adverse impacts on elements of biological diversity that survived millennia of land management by Indigenous people. Some of the rainforest and alpine elements that depend on south-west Tasmania's World Heritage Area have been in decline since European settlement of Tasmania due to an increase in the incidence of landscape-scale fires in the period 1850–1940. Some of the buttongrass moorland elements that also depend on the region are in decline or impending decline because of a decreased incidence and/or size of burns since 1940. Will an Indigenous-style fire regime serve the interests of biological diversity? We examine this question in the context of the fire ecology and fire history of south-west Tasmania. From this assessment we argue that a return to Indigenous- style burning, modified to address contemporary issues such as the prevention of unplanned ignition, suppression of wildfires and burning to favour rare and threatened species may help to reverse trends towards ecosystem degradation in this region.

The progress of biodiversity conservation is a function of the historic development of reserve systems, studies of which provide data on reservation gaps and direction for more systematic conservation planning. We used mapped plant communities as a surrogate for the globally significant biodiversity of Tasmania in an analysis of reservation status in relation to a range of conservation targets for 1937, 1970, and 1992. Before the 1970s the representation of plant communities in the Tasmanian National Park system was strongly biased toward the reservation of communities that are not economically valuable, typically those occurring in scenic alpine and subalpine areas. In 1970 <3% of economically valuable communities were reserved above 15% of their pre-European area, compared with over 17% of communities without economic value. These statistics support the "worthless lands" hypothesis. Between 1970 and 1992 there was a dramatic rise in the representation of communities in the reserve system in response to a change in motivations for reserve establishment and the availability of gap analyses for many plant communities and species. This increase included large increases in the reservation of both economically valuable and noneconomically valuable plant communities. In 1992, one-third of the plant communities in Tasmania had 15% of their pre-European area represented in the reserve system, with over 20% of economically valuable communities and 58% of noneconomically valuable communities having over 15% of their pre-European area reserved. Although gaps in the reservation of forest communities have been partially filled since 1992, some treeless lowland communities are still highly depleted and unreserved. The reserve system in Tasmania, however, is closer to a representative system of biodiversity than in most other countries.

Athrotaxis cupressoides forms stands of varying size class and age class structure in the high subalpine and alpine environments of Tasmania. As with some other southern hemisphere gymnosperms with great longevity, A. cupressoides does not successfully regenerate in dense forest stands without disturb- ance but does so in many open stands. Vegetative regeneration through root suckers occurs in many such stands. Suckers are most frequent in bogs and least evident in blockstreams. There has been little successful seedling or sucker regeneration in open stands in the east of the range of the species since European occupation of the Central Plateau. Exclosure experiments and field observations show that seedlings, suckers and adult foliage are heavily grazed by introduced placental and native marsupial mammals.

Athrotaxis selaginoides and A. cupressoides are potentially interbreeding species with partly overlapping ranges. The two Athrotaxis species occur in a wide range of floristic types, with A. selaginoides being concentrated in thamnic and implicate rainforest communities and A. cupressoides in open montane communities. As is consonant with its distribution pattern and the cold resistance of its adult foliage, A. cupressoides seedlings are more frost resistant than those of A. selaginoides. Preliminary experiments showed no difference between the two species in resistance to waterlogging or drought. However, stand structure data indicate that A. selaginoides can survive better in shaded conditions than its congenor. This pattern of ecological differentation is consistent with an origin by parapatic speciation.

Two species of endangered Brassicaceae, Barbarea australis and Lepidium hyssopifolium, occur in a few small populations in Tasmania. The former species is associated with streams where it occurs in vegetation with numerous exotics. The latter species is usually found in the root zone of exotic large trees, usually on roadsides, and often in the absence of many other native species. Populations of both species have disappeared since European settlement, some in the last two decades. Both species are rapid and prolific producers of easily germinated seed. Both species are absent from places grazed moderately or intensively by sheep or cattle. The establishment of new individuals of Lepidium occurs only on relatively bare ground. The species is tolerant of root competition and intolerant of above ground competition. It will also establish from soil-stored seed after mechanical disturbance. Its future is linked to the survival of grazing-free locations where above ground competition from herbs and grasses is subdued. Barbarea is a ruderal that requires freedom from stock grazing for its persistence in Tasmanian riparian habitats. These results reinforce the importance of some degraded ecosystems for biodiversity conservation, and the critical role of disturbance regimes in influencing the survival or extinction of a subset of native plant species. In the fragmented and variegated landscapes of today, weedy natives cannot necessarily be expected to survive in non-weedy environments.

Very little research has been undertaken on the impacts of human toilet waste disposal in non-serviced sites in the wild. The objective of the present project was to determine the relative impacts of the mechanical disturbance of digging during the burial of toilet waste (faeces and toilet paper), and urination, on Tasmanian vegetation types that occur in areas used for wild country camping, in order to develop appropriate guidelines. The mechanical disturbance of digging cat-holes 15 cm deep, typical of those used for toilet disposal in the Tasmanian wild, had largely negative effects on the growth of a few native plant species. These effects were of little or no conservation significance. The nutrient additions simulated by the addition of artificial urine to undug ground and dug ground had largely positive effects on nine distinct types of native vegetation, encouraging the growth of many plant species at many sites, while discouraging the growth of moss at one site. No weed species found at any of the sites were significantly affected by the treatments. Thus, it appears that scattered disposal of urine, even combined with digging, is unlikely to present a major conservation problem in the Tasmania's wild country, and that present guidelines are appropriate, where achievable

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.

To determine the environmental factors associated with bryophyte diversity in remnants in a fragmented, agricultural landscape. Location Eighty-two remnants of tussock grassland, eucalypt woodland and eucalypt forest in the subhumid Midlands region of Tasmania, Australia. Methods Remnants were surveyed for bryophytes and predictor variables, such as vascular plant cover, climate, and topography. Management histories for each remnant were compiled using both site observation and landowner surveys. Bryophyte cover, richness, and composition were related to the independent variables using simple correlation and general linear models. Results We found weak relationships between the dependent variables and the fragmentation variables (remnant area, remnant perimeter to area ratio, distance to nearest remnant, distance to nearest larger remnant, and remnant age). Instead, climatic variables were important in predicting bryophytes, in particular those affecting humidity (minimum temperature of the coldest month, precipitation). Despite extensive sheep grazing in this landscape, grazing was not correlated with bryophyte diversity. Bryophyte diversity was not explained by vascular plant richness and was only weakly explained by composition, but was predicted by the cover of vascular plants. There was greater bryophyte cover and richness and different composition where the cover of native vascular plants was lower. Main conclusions The implications of our results are that all remnants, regardless of area, age and isolation, appear to be valuable for bryophyte conservation in this highly altered landscape. Our results also suggest that the cover of the vascular plant community, rather than its diversity, holds promise as a guide to bryophyte diversity. Bryophyte composition was similar between sites and a focus on the most species-rich sites may be the best conservation strategy in this ecosystem.

Patterns of variation in the Eucalyptus globulus Labill. complex are reassessed by combining capsule measurements from an earlier study with recent collections, mainly of subspecies globulus. Four groups of populations are apparent and can be ascribed to the four subspecies maidenii, pseudoglobulus, bicostata and globulus. Intergrade populations between the latter three subspecies are widespread and mainly occur in the Otway Ranges and west Gippsland. There is a continuum in capsule morphology between the three-fruited subspecies, pseudoglobulus and bicostata. Subspecies globulus intergrades with these three-fruited intermediates. Three-fruited intergrade populations occuning north and south of the range of core pseudoglobulus can be differentiated and probably represent intergrades between pseudoglobulus and bicostata and between pseudoglobulus and globulus respectively. Reports of bicostata in the Furneaux Group and southern Victoria are thus probably erroneous and result from convergence in capsule morphology. The previously described taxon E. stjohnii (R. T. Bak.) R. T. Bak. is part of the continuum between subspecies pseudoglobulus and bicostata, but closer to pseudoglobulus. Populations phenotypically intermediate between and significantly different from globulus and the three-fruited intergrades are highly variable and occur in western Tasmania, on the northern end of Flinders Island, in the Otway Ranges and in west Gippsland. An isolated population on Rodondo Island is highly variable and has closest affinities to pseudoglobulus despite being within the geographical range of core globulus. The population from King Island is intermediate between the Otway phenotype and core globulus. The climatic regimes of the subspecies are markedly different and most three-fruited and globulus intergrade populations have closer climatic affinities to pseudoglobulus and globulus respectively. Hypotheses relating to the origin of the pattern of variation in E. globulus are d

The relative impacts of clearfelling followed by slash-burning, clearfelling, and no treatment were monitored for 2 years in two major types of eucalypt forest in south-eastern Tasmania. Rates of change in species cover were significantly greater in the burned area than in both the clearfell and control areas. More than half the species for which suitable data were available increased most in the burned area and least in the control. More higher plant taxa were present in the permanent burned plots 4 months after the burn than before the burn. By the last 8 months of recording, new taxa were invading at a rate of only 0.1 per month. Composites and shrubs constituted most of the late invaders. The behaviour of diversity measures was largely a function of the behaviour of a few of the taxa. Fire intensity, as measured by degree of soil baking, had a pronounced influence on species composition and cover. The species composition of aerially sown seed had little influence on the species composition of the eucalypt regeneration, with species not sown by the Forestry Commission recovering vegetatively, and much of the sown seed not resulting in seedling establishment. The clearfelling and burning, and clearfelling treatments did not result in the loss of any native species but there was substantial invasion by introduced herbs. However, lack of substantial impact in the short term does not guarantee the same in the long term.