Challenges for native grassland conservation on Victoria's Northern Plains

Discusses some of the challenges faced in attempting to retain and conserve grasslands on Victoria's Northern Plains over the past decade. The development of a strategic vision and directions and opportunities for the future are highlighted.

Grassland conservation and the plains-wanderer: A small brown bird makes an effective local flagship

This study explored whether the plains-wanderer (Pedionomus torquatus), a species lacking the criteria outlined in the traditional flagship model, is a suitable local flagship for the Northern Plains Grasslands of Victoria in Australia. Questionnaires and telephone interviews were used to survey residents and natural resource management professionals and volunteers ('NRM participants') in communities living close to the Northern Plains Grasslands. Questionnaires were completed by 146 residents and 69 NRM participants, and 15 interviews were conducted. Results suggest that a significant proportion of the local community was aware of, and valued, the plains-wanderer, and that the species is currently functioning as an effective flagship for the region. Recommendations are provided for the future selection of flagship species in ecosystems where traditional flagships are not present.

Effects of fragmented habitat and fire on the distribution and ecology of the swamp antechinus (Antechinus minimus maritimus) in the Eastern Otways, Victoria

This study investigated the distribution, habitat and population dynamics of the swamp antechinus (Antechinus minimus maritimus) in the eastern Otway Ranges. The species has a restricted, disjunct distribution and has been recorded at 25 sites between 1969 and 1999. All sites were located within 7 km of the coast, occurred at altitudes up to 80 m above sea level and within 10 m of a gully. Analysis of landscape site variables identified sun index as being significant in determination of the probability of occurrence of A. minimus. The presence of A. minimus is negatively associated with sun index, occuring at sites that have a southerly aspect and gentle slope. A. minimus was located in a range of structural vegetation including Open Forest, Low Woodland, Shrubland and Hummock Grassland and a number of floristic groups, some characterised by high frequencies of sclerophyll shrubs, others by high frequencies of Pteridium esculentum, hummock grasses and herbaceous species. A. minimus occurs in fragmented, small populations with maximum population densities of 1.1–18 ha^–1. Populations at inland sites became extinct after the 1983 wildfire which burnt 41 000 ha. These sites have not been recolonised since, while on the coast the species did not re-establish until 1993–97. One population that is restricted to a narrow coastal strip of habitat is characterised by high levels of transient animals. The species is subject to extinction in the region due to habitat fragmentation, coastal developments and fire. Management actions to secure the present populations and ensure long-term survival of the species in the area are required and include implementation of appropriate fire regimes, prevention of habitat fragmentation, revegetation of habitat, and establishment of corridor habitat.

Habitat characteristics for New Holland mouse Pseudomys novaehollandiae in Victoria

Pseudomys novaehollandiae is 'Endangered' in Victoria, where it is presently considered to be extant at only three localities Loch Sport, Providence Ponds, and Wilsons Promontory. This study aimed to determine indicators of suitable habitat for the species that could assist in identifying potential habitat and sites for planned re-introductions as part of a recovery program. Vegetation and site data (soils, topography, rainfall, fire age-time since fire) were assessed at localities where P. novaehollandiae was recorded. The species occurred in five structural vegetation groups - open-forest, woodland, heathland, shrubland, grassland, with the most common being open-forest and woodland. Grassland and shmbland were restricted to coastal sand-dunes in south Gippsland. Understorey vegetation at most sites was dominated by sclerophyllous shrubs ranging in cover from 10 - 70%. Classification of quadrats produced eight floristic groups in which the trend was for quadrats to cluster according to geographical location. Ordination confirmed the classification pattern and vector-fitting produced significant correlations between vector points and five variables: species richness, latitude, longitude, fire age and annual rainfall. The study identified a range of vegetation communities where P. novaehollandiae occurs and provided evidence that the species is not restricted to floristically rich and diverse heathlands. The findings can be used to determine further localities with suitable habitat. However, factors other than vegetation are also likely to be important in predicting suitable habitat.

Aspects of the ecology of swamp antechinus (Antechinus minimus maritimus) on a Bass Strait island

The swamp antechinus (Antechinus minimus maritimus) is a small insectivorous marsupial inhabiting closed heath and tussock grassland in south-eastern Australia. The species is considered 'Near Threatened' on the
Australian mainland. Populations persist on coastal islands off Wilsons Promontory, but their current status is unknown. This study investigated the density, diet and reproduction of the swamp antechinus on Kanowna Island.
Data were collected by live trapping in different vegetation types during four trips between August 2003 and January 2004. Higher animal densities (47-129 ha^-1) were found for Kanowna Island than for previously studied mainland populations (1-18 ha^-1). Examination ofscats showed that this species eats a wide variety ofprey types, with moth larvae a major dietary component, particularly during the breeding season. Births were estimated to have occurred between 28 June and 8 August, which is a longer period than reported for other populations of this species. Factors including reduced predation, restricted dispersal and increased food availability may be responsible for supporting this dense population.

Fire fighters' assessments of fireground risk

Fire fighters are often required to work in dynamic and hazardous environments involving a high level of uncertainty. The present study investigated 110 volunteer fire fighters’ assessments of levels of risk associated with a photographic depiction of a typical grassland fire situation. The fire fighters used a standard fire agency risk-rating matrix procedure requiring them to specify the severity of the hazards depicted and the probability of a mishap in order to rate overall level of risk (1 = Low; 4 = Extreme). The risk ratings made by the fire fighters varied greatly. The overall rate of agreement with the risk level rating of the situation made by a panel of expert fire officers (=1, Low) was only 27%. It seems that use of a standard risk-rating matrix procedure by fire fighters at incidents, as recommended currently by many fire agencies, is likely to result in unreliable risk assessments, at least in the absence of effective training in the risk assessment procedure. The 110 volunteers were also asked to identify the total number of potential hazards apparent in five photographs depicting different kinds of emergency incidents. Identifying more hazards was found to be associated with (a) previous personal experience of a ‘near-miss’; and (b) higher levels of education. The findings imply that when faced with identical fire ground situations, individual fire fighters are likely to differ in their situational awareness of hazards and consequent risk assessments.

Fuels of the future : the challenge of new fuel types

Landscape disturbances associated with human activities result in many changes in vegetation structure and floristics. These changes include invasion of native vegetation by both introduced and native species, which leads to the development of 'new' vegetation types. These new vegetation types are often associated with greatly increased fuel loads, and increased levels of fire hazard. Two of these 'new' fuel types are dense thickets of woody weeds, such as Coyote Bush (Baccharis pilularis) and swards of exotic grasses with very high fuel loads, such as Buffel Grass (Cenchrus ciliaris) and Para Grass (Urochloa mutica). The 'new' fuel types which can now be recognized have significant implications for the accuracy of fire behaviour prediction and modelling. For example, modelling fire behaviour in areas invaded by exotic grasses in Australia is problematic, as current grassland fire behaviour models do not allow for the input ofthe high fuel loads associated with these invasive grasses. In forest, McArthur Forest Fire Danger Meters may not be appropriate for forests with significant levels of elevated fuels. Two case studies from southeastern Australia are discussed: the invasion of native vegetation in the urban interface by the woody shrub Burgan (Kunzea ericoides) and invasion of native grasslands by Phalaris (Phalaris aquatica).

Water repellency, near-saturated infiltration and preferential solute transport in a macroporous clay soil

Little attention has been paid to the possibility that soil water repellency could enhance non-equilibrium water flow and solute transport through macropores present in structured clay soils. In this study, we measured infiltration and solute transport in a clay soil under near-saturated conditions in both the field using tension infiltrometers and in the laboratory on undisturbed soil columns. Measurements were made on adjacent plots under grass and continuous arable cultivation. Steady-state field infiltration rates measured using water and ethanol as the infiltrating fluids demonstrated that the soil macroporosity under grass was better developed, but that much of the structural pore system was inactive due to water repellency. No water repellency was detected on the arable plot disturbed by tillage. Dye tracing showed that the conducting macroporosity was largely comprised of earthworm channels in the grassed plot and inter-aggregate voids resulting from ploughing in the arable plot. Tracer breakthrough curves measured on field-dry soil indicated rapid macropore transport in columns taken from both plots, although the degree of non-equilibrium transport appeared somewhat stronger under grass. This result, which was attributed to water repellency, was also consistent with the larger flow-weighted mean pore size found in the field infiltration experiments. It is concluded that water repellency in undisturbed structured clay soils can have significant effects on the occurrence of non-equilibrium water and solute transport in macropores.

Origins of agriculture at Kuk Swamp in the highlands of New Guinea

Multidisciplinary investigations at Kuk Swamp in the Highlands of Papua New Guinea show that agriculture arose independently in New Guinea by at least 6950 to 6440 calibrated years before the present (cal yr B.P.). Plant exploitation and some cultivation occurred on the wetland margin at 10,220 to 9910 cal yr B.P. (phase 1), mounding cultivation began by 6950 to 6440 cal yr B.P. (phase 2), and ditched cultivation began by 4350 to 3980 cal yr B.P. (phase 3). Clearance of lower montane rainforests began in the early Holocene, with modification to grassland at 6950 to 6440 cal yr B.P. Taro (Colocasia esculenta) was utilized in the early Holocene, and bananas (Musa spp.) were intensively cultivated by at least 6950 to 6440 cal yr B.P.

Does agricultural food provide a good alternative to a natural diet for body store deposition in geese?

Over the past decades most goose populations have become increasingly dependent on agricultural crops during wintering and migration periods. The suitability of agricultural crops to support all nutritional requirements of migratory geese for the deposition of body stores has been questioned; feeding on agricultural crops may yield higher rates of fat deposition at the cost of reduced protein accretion due to an unbalanced diet. We compared amino-acid composition of forage, and investigated food-habitat use and dynamics and composition of body stores deposited by barnacle geese feeding on agricultural pasture and in natural salt marsh during spring migratory preparation. Overall content and composition of amino acids was similar among forage from both habitats and appeared equally suitable for protein accretion. There was no relationship between body composition of geese and their preferred food habitat. Fat and wet protein contributed with 67% and 33%, respectively, to body stores gained at a rate of 11 g/d throughout the one-month study period. We found no evidence of impaired protein accretion in geese using agricultural grassland compared to natural salt marsh. Our study supports the hypothesis that the expansion of feeding habitat by including agricultural grassland has played an important role in the recent growth of the East Atlantic flyway population of barnacle geese and other herbivorous waterbirds. Feeding refuges of improved grassland provide geese with an adequate diet for the deposition of body stores crucial for spring migration and subsequent reproduction, thereby alleviating the conflict with agriculture.

The world-swimmers

For days now you have been driving across unbroken grassland, which you know you’ll never be able to leave behind forever, no matter how fast you might go, or however deep into the night you persist in your journey. The northern coast of your country is far in the distance and darkness, yet nothing is clearer to you than the knowledge that the plain you once in a while spit into will surely not disappear when it gets to the water. You have faith it will move without interruption through the breakers, even picking up speed across the ocean, until there is no more ocean—and with all the more reality if it takes on a form you could not even begin to comprehend. After so much confusion—the wrack of entire cities on sickening flats of sand—this alone seems certain.

Home range, habitat use and movements by the little raven (Corvus mellori) in a coastal peri-urban landscape

Context In peri-urban environments, high availability of anthropogenic resources may result in relatively high abundances of some species, with potentially negative implications for other native biota. Effective management of such impacts requires understanding of the spatial ecology of problem species. However, home range and habitat use have not been described for the little raven (Corvus mellori), a superabundant native predator that occurs in urban and natural habitats, including those where threatened shorebirds breed. Aims The aim of this study was to provide basic information on little raven home range, habitat use and movements in a coastal peri-urban landscape. Methods Between October 2011 and January 2012 we radio-tracked 20 little ravens captured in a coastal wetland (near Melbourne, Australia). Key results Little ravens were highly mobile, moving up to 9.9km in an hour (median≤2km), and had large ranges: Minimum Convex Polygons were 1664-9989ha (median≤3362ha). Although most birds used both anthropogenic and natural habitats, some birds strongly selected for coastal wetland habitat. Birds used multiple roosts during the study period, most of which occurred in grassland (58.7%) or urban (22.3%) areas. Movement of up to 8.3km (median≤2.2km) between roosts during the night was also detected. Conclusions Ravens were highly mobile and used large home ranges and a variety of habitats, with habitat preferences varying between birds. Implications Considering the large home ranges and inter-individual variation in habitat preferences of little raven populations, localised management to reduce their impacts on breeding shorebirds is unlikely to be successful. Journal compilation