McCallum K.P.,University of Adelaide |
McCallum K.P.,Eco Logical Australia Pty Ltd |
McDougall F.O.,University of Adelaide |
Seymour R.S.,University of Adelaide
Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology | Year: 2013
Pollination biology is often associated with mutualistic interactions between plants and their animal pollen vectors, with energy rewards as the foundation for co-evolution. Energy is supplied as food (often nectar from flowers) or as heat (in sun-tracking or thermogenic plants). The requirements of pollinators for these resources depend on many factors, including the costs of living, locomotion, thermoregulation and behaviour, all of which are influenced by body size. These requirements are modified by the availability of energy offered by plants and environmental conditions. Endothermic insects, birds and bats are very effective, because they move faster and are more independent of environmental temperatures, than are ectothermic insects, but they are energetically costly for the plant. The body size of endothermic pollinators appears to be influenced by opposing requirements of the animals and plants. Large body size is advantageous for endotherms to retain heat. However, plants select for small body size of endotherms, as energy costs of larger size are not matched by increases in flight speed. If high energy costs of endothermy cannot be met, birds and mammals employ daily torpor, and large insects reduce the frequency of facultative endothermy. Energy uptake can be limited by the time required to absorb the energy or eliminate the excess water that comes with it. It can also be influenced by variations in climate that determine temperature and flowering season. © 2013 Springer-Verlag Berlin Heidelberg.
Sadlier R.A.,College Street |
Bauer A.M.,Villanova University |
Wood Jr. P.L.,Villanova University |
Wood Jr. P.L.,Brigham Young University |
And 3 more authors.
Zootaxa | Year: 2013
A new species of skink, Caledoniscincus notialis sp. nov., is described from the ultramafic ranges in southern New Caledonia. It is most similar to, and has previously been referred to Caledoniscincus atropunctatus (Roux), a species with a widespread distribution throughout the Grand Terre and Loyalty Islands. The new species is distinct genetically from all other Caledoniscincus and can be distinguished by a unique pattern of dorsal coloration in males. Its range extends over much of the extensive ultramafic block in the south of the island, including the Goro Plateau and the mountain ranges at the southern edge of the Chaine Centrale north to Mt. Humboldt. It occurs mainly in humid forest habitat, much of which is now present only as isolated fragments in southern New Caledonia. Its preference for a habitat that has undergone a significant reduction in area of extent in a region under pressure from a range of anthropogenic threats suggests this new species is of conservation concern, and could be ranked as Vulnerable under IUCN listing. The genetic relationships of a redefined Caledoniscincus atropunctatus identifies two major subgroups, one located mainly in the northern and centraleast regions of Grand Terre and the other in the southern and central-west regions and also including the population on the Loyalty Islands. Copyright © 2013 Magnolia Press.
Nicholson E.,University of Melbourne |
Regan T.J.,University of Melbourne |
Auld T.D.,NSW Office of Environment and Heritage |
Burns E.L.,University of Sydney |
And 16 more authors.
Austral Ecology | Year: 2015
Ecosystem-level conservation is increasingly important at global, national and local levels. Many jurisdictions have developed and apply their own protocols for assessing the threat status of ecosystems, often independently, leading to inconsistencies between and within countries which are problematic for cross-jurisdictional environmental reporting. Australia is a good example of these historic legacies, with different risk assessment methods applied nationally and in most states. The newly developed criteria for the International Union for the Conservation of Nature (IUCN) Red List of Ecosystems (RLE) provide a framework to compare and contrast apparently divergent protocols. We critically reviewed the Australian protocols and compared them with the IUCN RLE, based on the following components of a risk assessment protocol: (i) categories of threat; (ii) assessment units; (iii) underlying concepts and definitions; (iv) assessment criteria; (v) uncertainty methods; and (vi) assessment outcomes. Despite some differences in specific objectives, criteria and their expression, the protocols were structurally similar, included broadly similar types of criteria, and produced assessment outcomes that were generally concordant. Alignment with the IUCN RLE would not require extensive changes to existing protocols, but would improve consistency, rigour and robustness in ecosystem risk assessment across jurisdictions. To achieve this, we recommend: (i) more quantitative assessments of functional change; (ii) separation of management and policy considerations from risk assessment; and (iii) cross-referencing of assessment units in different jurisdictions. We argue that the focus on processes and ecological function, rather than only patterns, is key to robust risk assessment. © 2014 Ecological Society of Australia.
Broome L.,Office of Environment and Heritage |
Ford F.,Defence Support Group |
Dawson M.,Eco Logical Australia Pty. Ltd. |
Green K.,Snowy Mountains Region |
And 2 more authors.
Australian Zoologist | Year: 2013
The New South Wales population of the Mountain Pygmy-possum Burramys parvus was estimated at 500 adults in 8 km2 of boulder-heath habitat during surveys in the 1980's. In 1989, this estimate was increased to 1312 adults based on further surveys in four of the identified habitat patches. However, further research indicated that population density varied greatly between habitat patches and that the original extent of habitat and the revised population estimate had been overestimated. Because of the high degree of uncertainty regarding the total population size of B. parvus in New South Wales and the relative value of each habitat patch, including those in ski resorts, it was necessary to re-evaluate these estimates. Results based on data collected between 1996 and 2001 indicated an adult population of around 613±92 in 1.85 km2 of boulderfield habitat.This population was distributed in scattered colonies within a modelled bioclimatic range of 444 km2 of suitable climate, based on modelling of the then known southern Kosciuszko B. parvus population. However the notional extent of suitable climate has been greatly enlarged by the recent discovery of a northern Kosciuszko population. Establishing which boulderfields to target for future surveys within the enlarged potential climate envelope is not simple. No strong association with any habitat characteristics were identified by habitat analysis, however, deeper boulderfields with a variety of boulder sizes and reasonable vegetation cover were generally preferred. Changes in habitat characteristics across the elevational gradient partly explained the difficulty in modelling habitat preference.
Pisanu P.,Water and Natural Resources |
Kingsford R.T.,University of New South Wales |
Wilson B.,Eco Logical Australia Pty Ltd |
Bonifacio R.,Water and Natural Resources
Austral Ecology | Year: 2015
The Lake Eyre Basin, one of the world's last unregulated wild river basins, covers almost one sixth of the Australian continent, with large areas of connected wetlands (73903km2), including floodplains, lakes, waterholes and river channels. Few data existed and so we used literature and government biotic and abiotic data and anthropogenic impacts to assess the conservation risk of the ecosystem as Least Concern (IUCN Red List criteria for ecosystems, version 2.0). This was based on limited distributional change and low levels of degradation or anthropogenic threatening processes. The approach could be applied to ecosystem assessments of other large river basins around the world, given the Lake Eyre Basin occupies one extreme (unmodified) while the Aral Sea (collapsed), previously assessed, occupies the other extreme (highly modified). River flow analysis with available biotic data is critical for risk assessment as well as identification and tracking of long-term threats. Assessment was possible at this large basin scale and appropriate, given the critical importance of connectivity but could also occur at finer spatial scale. Increased diversions for irrigation, mining impacts on floodplains and projected increased temperatures threaten the current status (Least Concern) of the connected wetlands of the Lake Eyre Basin ecosystem. © 2014 Ecological Society of Australia.
Dalgleish S.A.,Edith Cowan University |
Dalgleish S.A.,Eco Logical Australia Pty Ltd |
Van Etten E.J.B.,Edith Cowan University |
Stock W.D.,Edith Cowan University |
Knuckey C.,Edith Cowan University
International Journal of Wildland Fire | Year: 2015
Understanding fuel dynamics in fire-prone ecosystems is important because fuels play a central role in shaping fire hazard and behaviour. There is ongoing debate over whether fire hazard continually increases with time since fire in shrublands of Mediterranean-Type climates, and studies of the temporal changes in fuel loads can contribute to this discussion. We used a chronosequence of fire ages to investigate fuel dynamics and recovery of vegetation structure in the Acacia-dominated shrublands of interior south-west Western Australia. We collected and measured fuels from vegetation with fire ages ranging from 6 to 80+ years and then fitted linear, negative exponential, quadratic and logarithmic models to explore temporal patterns of fuel accumulation. Components of fine (<1cm) fuel (ground, aerial live, aerial dead) and total fine fuel levels were found to accumulate rapidly in the first few years following a fire and then gradually increase for many decades thereafter. On average, total fine fuel was ∼10tha-1 at 10 years post fire, and ∼20tha-1 after 40-60 years. Akaike's Information Criterion did not confidently discriminate between linear models and those that plateau at a certain fire age. However, all models showed gradual accumulation of fuel between 10 and 60 years post fire. Dead fine fuel (both litter and aerial) was virtually absent from young shrubland (<10 years) but accumulated slowly with age and comprised around 40% of total fine fuel in long-unburnt stands (>50 years). Although there is some evidence of shrub senescence in very long-unburnt vegetation (>60 years), no corresponding decline in fuel levels was detected, suggesting lag effects or inter-fire recruitment to maintain vegetation structure and fuel levels. Fuel structure and quantity varied considerably across the landscape, even within areas of the same landform and time since fire. We found that some of this variation was attributable to soil depth but suggest that other environmental factors may also cause variation in vegetation and fuel characteristics.