Spinifex–mallee revegetation: implications for restoration after mineral-sands mining in the Murray–Darling Basin

2016 ◽  
Vol 64 (6) ◽  
pp. 547 ◽  
Author(s):  
Ian R. K. Sluiter ◽  
Andrew Schweitzer ◽  
Ralph Mac Nally
Keyword(s):  
Arid Zone ◽  
Eucalyptus Species ◽  
Severe Drought ◽  
Remnant Vegetation ◽  
Spatial Coverage ◽  
Millennium Drought ◽  
Eastern Australia ◽  
Vegetation Class ◽  
Western Victoria

Mineral-sands mining in the semiarid and arid zone of south-eastern Australia is now a widespread disturbance that may adversely affect large areas of remnant vegetation, including mallee (Eucalyptus spp.) with hummock grass or spinifex (Triodia scariosa) understorey. No broad-scale restoration projects have been undertaken to revegetate mallee Eucalyptus species with spinifex. We report on the survivorship and relative importance (spatial coverage) of hand-planted tubestock 10 years after establishment in 2001, which included mallee Eucalyptus, Triodia scariosa, Acacia spp. and Hakea spp. These taxa are the dominant plants in a semiarid dune–swale system on a former mineral-sands mine licence area in semiarid, north-western Victoria. Mean survivorship of tubestock was 0.58 ± 0.04. Spinifex (Triodia scariosa), needlewood (Hakea) and several mallee species (Eucalyptus spp.) survived substantially better than the average of all tubestock-planted species, although Acacia spp. had low survivorships. Although the plantings were undertaken in the early stages of the most severe drought in the instrumental record (the ‘Millennium drought’), several taxa survived well and species such as spinifex established and developed ground coverage greater than the benchmark values for the ecological vegetation class of the location. We conclude that hand-planting of tubestock can achieve restoration objectives for this component of spinifex–mallee vegetation, even under extremely arduous conditions associated with long-term drought. We also herald the importance of taking a long-term view to the assessment of revegetation success, in this case 10 years.

Crop responses to lime in long-term pasture-crop rotations in a high rainfall area in south-eastern Australia

2001 ◽  
Vol 52 (3) ◽  
pp. 329 ◽  
Author(s):  
G. D. Li ◽  
K. R. Helyar ◽  
M. K. Conyers ◽  
B. R. Cullis ◽  
P. D. Cregan ◽  
...  
Keyword(s):  
Crop Production ◽  
Acid Soils ◽  
Crop Rotations ◽  
Severe Drought ◽  
High Rainfall ◽  
South Eastern ◽  
Permanent Pasture ◽  
Eastern Australia ◽  
South Eastern Australia

A long-term trial, known as ‘managing acid soils through efficient rotations’ (MASTER), commenced in 1992 to develop and demonstrate a cropping system that is economically viable on the highly acid soils of the traditional permanent pasture region in south-eastern Australia, so that their fertility is sustained or improved. There were 2 permanent pasture systems and 2 pasture–crop rotations, each with and without lime. This paper reports the effect of lime on crop production over the first cycle (6 years). On annual pasture–crop rotations, lime significantly increased the dry matter production at anthesis and grain yields of wheat (cv. Dollarbird) compared with the unlimed treatments. Averaged across years from 1992 to 1997 (excluding the severe drought year 1994), wheat crops produced 1.6 t/ha more grain on the limed treatments than on the unlimed treatments (3.6 v. 2.0 t/ha). On perennial pasture–crop rotations, the lime effects varied with crops grown at each phase and year. For example, despite being tolerant of acidity, oats (cv. Yarran) responded to lime in 1996. Likewise, triticale (cv. Abacus) responded to lime in 1997. Wheat (cv. Dollarbird) that is moderately tolerant to acidity responded to lime in phase 6 from 1992 to 1997 excluding 1994 (3.5 v. 1.7 t/ha). Acid-tolerant wheat varieties, triticale, and narrow-leaf lupins are considered the most viable crops for the soil and climatic conditions encountered in this high rainfall (5000—800 mm per annum) area of south-eastern Australia.

Regeneration of Three Tree Species in Arid South-Eastern Australia

1985 ◽  
Vol 33 (6) ◽  
pp. 715 ◽  
Author(s):  
CJ Chesterfield ◽  
RF Parsons
Keyword(s):  
Nature Conservation ◽  
Tree Species ◽  
Arid Zone ◽  
Tree Seedlings ◽  
Seedling Regeneration ◽  
Mammalian Herbivores ◽  
Eastern Australia ◽  
Rabbit Grazing ◽  
A Site

Grazing effects by introduced mammals on tree seedlings in the arid zone have caused concern for the long-term future of some tree species. This was investigated by measuring stem girths of Casuarina cristata Miq., Heterodendrum oleifoliurn Desf. and Myoporum platycarpum R.Br. in arid-zone wood- lands. Episodic seedling regeneration of Myoporum is inferred following series of wet years in the 1950s and 1970s. Although young Myoporum plants appear unpalatable to stock, regeneration may be sup- pressed by rabbit-grazing in some areas. Almost no Heterodendrurn seedlings were found but suckering was common after burning and clearing. This species is highly palatable to grazing mammals and suckers may grow to safety above the browse line only where stock are absent. Evidence for recent Casuarina seedling regeneration was limited to one cohort, on a site that had been flooded. While suckers can be found locally where surface roots become exposed, suckering appears insufficient to perpetuate many Casuarina stands. Mammal-grazing seems important in strongly limiting regeneration. While Casuarina and Heterodendrum stand densities decline due to natural senescence and occasional fire, the only species regenerating into gaps is Myoporum. There is concern for the future of Casuarina and Heterodendrum, given their widespread failure to regenerate despite the wettest 3 years ever recorded, in 1973-75. On pastoral land, at least 10 years without stock-grazing might be needed for successful regeneration of Heterodendrurn. In reserves, some nature conservation programs for woodlands might require virtual eradication of all exotic mammalian herbivores, including goats.

The rise and fall of a translocated population of the endangered Macquarie perch, Macquaria australasica, in south-eastern Australia

2013 ◽  
Vol 64 (9) ◽  
pp. 838 ◽  
Author(s):  
Mark Lintermans
Keyword(s):  
Single Individual ◽  
Spawning Habitat ◽  
Management Activity ◽  
South Eastern ◽  
Millennium Drought ◽  
Eastern Australia ◽  
Term Monitoring ◽  
South Eastern Australia

Translocation is an increasingly popular conservation management activity worldwide, but the success of translocation is often not measured or reported. A population of the endangered Macquarie perch was imperilled by the damming in 1977 of the Queanbeyan River, near Canberra in south-eastern Australia. In November 1980, 66 adult Macquarie perch (309–389-mm total length) individuals were collected from the newlyformed reservoir, and translocated approximately 4 km upstream into the Queanbeyan River past a waterfall (which prevented access to spawning habitat). Five years of post-translocation monitoring at the release sites resulted in the capture of only a single individual in late 1981. Consequently, monitoring ceased because the translocation was assumed to have failed. However, subsequent angler reports and a preliminary survey in 1991 confirmed that some translocated fish had survived, and a small recruiting population had established. More intensive follow-up surveys and subsequent monitoring from 1996 to 2006 demonstrated an established population with consistent recruitment until 2001. However, after 2001, there was no evidence of recruitment and the population is now undetectable, with the prolonged ‘millennium drought’ (1997–2010) being the most plausible cause. The present study demonstrates the potentially ephemeral nature of assessments of success and failure, and the importance of targeted long-term monitoring programs.

Life histories of two arid-zone shrubs change with differences in habitat, grazing and climate

2014 ◽  
Vol 36 (3) ◽  
pp. 249 ◽  
Author(s):  
P. Norman ◽  
R. Denham ◽  
M. J. Calvert
Keyword(s):  
Life Histories ◽  
Arid Zone ◽  
Survival Rates ◽  
Climatic Conditions ◽  
Severe Drought ◽  
High Survival ◽  
Ecosystem Structure ◽  
Background Rate ◽  
Average Maximum ◽  
Eastern Australia

Shrubs are an important component of vegetation throughout the world. They are particularly significant in semiarid environments where they can dominate, driving ecosystem structure and functioning, and shaping land use. Life-history information was derived for Eremophila sturtii R.Br. and Dodonaea viscosa subsp. angustissima J.G.West, two widespread and common shrubs of semiarid eastern Australia. Plants growing under background climatic conditions took between 2 and 4 years to become established, attained the capacity to reproduce sexually at between 10 and 12 years, were in a sexually reproductive stage for between 17 and 28 years and lived an average maximum of 33–40 years. Under background climatic conditions between 70 and 80% of plants that entered the juvenile stage survived to sexual maturity while under severe drought this proportion fell to between 40 and 60%. Juvenile plants, particularly of E. sturtii, experienced the highest mortality under background conditions while, when exposed to severe drought, older plants, particularly D. viscosa subsp. angustissima in the intermediate stage, experienced the greatest increase in mortality, dying at more than twice the background rate. The high survival rates of E. sturtii and D. viscosa subsp. angustissima shown here, even under extreme drought conditions and in grazed- and ungrazed areas, help to explain why these shrub species have been observed to dominate vegetation in large areas of eastern Australia.

Did Climate Change–Induced Rainfall Trends Contribute to the Australian Millennium Drought?

2014 ◽  
Vol 27 (9) ◽  
pp. 3145-3168 ◽  
Author(s):  
Wenju Cai ◽  
Ariaan Purich ◽  
Tim Cowan ◽  
Peter van Rensch ◽  
Evan Weller
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Southern Oscillation ◽  
Hadley Cell ◽  
Severe Drought ◽  
Climate Modes ◽  
Millennium Drought ◽  
Eastern Australia ◽  
Dry Zone ◽  
Instrumental Records

Abstract The Australian decade-long “Millennium Drought” broke in the summer of 2010/11 and was considered the most severe drought since instrumental records began in the 1900s. A crucial question is whether climate change played a role in inducing the rainfall deficit. The climate modes in question include the Indian Ocean dipole (IOD), affecting southern Australia in winter and spring; the southern annular mode (SAM) with an opposing influence on southern Australia in winter to that in spring; and El Niño–Southern Oscillation, affecting northern and eastern Australia in most seasons and southeastern Australia in spring through its coherence with the IOD. Furthermore, the poleward edge of the Southern Hemisphere Hadley cell, which indicates the position of the subtropical dry zone, has possible implications for recent rainfall declines in autumn. Using observations and simulations from phase 5 of the Coupled Model Intercomparison Project (CMIP5), it is shown that the drought over southwest Western Australia is partly attributable to a long-term upward SAM trend, which contributed to half of the winter rainfall reduction in this region. For southeast Australia, models simulate weak trends in the pertinent climate modes. In particular, they severely underestimate the observed poleward expansion of the subtropical dry zone and associated impacts. Thus, although climate models generally suggest that Australia’s Millennium Drought was mostly due to multidecadal variability, some late-twentieth-century changes in climate modes that influence regional rainfall are partially attributable to anthropogenic greenhouse warming.

Characteristics of refugia used by the threatened Australian growling grass frog (Litoria raniformis) during a prolonged drought

2013 ◽  
Vol 40 (5) ◽  
pp. 385 ◽  
Author(s):  
Nick Clemann ◽  
Michael P. Scroggie ◽  
Michael J. Smith ◽  
Garry N. L. Peterson ◽  
David Hunter
Keyword(s):  
Water Body ◽  
Aquatic Vegetation ◽  
Negative Relationship ◽  
Canopy Cover ◽  
Tree Canopy ◽  
Severe Drought ◽  
Body Type ◽  
Tree Canopy Cover ◽  
Millennium Drought ◽  
Eastern Australia

Context Because they are dependent on water, drought can have a deleterious impact on aquatic-breeding amphibians. One such species, the threatened growling grass frog (Litoria raniformis) occurs in south-eastern Australia, a region that has recently emerged from a decade-long, severe drought. Aims We aimed to identify features of drought refugia that facilitate persistence of L. raniformis, so as to provide guidance to natural-resource managers attempting to conserve populations of this species during drought. Methods We conducted repeat surveys for L. raniformis at 90 water bodies at the end of the ‘millennium drought’. We recorded the following six environmental variables for each water body: origin (natural or not), type (lotic or lentic), proportion of aquatic vegetation cover, conductivity of water, riparian tree-canopy cover and distance to the nearest woodland. We used occupancy models to relate the presence of L. raniformis to these variables, while accounting for uncertain detection. Key results Water-body type (natural or artificial, lentic or lotic) had minimal influence on the probability of occupancy by L. raniformis. We found a strong negative relationship between occupancy and conductivity of water (a surrogate for salinity), and a positive relationship between occupancy and the proportion of aquatic vegetation. We found a negative relationship between detection and the extent of aquatic vegetation, and a mildly negative effect of canopy cover on occupancy. Conclusions Habitat characteristics are more important indicators of the quality of drought refugia for L. raniformis than is the type of water body per se. Consequently, we identified aquatic vegetation and salinity as important targets for management when planning the retention, creation or restoration of habitat to facilitate persistence of L. raniformis during drought. Implications Our results highlighted aquatic vegetation and water-quality parameters that are likely to facilitate the persistence of L. raniformis during drought. Assessing the effectiveness of our recommendations in an experimental framework would ensure that conservation management of this frog can be refined over time.

scholarly journals Linking population size structure, heat stress and bleaching responses in a subtropical endemic coral

Coral Reefs ◽  
2021 ◽  
Author(s):  
Liam Lachs ◽  
Brigitte Sommer ◽  
James Cant ◽  
Jessica M. Hodge ◽  
Hamish A. Malcolm ◽  
...  
Keyword(s):  
Heat Stress ◽  
Size Structure ◽  
Temporal Trends ◽  
Early Recovery ◽  
Size Frequency Distribution ◽  
Frequency Distributions ◽  
Community Organisation ◽  
Size Frequency ◽  
Eastern Australia

AbstractAnthropocene coral reefs are faced with increasingly severe marine heatwaves and mass coral bleaching mortality events. The ensuing demographic changes to coral assemblages can have long-term impacts on reef community organisation. Thus, understanding the dynamics of subtropical scleractinian coral populations is essential to predict their recovery or extinction post-disturbance. Here we present a 10-yr demographic assessment of a subtropical endemic coral, Pocillopora aliciae (Schmidt-Roach et al. in Zootaxa 3626:576–582, 2013) from the Solitary Islands Marine Park, eastern Australia, paired with long-term temperature records. These coral populations are regularly affected by storms, undergo seasonal thermal variability, and are increasingly impacted by severe marine heatwaves. We examined the demographic processes governing the persistence of these populations using inference from size-frequency distributions based on log-transformed planar area measurements of 7196 coral colonies. Specifically, the size-frequency distribution mean, coefficient of variation, skewness, kurtosis, and coral density were applied to describe population dynamics. Generalised Linear Mixed Effects Models were used to determine temporal trends and test demographic responses to heat stress. Temporal variation in size-frequency distributions revealed various population processes, from recruitment pulses and cohort growth, to bleaching impacts and temperature dependencies. Sporadic recruitment pulses likely support population persistence, illustrated in 2010 by strong positively skewed size-frequency distributions and the highest density of juvenile corals measured during the study. Increasing mean colony size over the following 6 yr indicates further cohort growth of these recruits. Severe heat stress in 2016 resulted in mass bleaching mortality and a 51% decline in coral density. Moderate heat stress in the following years was associated with suppressed P. aliciae recruitment and a lack of early recovery, marked by an exponential decrease of juvenile density (i.e. recruitment) with increasing heat stress. Here, population reliance on sporadic recruitment and susceptibility to heat stress underpin the vulnerability of subtropical coral assemblages to climate change.

scholarly journals Development and Verification of the Available Number of Water Intake Days in Ungauged Local Water Source Using the SWAT Model and Flow Recession Curves

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1511
Author(s):  
Jung-Ryel Choi ◽  
Il-Moon Chung ◽  
Se-Jin Jeung ◽  
Kyung-Su Choo ◽  
Cheong-Hyeon Oh ◽  
...  
Keyword(s):  
Water Supply ◽  
Water Intake ◽  
Water Resource Management ◽  
Assessment Tool ◽  
Swat Model ◽  
High Water ◽  
Coefficient Of Determination ◽  
Severe Drought ◽  
Regional Government

Climate change significantly affects water supply availability due to changes in the magnitude and seasonality of runoff and severe drought events. In the case of Korea, despite high water supply ratio, more populations have continued to suffer from restricted regional water supplies. Though Korea enacted the Long-Term Comprehensive Water Resources Plan, a field survey revealed that the regional government organizations limitedly utilized their drought-related data. These limitations present a need for a system that provides a more intuitive drought review, enabling a more prompt response. Thus, this study presents a rating curve for the available number of water intake days per flow, and reviews and calibrates the Soil and Water Assessment Tool (SWAT) model mediators, and found that the coefficient of determination, Nash–Sutcliffe efficiency (NSE), and percent bias (PBIAS) from 2007 to 2011 were at 0.92, 0.84, and 7.2%, respectively, which were “very good” levels. The flow recession curve was proposed after calculating the daily long-term flow and extracted the flow recession trends during days without precipitation. In addition, the SWAT model’s flow data enables the quantitative evaluations of the number of available water intake days without precipitation because of the high hit rate when comparing the available number of water intake days with the limited water supply period near the study watershed. Thus, this study can improve drought response and water resource management plans.

Distribution of the southern brown bandicoot (Isoodon obesulus) in the Portland region of south-western Victoria

2000 ◽  
Vol 27 (5) ◽  
pp. 539 ◽  
Author(s):  
Michael Rees ◽  
David Paull
Keyword(s):  
Local Population ◽  
Historical Records ◽  
Limited Information ◽  
Field Surveys ◽  
Potential Habitat ◽  
Specimen Collection ◽  
Eastern Australia ◽  
Spatial Isolation ◽  
Observational Bias ◽  
Western Victoria

The southern brown bandicoot (Isoodon obesulus) occurs across the periphery of southern and eastern Australia as a series of isolated regional populations. Historical records and recent surveys conducted for I. obesulus indicate that it has disappeared or decreased significantly from many parts of its former range. Vegetation clearance, habitat fragmentation, feral predators and fire have all been implicated in the decline of the species. This paper examines the distribution of I. obesulus in the Portland region of south-western Victoria. Historical records of I. obesulus were compiled from the specimen collection of Museum Victoria, the Atlas of Victorian Wildlife, Portland Field Naturalists’ Club records and anecdotal sources. Field surveys were conducted to determine the current distribution of I. obesulus in the study area based on evidence of its foraging activity. The historical records reveal limited information: most are clustered around centres of human activity, indicating observational bias. The field surveys demonstrate that I. obesulus occurs in the Portland region as a series of local populations. Each local population is associated with a patch of remnant native vegetation separated from neighbouring patches by dispersal barriers. Within these habitat remnants the occurrence of the species is sporadic. Approximately 69% of the potential habitat is managed by the Forests Service, 31% is managed by Parks Victoria, and less than 0.5% is held under other tenures. Spatial isolation of habitat remnants, fires and feral predators are the main threats to I. obesulus in the Portland region.

Landscape-scale disturbances and regeneration in semi-arid woodlands of southwestern Australia

1994 ◽  
Vol 1 (3) ◽  
pp. 214 ◽  
Author(s):  
Colin J. Yates ◽  
Richard J. Hobbs ◽  
Richard W. Bell
Keyword(s):  
Tree Mortality ◽  
Landscape Scale ◽  
Eucalyptus Species ◽  
Natural Ecosystems ◽  
Fragmented Landscapes ◽  
The Past ◽  
Adult Tree ◽  
Western Australian ◽  
Semi Arid

Woodlands dominated by Eucalyptus salmonophloia occur both in the fragmented landscapes of the Western Australian wheatbelt and in the adjacent unfragmented goldfields area. We examined the responses of the unfragmented woodlands to landscape-scale disturbances caused by fire, floods, windstorms and drought. Sites known to have experienced disturbances of these types over the past 50 years all had cohorts of sapling-stage E. salmonophloia and other dominant Eucalyptus species. Sites disturbed either by fire, flood or storm during 1991-92 displayed adult tree mortality and extensive seedling establishment, although rates of establishment and survival varied between sites. No regeneration was observed at equivalent undisturbed sites. These results indicate that landscape-scale disturbances of several types are important drivers of the dynamics of these semi-arid woodlands. Lack of regeneration of fragmented woodlands in the wheatbelt is likely to be due to changed disturbance regimes coupled with altered physical and biotic conditions within remnants. We argue that it may be difficult to identify processes which are important for the long-term persistence of natural ecosystems in fragmented landscapes without reference to equivalent unfragmented areas.

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