Condition of fenced and unfenced remnant vegetation in inland catchments in south-eastern Australia

2008 ◽  
Vol 56 (7) ◽  
pp. 590 ◽  
Author(s):  
Sue V. Briggs ◽  
Nicola M. Taws ◽  
Julian A. Seddon ◽  
Bindi Vanzella

Considerable areas of remnant native vegetation have been fenced in the last decade to manage grazing by domestic stock. This study investigated vegetation condition in comparative fenced and unfenced remnant vegetation in the mid–upper Murrumbidgee and Lachlan catchments in south-eastern Australia. Native species richness, native groundcover and overstorey regeneration were higher at fenced than at unfenced sites. Area of bare ground was lower at fenced sites. Exotic groundcover did not differ between fenced and unfenced sites. Native species richness was higher at sites fenced for longer and with no stock grazing; neither native nor exotic groundcover at fenced sites was related to time since fencing or stock grazing pressure. Some tree species regenerated at both fenced and unfenced sites (Blakely’s red gum, Eucalyptus blakelyi; tumbledown gum, E. dealbata, long-leaved box, E. goniocalyx; red stringbark, E. macrorhyncha), some regenerated at few fenced and few unfenced sites (white box, E. albens; yellow box, E. melliodora) and some regenerated at fenced sites but not at unfenced sites (grey box, E. microcarpa; mugga ironbark, E. sideroxylon; white cypress pine, Callitris glaucophylla). Although less robust than pre- and postfencing monitoring, the comparisons reported here provide a logistically feasible and relatively inexpensive assessment of effects of the sizeable public investment in fencing on vegetation condition.

2015 ◽  
Vol 127 (2) ◽  
pp. 69
Author(s):  
Briony A. Norton ◽  
Linda J. Thomson ◽  
Michael A. Nash

The composition and ecology of the millipede fauna of Victoria remain poorly understood. We collected millipedes as part of a series of ecological arthropod surveys across south-eastern Australia, focusing mainly on Victoria. These samples almost exclusively contained millipedes from the introduced order Julida. We pursued species identification of the julids when it became apparent there were species other than the well-recorded Ommatoiulus moreleti (Lucas, 1860) (Portuguese millipede) in the samples. The majority of specimens were O. moreleti, but we also detected at least one species of Cylindroiulus Verhoeff, 1894, as well as an Ophyiulus Berlese, 1884, species, specimens of which have been identified as Ophyiulus cf. targionii. These are the first Ophyiulus records for Victoria to our knowledge. We present preliminary data on the abundance through the year of Ophyiulus. This is the first study to examine this species in Victoria and little is currently known about its likely impact on agriculture or on native species. Monitoring and research of the species in the future is therefore warranted.


1994 ◽  
Vol 45 (8) ◽  
pp. 1799 ◽  
Author(s):  
M Tyndale-Biscoe

The quantity of dung buried and shredded by dung beetles at four sites in south-eastern Australia was found to be positively correlated with the dry weight (biomass) of beetles in the pads. Each of the four sites has two abundant native species of dung beetles, and one to five well-established introduced species present. At Uriarra, where only one introduced species is common, a mean of 7 . 2 l � 1.94% (1990-91) and 6.01�1.31% (1991-92) of the dung was buried per week. At Fyshwick, with two common introduced species of dung beetles, 22.27� 4.03% (1990-91) and 12 04�2 72% (1991-92) of the dung was buried per week. Braidwood, with four introduced species, had a mean of 15.81� 2.82% (1991-92) weekly dung buried, and Araluen, with five introduced species, had 30.18�8- 73% (1992-93) dung buried per week. Dung beetle numbers were low at all sites during the first half of 1991-92 season due to a drought throughout the region. Dung shredding averaged less than 12% over the seasons at all sites, but fluctuated from 0 to 70%, depending mainly on beetle numbers in the dung pads on individual occasions. Increasing numbers of exotic dung beetles throughout the pastoral areas of Australia should result in increased amounts of dung buried and shredded, with correspondingly increased benefits to Australian agriculture.


1995 ◽  
Vol 43 (4) ◽  
pp. 349 ◽  
Author(s):  
SM Prober ◽  
KR Thiele

Before European settlement, grassy white box woodlands were the dominant vegetation in the east of the wheat-sheep belt of south-eastern Australia. Tree clearing, cultivation and pasture improvement have led to fragmentation of this once relatively continuous ecosystem, leaving a series of remnants which themselves have been modified by livestock grazing. Little-modified remnants are extremely rare. We examined and compared the effects of fragmentation and disturbance on the understorey flora of woodland remnants, through a survey of remnants of varying size, grazing history and tree clearing. In accordance with fragmentation theory, species richness generally increased with remnant size, and, for little-grazed remnants, smaller remnants were more vulnerable to weed invasion. Similarly, tree clearing and grazing encouraged weed invasion and reduced native species richness. Evidence for increased total species richness at intermediate grazing levels, as predicted by the intermediate disturbance hypothesis, was equivocal. Remnant quality was more severely affected by grazing than by remnant size. All little-grazed remnants had lower exotic species abundance and similar or higher native species richness than grazed remnants, despite their extremely small sizes (< 6 ha). Further, small, littlegrazed remnants maintained the general character of the pre-European woodland understorey, while grazing caused changes to the dominant species. Although generally small, the little-grazed remnants are the best representatives of the pre-European woodland understorey, and should be central to any conservation plan for the woodlands. Selected larger remnants are needed to complement these, however, to increase the total area of woodland conserved, and, because most little-grazed remnants are cleared, to represent the ecosystem in its original structural form. For the maintenance of native plant diversity and composition in little-grazed remnants, it is critical that livestock grazing continues to be excluded. For grazed remnants, maintenance of a site in its current state would allow continuation of past management, while restoration to a pre-European condition would require management directed towards weed removal, and could take advantage of the difference noted in the predominant life-cycle of native (perennial) versus exotic (annual or biennial) species.


1995 ◽  
Vol 22 (2) ◽  
pp. 217 ◽  
Author(s):  
IF Lumsden ◽  
AF Bennet

A total of 2075 captures of 11 taxa of bats was recorded during an extensive survey of the vertebrate fauna of the semi-arid Mallee region of Victoria. A further two species, Pteropus scapulatus and Saccolaimus flaviventris, are known from previous records, thus bringing the total to 13 taxa known from the region. There was a marked seasonality in activity patterns and in reproduction. Activity, as revealed by trap captures, peaked over the spring to early autumn months when daytime temperatures are high and nights are mild. Births occurred from October to December, lactating females were recorded from November to February, and juveniles were trapped between December and late February, with minor variation in timing between species. Morphometric measurements revealed that females were generally larger and heavier than males. There was a high level of overlap of species between broad vegetation types. Woodland habitats, especially Riverine Woodland, tended to have a higher frequency of capture and a greater species richness of bats per trapping event than did Mallee Shrubland. The assemblage of bats in the Mallee region, Victoria, like those in other semi-arid regions of southern Australia, includes species that are widespread in Australia (e.g. Chalinolobus gouldii and Nyctophilus geoffroyi), together with species that primarily occur in semi-arid and arid environments (e.g. N. timoriensis, Scotorepens balstoni and Vespadelus baverstocki). This region, which includes mesic riverine habitats, also supports a group of species that are characteristic of temperate south-eastern Australia (e.g. C. morio, V. regulus and V. vulturnus). In comparison with assemblages from temperate and tropical environmental regions, those from the semi-arid region tend to have a lower species richness with fewer families represented, a higher level of insectivory, and a smaller modal body size. The conservation status of bats from the Mallee region, Victoria, is believed to be secure, although the status of N. timoriensis warrants further attention.


2012 ◽  
Vol 63 (8) ◽  
pp. 659 ◽  
Author(s):  
Jed I. Macdonald ◽  
Zeb D. Tonkin ◽  
David S. L. Ramsey ◽  
Andrew K. Kaus ◽  
Alison K. King ◽  
...  

Defining the ecological impacts conferred by invasive fishes provides a framework for evaluating the feasibility of control efforts in invaded waterways, and for predicting the consequences of future incursions. Eastern gambusia (Gambusia holbrooki) is a remarkably successful invader of freshwater systems worldwide, with the capacity to detrimentally impact native fishes both directly (e.g. competition, predation, agonistic interactions) and indirectly (e.g. triggering trophic cascades). Here, we modelled the influence of eastern gambusia and several environmental covariates on fish species diversity, abundance and condition based on quantitative survey data collected from 93 wetlands in south-eastern Australia. We predicted that small-bodied, wetland specialist species sharing dietary- and habitat-niches with eastern gambusia would be most severely impacted, and that environmental stressors associated with wetland drying during late summer would magnify these impacts. Eastern gambusia influenced the occurrence, abundance and/or body condition of most common wetland species; however, the direction and level of impact appeared dependent on both biotic and environmental forces. From these results, we postulate that generalist life-history strategies that permit niche-segregation may release some native species from competitive/predatory pressures, allowing coexistence with eastern gambusia in resource-limited, environmentally harsh habitats, whilst specialist species that occupy narrower ecological niches may be less resistant.


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