Demographic characteristics of mallee pine (Callitris verrucosa) in fire-prone mallee communities of central New South Wales

2002 ◽  
Vol 50 (5) ◽  
pp. 653 ◽  
Author(s):  
R. A. Bradstock ◽  
J. S. Cohn
Keyword(s):  
New South ◽  
New South Wales ◽  
Plant Age ◽  
Age Classes ◽  
Site Factors ◽  
Feedback Effects ◽  
South Wales ◽  
Seed Crops ◽  
In Fire ◽  
Age Range

Aspects of the demography of Callitris preissii subsp. verrucosa (Cunn. ex. Endl.) J.Garden populations were studied in semi-arid mallee communities situated on sandy soils in central New South Wales. Rates of survival and fecundity were estimated in a range of populations of differing age (year of origin or last fire: 1920, 1957, 1972, 1974 and 1985) that were monitored between 1987 and 1997. Rates of survival of juveniles and adults were high (>0.99 p.a.), although juveniles less than 5 years of age survived at lower rates. Estimated seedbank at the time of first tagging (no. of closed cones per plant) followed an increasing trend with plant age. Density, overstorey, topography and within-age-class site factors had significant effects on stored seedbanks in particular age-classes. There was high interannual variation (1989 v. 1990) in the size of crops of new cones. Trends in seedbank with plant age and seed release rates from tagged cones indicated that the species exhibits strong serotiny. Measurements of litter weight and depth beneath plants from 1920 and 1957 age-classes, indicated relatively low fuel loadings (about 0.2�kg m–2). Bark was sufficiently thick in c. 60-year-old plants to render stems resistant to low-intensity fires. Thus, it is predicted that the probability of propagation of fire in populations >50 years old may decline and that survival of fire in this age range may increase. Given patterns of survivorship, fecundity and seedbank accumulation, populations may decline when fires are relatively frequent (<15-year interval). At longer intervals there is potential for population densities to remain stable or increase, although the nature of variability in sizes of individual seed crops may have a predominant influence on dynamics. The combination of strong serotiny and negative feedback effects of plant populations on their flammability is a paradox, given the likelihood that seedling establishment is tightly keyed to fire.

Effects of predation on the size structure of the gastropod Salinator solida (Martens) populations at Towra Point, NSW, Australia

1998 ◽  
Vol 49 (8) ◽  
pp. 779 ◽  
Author(s):  
A. C. Roach
Keyword(s):  
Population Size ◽  
Mangrove Forest ◽  
Size Structure ◽  
New South ◽  
New South Wales ◽  
Age Classes ◽  
South Wales ◽  
Mean Size ◽  
The Mean ◽  
Pulmonate Gastropod

The pulmonate gastropod Salinator solida inhabits intertidal mangrove and saltmarsh communities throughout New South Wales. Studies at Towra Point and elsewhere have consistently found that the mean size and range of size/age classes increases with height on shore. Afield experiment was undertaken to test the hypothesis that predation was responsible for reductions in the mean size of individuals inS. solida populations in the upper mangrove forest. Twelve months after the establishment of fenced plots, there were significantly more individuals in the fenced plots than in unfenced or partially fenced control plots; the number of snails in the 4.1–8.0 mm and > 8.1 mm size classes had increased in the fenced plots but not in the control plots. The results suggest that predation is a major factor determining variation in population size structure by acting to significantly reduce the abundance of adults in the upper mangrove forest.

The population pattern of Miniopterus schrebersii (Chiroptera) in north-eastern New South Wales

1966 ◽  
Vol 14 (6) ◽  
pp. 1073 ◽  
Author(s):  
PD Dwyer
Keyword(s):  
New South ◽  
New South Wales ◽  
Population Characteristics ◽  
Adult Males ◽  
Age Classes ◽  
Adult Females ◽  
South Wales ◽  
Wide Range ◽  
North Eastern ◽  
Population Pattern

In north-eastern New South Wales Miniopterus schreibersii is found at a wide range of cave and mine roosts as colonies that may include up to several thousands of individuals. Between April 1960 and September 1963 a field study of the biology and population characteristics of this species was carried out. Field criteria permitting aging of individuals were developed. Age classes considered were juveniles (< 9 months), yearlings (9-21 months), and adults (> 21 months). Seasonal changes in numbers, and in the sex and age composition of colonies were followed in detail at several roosts and comparative information was obtained at others. Movement patterns were assessed by a marking and recapture programme in which 1365 recoveries were obtained from a marked (toe clips and bands) population of 8775. Conspicuous sex or age biases or both were shown to exist in clusters of M. schreibersii at specific roosts and it was suggested that clustering in this species functions, in part, as a social spacing mechanism. Segregation of different sex or age classes at specific colonies permitted classification of colonies as (1) maternity colonies in which adult females and their young predominate, (2) "adult" colonies which are predominantly adult, or adult and yearling, in composition, and (3) "juvenile" colonies in which juveniles, or juveniles and yearlings, are almost prevalent. The observed social biases of colonies appeared to be related to particular phases of the reproductive cycle. Certain adult colonies were interpreted as important sites of copulatory behaviour. Recovery data for two of these mating colonies showed that adult females were more transient members of the colony than adult males. Juveniles are often well represented at adult colonies in the autumn, and during this season their presence may be correlated with a drop in the abundance of older males.

Effects of herbicides on wallaby grass (Danthonia spp.). 2. Established plants

1994 ◽  
Vol 34 (6) ◽  
pp. 759 ◽  
Author(s):  
GM Lodge ◽  
MG McMillan
Keyword(s):  
Seed Yield ◽  
Dry Matter ◽  
New South ◽  
New South Wales ◽  
Early Spring ◽  
Dry Matter Yield ◽  
Annual Grass ◽  
South Wales ◽  
Seed Crops ◽  
Seed Yields

Three experiments were conducted at Tamworth, New South Wales, in 1990-92 to assess the effects of a range of broadleaf and grass herbicides, 6 rates of glyphosate and paraquat + diquat, and 4 rates of 2,4-D amine and diuron on the phytotoxicity, dry matter yield, inflorescence number, and seed yield of established Danthonia (wallaby grass) plants. Phytotoxicity was scored visually on a 0-5 scale (0, no phytotoxicity; 5, 100%). Danthonia dry matter yields were not affected (P<0.05) by any herbicide tested, except glyphosate applied at 2360 g a.i./ha. Phytotoxicity was highest for the glyphosate treatment (1440 g a.i./ha) in that study. All rates of glyphosate, and paraquat + diquat rates >250 + 150 g a.i./ha reduced (P<0.05) inflorescence number compared with the unsprayed control. Paraquat + diquat had no significant effect on seed yield, but glyphosate rates >360 g a.i./ha reduced (P<0.05) seed yield compared with the control. In 1992, no damage was observed on 2,4-D amine treatments and phytotoxicity scores were low (<2) for all diuron treatments. Danthonia inflorescence numbers and seed yields were higher (P<0.05) on plots mown in early spring than on unmown treatments. The lack of effect of herbicides such as diclofopmethyl, simazine, fenoxaprop-ethyl, and diuron on Danthonia dry matter yield, and the low phytotoxicity, indicated that a range of chemicals may be used on established Danthonia swards to control perennial and annual grass weeds. Seed yield was more affected than dry matter yield by herbicide, and paraquat + diquat should be used in preference to glyphosate on seed crops.

The Survival and Population Response to Frequent Fires of Two Woody Resprouters Banksia serrata and Isopogon anemonifolius

1988 ◽  
Vol 36 (4) ◽  
pp. 415 ◽  
Author(s):  
RA Bradstock ◽  
PJ Myerscough
Keyword(s):  
High Intensity ◽  
New South ◽  
Population Decline ◽  
New South Wales ◽  
Fire Regimes ◽  
Small Tree ◽  
Population Response ◽  
South Wales ◽  
In Fire

Plants of B. serrata and I. Anemonifolius resprout after fire, although the species differ in morphology (single-stemmed small tree, multistemmed low shrub respectively). If fires occur before newly established plants are fire-tolerant, populations will decline. The age of first fire tolerance was found to be lower in B. serrata (6 years) than in I. Anemonifolius (about 13 years). Rates of survival between and during fires were measured in the field along with rates of stem regrowth in fire-tolerant B. serrata juveniles. These results were used to predict rates of population decline under repeated fires sufficiently closely spaced to prevent the survival of newly established genets. In both species, juveniles were more prone to death than adults in fires and high-intensity fires caused most deaths. In B. serrata, adult stems (>2.0 cm d.b.h.) are mostly fire-tolerant, but fires less than 10 years apart can prevent many juveniles which survive from reaching adulthood. This restriction is less likely in I. Anemonifolius. As a result stands of B. serrata may decline more rapidly than I. Anemonifolius under 5-year fire cycles. I. Anemonifolius populations, however, may be more prone to decline when the interval between fires is slightly longer (e.g. 10 years) because lignotubers in young juveniles develop at a slower rate than in B. serrata. Extinction or substantial depletions of adult numbers may be approached in stands of either species after 50 years under some repeated 5- or 10-year fire cycles. The rate of such declines will depend directly on the structure of populations (proportions of adults and juveniles). Declines in populations of these resprouters may be likely under current fire regimes within the Sydney region of New South Wales, although these species are more likely to persist through long runs of frequent fire (<lo year interval) than some cohabiting species of obligate seeders.

Inter- and Intra specific Conflict between Arid-zone Kangaroos at Watering Points

1985 ◽  
Vol 12 (3) ◽  
pp. 337 ◽  
Author(s):  
DB Croft
Keyword(s):  
Arid Zone ◽  
New South ◽  
New South Wales ◽  
Agonistic Behaviour ◽  
Age Classes ◽  
Equivalent Age ◽  
Red Kangaroo ◽  
South Wales ◽  
Macropus Rufus ◽  
Drinking Place

Red kangaroos Macropus rufus and euros M. robustus were observed drinking at a stock trough in northwestern New South Wales. The populations of both species were divided into five age-sex classes. Drinking and agonistic behaviour was similar across classes and species. Inter- and intraspecific conflict between these classes for a drinking position were analysed. Within species, there is a size-related hierarchy for gaining and maintaining a drinking space, favouring the larger class. Interspecifically, euros, the smaller species, dominate equivalent age classes of red kangaroos. Retaliation in aggressive encounters is more likely between adjacent rank neighbours than those more distant in the hierarchy. Drinking individuals tend to win more encounters than individuals attempting to gain a drinking place. The longer a kangaroo has been drinking the less likely it is to act aggressively to an intruder. When drinking, spacing between kangaroos is essentially random. Both species displace another individual at a similar mean distance of 0.6-0.8 m, but spacing between adult euros is wider than between adult red kangaroos. Spacing is modified by the relative positions of neighbours on either side of the trough. The results are discussed in terms of social and other factors that may have led to the euro's dominance of the red kangaroo at water.

scholarly journals Wildfire extreme events: Large-scale developments in fire activity of New South Wales, Australia

2021 ◽  
Author(s):  
Michael Nolde ◽  
Norman Mueller ◽  
Günter Strunz ◽  
Florian Fichtner ◽  
Simon Plank ◽  
...  
Keyword(s):  
Extreme Events ◽  
Large Scale ◽  
New South ◽  
New South Wales ◽  
The United States ◽  
Burnt Area ◽  
South Wales ◽  
Fire Activity ◽  
In Fire

&lt;p&gt;Disastrous wildfires have occurred in many parts of the world during the last two years (2019 and 2020), most notably in South America, Australia, the United States, and regions north of the polar circle. Such extreme wildfire events pose a pervasive threat to human lives and property and have thus been widely recognized in the global media. This study focusses on large-scale developments in fire activity. It investigates the occurrence of burnt areas regarding several relevant parameters, namely fire extent, fire severity and fire seasonality. The entirety of those parameters allows an extensive insight regarding large-scale, long-term fire activity trends.&lt;/p&gt;&lt;p&gt;The burnt area derivation process, which is fully automated, is described in the literature (see reference below). The analysis is based on an extensive set of satellite data, specifically 9,612 granules of the MODIS MOD09/MYD09 product in conjunction with 3,503 tiles of the OLCI (Ocean and Land Colour Instrument) instrument onboard Sentinel-3.&lt;/p&gt;&lt;p&gt;The study design consists of two parts:&lt;/p&gt;&lt;p&gt;Firstly, the long-term temporal variability in fire activity, covering the time span from 2000 until 2020, is analyzed for the study region of New South Wales, Australia.&lt;/p&gt;&lt;p&gt;Secondly, the large-scale spatial variability is investigated by comparing the New South Wales extreme events in 2019/2020 with events of comparable magnitude in California, US and the Siberian taiga.&lt;/p&gt;&lt;p&gt;The study shows that New South Wales features an upward trend regarding the extent of yearly affected area, as well as a shift towards a prolongated end of the fire season towards the Autumn months. It also shows the exceptionality of the Australian wildfire activity in comparison with other geographical regions.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Reference:&lt;/p&gt;&lt;p&gt;Nolde, Michael; Plank, Simon; Riedlinger, Torsten. &quot;An Adaptive and Extensible System for Satellite-Based, Large Scale Burnt Area Monitoring in Near-Real Time.&quot; Remote Sensing 12.13 (2020): 2162.&lt;/p&gt;

Area of Distribution, Movements, Age Composition and Mortality Rates of the Australian Salmon Population in Tasmania, Victoria and New South Wales

1978 ◽  
Vol 29 (4) ◽  
pp. 417 ◽  
Author(s):  
CA Stanley
Keyword(s):  
New South ◽  
New South Wales ◽  
Age Groups ◽  
South Australia ◽  
South Wales ◽  
Younger Age ◽  
Salmon Population ◽  
Show Evidence ◽  
Western Victoria ◽  
Age Range

Two subspecies of the Australian salmon, a perciform fish, occur in eastern Australian waters. The western subspecies, Arripis trutta esper (Whitley), is found only in Tasmania and Victoria. In Tasmanian waters fish do not occur above an age of 2+ years. In Victoria about 300 000 fish (180 tonnes) of an age range from of to 5+ years are caught annually. The younger age groups are found in sheltered areas, and the older age groups along the open coastline, especially in western Victoria. Returns of tags from fish thought to be of the western subspecies indicate that movement towards Western Australia takes place via western Victoria and South Australia, rather than by a direct seawards movement. For the eastern subspecies, Arripis trutta marginata (Cuvier & Valenciennes), young fish from 0+ to 2+ years are found predominantly in Tasmania and Victoria, and older fish from 4+ years in New South Wales. Recaptures of tagged fish indicate that there is a continual movement at all stages of the life cycle from Tasmania to Victoria and then to New South Wales. Fish within New South Wales also show evidence of a movement southwards, which probably occurs only once, to the eastern Bass Strait area. Fish older than 5+ years move increasingly northwards in New South Wales waters. For the eastern subspecies estimates of M, the instantaneous annual natural mortality coefficient, range from 0.5 to 1.0, and estimates of F, the instantaneous annual fishing mortality coefficient, range from 0.3 to 0.7. It is suggested that in the present eastern subspecies fishery greater yields should result from increasing the fishing pressure up to about twice the present value.

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