Comparison of Wheel Point and Point Frame Methods for Plant Cover Measurement of Semiarid and Arid Rangeland Vegetation of New South Wales.

1994 ◽  
Vol 16 (1) ◽  
pp. 94
Author(s):  
H Arzani ◽  
GW King

Ground cover is frequently estimated in rangeland monitoring and it is an important intermediate measurement between biomass estimation and satellite imagery. As a preliminary phase in a longer term program, wheel point and point frame methods were used to measure vegetation cover on four permanent Soil Conservation Service transects at each of four land systems in western New South Wales, at Nyngan (410 mm average annual rainfall), at Cobar (364 mm average annual rainfall) and two at Fowlers Gap (200 mm average annual rainfall) north of Broken Hill. The majority of this work used 400 wheel point hits per transect and 100 point quadrats sub sampled 9 - 13 times along each of four transects. There was no statistically significant difference between these techniques for total foliage cover over a combined analysis of all sites under pre-drought conditions, and for pre-drought and post-drought at Cobar. However, there was a 10% difference estimated between the techniques for total foliage cover at Nyngan when it was analysed in isolation. There were no consistent differences in technique for cover estimation for more than 40 plant species including annual grasses and herbs, perennial grasses and saltbushes. Significant differences between techniques were found for Medicago sp. and Thyridolepis mitchelliana on one occasion. We believe that these differences were due to the problems of finding small plants in tall grass and identifying heavily grazed grasses during drought conditions at Cobar and, in the latter case, this was also associated with a significantly greater estimate of mean cover for all grasses and thus total foliage cover. Although there was generally no statistical difference between techniques our observations suggest that the point frame tends to give lower estimates of cover than the wheel point in the situations measured. This may be associated with the circumference of the marker pins on the wheel point or perhaps observer error but as this effect appeared to be more noticeable with grasses we suspect that the former is most likely. The wheel point is less time consuming, more convenient and simpler to use than the point frame, and will readily accommodate most temporal and spatial variation in sampling requirements in similar land forms in western New South Wales.

1984 ◽  
Vol 11 (3) ◽  
pp. 415 ◽  
Author(s):  
J Caughley ◽  
P Bayliss ◽  
J Giles

Annual aerial counts of kangaroos within randomly selected blocks of the western plains of New South Wales showed that the numbers of kangaroos doubled between 1975-76 and 1982, and that the widespread drought of 1982 reduced the populations on average by 43%. Localized reductions of similar magnitude occurred after regional droughts in 1977 and 1980 within parts of the monitored area. The observed trends in kangaroo numbers, with eastern and western blocks treated separately, were correlated with annual rainfall with a time lag of 6 months in the response. The relationships show that kangaroos reach their maximum rate of increase following rainfall 100 mm above the annual average in the east and approximately 50 mm above the annual average in the west. At average annual rainfall kangaroos increase at 25% (greys) and 35% (reds) per annum in the east and at 25% (greys) and 30% (reds) per annum in the west. Rate of increase is zero when rainfall is 100 mm below average in the east and approximately 60 mm below average in the west. When rainfall is below these values, kangaroo numbers decline.


1986 ◽  
Vol 26 (5) ◽  
pp. 587 ◽  
Author(s):  
M Conyers

Surface soil samples (0-10 cm) from a range of soil types were collected in south-eastern New South Wales. Linear regression and analysis of variance were used to establish that, at a given pH (0.01M CaCl2), the amount of neutral salt exchangeable aluminium in surface soils tends to increase with increasing average annual rainfall. Where aluminium toxicity is a factor limiting plant growth, soils in higher rainfall areas will generally require higher pH for the removal of aluminium from the cation exchange complex.


2014 ◽  
Vol 65 (10) ◽  
pp. 973 ◽  
Author(s):  
A. D. Swan ◽  
M. B. Peoples ◽  
R. C. Hayes ◽  
G. D. Li ◽  
G. R. Casburn ◽  
...  

In 2009, 95 farmers in the mixed farming zone of southern New South Wales (NSW), average annual rainfall 450–700 mm, were surveyed about their use of perennial pasture species. Survey responses indicated that, on average, 52% of land was under crop, 29% contained perennial pasture and 19% annual pastures. The proportion of land sown to perennial pastures and the species used differed with rainfall. Farmers identified concerns about the cost of establishment and poor survival of perennial pasture species as constraints to wider adoption. The survey also revealed that cover-cropping (sowing pasture species under the final grain crop in a cropping phase) was the dominant method of pasture establishment. Large-scale, on-farm participatory experiments were sown with the farm machinery, three at Ariah Park and one at Brocklesby in southern NSW in 2009 (annual rainfall 100 mm less than long-term average), and a further two experiments (one at each location) commenced in 2010 (annual rainfall >200 mm above average). These experiments compared the effect of cereal cover-crop sowing rate (standard rates used by the collaborating farmer and half of the standard rate) on the establishment of the perennials lucerne (Medicago sativa), phalaris (Phalaris aquatica), cocksfoot (Dactylis glomerata), and chicory (Cichorium intybus) sown in different mixes and rates with various annual legume species. The persistence and productivity of individual species were monitored for 2 years after sowing. Results indicated little or no effect of the presence of a cover-crop on the initial establishment of any of the perennials, but pasture species survival were severely affected by cover-crop sowing rates as low as half of the farmer practice (10 kg barley or 12 kg wheat ha–1) in 2009. Despite higher than average annual rainfall in 2010 and 2011, the residual effect of establishing pastures under a cover-crop in 2009 was poorer persistence and lower productivity by lucerne at the standard cover-cropping rate, and by phalaris, cocksfoot and chicory at all cover-crop rates, and an increased incidence of weeds. Similar responses to cover-cropping occurred between 2010 and 2012, even with the wetter establishment conditions in 2010, for phalaris, chicory and weeds, despite demonstration at Ariah Park that higher populations of individual perennial species could be achieved by doubling the sowing rate of pasture seed in 2010. Lucerne compensated for lower plant numbers by increasing herbage growth in response to rainfall, but phalaris could not and total pasture productivity over the first 2 years after establishment was greatly reduced by the use of cover-crops in both 2009 and 2010. Cover-cropping also reduced annual legume seedset, which could have implications for future pasture performance. Lucerne was the most consistently productive perennial pasture species evaluated regardless of establishment technique or climatic conditions.


1995 ◽  
Vol 35 (1) ◽  
pp. 93 ◽  
Author(s):  
RD FitzGerald ◽  
ML Curll ◽  
EW Heap

Thirty varieties of wheat originating from Australia, UK, USA, Ukraine, and France were evaluated over 3 years as dual-purpose wheats for the high rainfall environment of the Northern Tablelands of New South Wales (mean annual rainfall 851 mm). Mean grain yields (1.9-4.3 t/ha) compared favourably with record yields in the traditional Australian wheatbelt, but were much poorer than average yields of 6.5 t/ha reported for UK crops. A 6-week delay in sowing time halved grain yield in 1983; cutting in spring reduced yield by 40% in 1986. Grazing during winter did not significantly reduce yields. Results indicate that the development of wheat varieties adapted to the higher rainfall tablelands and suited to Australian marketing requirements might help to provide a useful alternative enterprise for tableland livestock producers.


2000 ◽  
Vol 6 (1) ◽  
pp. 18 ◽  
Author(s):  
Rodney P. Kavanagh ◽  
Rodney P. Kavanagh

Populations of arboreal marsupials were assessed in forests before and after logging at different levels of logging intensity to determine the sensitivity of these species to habitat disturbance. The logging treatments imposed were unlogged controls and two intensities of integrated logging for sawlogs and woodchips. The mean basal area of trees retained in logged blocks ranged from 83% to 35% of pre-logging levels. The objective of the study was to develop better methods for managing arboreal marsupials within the wood production forests of southeastern New South Wales. Seven species of arboreal marsupials were recorded during the study, but the Greater Glider Petauroides volans was the only species recorded in sufficient numbers for analysis (86% of all records). No significant differences were observed between the treatments in counts of the Greater Glider before and after logging. However, given the observed trend and an a priori expectation of a decline in numbers of this species following intensive logging, a one-tailed statistical test was applied which resulted in a significant difference at P = 0.08 for the contrast between the unlogged controls and the most intensively logged treatment. The existence of a threshold in logging intensity within the range of 21 % to 39% retention of tree basal area, below which numbers of the Greater Glider suffer a marked decline, was inferred on the basis of comparisons with the results of other studies. Factors other than logging were important in determining the distribution of the Greater Glider. Elevation, in particular, was a significant environmental variable, with Greater Gliders more likely to occur in forests above 845 m a.s.1. The presence and absence of particular tree species also influenced the distribution of the Greater Glider. Forests containing Manna Gum E. viminalis and Mountain Gum E. dalrympleana were highly preferred compared to forests with a high proportion of E. obliqua. The presence of E. cypellocarpa appeared to improve the quality of habitat for the Greater Glider in forests dominated by E. obliqua. This study has shown that Greater Glider populations can be maintained at or near pre-logging levels when at least 40% of the original tree basal area is retained thoughout logged areas and when the usual practice of retaining unlogged forest in riparian strips is applied.


Sexual Health ◽  
2007 ◽  
Vol 4 (4) ◽  
pp. 306
Author(s):  
D. Mossman ◽  
C. Ooi ◽  
M. Loewenthal ◽  
M. Boyle

Background: Chlamydia Trachomatis is one of the most common sexually transmitted infections in Australia and world wide. This study was undertaken to map the frequency of Chlamydia genotypes in regional New South Wales (NSW), Australia, to explore the potential utility of genotype analysis in defining local sexual networks, and to investigate whether patterns of genotype frequency are correlated with demographic factors, including age and gender. Methods: We studied 204 urine samples infected with Chlamydia trachomatis, as determined by PCR analysis using the COBAS Amplicor system. Samples were collected from wide geographic area of regional New South Wales (Hunter, New England, Northern Rivers, South Eastern New South Wales). Sequencing and genotyping were performed after nested PCR of the omp1 gene. Results: Genotype E was found in 42.6% of infections, with genotypes F (23.5%) and G (16.7%) other common causes of infection. Mixed infection occurred in only 3 cases. There was no significant difference in genotype frequency based on gender or geographic location. There was a significant difference in gender frequency based on patient age, with older patients significantly more likely to demonstrate infection with genotype G (mean age (years) 23.7+/-7.29 sd, E: 21.7 +/-5.7 sd; G: 28.9; sd 10.18; p�=�0.022). Conclusions: There was no significant difference in genotype frequency in the various regions of New South Wales, suggesting genotype analysis is of limited use in defining sexual networks in regional NSW. The finding of a higher frequency of genotype G in older patients raises the possibility that genotypic variation may be driven by immune responses to genotypes that occur more frequently at a younger age. These results may have implications for the future design of a chlamydial vaccine.


1997 ◽  
Vol 24 (1) ◽  
pp. 1 ◽  
Author(s):  
P. C. Catling ◽  
R. J. Burt

The distribution and abundance of ground-dwelling mammals in the major vegetation alliances in the eucalypt forests within an area of c. 24000 km2 in north-eastern New South Wales were examined. Data for 33 species of mammal from 21 areas containing 30 vegetation alliances were collected. Four notable aspects of the data were the absence or low abundance of the introduced fox (Vulpes vulpes), the widespread distribution and abundance of the cat (Felis catus), the diversity and abundance of medium-sized native mammals and the diversity of small mammals. Although differences occurred between areas and alliances, there was no significant difference in the number of native and introduced species. The ground-dwelling mammals present in the eucalypt forests of north-eastern New South Wales were more diverse and in greater abundance than those found in forests of south-eastern New South Wales. However, some species, such as the spotted-tailed quoll (Dasyurus maculatus), appear to be in urgent need of protection and management if they are to persist.


2012 ◽  
Vol 52 (7) ◽  
pp. 675 ◽  
Author(s):  
R. D. Bush ◽  
R. Barnett ◽  
I. J. Links ◽  
P. A. Windsor

The prevalence of Caseous lymphadenitis (CLA) in Australia was estimated to be 5.2% using 2009 abattoir surveillance data from all States supplied by Animal Health Australia involving 5029 lines comprising 1 339 463 sheep. This is a decrease from the 26% estimated in a similar study in 1995. There was a significant difference (P < 0.001) in CLA prevalence between all states except Tasmania and Victoria (P = 0.75) with prevalences of 12.8 and 12.9%, respectively. Western Australia recorded the lowest prevalence with 1.0%. The average CLA prevalence for New South Wales was 5.3% and within three surveyed Livestock Health and Pest Authority regions (Tablelands, Central North and Central West) was 2.9, 4.9 and 4.4%, respectively. The attitude of the majority of producers surveyed in these three Livestock Health and Pest Authority areas was that CLA was of little or no significance (75%) but were aware of the need for CLA control with ~68% using 6-in-1 vaccine, though only 39.9% as recommended. It appears that the prolonged use of CLA vaccination has been successful in reducing the prevalence of CLA across Australia and particularly in New South Wales. Further improvements in communication of information on preventative management practices associated with lice control, importance of using an approved vaccination program, plus increasing producers’ awareness of the importance of CLA control, are indicated.


1981 ◽  
Vol 21 (109) ◽  
pp. 179 ◽  
Author(s):  
SJ Gray ◽  
JP Kennedy

Internal parasitism and its effects on survival, wool growth and liveweight gain of weaner sheep were studied over 3 years from 1977 to 1979 at Fowlers Gap Research Station, Broken Hill, New South Wales. During this period, annual rainfall was 33, 152 and 141 % respectively, of the annual mean of 195 mm. Worm burdens and production of sheep given anthelmintic treatment at approximately monthly intervals were compared with those in untreated sheep. Total worm counts in untreated sheep were low, ranging from 1 5 to 3750. Nematodirus spp. were the most common nematode parasites recovered. lnfections with Trichostrongylus spp, were recorded in 2 of the 3 years; T. rugatus was the only species represented when species identification was made in 1979. Infections of Haemonchus contortus were only detected in the last year. Tapeworms (Moniezia spp.) were occasionally recovered. Anthelmintic treatment reduced worm burdens to a very low level but had no significant effect on survival rate, liveweight gain, or wool production. We concluded that in the arid areas of western New South Wales, worm infection would not limit production or cause mortality in young sheep, except in unusually wet years.


Sign in / Sign up

Export Citation Format

Share Document