The Brigalow Catchment Study: II. Clearing brigalow (Acacia harpophylla) for cropping or pasture increases runoff

Soil Research ◽  
2007 ◽  
Vol 45 (7) ◽  
pp. 496 ◽  
Author(s):  
C. M. Thornton ◽  
B. A. Cowie ◽  
D. M. Freebairn ◽  
C. L. Playford

The Brigalow Catchment Study (BCS) was established to determine the impact on hydrology when brigalow land is cleared for cropping and grazing. The paired catchment study was commenced in 1965 using catchments of approximately 15 ha, with natural vegetation dominated by brigalow scrub (Acacia harpophylla). Three contiguous catchments were selected near Theodore in central Queensland to represent the extensive brigalow bioregion of central and southern Queensland and northern New South Wales (~40 Mha). The hydrology of the 3 catchments was characterised during a 17-year calibration period (1965–81). The catchments were considered hydrologically similar, with sufficient data available for an empirical comparison between catchments. In 1982, two of the catchments were cleared, with one developed for cropping and the other sown to improved pasture. The third catchment was used as an uncleared control. Hydrologic characteristics were then compared for the following 21 years. In their virgin state, the catchments behaved similarly, with average annual runoff being 5% of annual rainfall. Once cleared, total runoff from the cropping catchment increased to 11% of annual rainfall and total runoff from the pasture catchment increased to 9% of annual rainfall; however, timing of the individual runoff events varied between land uses. In order to confirm that changes in hydrology were a function of land use and not just seasonal variability or sampling error, several analytic techniques were used: a simple comparison of runoff totals, comparison of events, comparison of probability of exceedance for daily runoff, and comparison of predicted and observed runoff using a water balance modelling approach.

Soil Research ◽  
2015 ◽  
Vol 53 (2) ◽  
pp. 178 ◽  
Author(s):  
Xihua Yang ◽  
Bofu Yu

Considerable seasonal and inter-annual changes exist in rainfall amount and intensity in New South Wales (NSW), Australia. These changes are expected to have significant effect on rainfall erosivity and soil erosion by water, but the magnitude of the impact is not well quantified because of the non-linear and dynamic nature of the relationship between rainfall amount and rainfall erosivity. The primary aim of this study was to model spatial and temporal variations in rainfall erosivity and impacts on hillslope erosion across NSW. We developed a daily rainfall erosivity model for NSW to calculate monthly and annual rainfall erosivity values by using gridded daily rainfall data for a continuous 53-year period including a baseline period (1961–90) and a recent period (2000–12). Model parameters were improved based on their geographic locations and elevations to be truly geo-referenced and representative of the regional relationships. Monthly and annual hillslope erosion risk for the same periods was estimated with the Revised Universal Soil Loss Equation. We produced finer scale (100-m) maps of rainfall erosivity and hillslope erosion through spatial interpolation techniques, and implemented the calculation of rainfall erosivity and hillslope erosion in a geographic information system by using automated scripts so that it is fast, repeatable and portable. The modelled rainfall erosivity values were compared with pluviograph calculations and previous studies, and the Nash–Sutcliffe coefficient of efficiency is >0.90. Outcomes from this study provide not only baseline information but also continuous estimates of rainfall erosivity and hillslope erosions allowing better monitoring and mitigation of hillslope erosion risk in NSW.


2013 ◽  
Vol 12 (2) ◽  
pp. 119-125

The present study concerns the impact of a change in the rainfall regime on surface and groundwater resources in an experimental watershed. The research is conducted in a gauged mountainous watershed (15.18 km2) that is located on the eastern side of Penteli Mountain, in the prefecture of Attica, Greece and the study period concerns the years from 2003 to 2008. The decrease in the annual rainfall depth during the last two hydrological years 2006-2007, 2007-2008 is 10% and 35%, respectively, in relation to the average of the previous years. In addition, the monthly distribution of rainfall is characterized by a distinct decrease in winter rainfall volume. The field measurements show that this change in rainfall conditions has a direct impact on the surface runoff of the watershed, as well as on the groundwater reserves. The mean annual runoff in the last two hydrological years has decreased by 56% and 75% in relation to the average of the previous years. Moreover, the groundwater level follows a declining trend and has dropped significantly in the last two years.


1996 ◽  
Vol 36 (3) ◽  
pp. 299 ◽  
Author(s):  
TS Andrews ◽  
RDB Whalley ◽  
CE Jones

Inputs and losses from Giant Parramatta grass [GPG, Sporobolus indicus (L.) R. Br. var. major (Buse) Baaijens] soil seed banks were quantified on the North Coast of New South Wales. Monthly potential seed production and actual seed fall was estimated at Valla during 1991-92. Total potential production was >668 000 seeds/m2 for the season, while seed fall was >146000 seeds/m2. Seed fall >10000 seeds/m2.month was recorded from January until May, with further seed falls recorded in June and July. The impact of seed production on seed banks was assessed by estimating seed banks in the seed production quadrats before and after seed fall. Seed banks in 4 of the 6 sites decreased in year 2, although seed numbers at 1 damp site increased markedly. Defoliation from mid-December until February, April or June prevented seed production, reducing seed banks by 34% over 7 months. Seed banks in undefoliated plots increased by 3300 seeds/m2, although seed fall was estimated at >114 000 seeds/m2. Emergence of GPG seedlings from artificially established and naturally occurring, persistent seed banks was recorded for 3 years from bare and vegetated treatment plots. Sown seeds showed high levels of innate dormancy and only 4% of seeds emerged when sown immediately after collection. Longer storage of seeds after collection resulted in more seedlings emerging. Estimates of persistent seed banks ranged from 1650 to about 21260 seeds/m2. Most seedlings emerged in spring or autumn and this was correlated with rainfall but not with ambient temperatures. Rates of seed bank decline in both bare and vegetated treatment plots was estimated by fitting exponential decay curves to seed bank estimates. Assuming no further seed inputs, it was estimated that it would take about 3 and 5 years, respectively, for seed banks to decline to 150 seeds/m2 in bare and vegetated treatments.


1995 ◽  
Vol 37 (2) ◽  
pp. 203-217 ◽  
Author(s):  
Michael O'Donnell

Decentralizing industrial relations within New South Wales is a central recom mendation of the Niland Green Paper (1989). Decentralism also represents the cornerstone of the New South Wales government's industrial relations reform agenda enshrined in the New South Wales Industrial Relations Act 1991. To date there has been little analysis of the impact o f this legislative change on industrial relations in the New South Wales public sector. This paper provides a case study that examines the degree to which responsibility for bargaining has been devolved within the Parks and Gardens of the New South Wales Ministry for the Environ ment. It argues that, in contrast to the rhetoric of the New South Wales Act, the central agency presiding over the introduction of enterprise bargaining in the public sector, the Public Employment and Industrial Relations Authority; has been reluctant to delegate responsibility to parties in the workplace.


2005 ◽  
Vol 29 (5) ◽  
pp. 429-435 ◽  
Author(s):  
Patricia Kenny ◽  
Emily Lancsar ◽  
Jane Hall ◽  
Madeleine King ◽  
Meredyth Chaplin

2018 ◽  
Vol 58 (8) ◽  
pp. 1470
Author(s):  
J. S. Richards ◽  
M. A. Sladek ◽  
G. J. Lee

Reproduction is an important driver of profitability in commercial sheep flocks. Historically, Merino flocks have been run with a fixed age structure, ignoring individual merit and casting for age at a specific age. More recently, research has focussed on utilising the variation within age groups by keeping productive older ewes longer and culling less productive ewes earlier. Previous studies have also examined the effect of age on reproduction and the impact of reproduction status on productivity, but little research has been conducted on cumulative effects of reproductive performance on later productivity, reproduction and health. The present study examined the impact of higher lifetime reproduction on other key production and fitness traits in older ewes run under commercial conditions. Data were collected from two commercial wool-producing properties in the South West Slopes and the Central West Plains of New South Wales during 2009–2011. Reproduction, fleece measurements, bodyweight and condition and dental health were recorded during the study. The results showed that age had a bigger effect on productivity and dental health than did cumulative lifetime reproduction. Environment and genetics determined the level of impact, with minimal loss in productivity from increased age of animals occurring in the South West Slopes flock, whereas the Central West Plains flock would appear to require closer monitoring of productivity as ewes aged. The data collected did not allow separation of the genetic and environmental influences within the study. Retaining animals with a higher reproductive performance past normal culling age does not necessarily result in reduction of productivity or ewe health, but this must be monitored.


2021 ◽  
Vol 55 (1) ◽  
pp. 84-94
Author(s):  
Andrea Wallace ◽  
Brian Dollery

Abstract In response to the COVID-19 pandemic, the New South Wales (NSW) government ordered the closure of all municipal libraries in order to limit the impact of the contagion. As a result, 372 public libraries in NSW ceased operation on the 23rd March 2020. While the closure of public libraries will undoubtedly contribute to restricting the spread of the coronavirus, given the pivotal role played by municipal libraries in local communities, as well as the special characteristics of library patrons, it will have other negative consequences. In this paper we consider the impact of the closure of municipal libraries in NSW from two perspectives: (a) its effect on the fiscal circumstances of local authorities and (b) its impact on the spread of the corona contagion as well as its broader effects on local community wellbeing. We conclude that rather than complete closure, partial constraints on library use should have been considered.


Author(s):  
Wojciech Niedbała ◽  
Agnieszka Napierała ◽  
Szymon Konwerski ◽  
Michał Zacharyasiewicz ◽  
Jerzy Błoszyk

The authors of the study present an analysis of the structure and changes in the examined community of ptyctimous mites (Acari: Acariformes: Oribatida) found in Dorrigo National Park in Australia. The research was conducted during two periods: between 1990 and 1993 and later in 2007. The analysed mite community comprises 35 species, though, the dominance and frequency of particular species were different for each period. In the first research period (1990–1993) in the area of Dorrigo National Park, 28 species were recorded, whereas in 2007 – 23 species were found. There were 16 species that occurred in both research periods, and 12 species only in the samples collected in the 90’s, and 7 species only in those collected in 2007. The analysis also embraces the geographical distribution of the species in the area of Australia. Three species were designated as endemic, occurring only in the area of the examined national park (Austrophthiracarus dissonus Niedbała et Collof, 1997, Austrophthiracarus parapulchellus Niedbała, 2006 and Notophthiracarus distinctus Niedbała, 1989). The analysed samples contained only few specimens of these species. Due to the low abundance, great rarity of the local populations and high endemism, these species should be regarded as potentially endangered (EN according to the IUCN scale). A comparative analysis of the community from Dorrigo National Park (New South Wales) with those found in other larger areas of Australia in Victoria (Otway Ranges Area, Yarra Ranges Area, Strzelecki Ranges Area and Errinundra Plateau Area) examined by Niedbała and Szywilewska-Szczykutowicz (2017) has revealed that the communities found in Dorrigo National Park contained far more species, which constituted 30% of the whole fauna of Australia. In contrast to the communities of ptyctimous mites from Dorrigo, the individual communities in the area of Victoria contained only between 5% and 14% of all known species in Australia from this group.


Sign in / Sign up

Export Citation Format

Share Document