Impact of Wildfire on the Avifauna of Kings Park, Perth, Western Australia

1997 ◽  
Vol 24 (6) ◽  
pp. 745 ◽  
Author(s):  
Harry F. Recher
Keyword(s):  
Western Australia ◽  
Native Vegetation ◽  
Bare Ground ◽  
Slow Recovery ◽  
New Approach ◽  
Intensive Intervention ◽  
Long Term Trends ◽  
The Impact

In January 1989, a wildfire burnt 120 ha (45%) of the 267 ha of native vegetation in Kings Park, Perth, Western Australia. The area burnt included a transect along which birds had been censused during 1986 for comparison with censuses on the same transect during 1928–37 and 1952–55. Counts of birds along the transect from 1989 to 1995 indicate a slow recovery in numbers for 11 (38%) of 29 species present in 1986. Two species disappeared from the transect, but one of these was found elsewhere in the park. There are many reasons for the changes in the avifauna of Kings Park, including changes to the structure of the vegetation, the increasing isolation of the park from other native vegetation, and changes in the distribution and abundance of species outside the Perth region. The long-term trends in the avifauna and the impact of the 1989 fire indicate that a new approach to the management of the Park’s vegetation may be required. For example, to avert continuing declines in the Park’s avifauna, it may be helpful to re-establish a canopy of eucalypts and to create a more open understorey with some bare ground. However, the impact of the 1989 fire and the slow recovery of the avifauna illustrate the sensitivity of small reserves to major disturbances and the difficulty of conserving the original biota without intensive intervention.

The impact of non-ideality on reconstructing spatial and temporal variations of aerosol acidity with multiphase buffer theory

2021 ◽  
Author(s):  
Yafang Cheng ◽  
Guangjie Zheng ◽  
Hang Su ◽  
Siwen Wang ◽  
Andrea Pozzer
Keyword(s):  
Molar Fraction ◽  
Temporal Variations ◽  
Spatial Variations ◽  
Acid Dissociation ◽  
Acid Dissociation Constant ◽  
Aerosol Acidity ◽  
Long Term Trends ◽  
Factor C ◽  
The Impact

<p>Aerosol acidity is a key parameter in atmospheric aqueous chemistry and strongly influence the interactions of air pollutants and ecosystem. The recently proposed multiphase buffer theory provides a framework to reconstruct long-term trends and spatial variations of aerosol pH based on the effective acid dissociation constant of ammonia (K<sub>a,NH3</sub><sup>*</sup>). However, non-ideality in aerosol droplets is a major challenge limiting its broad applications. Here, we introduced a non-ideality correction factor (c<sub>ni</sub>) and investigated its governing factors. We found that besides relative humidity (RH) and temperature, c<sub>ni</sub> is mainly determined by the molar fraction of NO<sub>3</sub><sup>-</sup> in aqueous-phase anions, due to different NH<sub>4</sub><sup>+</sup> activity coefficients between (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>- and NH<sub>4</sub>NO<sub>3</sub>-dominated aerosols. A parameterization method is thus proposed to estimate c<sub>ni</sub> at given RH, temperature and NO<sub>3</sub><sup>-</sup> fraction, and is validated against long-term observations and global simulations. In the ammonia-buffered regime, with c<sub>ni</sub> correction the buffer theory can well reproduce the K<sub>a,NH3</sub><sup>*</sup> predicted by comprehensive thermodynamic models, with root-mean-square deviation ~0.1 and correlation coefficient ~1. Note that, while c<sub>ni</sub> is needed to predict K<sub>a,NH3</sub><sup>*</sup> levels, it is usually not the dominant contributor to its variations, as ~90% of the temporal or spatial variations in K<sub>a,NH3</sub><sup>*</sup> is due to variations in aerosol water and temperature.</p>

Evaluating the impact of ballast undercutting on the roughness of track geometry over different subgrade conditions

2017 ◽  
Vol 232 (5) ◽  
pp. 1266-1276
Author(s):  
Kirk M Scanlan ◽  
Michael T Hendry ◽  
C Derek Martin
Keyword(s):  
Surface Roughness ◽  
Organic Soils ◽  
Western Canada ◽  
Railway Ballast ◽  
Track Geometry ◽  
Track Maintenance ◽  
Heavy Haul ◽  
Long Term Trends ◽  
The Impact

The progressive degradation of railway ballast is often cited as a primary factor that contributes to the development of track roughness, while ballast renewal (undercutting) attempts to manage its long-term development. Soft subgrades have been shown to strongly influence track geometry and are a contributing factor that has not been considered during conventional track maintenance. This study evaluated the impact of undercutting on long-term trends in track geometry roughness, and what impact softer subgrades had on the effectiveness of undercutting. A combined 6.90 km of Class II–IV heavy-haul track in Western Canada (undercut in 2010 and 2011) formed the basis for this analysis. Annual traffic on these sections typically totals 50 million gross tonnes. Long-term trends in the track crosslevel, alignment, and surface roughness after ballast renewal were derived from 50 track geometry surveys carried out over a five-year period (2010–2015). The results showed that undercutting significantly reduced track roughness over sand, silt, clay, or till subgrades; however, it was often ineffective when used over soft organic subgrades. Thus, while ballast degradation is the primary cause of track roughness in segments constructed on mineral subgrades, it is not a mechanism that results in track geometry roughness over soft organic soils.

scholarly journals The Impact of Improved Thermistor Calibration on the Expendable Bathythermograph Profile Data

2017 ◽  
Vol 34 (9) ◽  
pp. 1947-1961 ◽  
Author(s):  
Marlos Goes ◽  
Elizabeth Babcock ◽  
Francis Bringas ◽  
Peter Ortner ◽  
Gustavo Goni
Keyword(s):  
Small Sample Size ◽  
Heat Content ◽  
Small Sample ◽  
Profile Data ◽  
Expendable Bathythermograph ◽  
Different Types ◽  
Long Term Trends ◽  
The Mean ◽  
The Impact

AbstractExpendable bathythermograph (XBT) data provide one of the longest available records of upper-ocean temperature. However, temperature and depth biases in XBT data adversely affect estimates of long-term trends of ocean heat content and, to a lesser extent, estimates of volume and heat transport in the ocean. Several corrections have been proposed to overcome historical biases in XBT data, which rely on constantly monitoring these biases. This paper provides an analysis of data collected during three recent hydrographic cruises that utilized different types of probes, and examines methods to reduce temperature and depth biases by improving the thermistor calibration and reducing the mass variability of the XBT probes.The results obtained show that the use of individual thermistor calibration in XBT probes is the most effective calibration to decrease the thermal bias, improving the mean thermal bias to less than 0.02°C and its tolerance from 0.1° to 0.03°C. The temperature variance of probes with screened thermistors is significantly reduced by approximately 60% in comparison to standard probes. On the other hand, probes with a tighter weight tolerance did not show statistically significant reductions in the spread of depth biases, possibly because of the small sample size or the sensitivity of the depth accuracy to other causes affecting the analysis.

scholarly journals The Impact of Non-uniform Sampling on Stratospheric Ozone Trends Derived from Occultation Instruments

2017 ◽  
Author(s):  
Robert P. Damadeo ◽  
Joseph M. Zawodny ◽  
Ellis E. Remsberg ◽  
Kaley A. Walker
Keyword(s):  
Stratospheric Ozone ◽  
Primary Source ◽  
Data Sets ◽  
Sampled Data ◽  
Uniform Sampling ◽  
Ozone Trends ◽  
Long Term Trends ◽  
Non Uniform Sampling ◽  
The Impact

Abstract. This paper applies a recently developed technique for deriving long-term trends in ozone from sparsely sampled data sets to multiple occultation instruments simultaneously without the need for homogenization. The technique can compensate for the non-uniform temporal, spatial, and diurnal sampling of the different instruments and can also be used to account for biases and drifts between instruments. These problems have been noted in recent international assessments as being a primary source of uncertainty that clouds the significance of derived trends. Results show potential recovery trends of ~ 2–3 %/decade in the upper stratosphere at mid-latitudes, which are similar to other studies, and also how sampling biases present in these data sets can create differences in derived "recovery" trends of up to ~ 1 %/decade if not properly accounted for. Limitations inherent to all techniques (e.g., relative instrument drifts) and their impacts (e.g., trend differences up to ~ 2 %/decade) are also described and a potential path forward towards resolution is presented.

scholarly journals Investigation of the impact of the project office on the socio-economic development of the municipality

2021 ◽  
Vol 12 (1) ◽  
pp. 157-172
Author(s):  
Alla Yu. Trusova ◽  
Vladimir I. Aksenov
Keyword(s):  
Economic Development ◽  
Development Strategy ◽  
Scientific Article ◽  
Management Tools ◽  
Project Approach ◽  
Regional Development Strategy ◽  
Socio Economic Development ◽  
Long Term Trends ◽  
The Impact

The complexity of the socio-economic situation at all levels requires a detailed study of the regional development strategy issues and monitoring the implementation of presidential and government decrees. Various approaches to management were considered, for example, the national projects development implementation issues. National projecting, as a new tool for implementing state concepts, is an effective management method. The set of the project office functions provides control over the implementation of national projects at the level of development of municipalities of the Russian Federation. Historically, the level of socio-economic development of the territory has been measured and is measured using the identification of long-term trends in the development of key socio-economic indicators. The article presents a methodology that allows you to evaluate the effectiveness of project management tools since based on the results of its assessment, you can make informed management decisions and judge the effectiveness of the work of local authorities. Therefore, the aim of the scientific article was to develop an effective methodology that allows us to evaluate the effectiveness of the project office functions implemented in the management of the socio-economic development of the municipality. As a result of the study, systemic relationships were revealed of the impact of the project office on the indicators of the socio-economic development of the municipality, which was presented in the work as an important aspect of the study, the significance of which is due to the priorities of sustainable, balanced, competitive, integrated development of the Russian regions. In connection with the socio-economic policy pursued by the state, which requires speedy acceleration of the socio-economic development of municipalities, the effectiveness of the result of the application of the project approach in the municipal authorities was studied in detail.

Prehistoric Art in Europe: A Deep-Time Social History

2015 ◽  
Vol 80 (4) ◽  
pp. 635-654 ◽  
Author(s):  
John Robb
Keyword(s):  
Material Culture ◽  
Social History ◽  
Time Study ◽  
Deep Time ◽  
New Approach ◽  
Prehistoric Art ◽  
Long Term Trends ◽  
Specialized Form ◽  
Ways Of Life

Although many researchers have studied prehistoric European artthere has been virtually no attention paid to the broad prehistory of art as a specialized form of material culture: virtually all studies focus narrowly on single bodies of art. This paper presents a new approach to analyzing prehistoric art: quantitative deep time study. It analyzes a database of 211 art traditions from across Europe and from 40,000 B.C. to 0 AD.to identify changes in the amountnatureand use of prehistoric art. The results reveal clear long-term trends. The amount of art made increased sharply with the origins of sedentary farming and continued to rise throughout prehistory. New forms of art arise in conjunction with new ways of life: “period genres “ are closely tied into patterns of social change. There are also long-term shifts in aesthetics and the uses of art (such as a gradual shift from arts of ritual and concealment to arts of surface and display). These resultsthough preliminaryshow that a deep-time approach familiar from topics such as climate change is applicable to art; the resulting social history can illuminate both art and its social context.

The Supreme Court as a Countermajoritarian Institution? The Impact of Public Opinion on Supreme Court Decisions

1993 ◽  
Vol 87 (1) ◽  
pp. 87-101 ◽  
Author(s):  
William Mishler ◽  
Reginald S. Sheehan
Keyword(s):  
Public Opinion ◽  
Supreme Court ◽  
Membership Change ◽  
Collective Decisions ◽  
The Supreme Court ◽  
Long Term Trends ◽  
Time Series Analyses ◽  
The Impact

Although normative questions about the role of the Supreme Court as a countermajoritarian institution have long excited controversy in democratic theory, empirical questions about how far the Court acts contrary to majoritarian opinion have received less attention. Time series analyses for the period 1956–89 indicate the existence of a reciprocal and positive relationship between long-term trends in aggregate public opinion and the Court's collective decisions. The Court's ideological composition changes in response to previous shifts in the partisan and ideological orientation of the president and Congress. The Court also responds to public opinion at the margins even in the absence of membership change. Since 1981, the relationship has vanished or turned negative in direction. The Court's ideological balance has been upset by an unbroken string of conservative-to-moderate appointments, thereby undermining the dynamics that promote judicial responsiveness and raising questions about the majoritarianism of the contemporary and future Court.

scholarly journals Data-based stochastic subgrid-scale parametrization: an approach using cluster-weighted modelling

2012 ◽  
Vol 370 (1962) ◽  
pp. 1061-1086 ◽  
Author(s):  
Frank Kwasniok
Keyword(s):  
Clustering Algorithm ◽  
Prediction Models ◽  
Statistical Modelling ◽  
Scale Model ◽  
Ensemble Prediction ◽  
Subgrid Scale ◽  
New Approach ◽  
Lorenz 96 ◽  
The Impact

A new approach for data-based stochastic parametrization of unresolved scales and processes in numerical weather and climate prediction models is introduced. The subgrid-scale model is conditional on the state of the resolved scales, consisting of a collection of local models. A clustering algorithm in the space of the resolved variables is combined with statistical modelling of the impact of the unresolved variables. The clusters and the parameters of the associated subgrid models are estimated simultaneously from data. The method is implemented and explored in the framework of the Lorenz '96 model using discrete Markov processes as local statistical models. Performance of the cluster-weighted Markov chain scheme is investigated for long-term simulations as well as ensemble prediction. It clearly outperforms simple parametrization schemes and compares favourably with another recently proposed subgrid modelling scheme also based on conditional Markov chains.

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