Ethnic discrimination in private rental housing markets in Australia

Over the last two decades new and significant demographic, economic, social and environmental changes and challenges have shaped the production and consumption of housing in Australia and the policy settings that attempt to guide these processes. These changes and challenges, as outlined in this book, are many and varied. While these issues are new they raise timeless questions around affordability, access, density, quantity, type and location of housing needed in Australian towns and cities. The studies presented in this text also provide a unique insight into a range of housing production, consumption and policy issues that, while based in Australia, have implications that go beyond this national context. For instance how do suburban-based societies adjust to the realities of aging populations, anthropogenic climate change and the significant implications such change has for housing? How has policy been translated and assembled in specific national contexts? Similarly, what are the significantly different policy settings the production and consumption of housing in a post-Global Financial Crisis period require? Framed in this way this book accounts for and responds to some of the key housing issues of the 21st century.

Edge of centre: Australian cities and the public architecture of recent immigrant communities

In the late 1990s, the author undertook a survey of the public architecture of non-western immigrant communities in Melbourne (Beynon 2002). The survey was undertaken within a social context of rapid recent growth in non-Western immigration to Australian cities, coupled with a political context where at state and local level Australian governments were engaged in managing cultural diversity through multiculturalist policies. By the late 1990s, the number of overseas-born, or with overseas-born parentage, had become almost 40% of Australia's total population (Australian Bureau of Statistics 1998-89). Substantial numbers of such immigrants originated from outside the 'West'. Compared to other Australian cities, Melbourne had at the time of the survey the largest communities of certain birthplace groups: notably Sri Lankans, Malaysians, Turks and Somalis. The purpose of this survey was to see to what extent Melbourne's diversifying demography had changed its architectural landscape, and more broadly, what such changes in the built environment indicated about Melbourne's (and by extension Australia's) cultural identity.

High adult mortality in disease-challenged frog populations increases vulnerability to drought

Pathogen emergence can drive major changes in host population demography, with implications for population dynamics and sensitivity to environmental fluctuations. The amphibian disease chytridiomycosis, caused by infection with the fungal pathogen Batrachochytrium dendrobatidis (Bd), is implicated in the severe decline of over 200 amphibian species. In species that have declined but not become extinct, Bd persists and can cause substantial ongoing mortality. High rates of mortality associated with Bd may drive major changes in host demography, but this process is poorly understood. Here, we compared population age structure of Bd-infected populations, Bd-free populations, and museum specimens collected prior to Bd emergence for the endangered Australian frog, Litoria verreauxii alpina (alpine tree frog). We then used population simulations to investigate how pathogen-associated demographic shifts affect the ability of populations to persist in stochastic environments. We found that Bd-infected populations have a severely truncated age structure associated with very high rates of annual adult mortality. Near-complete annual adult turnover in Bd-infected populations means that individuals breed once, compared with Bd-free populations where adults may breed across multiple years. Our simulations showed that truncated age structure erodes the capacity of populations to withstand periodic recruitment failure; a common challenge for species reproducing in uncertain environments. We document previously undescribed demographic shifts associated with a globally emerging pathogen and demonstrate how these shifts alter host ecology. Truncation of age structure associated with Bd effectively reduces host niche width, and can help explain the contraction of L. v. alpina to perennial waterbodies where the risk of drought-induced recruitment failure is low. Reduced capacity to tolerate other sources of mortality may explain variation in decline severity among other chytridiomycosis-challenged species and highlights the potential to mitigate disease impacts through minimising other sources of mortality.

Dispersal responses override density effects on genetic diversity during post-disturbance succession.

Dispersal fundamentally influences spatial population dynamics but little is known about dispersal variation in landscapes where spatial heterogeneity is generated predominantly by disturbance and succession. We tested the hypothesis that habitat succession following fire inhibits dispersal, leading to declines over time in genetic diversity in the early successional geckoNephrurus stellatus We combined a landscape genetics field study with a spatially explicit simulation experiment to determine whether successional patterns in genetic diversity were driven by habitat-mediated dispersal or demographic effects (declines in population density leading to genetic drift). Initial increases in genetic structure following fire were likely driven by direct mortality and rapid population expansion. Subsequent habitat succession increased resistance to gene flow and decreased dispersal and genetic diversity inN. stellatus Simulated changes in population density alone did not reproduce these results. Habitat-mediated reductions in dispersal, combined with changes in population density, were essential to drive the field-observed patterns. Our study provides a framework for combining demographic, movement and genetic data with simulations to discover the relative influence of demography and dispersal on patterns of landscape genetic structure. Our results suggest that succession can inhibit connectivity among individuals, opening new avenues for understanding how disturbance regimes influence spatial population dynamics.

Timing, frequency and environmental conditions associated with mainstem-tributary movement by a lowland river fish, golden perch (Macquaria ambigua)

Tributary and mainstem connections represent important links for the movement of fish and other biota throughout river networks. We investigated the timing, frequency and environmental conditions associated with movements by adult golden perch (Macquaria ambigua) between the mainstem of the mid-Murray River and a tributary, the Goulburn River, in south-eastern Australia, using acoustic telemetry over four years (2007-2011). Fish were tagged and released in autumn 2007-2009 in the mid-Murray (n = 42) and lower Goulburn (n = 37) rivers within 3-6 km of the mid-Murray-lower Goulburn junction. 38% of tagged fish undertook mainstem-tributary movements, characterised mostly by temporary occupation followed by return of fish to the original capture river. Approximately 10% of tagged fish exhibited longer-term shifts between the mainstem and tributary. Movement of fish from the tributary into the mainstem occurred primarily during the spawning season and in some years coincided with the presence of golden perch eggs/larvae in drift samples in the mainstem. Many of the tributary-to-mainstem movements occurred during or soon after changes in flow. The movements of fish from the mainstem into the tributary were irregular and did not appear to be associated with spawning. The findings show that golden perch moved freely across the mainstem-tributary interface. This demonstrates the need to consider the spatial, behavioural and demographic interdependencies of aquatic fauna across geographic management units such as rivers.

Post-fire succession affects abundance and survival but not detectability in a knob-tailed gecko

Altered fire regimes threaten the persistence of many animal species globally, thus understanding how fire affects demographic processes is critical for conservation. Using 2. years of mark-recapture data from the Australian gecko Nephrurus stellatus, we investigated the effect of fire on (i) detectability to reliably measure post-fire changes in abundance, and (ii) survival and reproductive rates to investigate the mechanisms of successional change. Data were collected from two conservation reserves each with three different fire categories based on time since the last fire "Early", "medium" and "late" sites had 2-3, 7-9 and 42-48. years since fire, respectively. A robust design modelling framework was used to estimate the effect of fire category on abundance, survival and capture probability while also examining the influence of temperature and behaviour on detectability. Geckos showed trap-shy behaviour and detectability increased significantly with increasing temperature but was not affected by time since fire. Accounting for detectability, geckos were more abundant in the medium than the early sites, and were rare in the late sites. Although trends in survival are more difficult to address with short-term data, our results showed lower monthly survival rates, but higher fecundity in the early than the medium sites. These results were possibly related to successional changes in predation, the thermal environment, and food availability. We demonstrated how mark-recapture analysis can show the causes of animal fire responses while realistically accounting for detectability. Such information is necessary to provide a predictive framework to guide fire management for biodiversity. .

The relationship between house prices and demographic variables: an Australian case study

Purpose – The process for examining the value of house prices in an urban city has given limited attention, if any, to demographic variables associated with urban geography. Although the disciplines of property/real estate and demography have moved closer, little progress has been made when modelling house prices using population-related data in the field of urban geography to explain the level of house prices.

Design/methodology/approach – This paper proposes an innovative model to examine the influence of population variables on the level of house prices. It used a two-stage approach as follows: principal components analysis (PCA) identified social dimensions from a range of demographic variables, which were then retained for further analysis. This information was sourced from two Australian Bureau of Statistics censuses undertaken involving all Melbourne residents during 1996, 2001, 2006 and 2011; multiple regression analysis examined the relationship between the retained factor scores from the PCA (as independent variables) and established residential house prices (as the dependent variable).

Findings – The findings confirm the demographic profile of each household, which is directly related to their decisions about housing location and house prices. Based on a case study of Melbourne, Victoria, it was demonstrated that households with specific demographic characteristics are closely related to a certain level of house prices at the suburban level.

Originality/value – This is an innovative study which has not been previously undertaken for an extended period of time to facilitate an analysis of change over time.