Bird data : Australia, Brisbane

Abstract

Unprecedented loss of global biodiversity driven by anthropogenic actives continues, and in response governments and researchers around the world have prioritised efforts to slow the continued decline in species diversity. Most conservation efforts to date have focused on protecting areas of ecological importance that are often far removed from human settlement. However, the flora and fauna in and around urban areas are important for achieving conservation objectives and influence human health and wellbeing. The persistence of species in urban environments is threatened by continuing urbanisation, and people are becoming increasingly isolated from opportunities to experience nature, which may impact human health and wellbeing. Urban areas are unique and challenging environments for biodiversity conservation and success will require conservation plans that incorporate social, economic, and environmental trade-offs. In this thesis, I address the growing need for effective conservation in urban environments using the city of Brisbane, Australia as a case study. I develop predictive models of changes in bird distributions across the city, and evaluate the impacts of future urban growth on local species distributions and how changes in these distributions impact people. In chapter two, I compare the consequences of two alternative urban growth strategies for the persistence of local species using bird distributions in the city of Brisbane. A city with low residential density and large backyards is likely to have a lower local environmental impact across the actual urbanised area than a city with a more compact urban form. However, this sprawling style of development requires greater land take than compact urban forms, and the so impact of sprawling growth on biodiversity at the city scale might be greater. In this chapter, I directly compare the impacts of compact and sprawling urban growth forms for biodiversity. I show that urban growth of any form reduces mean predicted area of occupancy across bird species, but compact development substantially slows these reductions. As well as minimising ecological disruption, compact urban development maintains human access to public green spaces, however, backyards are smaller which impacts opportunities for people to experience nature close to home. These results suggest that cities built to minimise overall ecological impact are characterised by high residential density, with large interstitial green spaces and small backyards. In chapter three, I describe the spatial and social distribution of the extinction of experience in Brisbane using predictions of local extinctions of bird species resulting from future urban growth. The loss of species diversity, or the extinction of experience, increases people’s isolation from nature in urban areas which has negative consequences for human health and wellbeing. Thus, understanding the spatial and social patterns of the extinction of experience is critical if cities are to manage their biodiversity capital, and ensure that the associated health benefits are effectively delivered to current and future residents. I show that the extinction of experience has a strong spatial pattern, that it is not always evenly distributed across different social sectors of society, and that the form of urban growth impacts these distributions. Local species extinctions tend to be concentrated around the edges of the city, and disadvantaged areas are disproportionately affected, particularly where urban development is sprawling. The spread of the extinction of experience across both space and society is minimised across the city with a more compact form of urban growth. In this thesis I address the urgent need for effective conservation in urban areas. By incorporating biological data into urban growth simulations I am able to directly compare the biodiversity consequences of alternative urban growth strategies, and explore the connection between species loss and human health and wellbeing in urban areas. I have effectively identified specific actions which can help to minimise species’ declines and the negative impacts of species’ extinctions on people in growing cities. As well as practical applications in Brisbane, I hope that my work will encourage governments, practitioners, and researchers to approach biodiversity conservation in urban areas with new energy and ideas.