Effects of urbanization on remnant woodlands

[Truncated abstract] This study aims to understand the effects of contemporary urbanization on remnant plant communities. In growing cities worldwide, urbanization is leading to the rapid loss of natural vegetation and its fragmentation into small and isolated urban remnants. Not only is this phenomenon fairly recent, embodying the major urban transition the world is currently experiencing and that gained momentum in the last 10-20 years, but also its spatial extent is unprecedented. Although there is growing awareness of the impacts of urbanization on biodiversity, how plant communities in these newly formed urban remnants change over time following landscape fragmentation is not well-understood. Yet, as cities sprawl, the importance of these remnant ecosystems for conservation of biodiversity and provision of ecosystem services cannot be overlooked. I studied 30 remnant Banksia woodlands in the rapidly urbanizing city of Perth, located in the south-western Australian global biodiversity hotspot. First, I developed a conceptual framework supporting the study of the effects of contemporary urbanization on remnant ecosystems (Chapter 2). This framework highlights the importance of considering the temporal dynamics of landscape change, land-use history, and the main environmental drivers. Second, I attempted to identify the main driving factors of plant community change in the remnant Banksia woodlands of the Perth Metropolitan Area. I considered a comprehensive set of factors characterizing the landscape fragmentation dynamics (current and past remnant area and landscape connectivity, time since isolation and since urbanization, trajectories of landscape change), remnant local environmental conditions (soil nutrient status and litter depth), and disturbance regimes (fire, grazing, and human activities)...