Characterization of landscape pyrodiversity in Mediterranean environments: contrasts and similarities between south-western Australia and south-eastern France

Landscape pyrodiversity encapsulates the range of spatiotemporal variability in disturbance by fire. There is a widely-held view that diversity in fire regimes promotes biological diversity (i.e., the Pyrodiversity–Biodiversity paradigm). However, this relationship needs to be examined more carefully as pyrodiversity at the landscape scale remains poorly defined and difficult to quantify. Here, we used a novel approach to analyze landscape pyrodiversity by selecting and quantifying appropriate descriptors of fire variability at the landscape level. We characterized and classified observed fire mosaics at the 1 km scale using temporal attributes (fire frequency, time-since-fire and mean fire interval) and a variety of spatial attributes derived from landscape metrics. We trialed our approach on a 50-year record of fire patterns in two Mediterranean environments; (1) in southern France where fire regimes are dominated by unplanned (‘wild’-)fires and (2) in south-west Australia, where fire regimes are dominated by planned fires. We found that the landscape pyrodiversity of both regions was expressed by distinct gradients of both fire frequency and spatial diversity of fire patterns. As expected, the two environments were significantly different in landscape pyrodiversity, with contrasting mean fire frequency and mean time-since-fire patterns. However, we also found similarities between southern France and south-west Australia in the composition and configuration of their spatial fire patterns. Our results show that these two Mediterranean environments form a pyrodiversity continuum despite the disparate management regimes. Our findings also demonstrate that a quantitative characterization of pyrodiversity is central to developing new perspectives and practical tools for biodiversity conservation in fire-prone landscapes.