Coarse-scale effects of land cover and fragmentation on Pyrodiversity

Sofia Bajocco, Daniela Guglietta, Jose Maria Costa Saura, Gianna Vivaldo, Carlo Ricotta 

Fire plays a crucial role in shaping ecosystem functions at multiple spatial and temporal scales. While traditional studies on fire regimes focus on central tendencies of fire attributes, such as average fire frequency, size, and seasonality, recent research highlights the importance of pyrodiversity as a critical ecological factor. Pyrodiversity reflects the variability in fire attributes across space and time and is generally thought to increase biodiversity. Although many authors have extensively studied the effects of pyrodiversity on ecosystem functioning, much less attention has been given to the factors driving pyrodiversity. In this paper we explore the influence of landscape drivers, such as land use/land cover (LULC) and fragmentation on the central tendencies and variability of fire regimes in Sardinia (Italy). We use multivariate redundancy analysis (RDA) to investigate how LULC and fragmentation affect the mean and variance of different fire attributes, including fire size and seasonality and the land cover diversity of the fire ignition points. Our results reveal that at the landscape scale, LULC types significantly influence both the central tendency and variability of fire regimes and that the different components of pyrodiversity are driven by distinct LULC types, thus highlighting the complementary nature of pyrodiversity to traditional fire regime parameters. These findings emphasize the need for integrating pyrodiversity into fire management strategies at the landscape scale.