Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Reptile dispersal and demography after fire : process-based knowledge to assist fire management for biodiversity

Auteur : Smith, Annabel L.

Université de soutenance : Australian National University

Grade : Doctor of Philosophy (PhD) 2012

Description partielle
The disruption of natural fire regimes has threatened animal species in many ecosystems around the world. A combination of prescribed burning and fire suppression is often used to promote successional variation in vegetation (i.e. fire mosaics), with little knowledge of how this will affect animal persistence. Understanding the processes that govern species responses to fire regimes is essential to build a predictive capacity for ecological fire management. I examined life-history, demographic (survival, reproduction and mortality) and dispersal attributes of reptiles to investigate mechanisms of fire responses in reptiles. I studied reptiles in conservation reserves of semi-arid southern Australia dominated by mallee vegetation (multi-stemmed Eucalyptus spp. with a shrubby understory). An introduction describes the ecological and management context of my research (Chapter 1). A community-level framework was used to determine if a generalised model of fire responses could be developed based on traits shared by groups of species (Chapters 2-3). I found a number of fire responses in reptiles that were previously undetected in analyses of smaller, but substantial subsets of the same data (Chapter 2). Nocturnal burrowers tended to be early-successional, while diurnal leaf-litter dwellers tended to be late successional, but a trait-based model of succession had limited power to describe responses among the community. I also documented some observations that suggested non-burrowing reptiles were more vulnerable to mortality during wildfire than burrowers (Chapter 3). A species-level framework was then used to examine variation in demographic and dispersal attributes within species among different post-fire successional stages (Chapters 4-7). These studies focussed on three species with significant and contrasting responses to fire : Amphibolurus norrisi (Agamidae ; mid/late successional species), Ctenotus atlas (Scincidae ; late successional) and Nephrurus stellatus (Gekkonidae ; early/mid successional). Using mark-recapture modelling

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