Edge effects in fire-prone landscapes: Ecological importance and implications for fauna.

Kate Parkins,Alan York,Julian Di Stefano

doi:10.1002/ece3.4076

Abstract

Edges are ecologically important environmental features and have been well researched in agricultural and urban landscapes. However, little work has been conducted in flammable ecosystems where spatially and temporally dynamic fire edges are expected to influence important processes such as recolonization of burnt areas and landscape connectivity. We review the literature on fire, fauna, and edge effects to summarize current knowledge of faunal responses to fire edges and identify knowledge gaps. We then develop a conceptual model to predict faunal responses to fire edges and present an agenda for future research. Faunal abundance at fire edges changes over time, but patterns depend on species traits and resource availability. Responses are also influenced by edge architecture (e.g., size and shape), site and landscape context, and spatial scale. However, data are limited and the influence of fire edges on both local abundance and regional distributions of fauna is largely unknown. In our conceptual model, biophysical properties interact with the fire regime (e.g., patchiness, frequency) to influence edge architecture. Edge architecture and species traits influence edge permeability, which is linked to important processes such as movement, resource selection, and species interactions. Predicting the effect of fire edges on fauna is challenging, but important for biodiversity conservation in flammable landscapes. Our conceptual model combines several drivers of faunal fire responses (biophysical properties, regime attributes, species traits) and will therefore lead to improved predictions. Future research is needed to understand fire as an agent of edge creation; the spatio‐temporal flux of fire edges across landscapes; and the effect of fire edges on faunal movement, resource selection, and biotic interactions. To aid the incorporation of new data into our predictive framework, our model has been designed as a Bayesian Network, a statistical tool capable of analyzing complex environmental relationships, dealing with data gaps, and generating testable hypotheses.

Highlights

Edges, barriers, boundaries, or ecotones are ubiquitous environmental phenomena, occurring in a wide range of ecosystems and across multiple spatial scales (Cadenasso, Pickett, Weathers, Bell et al, 2003)
Explicit consideration of the factors that cause fires to extinguish will be central to understanding the ecological dynamics occurring at fire edges, as different methods of extinguishment are likely to result in different edge characteristics, influencing species edge response
While these models have proven effective in predicting edge effects across a range of environments, they are unlikely to perform well in flammable ecosystems for two reasons. These models do not explicitly consider the process of edge creation and we argue that edge effects cannot be effectively understood in isolation from the processes that generate them. This is of particular importance for edges created by fire where temporal changes in edge architecture are expected to be influenced by fire regime attributes and both static and dynamic biophysical properties

Summary

Introduction

Barriers, boundaries, or ecotones are ubiquitous environmental phenomena, occurring in a wide range of ecosystems and across multiple spatial scales (Cadenasso, Pickett, Weathers, Bell et al, 2003). Explicit consideration of the factors that cause fires to extinguish will be central to understanding the ecological dynamics occurring at fire edges, as different methods of extinguishment are likely to result in different edge characteristics (e.g., size, shape, contrast), influencing species edge response.

Results

Conclusion