Wildfire refugia in forests: Severe fire weather and drought mute the influence of topography and fuel age.
Glob Chang Biol
; 25(11): 3829-3843, 2019 11.
Article
em En
| MEDLINE
| ID: mdl-31215102
ABSTRACT
Wildfire refugia (unburnt patches within large wildfires) are important for the persistence of fire-sensitive species across forested landscapes globally. A key challenge is to identify the factors that determine the distribution of fire refugia across space and time. In particular, determining the relative influence of climatic and landscape factors is important in order to understand likely changes in the distribution of wildfire refugia under future climates. Here, we examine the relative effect of weather (i.e. fire weather, drought severity) and landscape features (i.e. topography, fuel age, vegetation type) on the occurrence of fire refugia across 26 large wildfires in south-eastern Australia. Fire weather and drought severity were the primary drivers of the occurrence of fire refugia, moderating the effect of landscape attributes. Unburnt patches rarely occurred under 'severe' fire weather, irrespective of drought severity, topography, fuels or vegetation community. The influence of drought severity and landscape factors played out most strongly under 'moderate' fire weather. In mesic forests, fire refugia were linked to variables that affect fuel moisture, whereby the occurrence of unburnt patches decreased with increasing drought conditions and were associated with more mesic topographic locations (i.e. gullies, pole-facing aspects) and vegetation communities (i.e. closed-forest). In dry forest, the occurrence of refugia was responsive to fuel age, being associated with recently burnt areas (<5 years since fire). Overall, these results show that increased severity of fire weather and increased drought conditions, both predicted under future climate scenarios, are likely to lead to a reduction of wildfire refugia across forests of southern Australia. Protection of topographic areas able to provide long-term fire refugia will be an important step towards maintaining the ecological integrity of forests under future climate change.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Incêndios Florestais
/
Incêndios
Tipo de estudo:
Prognostic_studies
País/Região como assunto:
Oceania
Idioma:
En
Revista:
Glob Chang Biol
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Austrália