Exotic grass fuel in south eastern Australia

摘要

One potentially serious impact of environmental weed invasion is an alteration to the fuel characteristics and subsequent fire regimes of an area. Considerable global evidence indicates that environmental weed invasion may produce 'new' fuel types, but there is little documented evidence of the impact of invasive exotic species on fuel characteristics and fire regimes in south-eastern Australia. This study on the impact of invasive exotic grasses in southeastern Australia has revealed major changes to fuel characteristics, particularly fuel loads. The invasive exotic pasture grass Phalaris aquatica L. has dramatically increased fuel loads in conservation reserves, urban parkland, roadside reserves, and remnant woodland on private land. Areas invadedby P. aquatica can have over three times the fuel load of native Themeda triandra Forssk. grasslands. The arrangement of the fuel, particularly the depth of the fuel bed, is also significantly altered. Fuel characteristics have a major impact on fire behaviour. Therefore, alterations to fuels due to exotic grass invasion may have serious ecological, fire suppression and fire safety implications.