Are moorland invertebrates resilient to fire?

Fire is an integral part of ecosystem management in many biomes around the world. This is particularly the case for the fire-prone and highly flammable moorlands of the Tasmanian Wilderness World Heritage Area. To maintain ecosystem processes and to conserve biodiversity, fire management in protected areas needs to be based on an understanding of the consequences of fire regimes. Invertebrates are a very diverse group of organisms that are critical for sustaining ecosystem processes. However, world-wide, there are few well-designed, long-term studies involving a broad range of taxa that have investigated the resilience of invertebrates to fire, and none in Tasmanian moorlands. I investigated the resilience of ground- and foliage-active invertebrate assemblages to low-intensity fire in low and moderate productivity moorlands, and identified predictors of assemblage change and its return to the pre-fire state. I used two complementary research designs: (1) a before-after-control impact design that aimed to minimise spatial variation, and (2) a replicated space-for-time design that provided insight into longer-term invertebrate responses to fire, and had a broad spatial scale. Species-level resolution for a broad range of invertebrate groups was used. I found that ground- and foliage-active invertebrate assemblages in moorland were resilient to single fires and to a fire regime with a mean fire interval of at least 24 years in low productivity moorlands and 37 years in moderate productivity moorlands. Low-intensity fire in moorland altered the composition of invertebrate assemblages because many taxa had low abundance in early successional stages. However, contrary to expectations, I found that some ground-active taxa had higher abundance in early successional stages. Very few taxa were absent from early (