Long term monitoring reveals the importance of large, long unburnt areas and smaller fires in moderating mammal declines in fire-prone savanna of northern Australia

Biodiversity loss is often attributable to multiple interacting pressures that are moderated across environmental gradients. These processes contribute to complex responses that are challenging to interpret and understand. Well-designed and well-implemented monitoring can play a vital role in this but is rarely undertaken.
Mounting evidence suggests that current fire regimes across savanna ecosystems have contributed to the decline of a range of biota. Hence, contemporary fire regimes are at odds with conservation goals.
Using an extensive spatio-temporal monitoring dataset from three large National Parks in northern Australia, we applied generalised linear mixed models to examine: 1) trends in mammal richness and abundance through time and how these vary across environmental gradients such as productivity or landscape position (e.g., terrain ruggedness); and 2) how fire, a potential driver, is moderated by environmental gradients.
Across 24-years, major declines in mammal richness and ..., We monitored the mammal community using standardised trapping and nocturnal searches.
During the 1995 – 2015 monitoring period, sites accessible by vehicle were sampled for 72 hrs, and sites accessible only by helicopter were sampled for 48 hrs. Sampling occurred from April to November, with each site visited in the same month and sampled with the same effort between sessions. For the 48 hr surveys, 30 Elliott traps (33 x 10 x 9 cm) were placed equidistantly around the perimeter of a 50 x 50 m trapping quadrat, six cage traps (56 x 20 x 20 cm) were placed at each corner and mid-way along the perimeter, and three 20 L pitfall traps (with 10 m of drift-line fence) were placed within the quadrat. For the 72 hr surveys, the same number of trap nights were achieved using 20 Elliott traps, four cage traps, and two pitfall traps. Between 2016 and 2019 sampling occurred from May – August, and the trapping period was increased to 96 hours, using 16 Elliott traps, eight cage traps, and three pitf..., Microsoft Excel