Jervis Bay Booderee National Park Plot Network: Temporal Trends in Mammal Responses to Fire Reveals the Complex Effects of Fire-regime Attributes, 2003-2013

Plot Setup The 97 sites in the study at Booderee National Park were drawn from a pool of 110 permanent sites which were first established in 2002. These study area was stratified into 7 vegetation types of which 2, sedgelands and swamps, were excluded on the basis of rarity. A stratified randomized and replicated process was employed to ensure that the 97 survey sites were widely distributed throughout Booderee National Park in order to limit the potential for geographic bias in the results. Sites were replicated within each vegetation type resulting in the number of samples being generally proportional to the total area occupied by each vegetation class. A 100 metre long transect was sited entirely in a single vegetation type at each of the 97 sites. The length of each transect was influenced by the substantial heterogeneity in vegetation cover at Booderee National Park Transects where major changes in vegetation type often occur over a short distance and transect lengths in excess of 100 metres would have resulted in many transects spanning two vegetation types. Spatial coordinates for each transect were recorded using a global positioning system.

ArcGIS, GPS, star picket markers.

Delineation of fire regime attributes (1) Number of fires refers to the number of fire events at a site from 1968 to 2003. These data were derived from extensive on-the-ground fire mapping of the location and size of each of the 198 fires known to have occurred in Booderee National Park since 1968 (Westgate et al. 2012). (2) Fire interval corresponded to the time elapsed between the 2003 fire and the preceding fire at a site. (3) The severity of the 2003 fire. For the purposes of this study, the fire severity variable was based on a fire severity category assigned to each one of the 97 long-term sites using on-the-ground field observations of the direct effects of the 2003 fire on vegetation cover and completed within 10 days of the conflagration: (i) No fire (43 sites). (ii) Moderate severity fire (36 sites) in which > 75% of the understorey and midstorey were burned but not killed and > 75% of the overstorey remained unburned. And, (iii) High severity fire (18 sites) in which > 75% of the midstorey was killed and > 75% of the overstorey was burned. Westgate, M., D. Driscoll, and D. B. Lindenmayer. 2012. Can the intermediate disturbance hypothesis and information on species traits predict anuran responses to fire? Oikos 121:1516-1524.

Field surveys of terrestrial and scansorial mammals Star picket markers were used at 0 m, 20 m, 40 m, 60 m, 80 m and 100 m points along each transect. The trapping infrastructure established at each site involved the use of: - a single Elliott aluminium box trap (10 cm x 10cm x 30 cm; Elliott Scientific Equipment, Upwey, Victoria) at 10 m intervals along the transect. - a small wire cage trap (20 x 20 x 50 cm) at 20 m intervals along the transect. - a large wire cage trap (30 x 30 x 60 cm) at the 0 m and 100 m points of the transect. Trapping protocols at each site involved opening Elliott traps and cage traps for four consecutive days in 2003 and three consecutive days in subsequent surveys years. All traps were baited with a mixture of peanut butter and rolled oats. Elliott traps and cage traps in which an animal had been captured were wiped clean, re-baited, and re-positioned where the initial capture had taken place. Trapping surveys for all 97 sites were completed in the summer of all years between late 2003 (immediately after the fire in that year) and 2013, although not all sites were surveyed in all years due to logistical issues associated with trapping effort.

Elliot cage traps and wire cage traps

Field surveys of arboreal marsupials Arboreal marsupials were counted by means of repeated spotlighting along each permanent transect at each of the 97 sites used in the study. In any given survey year, each transect was surveyed twice by a different observer on a different night. Spotlighting surveys were completed in each of eight years over a ten year period - 2003, 2004, 2005, 2006, 2007, 2009, 2011, and 2013 but was not undertaken on nights of poor weather (rain, high wind, fog or heavy cloud cover).

Species targeted for detailed analysis Native mammal species detected in the study fall into five broadly different groups characterized by marked differences in life history and other attributes (Hume 1999, Tyndale-Biscoe 2005, Breed and Ford 2007) (see Appendix 2) including body size, diet, mating system, fecundity, longevity, social organization, habitat requirements and other characteristics. The study focussed on 11 of the more commonly recorded species of mammals that were representative of six broad groups of taxa. These were: terrestrial rodents (Bush Rat Rattus fuscipes, Swamp Rat Rattus lutreolus, and Eastern Chestnut Mouse Pseudomys gracilicaudatus), terrestrial marsupial omnivores (Long-nosed Bandicoot, Perameles nasuta), terrestrial herbivorous macropods (Eastern Grey Kangaroo Macropus giganteus and Black Wallaby Wallabia bicolor), scansorial marsupial carnivores (Brown Antechinus Antechinus stuartii), arboreal marsupial omnivores (Sugar Glider Petaurus breviceps, Common Ringtail Possum Pseudocheirus peregrinus, and Common Brushtail Possum Trichosurus vulpecula), and arboreal marsupial folivores (Greater Glider Petauroides volans).

Notably, invasive mammals such as the House Mouse (Mus musculus), Black Rat (Rattus rattus), and the Feral Cat (Felis cattus) and the Red Fox (Vulpes vulpes) are extremely uncommon in Booderee National Park. The latter species in particular is targeted by an intensive poison baiting program that has been conducted throughout Booderee National Park for more than a decade (Lindenmayer, D. B., C. McGregor, N. Dexter, and M. Fortescue. 2014b. Booderee National Park: The Jewel of Jervis Bay. CSIRO Publishing, Melbourne).