Mallee Plot Network: Herbivore Activity Data, Western New South Wales and South Australia, Australia, 2013

Grazing exclosure set-up Grazing exclosures were constructed at all sites except those in Dangalli CP and the Scotia Sanctuary sites burnt in 2009 and 2010. The latter site was within the Scotia Stage 1 fenced area from which goats and rabbits had been eliminated, kangaroos were at low densities and in which Bilbies, Numbats, Burrowing Bettongs and Bridled nail-tail wallabies had been introduced (Tony Cathcart, Australian Wildlife Conservancy, pers. comm.). The design of all exclosures constructed since year 2000 (inclusive) followed the layout in Figure 7.4.2. Each comprised five contiguous fenced cells 15 m square. Initially all five cells were closed to all vertebrate herbivores for approximately one year after their construction. The basic fence design comprised treated pine posts at each corner, four star pickets along each side with two droppers per panel between pickets supporting a 1.8 m tall sheep mesh wire fencing with chicken mesh covering the lower 0.6 m of vertical fall and turned outward at ground level to a further 0.6 m lateral apron. After being surveyed at the end of this period, the fences of respective cells were modified to allow selective access to different combinations of vertebrate herbivores as shown in Figure 7.4.3. One cell was retained in an unmodified state as a total exclusion treatment (None plot). In a second cell, the chicken wire mesh was removed from two sides, leaving a gap of 0.6 m beneath the sheep wire mesh and allowing access to macropods, goats and rabbits (All plot). In a third cell, the sheep mesh was removed from two sides leaving a 0.6 m tall chicken mesh fence, allowing access to macropods but not goats or rabbits (Kangaroo plot). In a fourth cell, the mesh apron was lifted and pinned to the fence, leaving a 10 cm gap at the base of the 1.8 m tall fence, allowing access to rabbits, but not macropods or goats (Rabbit plot). The fifth cell was designed to allow access to goats, but not macropods or rabbits (Goat plot). A wooden ramp 30 cm wide was constructed on the outside of the exclosure leading to a gap in the upper part of the fence 1.2 m above ground level in one corner of the plot. A similar ramp was constructed on the opposite corner of the cell, but with the ramp installed on the inside to allow exit from the cell. Subsequent scat counts indicated that neither goats, macropods or rabbits gained access to this cell, so that in practice Goat plots functioned as a second total exclusion treatment (cf. None plot). In addition, three external plots 13 m x 7.5 m were established outside and 7.5 m from the exclosure fence, where all vertebrate herbivores had continual access to the vegetation before and after burning treatment. The standard exclosure layout was not followed at the four pilot sites established prior to year 2000. T1996/1 had a single-celled exclosure comprising a 1.8 m fence with 0.6m ground apron to exclude all vertebrate herbivores (None plot). T1997/1, T1997/2 and T1998/CON1 comprised four cells as described above for the None, All, Kangaroo and Rabbit plots, except that all vertebrates were initially excluded using an electric fence constructed 2 m outside the perimeter of the exclosure fence and powered by 12-Volt batteries. The electric perimeter fences were dismantled 1.5 - 2.5 years after construction to allow access to respective herbivores. Collectively, the experiment established a set of sites that represented a chronosequence of fire ages crossed with different grazing treatments and measured sequentially before and after implementation of the treatments. In addition to the sequence of three surveys carried out during establishment of the plots, an additional contemporaneous survey was carried out during spring 2011 - summer 2013 across all sites except those in Danggali CP. The sampling order was stratified by year of establishment and burn history.