Grazing and fire in two subalpine peatlands

Abstract

The floristic composition and structure of peatland vegetation in adjoining subalpine catchments of the Bogong High Plains (north-eastern Victoria) were monitored between 1979 and 2006. Grazing by cattle had been excluded from one catchment since 1946, when it was fenced. Peatland vegetation in both catchments was partially burnt in a wildfire in 2003. Between 1979 and 1999, in the ungrazed peatland, the cover of Sphagnum cristatum Hampe and Baeckea gunniana Schauer increased and the cover of pools decreased, whereas in the grazed peatland the cover of B. gunniana and Epacris paludosa R.Br. decreased and the cover of Empodisma minus (Hook.f.) L.A.S.Johnson & D.F.Cutler increased. The cover of all recorded species decreased following a fire in 2003. Between 2004 and 2006, a significant increase in cover was detected in two of eight species measured in burnt areas. In burnt areas, the number of native species per quadrat increased in the grazed peatland and the numbers of exotic species per quadrat increased in both peatlands over that period. By 2006, the peatlands had largely recovered floristically from the 2003 fires but it is likely to be decades before the cover of S. cristatum and Richea continentis B.L.Burtt. reaches pre-fire levels. Control of several exotic species that established after the fire (especially Salix cinerea L. and Juncus spp.) may be required.