University Of Tasmania

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Practical and theoretical implications of a browsing cascade in Tasmanian forest and woodland

journal contribution
posted on 2023-05-18, 16:01 authored by Hazeldine, A, James KirkpatrickJames Kirkpatrick
Browsing cascades have strong implications for biodiversity conservation and fire management. The associational resistance and associational susceptibility hypotheses suggest different mechanisms. We tested the veracity of these two hypotheses by using small dry eucalypt forest and woodland trees. At 67 sites, we measured the height of the browse line and estimated the proportion of foliage remaining below it for all adult individuals of small trees within a 50 × 50 m area, recorded scat numbers, browsing damage to tree seedlings by species and environmental data. The 110–130-cm browse line, and strong relationships between macropod scat numbers and the remaining foliage below the browse line, suggested that Bennetts wallabies (Macropus rufogriseus Shaw) were the main cause of umbrella-shaped trees. The browsers preferred Exocarpos cupressiformis Labill. and Bursaria spinosa Cav. At the other extreme, adult Acacia dealbata Link suffered no browsing damage. All species were browsed as seedlings. Associational resistance occurred in some species and associational susceptibility in others, with the degree of difference in palatability between alternative sources of browse possibly resolving this apparent contradiction. Low browsing pressure is likely to cause woody thickening, an increase in fire hazard and a decrease in biodiversity. Extremely high browsing pressure had no such effects.


Publication title

Australian Journal of Botany










School of Geography, Planning and Spatial Sciences


CSIRO Publishing

Place of publication

150 Oxford St, Po Box 1139, Collingwood, Australia, Victoria, 3066

Rights statement

Journal compilation Copyright CSIRO 2015

Repository Status

  • Restricted

Socio-economic Objectives

Other environmental management not elsewhere classified