To assess the variability of the impact of the removal of grazing pressure over an environmental (productivity) gradient (pp. 55).
Type of Study:
Manipulative experiement, with pre-existing gradient
The response of grassy vegetation to exclusion from grazing was found to be related to a major productivity gradient in the central highlands of Tasmania. All sites showed a trend toward increased structural complexity, a decrease in bare ground and a decrease in species richness when grazing was excluded. However, the effect was much more pronounced at sites of high productivity (pp. 55).
Paired quadrats in grazed and ungrazed plot at each site.
Frequentist (P values): two-way ANOVA, paired t-test
Demonstration in Tasmanian high country of the responses of high subalpine ecosystems to the removal of livestock grazing. Consistent with Wahren et al. (1994).
Imogen Fraser; Dick Williams
Central Plateau, Tasmania, Australia
Response variable :
Species richniess, composition and cover (Braun-Blanquet scale).
Vegetation surveyed in 80 quadrats (0 0.5 x 1.0 m) across 8 plots (10 quadrats per plot; 2 plots per site). Grazing intensity estimated in 10 quadrats (2 x 2 m) per plot.
Subalpine grassland and gassy woodland.
Gibson N., Kirkpatrick J.B. (1989) Effects of cessation of grazing on the grasslands and grassy woodlands of the central plateau, Tasmania. Australian Journal of Botany 37, 55–63.