Cattle and Weedy Shrubs as Restoration Tools of Tropical Montane Rainforest

background

In abandoned Latin American pastures, grasses often inhibit the establishment of woody species. This study tests the effect of cattle grazing on woody and herbaceous vegetation establishment in pastures of P. clandestinum and M. minutiflora.

goals & methods

The study establishes twelve corralled plots in recently ungrazed pastures in a montane region of Colombia. Half of the plots are dominated by P. clandestinum and half by M. minutiflora. Seeds of five vegetative plants are sown in 1m-diameter patches chosen at random across all plots. Half of the plots in each pasture type are treated to one season of grazing. All individuals of woody species greater than 10cm in height across a transect in each plot are measured six months before and after the grazing treatment.

conclusions & takeaways

The study finds that a low stocking density of cattle greatly increases basal area and ‘shrubbiness’ of woody plants while reducing grass biomass by over 50%, but reduces woody plant species richness and diversity compared to the pre-grazing condition. In pastures treated with grazing, the shrubs Baccharis latifolia and Salvia sp. are most abundant. Where seed was sown, abundance of Verbesina arborea in particular increases.