Domestic livestock decrease vegetation structure
Domestick livestock decrease plant cover, density and richnes in Monte Desert. This vegetation cannot recover from plant damage caused by domestic livestock
Question: Does livestock grazing affect plant density,
cover and species richness in arid ecosystems?
Location: Monte Desert, SW Argentina.
Methods: I analysed the effect of livestock grazing on plant density,
cover and species richness across a stocking rate gradient
within the same habitat. Six ranhelands were used with stocking
rates ranging between 0.002 - 0.038 livestock/ha. Plant density,
species richness, plant cover and percentage of grazed
branches were determined by sampling plots within each
rangeland.
Results: Higher stocking rates were assocuated with lower plant
density, species richness and cover. The rangeland with
the lowest grazing intensity had 86% more plants per unit area,
63% more plant cover and 48% higher plant richness. The
percentage of grazed branches and the quantity of dung increased
with stocking rate.
Conclusions: Introduced livestock seriously affect native vegetation
in Monte Desert. The damage observed in this
xerophytic plant community suggests that plant adaptations to
aridity do not provide an advantage to tolerate or avoid grazing
by vertebrate herbivores.