Vegetation recovery after 11 years of wild boar exclusion in the Monte Desert, Argentina

Abstract

The wild boar (Sus scrofa) is considered an ecosystem engineer. It roots up the ground looking for forage, generating patches of different sizes and without vegetation. Studies of wild boar’s impact on vegetation can be addressed in two contrasting ways: short-term effects (immediately after boar’s disturbance) and long-term effects. Short-term studies in the Monte Desert of Argentina showed that wild boar rooting modifies soil properties, reduces plant cover, and decreases plant richness and diversity. The objective of this study was to analyse the vegetation response in a desert ecosystem after 11 yr of wild boar disturbance establishing a replicated experiment of medium and large-sized animal’s exclusion. In this long-span study, time was the most important variable to predict the cover of different plant life forms and richness in disturbed soils. Herb cover was higher in disturbed soils, with grasses and woody species showing the opposite. Over the long-term, wild boar positively affect alpha diversity and richness, while the species turnover (rate of species replacement) was only influenced by the replacement of herbs. Disturbed soils were mainly dominated by annual species with a relatively high (60%) extent of species turnover. These vegetation changes throughout time are influenced by the occurrence of unexpectedly high rainy episodes, and probably by the system’s own fragility of Monte Desert.