Abstract Introduction The slow recovery of native dryland vegetation caused by extreme temperatures, limited water and nutrient availability, and intensified by grazing makes its ecological restoration particularly challenging. In this context, facilitation among plant species plays a key role in improving microenvironmental conditions and providing protection against herbivory. Objectives We experimentally explore the combined effects of four key factors influencing plant establishment in overgrazed drylands: facilitation among species, water and nutrient supplementation, and grazing exclusion. We hypothesized that subsidizing the limiting factors (water and nutrients), removing the disturbance, and enhancing facilitation among species, would synergistically improve vegetation establishment. We also assessed whether successional type of species (i.e. early, intermediate, and late) influenced species responses, according to their life history traits, expecting higher survival in early species than in the rest, and stronger facilitation between species of contrasting successional type (e.g. early–late) than between more similar ones (e.g. early–intermediate). Methods We evaluated facilitation effects among species (species associations and nurse effects), water addition (hydrogel), nutrient supplementation (organic fertilization), and grazing exclusion (individual protection) on the survival of transplanted plants of several species. Results Plant survival was highest when combining water and nutrient addition with grazing exclusion. Nurse species significantly improved survival rates, regardless of their successional type of species. Early successional species showed greater survival than intermediate and late species. Conclusion The synergistic effects of subsidizing limiting factors and disturbance removal allow plants to better absorb and allocate resources to growth, enhancing vegetation recovery. Restoration efforts should focus on early and intermediate successional species for revegetation, while assigning conserving actions on late successional species.
Pelliza et al. (Mon,) studied this question.