High Stocking Density Controls Phillyrea Angustifolia in Mediterranean Grasslands

Area of Science:

• Ecology
• Conservation Biology
• Rangeland Management

Background:

• Extensive grazing is common in protected areas but often fails to control woody plant encroachment.
• Mediterranean coastal grasslands face invasion by shrubs like Phillyrea angustifolia despite grazing.
• Traditional grazing management may not be sufficient for conserving these unique habitats.

Purpose of the Study:

• To compare the impact of mob grazing versus continuous low-density grazing on Phillyrea angustifolia and herbaceous cover.
• To evaluate the effectiveness of different grazing strategies in Mediterranean xero-halophytic grasslands.
• To assess the role of grazing in maintaining grassland biodiversity and open habitats.

Main Methods:

• An in situ experiment over 7 years compared mob grazing with continuous low-density grazing at equal annual stocking rates.
• Both methods were tested against a control with domestic grazing exclusion.
• Impacts on Phillyrea angustifolia cover, mortality, and herbaceous community parameters were measured.

Main Results:

• Mob grazing significantly controlled Phillyrea angustifolia establishment and increased its mortality.
• No significant differences in herbaceous species richness, diversity, or evenness were found between the two grazing methods.
• Excluding domestic grazing led to a substantial reduction in herbaceous community values.

Conclusions:

• Mob grazing is a promising tool for managing woody plant invasion and conserving open habitats in Mediterranean grasslands.
• Continuous extensive grazing is less effective for controlling shrub encroachment than mob grazing.
• Grazing, particularly mob grazing, is crucial for maintaining the biodiversity of these valuable ecosystems.