Megaherbivores influence trophic guilds structure in African ungulate communities

Area of Science:

• Ecology
• Zoology
• African Ecosystems

Background:

• African ungulate communities exhibit diverse feeding guilds.
• Understanding trophic interactions is crucial for ecosystem functioning.

Purpose of the Study:

• To test if megaherbivores dominate high-rainfall, low-nutrient ecosystems.
• To determine if megaherbivore abundance influences mesoherbivore guilds.
• To analyze the distinct responses of mesograzers, mesobrowsers, and mesomixed feeders.

Main Methods:

• Utilized ungulate census data from 31 East and Southern African natural ecosystems.
• Applied multivariate analysis to discriminate sites based on herbivore dominance and feeding guilds.
• Examined the relationship between environmental factors (rainfall, soil nutrients) and herbivore biomass density.

Main Results:

• Megaherbivores form a distinct trophic guild, increasing with rainfall.
• Megaherbivores comprised a larger biomass proportion in high-rainfall, low-nutrient soils.
• Mesograzers were unaffected by megaherbivores, while mesobrowsers and mesomixed feeders declined with increased megaherbivore abundance, particularly elephants.

Conclusions:

• Megaherbivores are a separate trophic guild influenced by rainfall.
• Mesograzers and mesobrowsers respond differently to environmental and trophic variations.
• Megaherbivores, especially elephants, compete with mesomixed feeders and mesobrowsers, impacting African ungulate community dynamics.