Large herbivores maintain termite-caused differences in herbaceous species diversity patterns

Area of Science:

• Ecology
• Plant Community Ecology
• African Savannas

Background:

• Termites and large herbivores are key functional groups in African savannas.
• They significantly influence plant community structure and nutrient redistribution.
• Understanding their combined effects is crucial for savanna ecosystem management.

Purpose of the Study:

• To investigate the individual and combined impacts of termites and large herbivores on herbaceous species diversity in an African savanna.
• To compare vegetation patterns on termite mounds versus adjacent savanna areas.
• To assess the role of herbivores in mediating termite-induced vegetation heterogeneity.

Main Methods:

• Field experiment over three years in Lake Mburo National Park, Uganda.
• Monitoring herbaceous vegetation on Macrotermes mounds and adjacent savanna.
• Exclusion of large herbivores using fencing to assess their impact.
• Analysis of species richness, alpha, beta, evenness, and stability.

Main Results:

• Significant differences in species richness, evenness, and stability existed between termite mounds and savanna.
• Fencing (herbivore exclusion) reduced species richness, especially forbs (48% loss).
• Herbivores amplified vegetation heterogeneity by reducing beta diversity on savannas, while termites created heterogeneity on mounds.

Conclusions:

• Termites create significant vegetation heterogeneity in savannas.
• Large herbivores amplify these differences and are crucial for maintaining forb diversity at the landscape level.
• Combined actions of termites and herbivores shape savanna community structure and dynamics.