2008/01/10 by Todd M. Palmer, Maureen L. Stanton, Truman P. Young +3 · 9 citations
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · Environmental Science · #Plant and animal studies #Insect and Arachnid Ecology and Behavior #Ecology and Vegetation Dynamics Studies
paper · doi:10.1126/science.1151579
openalex publication_date 2008/01/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Mutualisms are key components of biodiversity and ecosystem function, yet the forces maintaining them are poorly understood. We investigated the effects of removing large mammals on an ant-Acacia mutualism in an African savanna. Ten years of large-herbivore exclusion reduced the nectar and housing provided by plants to ants, increasing antagonistic behavior by a mutualistic ant associate and shifting competitive dominance within the plant-ant community from this nectar-dependent mutualist to an antagonistic species that does not depend on plant rewards. Trees occupied by this antagonist suffered increased attack by stem-boring beetles, grew more slowly, and experienced doubled mortality relative to trees occupied by the mutualistic ant. These results show that large mammals maintain cooperation within a widespread symbiosis and suggest complex cascading effects of megafaunal extinction.