SP7: Biotic defenses - Multitrophic effects of ant-plant mutualisms in forest recovery

• Applicant: Professorin Dr. Heike Feldhaar
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 444827997

The effects of global anthropogenic change on mutualisms are poorly understood and while the dissolution of ant-plant mutualisms due to anthropogenic disturbance has received some attention we know even less about the recovery of such interactions and their abiotic and biotic drivers during forest recovery. Ants are a particularly important invertebrate group in tropical forests in terms of abundance and biomass, and are a keystone group in the redistribution of resources in tropical rainforests, linking higher trophic levels with primary producers and decomposers. Ant-plant protective mutualisms have been shown to be highly relevant in tropical rainforests, with many plant species providing food rewards and / or nesting space in this biome, and thus relying on this biotic defense syndrome. However, such mutualistic interactions may be disrupted by deforestation and fragmentation when partners respond differently to changing abiotic conditions, e.g., with changes in ant community composition or ants being less active and abundant potentially disrupting ant-mediated ecosystem functions. Likewise, the biotic conditions will change due to feedbacks between different species groups such as plants, ants, herbivores, and predators that are in turn also impacted by abiotic and biotic conditions. In the present project we will therefore characterize ant-plant interaction networks along the forest recovery gradient and how these are influenced by ant as well as plant functional traits. We will measure the effect of ants on herbivory, herbivore and predator assemblages, as well as the development of epiphylls on leaf surfaces, which may indirectly affect plant performance. With this project we will provide important information on the reassembly of defensive mutualisms and their potential for passive restoration of forests tropical rainforests.

• DFG Programme: Research Units
• Subproject of: FOR 5207: Reassembly of species interaction networks – Resistance, resilience and functional recovery of a rainforest ecosystem
• International Connection: Ecuador
• Cooperation Partner: Professor David Donoso, Ph.D.