Plant-animal interactions


Biotic interactions between plants and animals play a key role in maintaining ecosystem functioning and integrity. These processes are, however, often negatively affected by humans, either directly through habitat modifications or indirectly, e.g., through the introduction of invasive alien species. To understand the impact of human actions on plant-animal interactions and biodiversity conservation, Christopher Kaiser-Bunbury (TU Darmstadt) established in 2007 a long-term, collaborative research project (then based at ETH Zurich), together with Seychelles National Parks Authority (SNPA), Ministry of Environment and Energy, and Plant Conservation Action Group (PCA). The work focuses primarily on highly endangered, endemic plant and associated animal communities on inselbergs (rocky outcrops) on the island of Mahe. The impact of the work can be measured by its contribution towards three main areas:

1) Advancing research on ecosystem function and biodiversity conservation

2) Providing a knowledge basis for evidence-based management and policy decision-making

3) Building capacity in Seychelles for conducting evidence-based conservation


Several of our studies have contributed detailed insights on the importance of plant-animal interactions for the integrity of inselberg ecosystems on Mahe. We could show, for example, how invasive alien plant species affect pollinator behaviour of native and alien insect species differently, resulting in shifts in the plant-pollinator network structure when densities of invasive alien plant species are high. At low densities of invasive alien plant species, however, these effects were negligible, which has direct implications for the management of invaded plant communities in Seychelles and elsewhere (Kaiser-Bunbury et al. 2011). The Seychelles data on plant-animal interactions was also used to further our theoretical understanding thereby providing a crucial step towards predicting how species communities and ecosystem functions respond to human disturbances (Kaiser-Bunbury et al. 2014).

Advancing research on ecosystem function and conservation

Throughout the research all project partners are regularly updated on the latest findings, which were immediately incorporated in several recent management projects. For example, PCA in collaboration with SNPA is currently conducting a GEF/Small Grants Project-funded habitat restoration project, which aims to restore not only vegetation composition but also plant-animal interactions with the help of our scientific results. The project is accompanied by a monitoring scheme that should enable adaptive management.

Support of evidence-based management and policy decision-making

Over the course of the project, practitioners working for the partner organisations, and especially the National Park authorities, have been trained in plant and insect identification, collection and curation skills, independent data collection and analysis, and project management and budgeting. This information is passed on continuously throughout the project as part of collaborative field-work as well as through training courses.

Capacity building