H2020 Marie S-Curie Actions Individual Fellowship

The importance of animal-mediated seed dispersal for plants

Alaska river

Many plant seeds and invertebrates can be transported within and among suitable habitat by large, mobile animals. Among best-known animal vectors in wetland ecosystems are waterbirds, fish and large mammals - that can ingest, transport and release a broad range of smaller organisms. Many plants have seeds that are suitable for transport in teh digestive system or on the outside of animals, and also many aquatic invertebrates can be transported.

Animal-mediated dispersal is thought to contribute greatly to the dispersal of a broad range of plant and invertebrate species worldwide. However, it is still unclear how important this dispesal mechanism is relative to other potential mechanisms. In my H2020-project I aim to generate a mechanistic understanding of animal-mediated dispersal of plant seeds by waterbirds, fish and large mammals in wetland ecosystems. This includes quantifying the functional role of animal-mediated dispersal for plant communities. I study dispersal in wetlands, because these are often spatially isolated and temporally variable, which makes dispersal crucial for the persistence of many aquatic species. My project combines lab experiments, modelling and fieldwork.

The first output of the project has been a publication on the transport of plant seeds and invertebrates by piscovorous birds in Biology Letters. Great cormorants (Phalacrocorax carbo) were found to regurgitate plant seeds and resting stages of invertebrates, that were initially ingested by fish, and only dispersed secondarily by fish-eating birds. Such two-step dispersal provides an additional mechanism for seeds and invertebrates to be transported over land. The second output of the project to date is a review in Frontiers in Plant Sciences, highlighting the potential of alien plant species to interfere with animal-mediated dispersal of native plant species. This publication provides an overview of how the arrival of alien plants can alter animal-mediated dispersal of native species, particularly for aquatic ecosystems.

The project also launched a Research Topic in Frontiers in Ecology and Evolution: "Animal-mediated dispersal in understudied systems" - of which the first publications will soon appear online.