As seed spreaders, animals help keep ecosystems healthy
EU-funded research has revealed an increased urgency to protect the diversity of animals, showing they play a much larger and more intricate role in the dispersal of plant seeds than previously thought. This is important for maintaining our global environment.
© Tatiana #186866348, source: fotolia.com, 2018
Seeds can reach isolated places such as far off islands with the help of animals or by wind and sea currents, creating ecosystems vital to the planet. With increasing numbers of animals becoming extinct, we need to better understand how these changes to fauna are affecting the global flora.
The EU-funded SEEDS project addressed this by mapping out the intricate relationships between many plants and the animals that carry their seeds. It focused on how seeds initially got from mainland areas to isolated islands and also on how plants are moved around by animals.
Through laboratory experiments, it showed that birds and sea currents are the two most likely transporters of many different types of seeds. The project also identified links between specific birds and specific seeds, enabling researchers to model what would happen to the environment if a particular bird species became endangered or extinct.
Birds have been moving seeds around for millions of years and this is now being disrupted by human action, says the projects principle investigator, Ruben Heleno of the Centre for Functional Ecology at the University of Coimbra in Portugal. We see that the reduction in the number of birds and the diversity of bird species is creating an unexpected multiplier effect. For example, land affected by fire will take far longer to regain flora if key animal dispersers are not present.
Isolated islands: a natural laboratory
SEEDS was conducted in three key sets of islands: the Galapagos in the Pacific, as well as the Azores and the Canaries in the Atlantic. Their isolation made them perfect natural laboratories.
By collecting samples of bird droppings, project researchers identified exactly which birds carried which seeds where, and when.
The team also identified seeds that could still germinate after subjecting them to conditions imitating long sea journeys. The data produced was entered into computer models to simulate the effect of seed transport mechanisms on the plant life of the islands.
Today, we are concerned about the number of animal species we are losing, says Heleno. We also need to remember that when we lose a species, we also lose what that species was doing its role in the ecosystem. We lose the functions that animals perform and these are important to the entire planet.
Amid this backdrop, SEEDS highlighted a need for action.
We are losing functions faster than we thought and there is an urgency to protect these intricate relationships as we depend on them to maintain healthy environments, Heleno warns.
Seeds of change
The project has influenced decisions in the Galapagos, including prioritising the conservation of key species. In addition, practical tools were developed such as a Galapagos seeds guide to be used by agriculture and sanitation authorities responsible for the biosecurity of these islands. SEEDS also received international media attention and ran informative outreach events for schoolchildren.
In addition, the project yielded some 14 research papers published in leading journals and trained a dozen scientists.
SEEDS received funding through the EUs Marie Skłodowska-Curie actions programme.