Large animals disperse large seeded plant species often associated with large trees and high wood density, which are more effective at capturing and storing carbon dioxide from the atmosphere than smaller trees. A decline in fruit-eating animals such as large primates, tapirs and toucans could have a knock-on effect for tree species, revealed a new study by the University of East Anglia.
Seed dispersal by large-bodied vertebrates is via the ingestion of viable seeds that pass through the digestive tract intact. Removing large animals from the ecosystem upsets the natural balance and leads to a loss of heavy-wooded large trees, which means that less CO2 can be locked away.
‘Extinction of large animals will over time induce a decline in large trees. This in turn negatively affects the capacity of tropical forests to store CO2 and therefore their potential to counter climate change.’
Carlos Peres, from UEA's School of Environmental Sciences, said, "Large birds and mammals provide almost all the seed dispersal services for large-seeded plants. Several large vertebrates are threatened by hunting, illegal trade and habitat loss. But the steep decline of the megafauna in overhunted tropical forest ecosystems can bring about large unforeseen impacts. We showed that the decline and extinction of large animals will over time induce a decline in large hardwood trees. This in turn negatively affects the capacity of tropical forests to store carbon and therefore their potential to counter climate change. We hope that the findings will encourage UN programs on Reducing Emissions from Deforestation and Forest Degradation (REDD+) to consider faunally intact forests and their full functionality as a critical precondition of maintaining forest carbon stocks."
The study is published in Science Advances.