Tropical forests can't recover naturally without fruit eating birds, carbon recovery study shows
New research from the Crowther Lab at ETH Zurich illustrates a critical barrier to natural regeneration of tropical forests. Their models—from ground-based data gathered in the Atlantic Forest of Brazil—show that when ...
Fruit eating birds such as the Red-Legged Honeycreeper, Palm Tanager, or the Rufous-Bellied Thrush play a vital role in forest ecosystems by consuming, excreting, and spreading seeds as they move throughout a forested landscape.
Between 70% to 90% of the tree species in tropical forests are dependent on animal seed dispersal. This initial process is essential for allowing forests to grow and function. While earlier studies have established that birds are important for forest biodiversity, researchers at the Crowther Lab now have a quantitative understanding of how they contribute to forest restoration.
The new study, published in the journal Nature Climate Change provides evidence of the important contribution of wild birds (frugivores) in forest regeneration. Researchers compared the carbon storage potential that could be recovered in landscapes with limited fragmentation, with that of highly fragmented landscapes. Their data shows that highly fragmented landscapes restrict the movement of birds, thereby reducing the potential of carbon recovery by up to 38%.
Across the Atlantic Forest region in Brazil, the researchers found that it is critical to maintain a minimum of 40% forest cover. They also find that a distance of 133 meters (approximately 435 feet) or less between forested areas ensures that birds can continue to move throughout the landscape and facilitate ecological recovery.
The Collared Araçari (Pteroglossus torquatus) is among the few birds that can disperse plants with large seeds and play a key role in dispersal in forests in Central and South America. It is especially important for young forests growing on abandoned land, as they bring in seeds of many different species that will help the forest regenerate a diverse tree community. Credit: ETH Zurich / Christian Ziegler
The Keel-billed Toucan (Ramphastos sulfuratus) is among the few birds that can disperse plants with large seeds and play a key role in dispersal in forests in Central and South America. It is especially important for young forests growing on abandoned land, as they bring in seeds of many different species that will help the forest regenerate a diverse tree community. Credit: ETH Zurich / Christian Ziegler