In a recently published article, PhD candidate Pablo Aycart-Lazo from the University of Vienna, together with an international group of co-authors, analyzed how agroforestry management and the surrounding landscape affect birds and bats in the Peruvian Amazon - one of the most biodiverse regions in the world. Based on the study, published in Agriculture, Ecosystems and Environment, the authors suggest that conserving flying vertebrates, such as birds and bats, in tropical agroforestry areas requires adapting shade tree management to the specific characteristics of the surrounding landscape.
The researchers studied 28 cacao agroforestry systems which diverged in the number of shade tree species they included, and the percentage area that the canopy of these trees covered. The agroforests were distributed in two regions with contrasting intensity of agricultural practices in the Peruvian department of San Martín. They studied how bird and bat diversity changes with shade tree management, landscape features like agricultural intensification and tree cover loss.
The role of shade trees in supporting birds and bats
"We found that birds and bats prefer agroforests that are similar to the surrounding landscape. Either agroforests with few shade trees if landscapes are rather open, or highly shaded agroforests in landscapes that are well forested", reports first author Pablo Aycart-Lazo. This is mainly because birds and bats adapt to the resources available and deforestation disrupts ecological balance, favouring open-area species. "This shift can threaten biological pest control, since insectivorous species from forests, which are expected to control pests, would be absent in cacao agroforests in agricultural matrices", he adds. The study indicates that restoring tree cover in the landscape is an essential step to enhance biological pest control in tropical agroforests. "These systems cannot maintain biodiversity if they become isolated islands in landscapes dominated by intensive agriculture like monocultures", adds co-author Dr. Carolina Ocampo-Ariza from the University of Göttingen, Germany.
Diversity promotes abundance
Besides the interplay between landscape and local tree cover, the authors found an important role of tree species diversity in protecting insectivorous birds and bats. A higher diversity of shade tree species promoted higher abundances of insectivorous birds in agroforests within the intensive agriculture region. "Diverse cacao agroforests seem to serve as an oasis where birds can find food and refuges that might be scarce in other agricultural systems such as rice paddies or papaya monocultures", says co-author Dr. Bea Maas from the University of Vienna.
The study underscores the importance of adapting agroforestry to the local landscape to conserve biodiversity and promote sustainable cacao production. Moreover, the authors provide landscape-adapted agroforestry management recommendations focused on improving bird and bat conservation in tropical agricultural areas. The article is also available in Spanish upon direct request to the authors.
Paper:
Aycart-Lazo, P., Ivañez-Ballesteros, B., Ocampo-Ariza, C., Wessely, J., Dullinger, S., Steffan-Dewenter, I., Thomas, E., Tscharntke, T. & Maas, B. (2025). Landscape context influences local management effects on birds and bats in Amazonian cacao agroforestry systems. Agriculture, Ecosystems and Environment 385, 109545, https://doi.org/10.1016/j.agee.2025.109545
Contact:
Pablo Aycart-Lazo
Department of Botany and Biodiversity Research, University of Vienna
Rennweg 14, 1030, Vienna, Austria
Email: pablo.aycart@univie.ac.at
