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Harvested cacao pods before the beans are fermented and processed into chocolate.
Photo Credit: © Pablo Aycart Lazo
Scientific Frontline: Extended "At a Glance" Summary: Biodiversity in Cacao Agroforestry
The Core Concept: Agroforestry integrates crop cultivation with shade trees, allowing tropical biodiversity conservation to directly reinforce agricultural production. This synergistic farming method utilizes ecosystem services, such as natural pest control, to enhance yields while sustaining local wildlife.
Key Distinction/Mechanism: Rather than relying on dense, uniform shade—which limits sunlight and restricts crop yields—successful agroforestry utilizes a structurally diverse canopy mosaic of tall and short trees. Furthermore, it relies heavily on the surrounding landscape's composition, where nearby forests and tree-based habitats provide refuge for predatory birds and bats that feed on crop-damaging arthropods.
Origin/History: The precise mechanisms of successful agroforestry were investigated across 28 organic cacao farms in the northern Peruvian Amazon by an international research team led by the University of Vienna, with findings published in Communications Earth & Environment.
Major Frameworks/Components:
- Canopy Structural Diversity: Utilizing varied tree heights, clusters, and open patches to balance optimal sunlight, microclimate buffering, and soil fertility.
- Landscape-Level Management: Recommending a regional composition of 30 to 35 percent contiguous forest cover, 40 to 45 percent tree-based habitats, and 20 to 30 percent open agricultural areas.
- Ecosystem Services Valuation: Quantifying the economic impact of natural pest control by birds and bats, which can increase production value by an estimated $1,640 per hectare annually in tree-rich landscapes.
- Remote Sensing Analysis: Employing drones and spatial data mapping to measure the influence of shade-tree structure and regional forest cover on agricultural outcomes.
Branches of Science: Agroecology, Conservation Biology, Landscape Ecology, Zoology, Environmental Science.
Future Application: Developing socio-ecologically viable, multifunctional land-use strategies customized alongside local communities to stabilize tropical farming systems and reverse the spread of agricultural monocultures.
Why It Matters: By fostering habitats for natural predators, farmers can bypass the traditional trade-off between agricultural yield and ecological conservation. Preserving diverse surrounding landscapes can nearly quadruple cacao production—from 265 kilograms to 1,000 kilograms per hectare annually—while protecting some of the most biodiverse regions on the planet.
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| Researchers installing bird and bat exclosures to measure their contribution to natural pest control and cacao yields. Photo Credit: © Pablo Aycart Lazo |
Tropical farmers are often expected to choose between high crop yields and protecting wildlife. However, an international team of researchers led by the University of Vienna, in collaboration with the universities of Göttingen and Würzburg in Germany and Bioversity International in Peru, shows that biodiversity conservation reinforces cacao production in agroforests via associated ecosystem services, such as natural pest control. The new study, published in Communications Earth & Environment, provides important evidence for sustainable farm and landscape management in one of the world's most biodiverse regions.
Agroforestry integrates crop cultivation with shade tree canopies. This type of farming can protect biodiversity while supporting food production. It can also promote natural pest control, improve soils, and buffer extreme temperatures. The current study investigates the precise mechanisms of successful agroforestry. "Our results show that these benefits depend strongly on how trees are managed both within farms and across the surrounding landscape," says Pablo Aycart-Lazo of the University of Vienna, lead author of the study.
Researchers studied 28 organic cacao agroforests in the northern Peruvian Amazon. They surveyed birds, bats, and arthropods and measured cacao yield, natural pest control, pollination, pest and disease incidence, soil fertility, and microclimate. Drone and remote-sensing data allowed them to test how shade-tree structure within farms and tree cover in the surrounding landscape influenced these outcomes.
Cacao agroforests combine cacao trees with taller shade trees, creating structurally diverse habitat for wildlife.
Photo Credit: © Pablo Aycart Lazo
The Structure of the Canopy Matters
Contrary to expectations, researchers found that increased shade cover did not universally improve outcomes. In the study, shade-tree cover benefited wildlife, soils, and microclimate, but very dense shade substantially reduced cacao yields because less light reached the crop. However, the researchers found a promising alternative: Farms with a more varied arrangement of tall and short shade trees supported greater biodiversity without the same yield losses. "Our data show that cacao farms do not need uniform shade to support biodiversity. A mosaic of tall and short trees, tree clusters, and open patches can create habitat for wildlife while maintaining production," explains Aycart-Lazo.
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Cacao farms form part of complex tropical landscapes containing crops, pastures and forest remnants.
Photo Credit: © Pablo Aycart Lazo
What Happens Outside the Farm May Be Just as Important
The surrounding landscape composition significantly influenced cacao productivity. Cacao yields increased from 265 kg per hectare per year in deforested landscapes to about 1,000 kg per hectare per year in landscapes combining medium levels of forest cover and additional tree crops. Birds and bats played a key role by feeding on arthropods that damage cacao flowers and pods. This nearly doubled cacao yields in these tree-rich landscapes, equivalent to an estimated $1,640 per hectare per year in additional production value. "Birds and bats can be powerful allies for cacao farmers, but only if the surrounding landscape provides enough habitat. If these landscapes become large monocultures, much of this natural pest-control benefit is lost," says senior author Bea Maas of the University of Vienna.
Sustainable cacao production relies on both localized farm management and regional landscape composition. The authors advocate for a landscape-level strategy. In a contiguous region, the researchers recommend maintaining 30–35% forest cover, together with another 40–45% of tree-based habitats such as agroforests or orchards, and an additional 20–30% of open areas like annual crops. This could create multifunctional landscapes with high biodiversity while supporting cacao production and farmer livelihoods. "This is not a one-size-fits-all blueprint. Landscape strategies need to be adapted to local land availability and developed together with local communities," adds co-senior author Carolina Ocampo-Ariza of the Technische Universität Darmstadt and the University of Göttingen, Germany.
Funding: This research was funded by the Austrian Science Fund (FWF grant number I5272) and the German Research Foundation (DFG grant number TS 45/42-1, STE 957/27-1). E.T. received funding from the Multifunctional Landscapes Science Program of the oneCGIAR.
Published in journal: Communications Earth & Environment
Authors: Pablo Aycart-Lazo, Blanca Ivañez-Ballesteros, Abed Alvino-Rosas, Daniel Ochterbeck, Melvin Opolka, Oscar Cabezas Huayllas, Stefan Dullinger, Evert Thomas, Teja Tscharntke, Ingolf Steffan-Dewenter, Carolina Ocampo-Ariza, and Bea Maas
Source/Credit: Universität Wien
Edited by: Scientific Frontline
Reference Number: agri110926_01
