Cacao Plant

The act of deforestation removes physical barriers for land cultivation, but, in doing so, it also removes the element of shade from taller vegetation. Moreover, the removal of surrounding vegetation eliminates the opportunity for local ecosystems to diversify and to build complex plant and wildlife relationships. The difference between a heterogeneous small farm and a monoculture present in a large plantation is responsible for the difference in biodiversity of these two ecosystems and may result in different yields (Armengot et. al, 2016). In this brief, an example is used to help further explain the differences in productivity and microclimates between a small cacao plant and a large cacao plantation:

A new manager for a large plantation (left) has observed that her yields of cacao are often considerably lower than her neighbors', who are small land holders (right). Concerned that this difference might be the result of insect pests, she asks an entomologist from a nearby university to collect data on the insect communities on her plantation, as well as her neighbors'.

Because the small farm has overhanging, lush vegetation surrounding the cacao plants, the community is able to sustain higher species richness than the open plantation. A higher species richness allows for more checks and balances between predators. This can be seen by analyzing the relationship between various ant species and the cacao yield in the small farm and the large plantation. As seen in Figure 1, some species of insects are significantly more prevalent in the large plantation than the small farm, such as the Conopomorpha. The Conopomorpha’s nickname, cocoa pod borer, reveals the negative effects of the species on producing cacao. Figure 2 shows that there are 960 more Conopomorpha in the large plantation.


Figure 1

Figure 2

Because there is greater species richness in the smaller farm, there is a greater chance that it provides a niche for a species that controls the Conopomorpha population as well as other pests to the cacao plants. To confirm this, an analysis of the ΔN data and concepts regarding trophic levels was carried out. By isolating the species with the highest ΔN levels (>10), one can determine which species are secondary consumers. As trophic pyramids progress, ΔN increases: secondary consumers eat and take in the ΔN levels of primary consumers and/or producers (Zanden et. al, 1999). Figure 3 reveals that the small farm has more secondary consumers. However, because the cocoa pod borer does its damage in the pod, the only relevant species to this discussion are those that are arboreal. Still, there are more arboreal secondary consumers in the small farm than the large plantation (Figure 4). A community having a multitude of predator/prey relations as opposed to having a limited amount of predator/prey relations has been shown to produce a more successful crop (Wielgoss et. al, 2013). So, not only is having more secondary consumers productive in limiting the cocoa pod borer’s destruction, but it also is productive in growing the community.

Figure 3

Figure 4


Andres, Christian, et al. “Cocoa in Monoculture and Dynamic Agroforestry.” Sustainable Agriculture Reviews, 2016, pp. 121–153., doi:10.1007/978-3-319-26777-7_3.

Armengot, Laura, et al. “Cacao Agroforestry Systems Have Higher Return on Labor Compared to Full-Sun Monocultures.” Agronomy for Sustainable Development, vol. 36, no. 4, 2016, doi:10.1007/s13593-016-0406-6.

Bisseleua, Hervé Bertin Daghela, et al. “Shade Tree Diversity, Cocoa Pest Damage, Yield Compensating Inputs and Farmers' Net Returns in West Africa.” PLoS ONE, vol. 8, no. 3, 2013, doi:10.1371/journal.pone.0056115.

Wielgoss, A., et al. “Interaction Complexity Matters: Disentangling Services and Disservices of Ant Communities Driving Yield in Tropical Agroecosystems.” Proceedings of the Royal Society B: Biological Sciences, vol. 281, no. 1775, 2013, pp. 20132144–20132144., doi:10.1098/rspb.2013.2144.

Zanden, M. Jake Vander, and Joseph B. Rasmussen. “PRIMARY CONSUMER δ13C AND δ15N AND THE TROPHIC POSITION OF AQUATIC CONSUMERS.” Ecology, vol. 80, no. 4, 1999, pp. 1395–1404., doi:10.1890/0012-9658(1999)080[1395:pccana];2.