Cassio Pinheiro Edelstein ^1* Rolando Cerda ¹ Marney E Isaac ² Luis Orozco Aguilar ¹ Felipe Peguero ³ Diego Delgado ¹

• ¹ Centro Agronomico Tropical De Investigacion Y Ensenanza Catie, Turrialba, Costa Rica
• ² University of Toronto, Toronto, Ontario, Canada
• ³ Texas A&M AgriLife Research and Extension Center at Weslaco, Weslaco, Texas, United States

Cocoa agroforestry systems (AFS) provide multiple ecosystem services, which are influenced by features of the shade tree community. By strategically selecting and managing shade trees based on their functional traits, cocoa farmers can affect functional diversity of AFS and potentially enhance the benefits they deliver. In this research we applied functional trait ecology to better understand the effect of functional diversity of cocoa AFS on three ecosystem services: carbon storage, soil fertility, and provisioning of cocoa and other products. To do so, we characterized 30 AFS across a gradient of ecological complexity and established relationships between functional diversity indices and targeted ecosystem services. As a result, two contrasting ecological dynamics were observed among the AFS. On one hand, low-complexity AFS were characterized by the dominance of resource-conservative traits (higher leaf dry matter content, higher stem specific density, and low leaf nitrogen concentration) and were associated with lower carbon stocks and soil fertility. On the other hand, the most complex AFS exhibited resource-acquisitive traits (low leaf dry matter content, low stem specific density, and high leaf nitrogen concentration) and deliver greater ecosystem services. We further instrumentalized functional diversity into a management approach by analyzing the relationships between functional traits and ecosystem services using multiple regressions. We found that AFS dominated by species with greater maximum potential height, greater leaf nitrogen concentration, lower leaf dry matter content, lower leaf mass per area, and lower leaf nitrogen-phosphorus ratio were associated with higher carbon storage (R 2 = 0.84), soil fertility (R 2 = 0.7 for soil nitrogen), and multiple ecosystem services (R 2 = 0.78). Our results indicated that cocoa yields were negatively correlated with shade cover and the dominance of largeleaf shade trees. Finally, our study illustrates critical relationships between shade tree traits and delivery of key ecosystem services for farm sustainability and farmer livelihoods.