Vincent de Leijster

142 Chapter 7 my co-authors and I used a space-for-time substitution to reconstruct a chronosequence of the time since the adoption of agroforestry in coffee farms. Agroforestry relates to the agroecological principle of vegetation diversification and to a more complex vegetation structure. We assessed the development of ecosystem services over time since adoption of agroforestry. We found that most canopy structure characteristics (such as canopy closure and tree height) increased over time, following an asymptotic shape. Indicators of carbon storage and habitat provisioning had similar trajectories to the development of canopy structure, whereas timber volume had a sigmoid trajectory. However, coffee yield did not significantly change over time. Overall, we found that ecosystem service supply changed most in the first ten years and largely stabilized after approximately twenty years. In the first ten years after adoption, coffee yield was negatively related to above-ground carbon, suggesting a trade-off. In the subsequent ten-year period, coffee yield was positively related to erosion control, which suggests a synergy. In addition, we found that above-ground carbon stock and erosion control formed a bundle that was stable over time, and this bundle related positively to epiphyte abundance and in the short term negatively to coffee berry borer control. Agroforestry farms with a dispersed tree spatial arrangement provided a higher accumulated ecosystem service supply than farms with trees in alley formation or in living fences. Finally, we found that canopy characteristics were the most important driver of ecosystem services in this system; however, agrochemical input management, altitude and slope also influenced their supply. In this chapter, we concluded that adoption of agroforestry can be used to rehabilitate some ecosystem services, such as carbon storage, erosion control and habitat provisioning, but that the effects on provisioning services are variable. Additionally, we concluded that interactions among ecosystem services often vary over time and that only above-ground carbon and erosion control had a stable positive relationship. Chapter 6 followed up on the findings of Chapter 5, as we investigated whether the coffee agroforestry systems were profitable and how costs, benefits and net revenues have developed over time since the adoption of agroforestry. Again, we conducted a chronosequence analysis on agroforestry coffee farms, but here we included more farms than in Chapter 5. Using a questionnaire, we obtained information about costs, benefits, and management regime along with information about farm, location, and supply chain characteristics. We found that coffee yields significantly decreased over time, but that this did not translate into lower coffee gross revenues, lower coffee net revenues or lower actual net revenues over time. This could be explained by a reduction in harvest and post-harvest costs and an increase in revenues from co-products such as timber and fruit. Specifically in