Vincent de Leijster

116 Chapter 6 Runhaar, 2018). Therefore, we need a better understanding of how the transition affects the development of costs, benefits and net revenues of smallholder plantations and whether external investments are needed. The effect of agroforestry on farm profitability is still debated (Grass and et al., 2020; Tscharntke et al., 2011). Vegetation management options associated to agroforestry or monoculture may influence farm profitability by affecting yield of the main crop, market prices, management costs and income from other products grown on the farm (Jezeer et al., 2018). For coffee, excessive shading in the agroforestry system may reduce coffee yields compared to unshaded monoculture coffee plantations (Jezeer et al., 2017; Vaast et al., 2006a). However, other studies have shown that the relationship between shade cover and perennial yields is more complex as low shade cover seems not to affect yields negatively, and other characteristics also play an important role (Cerda et al., 2017; Jezeer et al., 2018; Soto-Pinto et al., 2000). For example, the tree species used as timber trees strongly affect coffee yield (Farfán-Valencia and Baute-Balcázar, 2010), as well as abiotic factors such as cloudiness (Farfán and Jaramillo, 2009), altitude (Cerda et al., 2017; Jezeer et al., 2018) and climate (Jaramillo et al., 2011). Further, yield of the main cash crop is not a comprehensive indicator for economic performance, since lower yields may be compensated by higher prices, lower costs, or benefits from other goods and services (Jezeer et al., 2017). A study on coffee plantations in Peru showed that agroforestry and monoculture coffee had similar yields, however, agroforestry plantations had lower management costs and received a higher price for the coffee, and therefore net revenues were higher for agroforestry farms (Jezeer et al., 2018). In some cases, higher prices are paid because farms are certified by labels that require the use of shade trees, for example, Rainforest Alliance and Organic (Lyngbæk et al., 2001; Verburg et al., 2019). Moreover, agroforestry can compensate for (potential) lower yield of the main cash crop through the production of other marketable products, such as tree fruits, plantains and timber (Jezeer et al., 2018; Schneider et al., 2017), although these additional goods (and services) are often not yet marketed. For example, an Ethiopian study estimated that the profitability of agroforestry can increase by around 20% with revenues from the sequestered carbon (Waldén et al., 2020). Coffee prices may also be affected by the quality of the coffee beans. Shade has been reported to improve the quality of coffee beans, because the stable temperature and humidity in shaded systems can lead to a more uniform ripening of the berries (Jaramillo et al., 2011; Muschler, 2001; Vaast et al., 2006a); however, lower coffee quality in shaded compared to unshaded conditions has also been reported (Skovmand Bosselman et al., 2009). Coffee agroforestry farms also have a higher suppression of pests by their natural enemies (Armbrecht and Gallego, 2007), and lower growth rates of herbaceous plants (Bellamy, 2011; Soto-Pinto et al., 2002). These two elements can be