Vincent de Leijster

86 Chapter 5 for erosion control, habitat provisioning and pest control positive linear relationships with canopy cover were often found in coffee systems (Blanco Sepúlveda and Aguilar Carrillo, 2015; Cerda et al., 2017; Jaramillo et al., 2011; Jezeer et al., 2019), we expect the trajectories of these ecosystem services to be similar to the development of the farm’s vegetation structure. We focusonone landmanagement intervention– the implementationof agroforestry in coffee systems – which is expected to have an effect on ecosystem services as coffee agroforestry systems provide higher levels of regulating services thanmonocultures (Cerda et al., 2017). Compared to coffee monocultures, coffee agroforestry is reported to be associated to higher pollination activity (Jha and Vandermeer, 2009), more insect pest suppression by birds (Johnson et al., 2009), higher carbon stocks (Jezeer et al., 2019), more favorable micro- climatic conditions (Siles et al., 2010), and stronger erosion mitigation (Blanco Sepúlveda and Aguilar Carrillo, 2015). Furthermore, coffee agroforestry generally provides better habitat to fauna than monoculture coffee, as it was reported that agroforestry harbor, for example, more bird species (Wunderle and Latta, 1996), butterflies and ants (Perfecto et al., 2005), and spiders (Hajian-forooshani et al., 2013) in comparison to unshaded coffee. As coffee agroforestry can provide multiple environmental benefits, it has been proposed as a tool to rehabilitate biophysically degraded land (Rey Benayas and Bullock, 2012). Nevertheless, the effect of agroforestry on the fundamental provisioning service in coffee systems, coffee production, is variable in different regions. Some studies found that coffee agroforestry systems produced lower coffee yields than monoculture coffee (Campanha et al., 2005; Farfán V., 2014), others found no significant effects on yield (Cerda et al., 2017; Clough et al., 2016; Jezeer et al., 2019), and yet other studies found a hump-shaped relationship between shade cover and coffee yield, with intermediate shade cover positively affecting yields, while high shade cover (>50%) reduced yields (Soto-Pinto et al., 2000). The interaction between coffee yield and shade cover likely results from a potential commensal relationship where coffee plants benefit from the favorable microclimatic conditions provided by shade (lower temperatures and more humid conditions), while under intermediate to dense shade covers competition for light and nutrients limit the growth of coffee plants and their fruits (López- Bravo et al., 2012; Soto-Pinto et al., 2000). Moreover, the interaction between coffee yield and shade depends on local conditions, altitude, soil characteristics, rainfall, cloudiness and farm management intensity (Beer et al., 1998; Farfán and Jaramillo, 2009). The inconsistent relationships between coffee yields and shade cover suggest that within the same system, ecosystem services can develop in different directions. Several studies have shown that pairs of ecosystem services may interact in synergistic, trade-off, or