Vincent de Leijster

94 Chapter 5 5.2.4.2 Erosion control and water infiltration Based on the soil surface properties (n=8 per farm), which we described in section 5.2.3.3, we calculated the potential soil loss using the Revised Universal Soil Loss Equation (RUSLE), following (Renard et al., 1997). This approach uses the factors rainfall erosivity (MJ mmha -1 h -1 ), soil erodibility (Mg h -1 MJ -1 mm -1 ), slope length (m), slope steepness (rad), cover management, and soil support, to calculate potential soil loss (Mg soil ha -1 y -1 ). Based on eight samples, we calculated eight potential soil loss data points per farm, which were then averaged to obtain one mean value per farm. We refer the reader to the appendix for more specific information about adjustments and assumptions in addition the RUSLE method. Further we included litter cover, understory vegetation cover and soil stability (see 2.3.1.2.) as indirect proxies for erosion control, because of their importance to preventing soil from water erosion (Blanco Sepúlveda and Aguilar Carrillo, 2015; Tongway and Hindley, 2004). 5.2.4.3 Habitat provisioning We estimated biodiversity intactness as a measure for habitat provisioning (IPBES, 2019). As biodiversity proxies we measured butterfly richness, abundance, and diversity, and richness of epiphyte taxonomic groups (sections 5.2.3.1 and 5.2.3.4). 5.2.4.4 Pest control Incidence of coffee berry borer and ant predation of leaf cutter ants were used as proxies for the ecosystem service of pest control. These were the most common pests and/or diseases in the region, coffee leaf rust was not common since rust-resilient coffee varieties were cultivated. 5.2.4.5 Provisioning service The provisioning of coffee was assessed using a proxy for quantity (plot-level and farm- level) and for quality (plot-level), which both contribute to gross income. At the plot-level, we calculated the maximum obtainable coffee productivity as the potential coffee to be produced on a plot using the formula described by Cerda et al. (2017): CP = (8.58 + 3.88 · NPS + 1.95 · NF Node + 0.03 · NFN Plant − 0.18 DeadB) 2 (equation 9)