Figure 1 Location of sampled farms and mammal study areas
is from April to June, with an intermediate harvest between September and November. Figure 1 shows the Cundinamarca and Santander regions, the locations of sampled farms and the mammal study area. Sample selection for farm studies The first three studies in Table 2 (referred to collectively as the “farm-based studies�) all use a similar experimental design to compare certified and noncertified farms, and they share many of the same farms in their respective samples. To establish these samples, researchers first randomly selected 36 certified farms in each of the two states, and then, for each certified farm, selected the nearest noncertified farm with a similar size, topography and elevation as a control. The Colombian National Coffee Growers Federation’s Coffee Production Information System (abbreviated as SICA in Spanish), which is a register of all coffee farms in Colombia, provided information on
all the farms in the study areas, including the location, area, variety and date planted, as well as the certification status of each parcel. This information allowed the researchers to identify pairs of similar farms. The samples for all three farm-based studies were obtained from this global set of 144 farms (72 in Cundinamarca and 72 in Santander). The different selection and sampling requirements of each study, combined with the logistical issues associated with sampling certain farms, meant that not all the 144 selected farms were included in all studies. Most notably, only farms with a water source originating on the farm were included in the water quality study. The final sample sizes of the three farm studies are presented in Table 3. Sample selection for mammal studies The mammal study was different from the farm studies in that night monkeys are so rare that a random sample of certified and noncertified farms 7