4.6. Species of conservation concern In our study area, we found 26 tree species either listed in the Red list of Endangered Trees or in the Red List of Mexican Cloud Forest Trees. We identified 18 CC species in forests and 17 in shade coffee farms; 9 species were common to both ecosystems; 9 species grew exclusively in forests and 8 exclusively in farms. In farms the mean relative frequency of CC species was 17%, whereas in forests this figure increased to 26%; this difference is marginally significant(p-value = 0.053). However, in forests, 25% of tree stems were of CC,a noticeably higher amount than the 10% of CC stems harbored in farms (p-value < 0.001).