Birds, insects, and occasionally bats are the most frequently studied taxa in shade coffee agrosystems. This paper looked at the diversity and abundance of frogs and salamanders in an area of tropical montane cloud forest, shade coffee farms, and corn plantations in southern Mexico.
The study took place near the community of El Molote in the state of Guerrero, part of the Sierra Madre de Sur de Guerrero. Montane forest remnants are embedded in a matrix of other land uses, primarily shade coffee, corn plantations, and areas of cultivated ornamental plants.
Researchers found that the diversity and abundance of amphibians in the forest was highly dependent on what type of land was adjacent to it — coffee or corn. Where shaded coffee plantations bordered forest patches, they helped to buffer the effects of the forest edge, improving the overall quality of the forest interior habitat. Amphibians prefer higher humidity and leaf litter cover which the shade coffee helped preserve, both in the forest and on the farms.
In contrast, where corn bordered the forest, high disturbance and the abrupt change in vegetation had a negative impact on habitat quality. None of the seven amphibian species were found in the corn plantations, and some species, including an endangered endemic frog, the Mourning Treefrog (Plectrohyla pentheter), were never found in the corn/forest ecotone.
The authors recommend that shade coffee farms should be managed to improve habitat and ecological connectivity.
Santos-Barrera, G., & Urbina-Cardona, J. N. (2011). The role of the matrix-edge dynamics of amphibian conservation in tropical montane fragmented landscapes. Revista Mexicana de Biodiversidad, 82, 679-687