Research on coffee growing

Birds and other biodiversity / Coffee regions / Research on coffee growing

Research: Forest birds using Costa Rican coffee farms

Persistence of forest birds in the Costa Rican agricultural countryside. C. H. Sekercioglu, S. R. Loarie, F. Oviedo Brenes, P. R. Ehrlich, and G. C. Daly. 2007.  Conservation Biology 21:482-494.

This study radiotracked several species of resident forest birds in the Coto Brus province of southern Costa Rica, now "dominated by sparsely-shaded coffee farms" — recall that in my post on coffee growing in Costa Rica that most farms, including those marketed as "shade" coffee, have few shade trees of only a couple of species, and lack the structural complexity necessary for true biodiversity preservation.  Two of the three species studied, Silver-throated Tanager (Tangara icterocephala) and White-throated Thrush (Turdus assimilis) are more habitat-sensitive and utilized the coffee farms, but were highly dependent on the remaining trees, and spent more time in remnant forest. The third species, Orange-billed Nightingale-Thrush (Catharus aurantiirostris), is more tolerant of deforestation, and preferred coffee farms and second-growth areas. The authors concluded that agricultural areas have high potential conservation value, which can be enhanced with even modest increases in tree cover. Imagine what true shade coffee would do!

Research on coffee growing

Research: Shade coffee buffers against climate change

Agroforestry management as an adaptive strategy against potential microclimate extremes in coffee agriculture. B. B. Lin.  2007. Agriculture and Forest Meteorology 144:85-94. DOI:10.1016/j.agrformet.2006.12.009.

A few months ago I wrote a detailed post on coffee growing and climate change. Climate change poses a significant threat to coffee growing, as arabica coffee grows best in temperatures around 20C (68F).  As this paper reiterates, the photosynthesis of coffee decreases markedly at temperatures between 20 and 24C (68-75F), and grinds to a halt at 34C (93F) and above. At the same time, the fruit ripens at an accelerated rate above 23C, reducing quality, as the best-tasting coffees come from cherries that have ripened slowly, intensifying and concentrating flavor.

This study looked at shade cover at farms in the Soconusco region of southern Chiapas, Mexico (Finca Irlanda, Finca Hamburgo, and Rancho Alegre) and how the amount of shade impacted temperature, humidity, and soil moisture. Although this has long been suspected, this study confirms that the fluctuations in microclimate decrease as shade level increases. Increased shade in coffee agrosystems can help mitigate the effects of climate change by buffering the coffee from climate variability.

Nearly 4 million Mexicans depend on coffee production. Farmers have already noticed changes in the climate, particularly longer dry seasons.  What will happen if farmers have to abandon their plots? As during the coffee crisis, many head north.

Birds and other biodiversity / Research on coffee growing

Research: Birds in shade coffee favor plant diversity

Dietsch, T.V., I. Perfecto, and R. Greenberg. 2007. Avian foraging behavior in two different types of coffee agrosystem in Chiapas, Mexico.  Biotropica 39:232-240.
Other studies have documented that structural diversity is important in coffee farms — it is the complexity of multiple layers of vegetation in shade coffee systems that are so important and attractive to birds and other organisms. This study looked at Finca Irlanda in Chiapas, a 290 hectare shade coffee farm, during both summer and winter seasons. Forty of those hectares are being further restored by additional plantings of native plants in order to qualify for Smithsonian Bird-Friendly certification. At the time of the study, the structural diversity of the entire farm was similar, but the 40 ha under restoration had a wide variety of plants.

Eighty-eight bird species were observed, and more species were found foraging in the restoration plot than the rest of Finca Irlanda. The study revealed the importance of plant diversity in addition to structural diversity. These diverse plants provide varying resources throughout the year — from nectar to insects to fruit — that are critical to birds.

Rogers Family Company is Finca Irlanda’s roaster in the U.S., but I was unable to determine which one of their brands or coffees uses beans from this farm. One expects it would be used in the Audubon coffee line, but as noted in our review of the Audubon Breakfast Blend, there is no information on the origin of those coffees; specific information is lacking on most Rogers Family coffees. You can also buy Finca Irlanda coffee from Cafe Altura.

Research on coffee growing

Research: Beneficial fungi in wild Ethiopian coffee forests

Composition of coffee shade tree species and density of indigenous arbuscular mycorrhizal fungi (AMF) spores in Bonga natural coffee forest, southwestern Ethiopia. Muleta, D., F. Assefa, S. Nemomissa, and U. Granhall. 2007.  Forest Ecology and Management 241:145-154.

Mycorrhizal fungi have mutualistic associations with plants. They benefit coffee plants by enhancing growth and tolerance to nematodes, increasing phosphorus and zinc uptake in young plants, and increasing overall survival. This study looked at which shade trees were associated with the highest levels of AMF in a wild coffee forest.  Four tree species were dominant: Millettia ferruginea, Olea welwitschii, Schefflera abyssinica, and Phoenix reclinata. Millettia are legumes, and thus fix nitrogen in the soil, an added benefit.  Higher mean counts of AMF were found under leguminous shade trees compared to non-legumes. This healthy ecosystem is considered to have high potential for conservation of the wild coffee gene pool.