Birds and other biodiversity

Birds and other biodiversity / Research on coffee growing

Research: Biodiversity in wild coffee farms in Ethiopia

Senbeta, F. and M. Denich. 2006. Effects of wild coffee management on species diversity in the Afromontane rainforests of Ethiopia. Forest Ecology and Management 232:68-74.

Traditional coffee management in Ethiopia ranges from harvesting cherries in relatively undisturbed forest, to reducing tree and shrub density in semi-forest systems. This study looked at plant species diversity in these two systems in the southeast (Bale Zone of Oromia) and southwest highlands (Bench-Maji Zone) of Ethiopia.

In the forest system, coffee plants made up less than 25% of the plant density versus greater than 88% in the same size class in the semi-forest system.  Continuous management of coffee in the semi-forest system suppresses tree regeneration, reduces tree density, and eventually leads to the disappearance of forest plant species.

This management is leading to a tall tree canopy with no intermediate layer, effecting not only diversity of plants but the structural diversity needed for other wildlife.  In some plots, not even young coffee trees were allowed to regenerate, which means coffee production will end up being affected.  Another way the production of coffee may suffer is that the lack of native forest plants species may also result in a decline of bees and other pollinators. Other studies have shown that coffee fruit set is strongly influenced by the abundance of pollinating insects.

The authors note that “Traditional wild coffee management methods are not based on systematic analysis, and hence opinions among the farmers vary on how to manage the forest.” With a higher demand and stronger market for Ethiopian coffee, farmers
in these areas tend to focus on seed production rather than
preservation of the natural regeneration of coffee trees.  The authors recommend a strategy that will strike a balance between plant diversity (and hence pollinator diversity, which contributes to coffee production, as well as other biodiversity) and coffee production.

They conclude that biodiversity conservation spots are crucial to maintain and enhance biodiversity, including acting as repositories for plant and animal diversity, and genetic resources of wild coffee populations — which are under increasing threat from deforestation — which can prove invaluable in developing new strains.

I consider this an important paper, as most of the emphasis on coffee and biodiversity has been on farming methods in the New World, while African coffees are usually considered “wild” and grown in an un-manipulated manner.  As the Ethiopian and African coffee industries gain momentum, we will have to see how management methods develop, and no longer take for granted that the coffees we purchase from these regions are always sustainable.

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Birds and other biodiversity

World biodiversity crisis

The main thrust of Coffee & Conservation is how to choose sustainable coffees — those that help preserve biodiversity.  The more you understand the depth and urgency of the biodiversity crisis we face on Earth today, the more motivated you will be to do what you can to help (including drinking sustainable coffee).

It would be easy to devote an entire blog just to explaining, summarizing, and analyzing the biodiversity crisis, and that kind of detail is beyond the scope of C&C.  However, there is an excellent web site that pulls together many resources.  Dr. David Ulansey’s site looks a little crude, but includes many worthwhile links which are frequently updated.  I urge readers to take a look. Here are some of the links that pertain to the general biodiversity crisis or coffee growing regions in particular:

Of course it is preferable — and necessary — to preserve intact forests in coffee growing regions.  Purchasing cheap, mass-produced coffee merely encourages the exploitation of that land for high, short-term yields at the lowest price.  Buying coffee from established farms which produce coffee in the least-technified manner, and indeed paying a premium for them, 1) provides incentive for farmers to grow coffee in a sustainable manner, preserving biodiversity on their farms, 2) discourages large corporations from clearing more land and subsidizing more inputs for cheap coffee, and 3) discourages small farmers from abandoning their farms or converting them to sun coffee or other crops.

If you drink coffee, drink responsibly and sustainably. C&C is here to help.

Birds and other biodiversity / Research on coffee growing

Research: Bat diversity in different types of shade coffee

Garcia Estrada, C., A. Damon, C. Sanchez Hernandez, L. Soto Pinto, and G. Ibarra Nunez.  2006.  Bat diversity in montane rainforest and shaded coffee under different management practices in southeastern Chiapas, Mexico.  Biological Conservation 132:351-361.

Southeastern Chiapas is Mexico's primary coffee-producing region.  Very little of the original montane rainforest remains.  Originally, coffee was grown under polyshade, or trees of various species found in the original forest.  Incentives have resulted in many farms using Inga trees for shade; these are native, hardy, fast-growing, deep-rooted, and fix nitrogen (however, production is not increased with Inga, there tend to be more weeds and soil erosion, so replacing forest with Inga doesn't offer many advantages).

This study looked at the diversity of bat species in shade coffee farms that use polyshade; or monoshade (Inga or Inga and bananas) with high, low, or no chemical inputs.  While unaltered montane rainforest had the highest number of species (37), all the others had 23-27 species.  Species composition was different, though, with more fruit and nectar eating bats found in farms with high chemical inputs, which had fewer insect-eating bats.  Application of pesticides decreases insect diversity for these species, especially insect families important to rare bat species. 

Birds and other biodiversity / Research on coffee growing

Research: Shade coffee farms as habitat for monkeys

Williams-GuillÁ©n, K., C. McCann, J.C. MartÁ­nez SÁ¡nchez, and F. Koontz.  2006. Resource availability and habitat use by mantled howling monkeys in a Nicaraguan coffee plantation: can agroforests serve as core habitat for a forest mammal? Animal Conservation 9: 331-338.

The incredible contact roars of Mantled Howler Monkeys (Alouatta palliata) are a frequent wake-up call to visitors to the New World tropics.  They were studied in a Nicaraguan shade coffee plantation, which had a diverse (60+ species) canopy which insured that preferred foods were available to the monkeys year-round. The monkeys did not avoid areas of coffee plantations, but stuck to the larger trees. The authors concluded that shade coffee can serve as alternate wildlife habitat and corridors between forest fragments for howling monkeys and possibly other forest mammals.