February
26, 2015
Your choice of coffee
can make a difference for birds in tropical parts of the world — and
biodiversity overall. In a study on coffee
plantations in Africa, we found that coffee farms with shade trees are best for
birds and that these tropical birds likely provide important environmental and
economic benefits to farmers.
Earnings related to
the coffee trade were an estimated US$173 billion in 2012,
making coffee one of the most valuable commodities. And for many tropical
countries, it is the largest export. Coffee is grown on 24.8 million acres, mainly in tropical forest ecosystems, some
of the most biologically rich terrestrial ecosystem on Earth.
Agriculture makes up 38% of global land cover,
which means farms are critical areas for wildlife conservation. Agroforestry –
a technique that combines crops with a mixture of trees and shrubs – is
particularly important for biodiversity conservation. Shade coffee farming,
where the crop is grown under a tree canopy, is one of the most biodiversity-friendly
agricultural habitats and harbors high bird diversity.
Unfortunately,
certified sustainable coffee is only about 8% of the global coffee
market. The vast majority of coffee is produced in monoculture farms
with few or no shade trees, which harbor minimal biodiversity and are a cause
of rainforest deforestation. Additionally, intensive-sun coffee farms can face
pollination and pest problems, increasing reliance on pesticides and further
perpetuating ecological degradation.
Going to the source:
Ethiopia
We monitor birds because they reflect the overall health of
ecosystems. Since they are specialized, have key ecological functions and are
susceptible to disturbances, their declines can affect ecological processes,
including insect regulation, seed dispersal, and pollination.
Forest birds are declining around the world, primarily because
deforestation is destroying their habitat. Currently, 14% of the world’s bird
species are threatened or near threatened with extinction and most of these birds live in tropical forests.
Coffea arabica makes
up two-thirds of the world’s coffee market and is native to southwestern
Ethiopia, where it has been cultivated for over 1,000 years. The agricultural
industry accounts for 80% of employment in
Ethiopia and coffee is the primary export crop.
Here, there are different types of coffee cultivation, including near-wild
coffee grown in forests, shade coffee farms with native tree canopies and
monoculture sun coffee plantations. Although Ethiopia has a long history of
shade coffee farming, it is following the global trend towards sun coffee
monoculture.
Over a three-year period, we studied bird communities on shade
coffee farms and nearby forests in southwestern Ethiopia, whereC. arabica was first domesticated from wild stock.
We set out to evaluate which and how many bird species were present on shade
coffee farms, in comparison to nearby forests.
We sampled the bird communities by using fine nets strung
between bamboo poles. When birds fly into the nets, they fall gently into one
of several pockets. Within 30 minutes we remove, identify, measure, tag and
release them unharmed. Using this technique, we were able to evaluate species
richness, diversity and bird community structure.
Our results showed that shade coffee farms had more than twice
as many bird species as forest sites and all but one of nine migratory species
were captured only in shade coffee habitat. Furthermore, all species that were
captured in nearby forests were also captured in shade coffee sites, where we
also found evidence that several threatened, forest-dwelling specialist birds
were likely breeding.
Forest sites did have a much higher relative abundance of forest
specialist species. Nonetheless, our study documents the only known location
where all forest understory bird species recorded in nearby forest were also
recorded on shade coffee farms. These results position Ethiopian shade coffee
as likely the most “bird-friendly” in the world.
Ecological services
Retaining shade cover on coffee farms helps to preserve insect-
and nectar-eating birds. In turn, these species provide important ecosystem
services –- that is, free services provided to humans by controlling insect
pests and pollinating crops.
For example, a study in
Jamaica concluded that insect-eating birds benefited coffee farmers by $125 per
acre per year by controlling pests. Our results show that shade coffee farms in
Ethiopia harbor a diverse and abundant insect-eating bird community that may
provide similar ecosystem services.
With a per-capita GDP of $505,
Ethiopia is one of the most impoverished nations on Earth. Such ecosystem
services could vastly improve the livelihoods of small-scale farmers.
More importantly, certifying, publicizing and marketing
Ethiopian coffee as “shade-grown” and “bird friendly” has the potential to
increase the incomes of local coffee farmers, providing a disincentive to
convert shade coffee farms into sun coffee plantations. Farms in Ethiopia with
shade grown certification may receive as much as 20% more revenue per
unit of crop.
So for your next cup, look for “shade grown” and “bird friendly”
coffee, certified by the Rainforest Alliance or Smithsonian Migratory Bird
Center and encourage these organizations to certify farms in
Ethiopia – the birthplace of coffee and likely the most biodiversity-friendly.
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