The most serious impact of coffee cultivation continues to be the conversion of natural forest areas to plant coffee.
Increasingly, it is full-sun coffee that is being established in plantations. Natural ecosystems are destroyed as a result of the expansion of sun coffee production. The affected natural systems will never fully recover.Sun coffee production & deforestation
The data suggests that there is a strong correlation between full-sun coffee production and deforestation. Of the 50 countries in the world with the highest deforestation rates from 1990 to 1995, 37 were coffee producers.
This is in part linked to the fact that the highest levels of deforestation are in tropical countries where coffee is also grown. Even so, the top 25 coffee exporters had a combined average annual forest cover loss of 70,000 square kilometres during the same years (Manion et al. 1999).
Considerable biodiversity loss
The large, monocrop plantations typical of full-sun plantations cause the greatest reductions in biodiversity. Studies in Colombia and Mexico indicate that full-sun coffee plantations support 90% fewer bird species than shade-grown coffee.
The severe thinning or clearing of forests for planting shade-grown coffee is also a major concern. Considerable biodiversity is lost both above and below ground. Microorganisms in particular are affected through clearing, soil disturbance, and exposure.
Even with shade coffee the number of tree species can be reduced by 80% or more. Mammals and reptiles show declines in populations and species diversity relative to natural forests. Bat species are reduced by half or more in agroforestry systems such as shade-grown coffee. Furthermore, species that do better in disturbed ecosystems tend to dominate ecosystems tend to dominate areas of shade-grown coffee.
Some observers have suggested that because much shade coffee is grown in areas of human habitation that are being deforested, species that can move easily often seek refuge in the shade-grown coffee areas. Migratory bird populations, for example, may be forced to seek shelter in an ever shrinking area, whether they are in transit or at a traditional seasonal resting place.
While shade-grown coffee can support high wild species diversity of mobile species in comparison to full-sun coffee or many other agricultural activities, it is no substitute for the preservation of pristine natural areas.
Irreversible damages to natural forests
There is no evidence that any area of coffee production, whether shade or full-sun, has ever been allowed to revert back to "natural" forest. Habitat conversion, it seems, is forever. In regions like Parana in Brazil and Java in Indonesia, shade-grown coffee has given way to full-sun coffee or other agricultural crops altogether. This conversion can mean a reduction in the local labour needs.
Human migration problems
Those displaced by the conversion of land from coffee production to other crops often migrate to frontier areas (e.g., in the Amazon and Cerrado in the case of soybean expansion in Brazil). Or, overpopulation in agricultural areas can cause the migration of poor farmers or landless people to frontier areas where they plant coffee (e.g., in the outer islands of Indonesia and in central Vietnam). In both instances, the production of coffee contributes to serious declines in both biodiversity and ecosystem functions.
In Vietnam, Papua New Guinea, Laos, Myanmar, and Mexico coffee production is expanding into previously pristine natural areas. Colombia, in turn, has increased production by converting to more sun-grown coffee. It is not clear whether the land used for new producers in China, New Caledonia, Samoa, and Mauritius has come from converting pristine areas, or from conversion of other agricultural lands. There is little data globally to indicate what the previous land use was for new coffee production areas.
Rising demand for high-grade speciality coffees
Another driving force of habitat conversion is the increasing market for high-grade speciality coffees. These coffees tend to be produced in new, out-of-the-way areas with unique soils and topographies that give the beans unusual flavour profiles. Such coffee is often produced in areas that are too steep or otherwise of too poor quality for the production of other food and cash crops.
These are precisely the types of areas that are rich in biodiversity or, at the very least, have become local biodiversity refuges in the face of the expansion of other forms of agricultural production. They are also typically the types of areas that are most prone to erosion. Consequently, the demand for higher-quality arabica coffee may exacerbate environmental degradation.
Illegal invasion of land by coffee producersEven the demand for shade-grown and songbird-friendly coffee may not actually reduce the impact of the business if it is produced in previously isolated areas rich in biodiversity. For example, lands that have been set aside for preservation in Mexico, Vietnam, Kenya, Nicaragua, and Indonesia have reportedly been invaded illegally by coffee producers.