section_path: Cultivation and production/Ecological effects
section_name: Ecological effects
paragraph_text: Ecological effects
  
  Originally, coffee was grown in the shade of trees that provided a habitat for many animals and insects. Remnant forest trees were used for this purpose, but many species have been planted as well. These include leguminous trees of the genera Acacia, Albizia, Cassia, Erythrina, Gliricidia, Inga, and Leucaena, as well as the nitrogen-fixing non-legume sheoaks of the genus Casuarina, and the silky oak Grevillea robusta.
  
  This method is commonly called " shade-grown coffee ". Starting in the 1970s, many farmers switched their production method to sun cultivation, in which coffee is grown in rows under full sun with little or no forest canopy. This causes berries to ripen more rapidly and bushes to produce higher yields, but requires the clearing of trees and increased use of fertilizer and pesticides, which damage the environment and cause health problems.
  
  Unshaded coffee plants grown with fertilizer yield the most coffee, although unfertilized shaded crops generally yield more than unfertilized unshaded crops: the response to fertilizer is much greater in full sun. While traditional coffee production causes berries to ripen more slowly and produce lower yields, the quality of the coffee is allegedly superior. In addition, the traditional shaded method provides living space for many wildlife species. Proponents of shade cultivation say environmental problems such as deforestation, pesticide pollution, habitat destruction, and soil and water degradation are the side effects of the practices employed in sun cultivation.
  
  The American Birding Association, Smithsonian Migratory Bird Center, National Arbor Day Foundation, and the Rainforest Alliance have led a campaign for 'shade-grown' and organic coffees, which can be sustainably harvested. Shaded coffee cultivation systems show greater biodiversity than full-sun systems, and those more distant from continuous forest compare rather poorly to undisturbed native forest in terms of habitat value for some bird species.
  
  Coffee production uses a large volume of water. On average it takes about 140 litres (37 US gal) of water to grow the coffee beans needed to produce one cup of coffee. Growing the plants needed to produce 1 kg (2.2 lb) of roasted coffee in Africa, South America or Asia requires 26,400 litres (7,000 US gal) of water. As with many other forms of agriculture, often much of this is rainwater, much of which would otherwise run off into rivers or coastlines, while much water actually absorbed by the plants is transpired straight back into the local environment through the plants' leaves (especially for cooling effects); broad estimates aside, consequential margins vary considerably based on details of local geography and horticultural practice. Coffee is often grown in countries where there is a water shortage, such as Ethiopia.
  
  Used coffee grounds may be used for composting or as a mulch. They are especially appreciated by worms and acid-loving plants such as blueberries. Climate change may significantly impact coffee yields during the 21st century, such as in Nicaragua and Ethiopia which could lose more than half of the farming land suitable for growing (Arabica) coffee. As of 2016, at least 34% of global coffee production was compliant with voluntary sustainability standards such as Fairtrade, UTZ, and 4C (The Common Code for the Coffee Community).