Cultivation of cardamom, a high value spice crop, can take a toll on evergreen forests in tropical countries, independent studies in Sri Lanka and India have shown. Apart from disturbing biodiversity, cardamom (Elettaria cardamomum), plantations affect water and soil quality in tropical forests, the studies said. Researchers from Sri Lanka and the United Kingdom studying abandoned cardamom plantations in the Knuckles Forest Reserve (KFR) in the uplands of central Sri Lanka found adverse effects lingering decades after cultivation was banned. Cardamom grows best in the shade and humidity beneath tall trees in tropical forests. But planters may thin out the canopy and clear natural undergrowth to improve yields. While India and Bolivia lead the world in cardamom cultivation, the spice is a major foreign exchange earner for Sri Lanka. Before cardamom cultivation was banned in KFR in 1985, plantations there accounted for more than half of Sri Lanka\'s total production. \"We visited most parts of KFR during our three-year project period and observed very little natural forest without planted cardamom,\" said Balram Dhakal of the Institute of Biological and Environmental Sciences at Aberdeen and lead author of a paper that appeared online in Forest Ecology and Management on 28 March.