General Impact
Rapid spread, fast growth and growth habit (tree with dense canopy) of C. pubescens result in fast invasion and replacement of native vegetation in naturally treeless environments. Shrub and herb layers experience dramatic loss of species diversity, with very few species able to grow below canopy.
Location Specific Impacts:Galapagos Islands (Ecuador) 
Competition: Replaces native trees, shades out ground understorey and layers, and otherwise out-competes native vegetation. Galápagos National Park (GNP) (Ecuador)
Economic/Livelihoods: Buddenhagen and Yánez (2005) analyse the cost of controlling in the highlands of Santa Cruz. From the authors abstract "Control costs in ten 400 m2 plots formed the basis for estimating the cost of control over the whole island. In the plots, densities were 2100–24,000 stems/ha (stems >150cm tall) and 55,000– 138,000 stems/ha (all size classes combined). Control involved uprooting small plants, and applying of a mix of metsulfuron methyl and picloram to cut stumps or to machete cuts in the bark of larger trees. These methods are presently used by Galapagos National Park (GNP) field crews to control quinine. Costs (in man hours, herbicide and US$) were related to stem density; the density of stems summed across four height classes was a better predictor of costs than density of any one size class. Regressions (on all size classes combined) formed the basis for predictive models of costs. Costs ranged from $14 to
$2225 per ha depending on stem density. The amount of herbicide (active
ingredient/ha) that must be applied to high density stands of quinine is higher than typical rates of application in an agricultural setting. The cost of treating all existing plants once across quinine’s known range on Santa Cruz Island (c. 11,000 ha) was estimated at c. US$1.65 million".
Habitat alteration: Cinchona pubescens is one among a number of introduced plant species to have spread from agricultural zones into the GNP and appear to have changed species composition and community structure (Buddenhagen et al. 2004). Santa Cruz Is. (Ecuador) (Ecuador)
Economic/Livelihoods: Buddenhagen and Yánez (2005) analyse the cost of controlling in the highlands of Santa Cruz. From the authors abstract "Control costs in ten 400 m2 plots formed the basis for estimating the cost of control over the whole island. In the plots, densities were 2100–24,000 stems/ha (stems >150cm tall) and 55,000– 138,000 stems/ha (all size classes combined). Control involved uprooting small plants, and applying of a mix of metsulfuron methyl and picloram to cut stumps or to machete cuts in the bark of larger trees. These methods are presently used by Galapagos National Park (GNP) field crews to control quinine. Costs (in man hours, herbicide and US$) were related to stem density; the density of stems summed across four height classes was a better predictor of costs than density of any one size class. Regressions (on all size classes combined) formed the basis for predictive models of costs. Costs ranged from $14 to
$2225 per ha depending on stem density. The amount of herbicide (active
ingredient/ha) that must be applied to high density stands of quinine is higher than typical rates of application in an agricultural setting. The cost of treating all existing plants once across quinine’s known range on Santa Cruz Island (c. 11,000 ha) was estimated at c. US$1.65 million".
Habitat alteration: Cinchona pubescens is one among a number of introduced plant species to have spread from agricultural zones into the GNP and appear to have changed species composition and community structure (Buddenhagen et al. 2004).
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