Abstract:Land-use change poses a major threat over much of the La Plata River Basin in South America. Paraguay, with one of the highest deforestation rates in the region, has experienced rapid loss of its natural forests. Such landscape transformation implies changes in vegetation traits that affect exchange of momentum, heat, and moisture between the surface and atmosphere. To understand how the regional climate of Paraguay could be affected by the deforestation that occurred between 1990 and 2000, we ran 1-month long simulations for each November during the 2006-2012 period for a control scenario and a past vegetation scenario. Climate responses to land-cover change differed with location and vegetation. In eastern Paraguay, replacement of forest with farmland increased albedo, leading to an overall lower latent heat and both lower and higher sensible heat fluxes. In western Paraguay, replacement of grassland with farmland slightly increased albedo, reducing the sensible heat and increasing evapotranspiration owing to greater surface soil wetness. Effects of land-use change on precipitation are more likely to change local patterns of precipitation than they are the country's total monthly precipitation.