Climate change effects on grasslands in Uruguay

The most significant climax vegetation in Uruguay is a type of grassland commonly known as evergreen prairie. The evolution of the Uruguayan prairie since the days of the first European settlements involved 3 main stages: (1) 'hardening' as a result of the introduction of livestock, (2) 'refinement' by the action of fire and overgrazing, and (3) further degradation, including preferential development of warm-season species, due to persistent overgrazing. Predicted climate changes (seasonal decrease in water availability coupled with increase in both temperature and atmospheric CO2 concentration) are likely to favor, in the short term, even further preferential development of warm-season species. Whether or not this trend will persist in the long term is difficult to predict with confidence because of uncertainties regarding the responses of the different prairie species to variation in atmospheric CO2 concentration.