For 8 years we sampled a temperate rainforest and a peatland in Chile to estimate their efficiency to capture carbon per unit of water lost. The efficiency is more related to the water lost than to the carbon captured and is mainly driven by evaporation instead of transpiration. This is the first report from southern South America and highlights that ecosystems might behave differently in this area, likely explained by the high annual precipitation (~ 2100 mm) and light-limited conditions.