Some trees in Africa already seem to be adapting to the warming climate by using water more efficiently.
Iain Robertson of Swansea University, UK, and his colleagues collected a small number of samples from three tree species in Ethiopia, Namibia and South Africa, covering a small area of the continent. By measuring the ratio of carbon isotopes in each tree ring, the team estimated the water-use efficiency of the trees from 1909 to 2003. They found that two of the three species increased their water-use efficiency — by an average of 25% — over the period.
Using water more sparingly may help to compensate for the predicted decreases in rainfall in Africa, allowing some plants to cope better with climate change than others.