The more species a subtropical forest has, the better at storing carbon it is.

A study of forests in China, published in Proceedings of the Royal Society B, found forests that were more species-rich cycled carbon faster and stored more carbon in trees, roots, litter, deadwood and soil. For every additional tree species, the total carbon stock increased by 6.4 per cent—suggesting that planting a mixture of trees rather than a monoculture creates more effective carbon sinks.