Is global warming making plants more water efficient?

The Conversation had reported on a paper published in Nature Communication this month reports that plants are responding to increased CO₂ in the atmosphere by taking up more CO₂ than they did thirty years ago. The interesting thing about this study is that the increased CO₂ uptake is not at the expense of increased water use.

Increasing carbon uptake typically comes at a cost. To let in CO₂, plants have to open stomata in their leaves, which in turn allows water out (called evapotranspiration). The study showed that the rate of evapotranspiration stayed relatively constant, while the CO₂ uptake had increased by 17%.

The plants appear to have adapted a mechanism to allow CO₂ uptake while minimising water loss.

The ratio of carbon uptake to water loss by ecosystems is called ‘water use efficiency’ and it seems that plants are becoming more water efficient

Image: The Conversation

Image: The Conversation