Plants are more resilient to climate change than thought: Warming will see some species adapt to thrive on LESS water
AFP and RYAN O’HARE FOR MAILONLINE
- Plants absorb CO2 through mouth-like pores on their leaves
- But when these pores are open they enable moisture to escape
- Increasing CO2 means these pores will be open for shorter periods
- As the plants lose less moisture, they will require less water to thrive
A warming planet might not dry out Earth as much as previously believed.
Scientists say that plants will become less thirsty as carbon dioxide in the atmosphere rises.
Previous studies suggest that more than 70 per cent of the planet will experience more drought as carbon-dioxide levels quadruple from pre-industrial levels over about the next 100 years.
But many of these models fail to account for how plant behaviour will change in a warming world, according to the study.
While scientists aren’t sure exactly how plants will be affected by increasing temperatures and CO2 levels in the atmosphere,they believe some crops including wheat, rice and soy bean, could thrive initially.
Plants take in CO2 through mouth-like openings called stomata, which also release moisture.
But when CO2 is abundant, these stomata stay open for shorter periods, lose less water, and therefore need less water from the soil.
‘A number of studies assume that plant water needs are staying constant, when what we know about plants growing in lots of carbon dioxide suggests the opposite,’ said lead author Dr Abigail Swann, an assistant professor of atmospheric sciences and biology at the University of Washington.
Swann found that only about 37 per cent of the world will face climate change-driven drought, because plants benefit from an environment with more carbon dioxide.
A hotter world with less rain will likely increase droughts across southern North America, southern Europe and northeastern South America, said the study.
‘But the results show that in Central Africa and temperate Asia – including China, the Middle East, East Asia and most of Russia– water conservation by plants will largely counteract the parching due to climate change,’ it said.
The findings still show that droughts will increase as the climate changes, just not as far and wide as some have predicted.
‘There’s a lot we don’t know, especially about hot droughts,’ said Dr Swann.
‘Even if droughts are not extremely more prevalent or frequent, they may be more deadly when they do happen.’
The findings are published in the journal Proceedings of the National Academy of Sciences.
CAN PLANTS REALLY DO MORE WITH LESS?
Scientists have long known that many plants will be able to cope and even thrive with the stress of a warming climate.
More carbon dioxide in the atmosphere – which adds to the warming greenhouse effect – will mean the pores on the leaves of plants, called stomata, will close more readily for some species.
These tiny mouth-like pores suck carbon dioxide from the atmosphere, but also enable moisture to escape.
But more carbon dioxide in the atmosphere will mean the plants can get the gas they need in a shorter period, closing the stomata and stopping further water loss.
While scientists aren’t sure exactly how plants will be affected, some crops including wheat, rice and soy bean, could thrive initially.
However, other groups have suggested yields could fall despite these adaptations as increased temperatures affect seed germination and water availability.
Source: UN Environment Programme