Climate change will test newly understood resilience in plants

(Phys.org) —Plants can adapt to extreme shifts in water availability, such as drought and flooding, but their ability to withstand these extreme patterns will be tested by future climate change, according to a new study by researchers from the U.S. Department of Agriculture (USDA) and UTS.

The research, recently published in the prestigious journal Nature, sought to better understand how fluctuating water availability affects the productivity of plants in different ecosystems around the world.

Professor Alfredo Huete from the UTS Plant Functional Biology & Climate Change Cluster led the Australian team in the study and was surprised at the findings.

"We've found that plants use water in a much more complex way than previously understood," Professor Huete said.

"For example, the study shows in a dry year plants use water more efficiently and produce better output with less water than would be otherwise be expected, which is good news.

"However, instead of producing a bumper crop in a wet year, it appears their water use efficiency suffers as nutrients and light become more important for growth.

"So the difference between a dry year and a wet year isn't as dramatic as you would think."

However, Professor Huete insists this newly-understood adaptability will be severely tested by future climate change.

"While Australia's vegetation has developed resilience to our highly variable climate, global warming will push that resiliency past a point where plants can not readily adapt, as already witnessed in the U.S. and Europe where plant mortality is widespread due to recent droughts."

The scientists combined satellite observations, field data and measurements from 2000 – 2009 to calculate the water-use of plants in 29 ecosystems in Australia, the United States and Puerto Rico. The 2000-2009 decade ranked as the ten warmest years world-wide on record between 1880 and 2009.

The researchers observed that fluctuations in water use occurred across entire ecosystems in accordance with water availability, suggesting that there is a cross-community capacity for tolerating low precipitation and responding to high precipitation during periods of warm drought.

Professor Huete believes the study will fundamentally change the way we manage water in our landscapes, such as agricultural and pasture land.

"Current methodologies and models used to determine how much water plants need in food and livestock production rely on a quite simplistic understanding of how much water plants need."

Read the full paper online: Ecosystem resilience despite large-scale altered hydroclimatic conditions.