Researchers from Purdue University, USA, have warned that Walnut trees are especially sensitive to changes in climate – cautioning that the restrictive range of climate conditions needed for growth mean that climate change may have “a real impact on walnuts.
“We may see some type of decline of the species," said Professor Douglass Jacobs, of Purdue.
Specifically, Jacobs explained that walnuts would have difficulty tolerating droughts that could be associated with a changing climate.
"Changes in moisture could restrict its ability to survive without irrigation," warned the Professor.
"Almost all climate change models predict that climates will become drier," he said.
Walnuts are big business in the USA. In California, for example, more than 500,000 tons of walnuts were sold for more than $1 billion USD in 2010, according to the U.S. Department of Agriculture.
The researchers said that one goal is to find walnut breeds that may be able to stand up to the heat or cold stresses that the trees could be subject to in a changing climate.