Warmer climate sees palm trees growing where they haven't before: U of S researcher

A study published this week shows that some palm trees can survive in climates far less tropical than you might expect.

Study finds some palms can survive in winters that average 2 C

Researcher Christopher West said some types of palms, including fan palms, are heartier and can withstand colder weather. (AFP/Getty Images)

A study published this week shows that some palm trees can survive in climates far less tropical than you might expect.

Christopher West, a graduate student from the University of Saskatchewan, co-authored the study, which asked "How cold is too cold for palm trees?" West said they chose palms because they have a rich diversity and bring to mind that tropical climate.

They found out that certain varieties of palms, including the Chinese windmill palm and the fan palm, can still spread to areas where the average temperature in the coldest month of the year is as low as 2 C.

"Any cooler than that, and they're just not able to survive," he said. "What's really important is whether or not it can reproduce. When it comes to palms, temperature is one of those limiting factors."

Small palms existed as recent as 60 million years ago in Alberta, representing one of the most northerly occurrences of the plant, according to West, who is a paleobotanist.

He said that locating palm fossils indicates a tropical climate at one point in time. They have also been found in Alaska and Antarctica.

More recently, Chinese windmill palms that were cultivated in gardens in Switzerland managed to escape and are now spreading in the Swiss Alps, bordering on becoming an invasive species.

"When an introduced species gets into these habitats, there's always potentials that it could dislodge some existing native species. Whether or not that happens, we'll have to wait and see," West said.  

West said windmill palms in Salt Lake City have also been found with seedlings.

Climate change is likely a factor in palm trees covering new ground, West said.

"The winters are warmer. And as the winters warm, these plants will be able to survive in these new localities," said West. "I think it's definitely something we should be thinking about and should be concerned about."

With files from CBC's Morning Edition