Jurassic Relic Offers Clues to Climate Change Survival

Susan Murch is nurturing 50 small Wollemi pines in her UBC Okanagan office - photo by Bud Mortenson
Susan Murch is nurturing 50 small Wollemi pines in her UBC Okanagan office – photo by Bud Mortenson

UBC Reports | Vol. 52 | No. 12 | Dec. 7, 2006

Learning secrets of conifer evolution could benefit forestry in a time of global warming

By Bud Mortenson

A long-lost tree species will soon begin to tell its 200-million-year-old story at UBC Okanagan, where Prof. Susan Murch, Canada Research Chair in Natural Products Chemistry, is nurturing a grove of baby Wollemi pines (Wollemi nobilis) in her office.

“In ancient times, the Wollemi was found across Australia,” says Murch. “But in modern times, the Wollemi occupies only one tiny habitat in the wild.”

The Wollemi dates back to the Jurassic era — outlasting dinosaurs, enduring 17 ice ages, long droughts and other climate catastrophes. The Wollemi are conifers with unique bubbly “popcorn” bark and tall, multiple trunks. Their distinctive swooping branches make the mature trees look a bit like chimney brushes, densely packed with attractive, unusual dark green foliage that’s flat-bladed, not needle-like.

An Australian park naturalist discovered a single mature Wollemi in the Blue Mountains 200 km northwest of Sydney in 1994. A grove of mature trees was later found nearby in a rocky canyon. Since then, botanists at Wollemi Pine International — an organization determined to conserve the Wollemi for future generations — have been attempting to propagate plants from the remaining trees.

“Most of the seeds do not germinate but the Australian team has successfully produced Wollemi for the horticultural industry through rooted cuttings,” says Murch. “We know very little about the Wollemi growth, development or reproduction. There’s so much we can learn here.”

Earlier this year, a selection of the first-release Wollemi was offered for sale through the auction house Sotheby’s. Nearly 300 trees were sold, raising more than $1 million. Intrigued by the opportunity to study the species, Murch asked for a tree “if there were any leftovers.” She received 50 small Wollemi.

“No one could possibly have foreseen this opportunity. I thought I might get one plant and with that I’d be able to do something little. But with this many plants I can actually do science. It’s an amazing opportunity,” says Murch.

Though they’re mere seedlings right now, in their natural Australian habitat they can grow up to 40 metres (131 feet) tall. She is investigating the chemistry of this unique species, looking for clues to help understand why so few Wollemi survived into modern times, how the Wollemi adapted to changing environments, and how it may be related to more modern conifers.

For a brief moment after its discovery, the Wollemi’s distinctive flat needles were mistaken for fern fronds. But botanists now classify the unusual growth pattern as a “modified Cook model,” says Christina Salvadore, a recent graduate from Stanford University visiting Murch’s labs at UBC Okanagan to work on the Wollemis. It’s another clue to the mystery of where the Wollemi fits into pine evolution.

With Murch, Salvadore and fellow grad student Ian Cole are beginning to put the small plants through several experiments to measure growth rates, reactions to environmental stress such as hot and cold temperatures, and they’re already looking at the chemical compounds in the pine’s tissues. Eventually, they’ll be able to compare the Wollemi’s chemical profile with related species.

“Rare species are particularly interesting as they provide a snapshot into the chemistry that must occur for a species to survive as climates change,” Murch says.

“Most people have heard of climate change and global warming and the effects of greenhouse gasses. One of the things that interests me is human adaptation versus plant adaptation. With the Wollemi, here is a species that has adapted very well even through changing conditions.”

The Wollemi might be a survivor, but one of the mysteries locked in its past is why it has been reduced to a few dozen wild trees. Murch says Earth’s atmosphere may hold the key. The Wollemi dates back to a time when the atmosphere had much higher levels of carbon dioxide (CO2).

“CO2 levels today may actually be too low for the Wollemi to thrive,” says Murch. “It’s a fascinating idea. In understanding the chemistry of that, we can learn a lot about how to help other species survive.”

Old genes are valuable in other ways, too. They can show us the paths along which species have evolved. Today’s ponderosa or lodgepole pines might drop a few needles now and then, but that’s highly evolved behaviour compared to the much more ancient Wollemi — instead of dropping needles, they drop entire branches.

“You could get hurt walking under these trees,” she says, noting that the Monkey Puzzle tree closely related to the Wollemi has indeed hurt people with falling boughs.

Murch is actively campaigning for greenhouse facilities at UBC Okanagan, explaining that greenhouse space would benefit her research with plants that might have medicinal uses, and also the research of colleagues investigating chemical cross-talk between the roots of trees and beneficial microbes that help plants grow.

These areas of research can have far-reaching impacts on timber and food production, she says, pointing out that the B.C. economy continues to lean heavily on the success of our conifer forests.

“These Wollemi are conifers and most of British Columbia relies on conifer trees for economic benefit,” she says. “The Wollemi can teach us about how conifers evolved. We will learn a lot from a better understanding of ancient but related species.”

A Gift for the Person Who has Everything

Looking for an extraordinarily rare gift for someone on your holiday shopping list? Consider the Wollemi pine. Adult population in the wild: fewer than 100.

A new program by Wollemi Pine International and the National Geographic Society hopes to place propagated Wollemi in countries around the world — including Canada. Proceeds from the sale of small seedlings will fund conservation of endangered plant species. Widespread distribution of the plants ensures that the rare Wollemi are never again limited to a potentially vulnerable single spot on Earth.

Making Wollemi available for purchase is also expected to relieve pressure from visitors to the Blue Mountains in Australia seeking up-close encounters with a plant that until recently was known to science only through fossil records.

Wollemi pines are suitable for growing indoors as ornamental trees, and outdoors where temperatures stay above -12 Celsius. Sales through Canadian garden centres are planned for 2007 but until then, Wollemi-seekers can follow their availability in Canada through the Wollemi Pine International website www.wollemipine.com.