Ancient plants reawaken after glacier recedes
Catherine La Farge from the University of Alberta has been studying the exposed ground left behind from receding glaciers. She is the curator of the Cryptogamic Herbarium and has overturned the long held belief that any plants emerging from under a glacier will be long since dead. Previously, it was assumed that any new plant growth in recently exposed areas was due to rapid colonization of modern plants surrounding the glacier. La Farge has proved this theory to be untrue, after conducting radiocarbon dating on living plants which were found to be between 400 and 600 years old. The plants were most likely sealed by glaciers during the little ice age ,which lasted between 1550 and 1850.
La Farge and her master’s student, Krista Williams, took a close look at 24 sub-glacial culture samples, and of those, seven samples were able to reproduce four species of long dormant Bryophyte plants from the original parent material. Bryophytes, like liverworts and mosses, are known to be resilient: “We know that bryophytes can remain dormant for many years and then are reactivated, but nobody expected them to rejuvenate after nearly 400 years beneath a glacier,” says La Farge, “These simple, efficient plants, which have been around for more than 400 million years, have evolved a unique biology for optimal resilience.” What makes bryophytes so special is that any cell can be re-purposed to develop a new plant, similar to how stem cells work in humans.
La Farge believes the bryophytes’ resilience means they hold great importance for ecosystems in extreme climates: “Bryophytes are extremophiles that can thrive where other plants don’t, hence they play a vital role in the establishment, colonization and maintenance of polar ecosystems. This discovery emphasizes the importance of research that helps us understand the natural world, given how little we still know about polar ecosystems — with applied spinoffs for understanding reclamation that we may never have anticipated.”