(Phys.org) —A team of researchers from the University of Alberta
led by, Catherine La Farge, has found that mosses and liverworts covered
by ice over 400 years ago and now exposed due to glacial melting, are
able to start growing again. In their paper published in the journal
Proceedings of the National Academy of Sciences, the team describes how carbon dating showed the plants to be from a time just prior to the Little Ice Age
The research team ventured to the Canadian Arctic Archipelago
to see what changes were occurring in the Arctic due to global
warming—the Teardrop Glacier on Ellesmere Island in Nunavut, they note,
has retreated more than 650 feet over the past several hundred years.
Just next to the glacier's edge, the team found some green growth among
clumps of exposed dead plant material that had been under the ice for
centuries. Intrigued, they collected some samples and brought them back
to their lab for study.
The team put 24
cultures in an ideal environment and found that 11 of them began to
grow, representing four distinct taxa. The plants, known as
bryophytes—moss, lichen, liverworts, etc—don't have vascular tissue to
pump fluids, a property that helps them survive in very
cold climates.
Carbon dating of the samples showed that the plants had been living approximately 400 to 615 years ago—a time just before the
Little Ice Age
(1550-1850). Byrophytes have another property, called totipotency that
allows any cell of the plant to reproduce and grow into a whole new
plant.
Read more at:
http://phys.org/news/2013-05-year-arctic-anew-glaciers-retreat.html#jCp
The
team put 24 cultures in an ideal environment and found that 11 of them
began to grow, representing four distinct taxa. The plants, known as
bryophytes—moss, lichen, liverworts, etc—don't have vascular tissue to
pump fluids, a property that helps them survive in very cold climates.
Carbon dating of the samples showed that the plants had been living
approximately 400 to 615 years ago—a time just before the Little Ice Age
(1550-1850). Byrophytes have another property, called totipotency that
allows any cell of the plant to reproduce and grow into a whole new
plant.
The findings dispel the common belief that land exposed by melting glaciers becomes populated by new plant growth exclusively via seeds or spores carried by the wind. Instead, some plants lying frozen beneath the ice are apparently able to survive and begin growing again when the environment changes. This suggests that Earth scientists will have to take a new look at models meant to portray how ecosystems recover from glaciers after they retreat.
The researchers note that plants aren't the only type of life being exposed by melting glaciers — cyanobacteria and green terrestrial algae have also been spotted, some of which haven't ever been seen before.
Reporter =
Phys.org
Original article =
"Regeneration
of Little Ice Age bryophytes emerging from a polar glacier with
implications of totipotency in extreme environments" by Catherine La Farge, Krista H. Williams, and John H. England
