400-year-old plants from the Little Ice Age were brought back to life, which could help us understand how the Earth will deal with climate change.
Moss(藓类植物) found buried beneath the Teardrop glacier(冰川) on Ellesmere Island in Canada has been brought back to life. Findings suggest that these plants could help repopulate regions exposed by melting ice caps. Plants that were buried beneath thick ice in Canada more than 400 years ago and were thought to have frozen to death have been brought back to life by Canadian scientists.
Samples of the moss plant, covered by the glacier during the Little Ice Age of 1550 to 1850 AD, were replanted in a lab at the University of Alberta and grew new stems(茎). Researchers now think these findings can give indication as to how regions can recover as the ice covering them melts.
Biologist Dr. Catherine La Farge and her team at the University of Alberta were exploring the region around the Teardrop glacier on Ellesmere Island. Ice on Ellesmere Island region has been melting at around four meters each year for the past nine years. This means that many areas of land that were previously covered by ice have since been exposed. Many ecosystems that were thought to have been destroyed during the Little Ice Age between 1550 and 1850 AD can now be studied, including many species that have never been studied before.
While examining an exposed area of land, La Farge and her team discovered a small area of moss called Aulacomnium turgidum. It is a type of bryophyte(苔藓类植物) plant that mainly grows across Canada, the US and the Highlands of Scotland.
Dr La Farge noticed that the moss had small patches of green stems, suggesting it is either growing again or can be encouraged to repopulate. Dr La Farge told the BBC, “When we looked at the samples in detail and brought them to the lab, I could see some of the stems actually had new growth of green branches, suggesting that these plants are growing again, and that blew my mind. When we think of thick areas of ice covering the landscape, we’ve always thought that plants have to come from refugia(濒绝生物保护区), never considering that land plants come from underneath a glacier. It’s a whole world of what’s coming out from underneath the glacier that really needs to be studied. The ice is disappearing pretty fast. We really have not examined all the biological systems that exist in the world; we don’t know it all.”
Dr La Farge took samples of the moss and, using carbon-dating techniques, discovered that the plants date back to the Little Ice Age. Dr La Farge’s team took the samples, planted them in dishes full of nutrient-rich potting soil and fed them with water.
The samples were from four separate species including Aulacomnium turgidum, Distichium capillaceum, Encalypta procera and Syntrichia ruralis. The moss plants found by Dr La Farge are types of bryophytes. Bryophytes can survive long winters and regrow when the weather gets warmer.
However, Dr La Farge was surprised that the plants buried under ice have survived into the twenty-first century. Her findings appear in proceedings（论文集）of the National Academy of Sciences.
小题1:Dr La Farge’s research is of great importance to ________.
A．knowing what the plants during the Little Ice Age were like
B．understanding how ecosystems recover from glaciers.
C．regrowing many species that have been destroyed before.
D．figuring out the effects of melting ice caps on moss.小题2:The underlined part “blew my mind” in Paragraph 6 can best be replaced by “________”.
A．surprised me
B．greatly frightened me
C．put my doubt out of my mind
D．was exactly what I had in my mind小题3:According to the passage, Aulacomnium turgidum ________.
A．lives better in small groups
B．is very active in hot weather
C．is strong enough to survive coldness
D．is chosen from Canadian refugia小题4:Which of the following would be the best title for the passage?
A．Bryophyte ecology is greatly affected by climate change.
B．400-year-old moss’s survival is a mystery to solve.
C．Moss in ancient times was discovered in Canada.
D．400-year-old plants were brought back to life.