We're all familiar with migration (迁徙): Wildebeests dash across Africa, Monarch butterflies fly across the Americas… but did you know that forests migrate, too?
In his new book The Journeys of Trees, science writer Zach St. George explores a very slow migration, as forests creep inch by inch to more pleasant places.
"The migration of a forest is just many trees sprouting (发芽) in the same direction,” St George writes "Through the fossils that ancient forests left behind, scientists can track their movement over thousands of years.They move back and forth across continents,sometimes following the same route more than once, like migrating birds or whales." This has happened over thousands of years, and climate tends to be the driving force.
Of course, today, climate change is seeding up, and tees can't keep pace. Take California for example, it's getting hotter and dryer and scientists estimate that before too long. Sequoia National Park may not be able to keep giant sequoias (巨杉).
"The scientists there had never seen anything like it," St. George says. "They worried, and I think at some point we will lose these ancient trees and we will have to think about what we do with the places, and do we plant new groves where they are easy to grow?"
This is known as "assisted migration" -humans planting trees in other places where they're more likely to flourish. But this process carries risks people can accidentally introduce insects and diseases to new places, where they may wipe out entire native populations. So, St. George writes, there's a debate among conservationists and foresters today: Should humans help the trees escape?
"There may be cases where people are probably going to step in and help species move to places where they'll be more suitable in the future," St. George says. "So far, there are no huge movements of citizen groups moving trees north. But that is kind of one vision of the future that the people I interview sort of hope to see."
12. What can be learned about the migration of a forest?
A.It is mainly the result of climate change. |
B.It often follows certain migrating species. |
C.It takes thousands of years to complete. |
D.It is very difficult to track the migration. |
13. Why does the author mention Sequoia National Park?
A.To stress the Park are facing a severe situation. |
B.To show trees fail to adapt to the climate change. |
C.To prove the assisted migration carries risks. |
D.To state scientists are hopeful about the environment. |
14. What does the underlined word "flourish" in paragraph 6 mean?
A.Become valuable. | B.Develop rapidly. |
C.Grow well. | D.Escape disease. |
15. What's St. George's attitude towards helping the trees escape?
A.doubtful. | B.Supportive. |
C.Objective. | D.Disapproving. |