密歇根新闻广播 美国的树木整体向西迁移究竟是为哪般

 

Most of us expect to hear that trees are moving north in search of colder temperatures because of global climate change. But trees don’t only need colder temperatures; they also need to have enough water.

A new study published in Science Advances suggests that trees are moving west in search of more moisture¹.

Associate Professor School for Environment and Sustainability Ines Ibanez joined us on Stateside to share her perspective² on the many other global change factors that are causing this migration³.

Forests provide humans with many services, include providing clean water and keeping soil in place. According to Ibanez, this migration west is a good thing because it shows that trees can adapt and continue to provide these services for humans.

“We have to understand that trees are not only responding to climate change, they are also responding to many other global change factors,” Ibanez said. “In this case it is probably also a response to changes in the landscape.”

One example Ibanez notes is that humans have been clearing out the land for agriculture and development. In the last century, much of that land that was cleared for agriculture has been abandoned and now is being naturally reforested.

“What we can see here is probably a combination⁴ of re-growth and also of responses to that increase in humidity,” Ibanez said. “The landscape being reforested has an impact⁵ in these plots, and I think that is part of what we see in this response.”

1 moisture   

n.水分；降雨量；水气；湿气

参考例句：

• This tree drank up more moisture than that one.这棵树吸收的水分比那棵树多。
• The moisture in the air makes it humid today.今天空气中水气大，天气很潮湿。

2 perspective   

n.视角，观点，想法

参考例句：

• You can get a perspective of the whole city from here.从这里你可以看到城市的全景。
• We may get a clear perspective of the people's happy lives.我们知道人民对幸福生活的展望。

3 migration   

n.迁移，移居，（鸟类等的）迁徙

参考例句：

• Swallows begin their migration south in autumn.燕子在秋季开始向南方迁移。
• He described the vernal migration of birds in detail.他详细地描述了鸟的春季移居。

4 combination   

n.组合，合并，联合；

参考例句：

• He carried on the business in combination with his friends.他与朋友们合伙做生意。
• The materials can be used singly or in combination.这些材料可以单独使用也可以混合用。

5 impact   

n.冲击，碰撞；影响；vt.装紧，压紧

参考例句：

• The computer had made a great impact on modern life.计算机对现代生活产生了巨大的影响.
• How will the war impact on such a poet?战争对这样一个诗人会产生什么影响？