奇速英语

Getting hit by lightning is not usually good. But in fact, one tree seems to benefit from the natural reward.

The height and broad head of almendro (杏) trees act as natural lightning rods (避雷针). They not only can survive powerful lightning, but actually attract it. In a thick jungle, such lightning strikes (击中) can even grant the tree a decisive advantage in the competition for survival. Why? Because the lightning will hurt its surrounding “enemies”.

The finding comes from a years-long study. Scientists studied lightning’s influence on trees and finally wrote a paper to share their new findings in the May New Phytologist.

This scientific team studied and recorded the fate (命运) of 93 trees hit by lightning. Among them were 9 almendros. After two years, every almendro tree of the 9 was doing fine. To their surprise, in fact, they were thriving (茂盛的), while 56 percent of the other species (种类) that had been hit are now dead.

Except a few leaves which are not so smooth as before, almendros weren’t hurt by lightning. However, scientists observed that the lianas (藤本植物) which grew on them were all burned by the electric shock. These vines (藤蔓) spread everywhere and they are a danger to almendros. At least, they cut off light to the trees that they climb up. They can also steal nutrients (营养) from almendros. And a liana may not climb just one tree. It can send up vines that connect to branches on neighboring different species. So when lightning strikes an almendro, the deadly current (电流) spreads through lianas to neighboring trees and burns them up. This can free up space, light and nutrients for an almendro to grow vibrantly (生机盎然地).

But why were almendros not hurt as other species nearby? Some of the scientists think the reason is that the tree’s wood has low electrical resistance (阻力). That might let it safely lead the current to the ground without suffering a buildup (积聚) of heat. Others think the structure of the tree’s head may direct electricity away from the branches—and toward its neighbors. It’s really difficult to understand all the biological and physical steps that take place when lightning hits trees. “It would be interesting to be able to say something more on that,” scientists noted. “We’re all curious how the almendro avoids getting burned by each lightning strike. But we are not sure. So we didn’t mention that in the paper.”