时差N小时 你知道植物也有夜生活吗?(上)

Most plants grow buds, flower, or lie dormant¹ at specific times of year.

大多数植物都在每年特定时间里发芽，开花，或者冬眠。

What triggers these seasonal² changes?

什么原因导致植物的季节性变化？

Temperature and rainfall often play a role, but the most important factor to many plants is the length of the day.

通常，影响因素包括温度和降雨，但是对许多植物来说，最重要的因素是昼长。

At least, that’s what biologists thought until the 1940s, when the whole concept of day length sensitivity in plants was turned upside down.

至少在20世纪40年代之前，生物学家们是这么认为的，直到植物对昼长敏感的理论彻底被推翻。

Experiments showed that plants that seem to flower in response to day length actually respond to night length.

实验显示，那些看起来受昼长影响而开花的植物其实是受夜长影响。

In other words, what prompts irises³ to bloom in summer in North America isn’t longer sunny days, but shorter nights.

换句话说，促使北美地区的鸢尾花在夏季盛开的不是更长的白昼而是短暂的夜间。

Here’s how biologists figured out how important nightlife can be to plants.

我们来看看生物学家是如何确定夜晚对植物的重要性吧。

They started with the cockle burr plant, which flowers when days are short.

他们先以苍耳为例，这种植物会在昼长较短时开花。

1 dormant   

adj.暂停活动的；休眠的；潜伏的

参考例句：

• Many animals are in a dormant state during winter.在冬天许多动物都处于睡眠状态。
• This dormant volcano suddenly fired up.这座休眠火山突然爆发了。

2 seasonal   

adj.季节的，季节性的

参考例句：

• The town relies on the seasonal tourist industry for jobs.这个城镇依靠季节性旅游业提供就业机会。
• The hors d'oeuvre is seasonal vegetables.餐前小吃是应时蔬菜。

3 irises   

n.虹( iris的名词复数 )；虹膜；虹彩；鸢尾（花）

参考例句：

• The cottage gardens blaze with irises, lilies and peonies. 村舍花园万紫千红，鸢尾、百合花和牡丹竞相争艳。 来自《简明英汉词典》
• The irises were of flecked grey. 虹膜呈斑驳的灰色。 来自《简明英汉词典》