TED演讲:野火的必要性(2)
时间：2018-12-08 作者：英语课 分类：TED演讲教育篇
英语课
But as the trees' pine cones 1 mature to release their twirling seeds, 但当这些树木的球果成熟，释放它们随风旋转的种子
this signals a problem for the lodgepoles' future. 这预示了美国黑松将面对一个问题。
Very few of these seeds will germintate in the cool, sunless shade created by their towering parents. 只有少数种子能在高耸母树下的阴凉地方发芽。
These trees have adapted to this problem by growing two types of cones. 为适应这问题，这些树木生长出两种球果。
There are the regular annual cones that release seeds spontaneously, 一种是一般的年生球果，会自发释放种子
and another type called serotinous cones, which need an environmental trigger to free their seeds. 而另一种是“晚熟球果”需要环境诱因来释放种子。
Serotinous cones are produced in thousands, 树木生长出数以千计的晚熟球果
and are like waterproofed 2 time capsules sealed with resinous 3 pitch. 它们被树脂封实，如同防水的时空胶囊。
Many are able to stay undamaged on the tree for decades. 多数能够留在树上数十年，不受破坏。
Cones that fall to the ground can be viable 4 for several years, as well. 这种球果掉落地上后，也可独立存活数年。
But when temperatures get high enough, the cones pop open. 而当温度够高，这些球果便会裂开。
Let's see that in action. 让我们看看实际发生情况。
Once it's gotten started, a coniferous forest fire typically spreads something like this. 当一场针叶林大火开始通常会如此蔓延开来。
Flames ravage 5 the thick understory provided by species like douglas fir, 火焰烧毁茂密的“灌木层”，当中包括花旗松
a shade-tolerant tree that's able to thrive under the canopy 6 of lodgepole pines. 花旗松耐荫，能在美国黑松的树冠下生长。
The fire uses these smaller trees as a step ladder to reach the higher canopy of old lodgepole pines. 大火利用这些小树作阶梯向上蔓延至以老美国黑松为主的“树冠层”。
That ignites a tremendous crown fire reaching temperatures of up to 2400 degrees Fahrenheit 7. 引燃巨大的树冠火火场温度高达华氏2400度。
1 cones
n.（人眼）圆锥细胞；圆锥体( cone的名词复数 )；球果；圆锥形东西；（盛冰淇淋的）锥形蛋卷筒
- In the pines squirrels commonly chew off and drop entire cones. 松树上的松鼠通常咬掉和弄落整个球果。 来自辞典例句
- Many children would rather eat ice cream from cones than from dishes. 许多小孩喜欢吃蛋卷冰淇淋胜过盘装冰淇淋。 来自辞典例句
2 waterproofed
v.使防水，使不透水( waterproof的过去式和过去分词 )
- Waterproofed 100% leather upper, with a light, durable polyurethane molded sole. 有一亮，持久聚氨基甲酸乙酯的使能防水100%皮革鞋帮塑造脚底。 来自互联网
- The outer covering of the egg is waterproofed to prevent the embryo from drying out. 鸡蛋的外壳是不透水的，防止胚胎失水。 来自互联网
3 resinous
adj.树脂的，树脂质的，树脂制的
- Alcohol is a solvent of resinous substances.酒精是树脂性物质的溶媒。
- He observed that the more resinous the wood, the more resistant it was to decay.他观察到木材含树脂越多，其抗腐力越强。
4 viable
adj.可行的，切实可行的，能活下去的
- The scheme is economically viable.这个计划从经济效益来看是可行的。
- The economy of the country is not viable.这个国家经济是难以维持的。
5 ravage
vt.使...荒废，破坏...；n.破坏，掠夺，荒废
- Just in time to watch a plague ravage his village.恰好目睹了瘟疫毁灭了他的村庄。
- For two decades the country has been ravaged by civil war and foreign intervention.20年来，这个国家一直被内战外侵所蹂躏。
6 canopy
n.天篷，遮篷
- The trees formed a leafy canopy above their heads.树木在他们头顶上空形成了一个枝叶茂盛的遮篷。
- They lay down under a canopy of stars.他们躺在繁星点点的天幕下。
7 Fahrenheit
n./adj.华氏温度；华氏温度计(的)
- He was asked for the boiling point of water in Fahrenheit.他被问到水的沸点是华氏多少度。
- The thermometer reads 80 degrees Fahrenheit.寒暑表指出华氏80度。
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