“绿色长城”是什么？
What is China's Great Green Wall?
Name: ________________ Date: ________
每到春天，不少北京人打开天气预报，最怕看到“沙尘”两个字。黄沙从西北方向刮来，天空变成土黄色，停在路边的汽车上很快就全是细土。为了挡住风沙，中国从一九七八年开始在北方种树，目标是种出一条又长又宽的林带，人们叫它绿色长城。
它的正式名称是三北防护林体系建设工程，简称三北工程。“三北”指的是西北、华北和东北。工程范围从新疆一直延伸到黑龙江，覆盖的面积超过全国陆地面积的四成。按照规划，它从一九七八年开始，到二〇五〇年结束，前后七十三年，人们常说它是世界上规模最大的生态工程之一。
防护林到底靠什么挡住风沙？道理并不复杂：树木和草能降低贴近地面的风速，它们的根系又能把土牢牢抓住，风刮过来时，能带走的沙就少多了。在沙漠边缘，人们还常用一种朴素的办法：把麦草插进沙中，排成一米见方的格子，叫“草方格”。格子挡住了风，沙丘就不容易移动；人们再在格子中种上耐旱的灌木，几年以后，光秃秃的沙地上慢慢长出了植被。
那么，这道绿色长城成功了吗？这个问题并没有一个简单的答案。支持的一方指出，几十年来，北方许多地区的植被明显增加，一些原本流动的沙地被固定下来，农田和村庄也得到了保护。
质疑的一方则提醒，北方很多地方降水稀少，本来就不适合大面积种树。如果当地的水不够，新种的树要么成片死掉，要么长了很多年仍然又矮又弯，当地人管这种树叫“小老头树”。还有研究者担心，树如果种得太密，会从土中吸走更多的水，反而让原本缺水的土地更干。
这些争论也在改变人们的做法。如今的原则是：适合种大树的地方种大树，适合种灌木的地方种灌木，只适合长草的地方，就让草来守住土地。换句话说，绿色长城不一定全是树。
当然，春天的沙尘天气至今仍会出现，因为刮到北京的沙，有时来自上千公里以外的蒙古国，而风是不看国界的。一道林带挡不住所有的风沙，但它或许能让风带走的沙减少一些。如果让你设计这道“绿色长城”，你会选择种树，还是让草来守住土地？
Key words
| Word | Pinyin | Meaning |
|---|---|---|
| 天空 | tiānkōng | sky |
| 宽 | kuān | wide; broad; width |
| 名称 | míngchēng | name (of a thing or organization) |
| 范围 | fànwéi | range; scope; extent |
| 面积 | miànjī | area (of a floor, piece of land, etc.) |
| 陆地 | lùdì | land; dry land |
| 规模 | guīmó | scale; scope; extent |
| 靠 | kào | damn; shoot (exclamation) |
| 树木 | shùmù | trees |
| 地面 | dìmiàn | ground; floor |
| 沙漠 | shāmò | desert |
| 插 | chā | to insert; to stick in |
Questions
“草方格”是怎么做的？
How is a 'straw checkerboard' made?
质疑的一方为什么觉得不应该大面积种树？
Why do the skeptics think large-scale tree planting is a problem?
现在种树的原则是什么？
What is the current principle for planting?
Lesson plan: 45 minutes (for the teacher)
HSK 6 · What is China's Great Green Wall?. By the end, students can read it aloud, say what it is about and use 天空 and 宽 in sentences of their own.
Warm-up 5 min
Write “绿色长城”是什么？ on the board. Ask what the class thinks it is about, then give the English: “What is China's Great Green Wall?”.
Key words 10 min
Teach 天空 (tiānkōng, sky), 宽 (kuān, wide; broad; width), 名称 (míngchēng, name (of a thing or organization)), 范围 (fànwéi, range; scope; extent), 面积 (miànjī, area (of a floor, piece of land, etc.)), 陆地 (lùdì, land; dry land). Say each one, the class says it back, then ask for its meaning with the word covered. The rest are in the handout’s table.
Listen 10 min
Play it read aloud from mandarinthewild.com/library/read/what-is-chinas-great-green-wall: once with the text face down, once reading along. Students tap any word there for its meaning.
Read and check 10 min
Students read it alone, then answer the 3 questions on the handout. Go through them together; the answers and the line that proves each are on the teacher’s page.
Use it 10 min
In pairs, each student writes two sentences of their own, one with 天空 and one with 宽, and reads one to the class.
Homework. Students read it again at home and Review its words. Put it in a free class (mandarinthewild.com/teachers/class) and you see who read it.
English (for the teacher)
Every spring, many people in Beijing open the weather forecast dreading the two characters for "sand and dust". Yellow sand blows in from the northwest, the sky turns the colour of earth, and cars parked by the road are soon covered in fine dust. To hold back the wind and sand, China began planting trees across the north in 1978, aiming to grow a long, wide belt of forest, which people call the "Great Green Wall".
Its official name is the Three-North Shelter Forest System Project, or the Three-North Project for short. "Three-North" means the Northwest, North China and the Northeast. The project stretches all the way from Xinjiang to Heilongjiang and covers more than forty per cent of China's land area. According to the plan, it runs from 1978 to 2050, seventy-three years in all, and people often call it one of the largest ecological projects in the world.
So how exactly does a shelter forest hold back the sand? The idea isn't complicated: trees and grass slow the wind near the ground, and their roots grip the soil firmly, so when the wind blows, it can carry away far less sand. At the edge of the desert, people also use a simple method: they push wheat straw into the sand in rows that form squares one metre on each side, called "straw checkerboards". The squares block the wind, so the dunes don't move so easily; then people plant drought-tolerant shrubs inside them, and after a few years, plants slowly grow on the bare sand.
So, has the Great Green Wall worked? There is no simple answer to that question. Supporters point out that over the past few decades, plant cover has clearly increased in many parts of the north, some once-moving sands have been fixed in place, and farmland and villages have been protected.
Sceptics, on the other hand, warn that many places in the north get very little rain and were never suited to planting trees on a large scale. If there isn't enough water locally, newly planted trees either die in whole stands or stay short and crooked after many years of growing, and local people call them "little old man trees". Some researchers also worry that if trees are planted too densely, they will draw more water out of the soil, making land that was already short of water even drier.
These debates are also changing how the work is done. The rule now is: plant big trees where big trees suit the land, shrubs where shrubs suit it, and where only grass will grow, let grass hold the land. In other words, the Great Green Wall doesn't have to be all trees.
Of course, spring sandstorms still happen today, because the sand that reaches Beijing sometimes comes from Mongolia, more than a thousand kilometres away, and the wind doesn't look at borders. One belt of forest can't stop all the wind and sand, but it may reduce the sand the wind carries away a little. If you were designing this "Great Green Wall", would you choose to plant trees, or let grass hold the land?
Answers
- A. 把麦草插进沙里，排成格子: 把麦草插进沙中，排成一米见方的格子，叫“草方格”。
- C. 很多地方雨水太少: 北方很多地方降水稀少，本来就不适合大面积种树。
- C. 按地方的情况种树、灌木或草: 适合种大树的地方种大树，适合种灌木的地方种灌木，只适合长草的地方，就让草来守住土地。