Ecology and Environment

Your environment is everything around you that affects your life: the air you breathe, the water you drink, the ground you walk on, and every plant, animal and microbe you share them with. Ecology is the study of how living things depend on one another and on these surroundings.

Scientists divide the Earth’s environment into four parts, often called spheres (from a Greek word for a ball, since each wraps round the Earth):

Part	What it is	Examples
atmosphere (atmo- = vapor, air)	the layer of air round the Earth	the oxygen we breathe, wind, clouds, rain
hydrosphere (hydro- = water)	all the water on and around the Earth	seas, rivers, lakes, glaciers, groundwater, water vapor
lithosphere (litho- = stone)	the solid, rocky outer layer of the Earth	mountains, rocks, soil, minerals
biosphere (bio- = life)	every place where life is found, and all the living things in it	forests, coral reefs, soil full of worms, you

The four don’t sit apart: they overlap Figure 7.1. A fish lives in the hydrosphere, breathes oxygen that came from the atmosphere, and eats insects that grew on plants rooted in the lithosphere. The biosphere is exactly where the other three meet. All four working together as one system are sometimes called the ecosphere (the whole Earth as one great ecosystem). Some pictures of the spheres write ecosphere in the middle and biosphere round the outside; the idea is the same: life is found where air, water and rock meet, and together they work as one system.

Before you read

What kind of text it is

The text is an informative essay (an expository text, as you saw in Unit 6): it explains, with facts and examples, and doesn’t tell a story or argue. A short introduction asks the question, then five paragraphs, labeled A to E, each give one answer: five ways animals get through the winter. The animals in it are mostly from North America and Europe (caribou, elk, weasels, snowshoe rabbits, skunks, chipmunks), but the same five ways work in Nepal’s hills and mountains too.

The text, part by part

Introduction: and what about animals?

As winter comes, the weather gets colder, the days get shorter, and leaves change color and fall. Snow covers the ground. People keep warm in houses and heavy coats, and buy their food from a grocery store (a shop for food and things used at home). Animals have none of these. So how do they survive?

A. Migrating

Some animals migrate: they travel to a place where the weather is warmer or food is easier to find.

• Birds: many migrate in autumn. The trip is dangerous, so some fly in large flocks (groups), like geese in their noisy V-shaped lines; others fly alone. How do they know when to go? Scientists are still studying this, but migration seems to be part of a yearly cycle in a bird’s body, controlled by changes in the amount of daylight and the weather.
• Long journeys: the Arctic tern nests near the North Pole in summer, flies all the way to Antarctica in autumn, and comes back north each spring. Most birds travel much shorter distances.
• Finding the way: birds seem to navigate (find their way) as sailors once did, by the Sun, Moon and stars, and they also seem to have a kind of compass in the brain that senses the Earth’s magnetic field.
• Other animals: some mammals (some bats, caribou, elk, whales) travel in search of food; many fish swim south or into deeper, warmer water; some insects migrate too. Monarch butterflies fly from Canada and the northern United States as far south as Mexico. Most insects only go a short way: termites and Japanese beetles move down into the soil, and earthworms go as deep as six feet (about 1.8 meters).

B. Adapting

Some animals stay and stay active. They must adapt (change to suit the new conditions), in their bodies or their behavior:

• Thicker fur: many grow a new, thicker coat in autumn. On weasels and snowshoe rabbits (snowshoe hares) it is white, to hide them in the snow.
• Storing food: squirrels, mice and beavers gather extra food in autumn to eat later.
• Eating what is there: rabbits and deer search for moss, twigs, bark and leaves. The red fox eats fruit and insects in spring, summer and autumn, but in winter, when those are gone, it eats small rodents (mice, voles and other gnawing animals).

C. Finding shelter

Animals shelter in holes in trees or logs, under rocks or leaves, or underground. Some mice even dig tunnels (underground passages) through the snow. Squirrels and mice huddle (crowd close together) to keep warm. Some spiders and insects stay active in places that don’t freeze, and a few insects, like the winter stonefly, the crane fly and snow fleas, are normally active in winter. Some fish stay active in cold water.

D. Hibernating

Some animals hibernate for part or all of the winter: they go into a special, very deep sleep. The body’s temperature drops, the heartbeat and breathing slow down, and the animal uses very little energy. To get ready, it eats extra food in autumn and stores it as body fat, which it lives on while it sleeps; some also store nuts or acorns to eat later. Bears, skunks, chipmunks and some bats hibernate.

E. Becoming dormant

Cold-blooded animals (fish, frogs, snakes, turtles) can’t keep their bodies warm with their own heat: they are as cold as the air or water around them. Snakes and many other reptiles shelter in holes or burrows and stay dormant (inactive, as if asleep) all winter, which is like hibernation. Many others use water as a shelter: in cold weather, frogs, turtles and many fish go to the bottom of lakes and ponds, hide under rocks, logs or fallen leaves, or bury themselves in the mud, and become dormant. Cold water holds more oxygen than warm water, so the frogs and turtles can take in enough oxygen through their skin.

Words from the text

Words linked here open in English Vocabulary, where you can see an example and practice them in the word game. The meanings below are the ones the words have in this text.

Word	Meaning here
grocery (store)	a shop that sells food and other things used at home
migrate	to move to another place for a season, to find warmth or food
flock	a large group of birds (or sheep, goats)
Arctic	of the cold region round the North Pole
navigate	to find your way; (also) to deal with a difficult situation
sailor	a person who works on a ship as one of its crew
adapt	to change so as to suit a new situation
weasel	a small, thin, fierce animal with a long body that hunts mice
moss	a small, soft green plant that grows in a thick mat on wet ground, rocks and trees
rodent	a small animal with long front teeth for gnawing, such as a rat, mouse or squirrel
tunnel	a passage under the ground (or through the snow)
huddle	to crowd closely together, usually because of cold or fear
hibernate	to spend the winter in a very deep sleep
dormant	not active for a time, as if asleep

A. Find the words

B. Match the titles

C. True or false

D. Answer the questions

E. Keeping safe from the cold

Ten words you hear in every weather report. The capital letters in “Sounds like” show the stressed syllable.

Word	Meaning	Sounds like	IPA
avalanche	a large mass of snow and ice sliding fast down a mountain	“AV-uh-lanch”	/ˈævəlɑːnʃ/, US /ˈævəlæntʃ/
blizzard	a snowstorm with very strong winds	“BLIZ-urd”	/ˈblɪzəd/
breeze	a light, gentle wind	“breez” (long ee, ending in a z sound)	/briːz/
drought	a long time with little or no rain	“drout” (rhymes with out)	/draʊt/
Fahrenheit	a scale of temperature: water freezes at 32 °F and boils at 212 °F	“FA-run-hite” (fa as in fat; the h after a is silent; -heit rhymes with kite)	/ˈfærənhaɪt/
flurries	short, light falls of snow	“FLUH-reez”	/ˈflʌriz/, US /ˈflɜːriz/
forecast	a statement of what the weather will probably be	“FOR-kahst” (US “FOR-kast”)	/ˈfɔːkɑːst/
frostbite	damage to fingers, toes, ears or nose from freezing	“FROST-bite”	/ˈfrɒstbaɪt/
humidity	the amount of water vapor in the air	“hyoo-MID-i-tee”	/hjuːˈmɪdəti/
precipitation	water that falls from clouds: rain, snow, sleet or hail	“pri-sip-i-TAY-shun”	/prɪˌsɪpɪˈteɪʃn/

An offer is when you say you are willing to do something for someone, or to give them something. You can accept it (say yes) or decline it (say no, politely).

Making an offer	Accepting	Declining politely
Can I help you?	Yes, please.	No, thanks. I’m just having a look.
Would you like (a cup of tea)?	Yes, please. That would be nice.	No, thanks.
Would you like me to (help you)?	That would be very kind of you.	That’s kind of you, but I can manage.
Shall I (help you with your homework)?	Yes, please. Thanks a lot.	It’s OK, I can do it.
I’ll (do the washing), if you like.	Oh, thank you!	Thanks, but there’s no need.
Let me (carry that for you).	Thanks, that would be great.	Thanks anyway, but it isn’t heavy.
Can I offer you (some cake)?	I’d love some.	I’m fine, thanks.

Three things to notice:

• After Would you like comes a noun (a cup of tea) or me to + a verb (Would you like me to carry it?). After Shall I and Let me comes the base verb (Shall I open it? Let me help).
• Shall I…? is only an offer: Shall I close the door? means “Do you want me to close it?”
• A polite refusal thanks the person, and often gives a reason: That’s kind of you, but my brother is coming to get me. A plain No. sounds rude.

A. Six conversations

B. Conversations from clues

C. Make, accept or reject offers

A conditional sentence has two parts: a condition (the if-clause) and a result (the main clause). The zero and first conditionals are about things that are real or possible.

Type	Form	Use	Example
zero	if + present, present	a fact that is always true: whenever this happens, that happens	If you heat snow, it melts. Water changes into vapor if it is heated.
first	if + present, will + base verb	a possible situation in the future, and its likely result	If it rains, you will get wet. If you don’t hurry, you will miss the bus.

In the zero conditional, if means “whenever”, and you can say when instead: When you heat snow, it melts. In the first conditional, the condition may or may not happen: If it rains (perhaps it will, perhaps not).

The result of a first conditional doesn’t have to use will:

• a modal for something possible, allowed or necessary: I may finish that letter if I have time. You can cause an accident if you drive so carelessly. You must study hard if you want to join college.
• an imperative (an order or advice): If you want to borrow a book from the library, show your library card.
• a question: What will you do if you miss the plane?

Unless

Unless means if … not. It is followed by a positive verb, because the not is already inside it:

• If you don’t use your English, it won’t improve. = Unless you use your English, it won’t improve.
• I won’t go to the doctor unless the pain increases. (= if the pain doesn’t increase, I won’t go)

A. Study the sentences

B. Use the correct form of the verbs

A paragraph is a group of sentences about one main idea. A good one has three parts:

1. The topic sentence states the main idea. It usually comes first, so the reader knows at once what the paragraph is about.
2. Supporting details explain, prove or give examples of the main idea: facts, reasons, examples, numbers, a short story from life.
3. The concluding sentence ends the paragraph: it sums up the main idea in new words, or says what should be done. It adds no new facts.

A paragraph also has unity: every sentence is about the main idea, and a sentence that wanders off the topic is cut, however true or interesting it is. Linking words (moreover, for example, as a result, unfortunately, so) join the sentences smoothly.

A. A paragraph about city buses

The paragraph to study is about a city whose buses and taxis can’t be relied on. Read it, then answer.

B. Write paragraphs

In your final exam, a paragraph like these can be asked in Guided writing I (about 100 words from given clues, 5 marks) or Free writing I (about 150 words giving your views, 6 marks).

Before you read

The picture before the reading shows a man in a wide hat with a tank on his back, walking through a bright green paddy field and spraying a fine white mist over the crop from a long nozzle.

What kind of text it is

It is a feature article, the kind of story a magazine or newspaper prints about real people: it tells one farmer’s experience in his own words, with quotations, and explains the wider problem around it. It was adapted from Campus English, a Macmillan English course book. Its theme is that chemicals sold as a quick fix can upset the balance of nature.

The text, part by part

1. A bitter farmer

Mahendra Yadav, a potato farmer, speaks bitterly (angrily and sadly). First, he says, they were told to buy poisons to kill the pests; then to buy more poisons to combat (fight) the problems the first pesticides caused; now they are told they shouldn’t have used so much. He fears the insects “will eat us alive”.

2. How it began

His fields have been swamped (flooded, overwhelmed) by a plague (a huge, harmful number) of moths that nothing will shift (get rid of). In the early 1990s, government officials told farmers about amazing pesticides that would kill the insects and soon make them rich. The farmers were only too willing to buy them, and shopkeepers made them easy to get. First one product, then another, then an avalanche of them (a huge number, all at once).

3. Too much, used badly

The salesmen were so energetic that it was hard to say no, and enormous amounts were sold. The chemicals were used indiscriminately (without care or thought): often in the wrong way and at the wrong time. “It wasn’t our fault,” Mahendra says: the farmers were so excited to be free of the whims of nature (the sudden, unpredictable changes of weather and pests). He asks: what would you have done?

4. The nasty surprise

After a few years came a nasty (very unpleasant) surprise. In spite of the mixture of powerful chemicals, a few moths survived. They reproduced at a terrifying rate, devouring (eating hungrily) every potato they could find. The chemicals had killed not only the pests but also their natural predators (the birds, spiders and insects that ate them), so the natural balance was upset and the new moth had the crop all to itself.

5. Stronger and stronger

The farmers first raised the dose, then tried new chemicals, one after another. But one or two resistant moths (moths the poison couldn’t kill) were enough: they bred a new, tougher strain (type), immune to even the most powerful pesticide. New pesticides came with new promises to finish off the “evil moth”, and worked for a while, but never for good.

6. Despair, and hope

Farmers are in despair (they have lost hope): they have watched their harvests disappear, and feel the land itself has lost its creative potential (its power to grow things). But Mahendra is more hopeful. He has gone back to more natural methods: he is letting some of his land lie fallow (unplanted for a season, to rest) and changing the way he irrigates his fields, hoping the moths will go away.

Why the moths became resistant

How could one or two moths make a whole strain that no poison can kill? The poison didn’t teach the moths to resist it. Among millions of moths, a very few happen to be born different, because of a small change in their genes: their bodies can break the poison down, or it can’t reach the place it attacks. Spraying kills the ordinary moths and leaves these few. With the field to themselves, and their predators dead, they breed, and their young inherit the same resistance. Spray again, and again only the resistant survive. After a few seasons nearly every moth in the field is resistant. This is natural selection, the same process Charles Darwin described, here sped up by people.

Words from the text

Word	Meaning here
pest	an insect or animal that damages crops or stored food
pesticide	a chemical used to kill pests
combat	to fight against, to try to stop
swamp	(swamped) to overwhelm with too much of something
plague	a very large number of harmful animals or insects that suddenly appear
avalanche	a huge amount of something arriving at once
overpowering	too strong to resist
indiscriminately	without care or thought, without choosing
whim	a sudden change of mind with no clear reason; the whims of nature: its sudden, unpredictable changes
nasty	very unpleasant
devour	to eat hungrily and quickly
predator	an animal that kills and eats other animals
resistant	not harmed or affected by something (resistant to a pesticide)
strain	a type of an animal, plant or germ with its own features
immune	not affected by something, protected from it
despair	the feeling of having lost all hope
potential	the power to develop, grow or produce
fallow	(of land) plowed but left unplanted for a time

A. Complete the sentences

B. Ways of eating

Devour means to eat hungrily, fast and in large amounts. English has many verbs for ways of eating.

C. True or false

D. Answer the questions

E. Pesticides and their alternatives

The listening is a short talk of facts about the Amazon rainforest. CDC’s own recording is below: read the questions in B first, then listen, as many times as you need.

A. Before you listen

B. Circle the correct answers

These answers have been checked against the recording. It also says that the Amazon is the biggest tropical rainforest in the world; that most of it is in Brazil (almost 60 percent), and the rest in Peru, Venezuela, Colombia, Ecuador, Guyana, Bolivia, Suriname and French Guiana; that it is home to cougars, jaguars and anacondas; that the forest is so dense that sunlight can’t reach the floor; and that it has 40,000 plant species, 3,000 types of fish and 20 percent of the world’s bird species.

C. Nepal’s forests

Remember: the if-clause takes the present; the result takes will, a modal (can, may, must) or an imperative; unless = if … not, with a positive verb.

A. Complete the sentences

B. Complete with your own endings

A letter to the editor is a formal letter to a newspaper, written to be printed so the public can read it. People write one to draw attention to a problem (bad roads, pollution, a dangerous crossing), to give their opinion on something in the news, or to ask the authorities to act.

A. Label the parts

How to write a letter to the editor

1. Your address and the date, at the top.
2. The editor’s address: The Editor, The Rising Nepal, Dharmapath, Kathmandu (or a local paper’s name and address).
3. Subject: a few words on what the letter is about.
4. Salutation: Dear Sir/Madam, or Dear Editor,
5. Body, in three or four paragraphs: the problem and why you are writing (Through your esteemed newspaper, I would like to draw the attention of…); details and effects, with an example or a fact; what should be done, and by whom; a closing request (I hope the concerned authorities will take action soon).
6. Subscription and signature: Yours faithfully, and your name (and, if you like, your address in a line under it).

Keep it formal: no short forms (don’t, can’t), no slang, and polite even when you are angry. In your final exam, a letter to the editor is a Free writing II task (about 200 words, 8 marks), marked on its content, organization, language and layout.

B. Write a letter

The water cycle is the endless movement of water between the Earth and the air Figure 7.6. Its main steps:

• Evaporation: the Sun warms seas, lakes and rivers, and liquid water turns into invisible water vapor. Plants also give off water vapor through their leaves (transpiration).
• Condensation: the vapor rises, cools, and turns into tiny droplets that make clouds.
• Precipitation: the droplets join into drops that fall as rain, or, where it is cold enough, as snow or hail.
• Collection: the water runs into rivers and lakes, soaks into the ground (groundwater, which feeds our springs and wells), or freezes into glaciers, and in the end flows back to the sea, where the cycle begins again.

Many animals have special names for the male, the female and the young.

Animal	Male	Female	Young
ass (donkey)	jack	jenny	foal
bear	boar	sow	cub
deer	buck (stag for large deer)	doe (hind for large deer)	fawn (calf for large deer)
horse	stallion	mare	foal (a young male is a colt, a young female a filly)
sheep	ram	ewe	lamb
dog	dog	bitch	puppy
cattle	bull	cow	calf
goat	billy goat (buck)	nanny goat (doe)	kid
chicken	cock (rooster)	hen	chick
duck	drake	duck	duckling
pig	boar	sow	piglet
lion	lion	lioness	cub
tiger	tiger	tigress	cub
elephant	bull	cow	calf

The first six rows are the textbook’s; the rest are animals you see in Nepal’s farms and national parks. Notice that bull, cow and calf are also used for elephants (and for rhinos and whales), and boar and sow for both bears and pigs. Ewe is said /juː/, exactly like you.

Practice on this unit in the style of the final exam (Grade 9’s exam follows the SEE’s kind of chart). Try each one as in the exam, then open the answer.