雅思阅读高频词汇·自然环境类

日期:2018/11/06  |  
雅思阅读高频词汇·自然环境类

剑桥雅思阅读中,关于自然环境类的文章出现过几十篇,可谓出题大户。掌握自然环境类词汇对于提升学生的阅读能力至关重要。

 

Environment & Nature

Passage1 Environmental Impacts of Logging

A

From shipping crates to paper bags, the logging industry supplies the raw materials for an array of products. However, this is not without untold harm to the environment. The damage includes habitat loss, pollution, and climate change, with the effects spanning the globe from the rain forests of Central Africa, Southeast Asia, and South America to the northern forests of Canada and Scandinavia. The effects of logging extend beyond just the felling of a swath of trees. Nutrients, water, and shelter for plants, animals, and microorganisms throughout the ecosystem are also lost; many life forms--both terrestrial and aquatic--are becoming endangered as forests vanish.

 

B

Trees protect the soil beneath them; thus, tree loss can affect soil integrity. For example, the rain forest floor, home to myriad plant life as well as insects, worms, reptiles and amphibians, and small mammals, relies on a dense canopy of branches and leaves to keep it healthy and intact. The canopy prevents surface runoff by intercepting heavy rainfall so that water can drip down slowly onto the porous earth. Tree roots also stabilize the soil and help prevent erosion. In return, a healthy soil encourages root development and microbial activity, which contribute to tree growth and well-being. A major factor in logging-related soil damage comes from road building, with trucks and other heavy equipment compressing the spongy soil, creating furrows where water collects, and disrupting the underground water flow. Eventually, the topsoil wears away, leaving behind an infertile layer of rocks and hard clay.

 

C

Logging can also damage aquatic habitats. Vegetation along rivers and stream banks helps maintain a steady water flow by blocking the entry of soil and other residue, and tree shade inhibits the growth of algae. Removing trees obliterates these benefits. When eroding soil flows into waterways, the organic matter within it consumes more oxygen, which can lead to oxygen depletion in the water, killing fish and other aquatic wildlife.

 

D

Trees provide a natural defense against air pollution. They remove carbon dioxide from the atmosphere while they emit oxygen, and their leaves filter pollutants from the air. Cutting down trees keeps pollutants airborne, where they can mix with water vapor and form add rain. Water quality in nearby streams and rivers also deteriorates as tree loss contributes to increased sedimentation

 

E

In a healthy forest ecosystem, trees draw moisture from the soil and release it into the atmosphere while they provide shade to lessen evaporation. Thus, deforestation impacts rainfall patterns, leading to flooding as well as drought and forest fires. Deforestation is responsible for about one-fifth of carbon dioxide emissions worldwide, making it a major contributor to climate change-in particular, global warming. In the Amazon basin alone, deforestation is responsible for millions of tons of carbon dioxide being released into the atmosphere annually. Some logging companies burn large tracts of forest just to facilitate access to one area-a practice that discharges even more carbon dioxide.

 

 

F

Forests, especially the tropical rain forests, are a vital natural resource with extensive biodiversity and irreplaceable wildlife habitats. More responsible logging practices would help ensure that they are protected for future generations.

Word Families

noun

evolution

Our research plans have gone through many evolutions and are now quite different from our original plans.

verb

evolve

Scientists believe that birds evolved from dinosaurs.

adjective

evolutionary

Through the evolutionary process, birds have developed adaptations that allow them to survive in different environments.

 

noun

fascination

His fascination with birds is not hard to understand, because there are several bird-watchers in his family.

verb

fascinate

The study of the lives of birds fascinates many people.

adjective

fascinating

The study of birdsong is a fascinating subject.

 

noun

migration

Bird migration generally takes place twice a year, in the spring and autumn.

noun

migrant

Migrants stop to rest several times during their journey.

verb

migrate

Some birds migrate thousands of miles to reach their summer breeding grounds.

adjective

migratory

Scientists study the habits of migratory birds.

 

noun

navigation

Birds use the sun, stars, and landforms for navigation.

noun

navigator

Migratory birds are amazing navigators.

verb

navigate

Birds navigate by looking at the sun and stars.

adjective

navigational

Migratory birds are born with navigational skills; they don’t have to learn them.

 

noun

observation

We can learn a great deal about the lives of birds through simple observation.

noun

observer

If birds become aware of the presence of an observer, they quickly fly away.

verb

observe

Many people observe birds as a hobby.

adjective

observant

You have to be really observant to spot most types of birds.

Passage 2 Bird Migration

Migration is the regular movement of animals between their breeding grounds and the areas that they inhabit during the rest of the year. Many types of animals mt&ate, but bird migration in particular has fascinated observers for centuries. Migration ts an excellent example of how nature has responded to the biological imperative for species to evolve and spread out into all possible ecological niches that can provide the conditions necessary for species to breed and raise young.

The most common form of bird migration involves traveling to higher latitudes to breed during the warm season and then returning to lower latitudes during the nonbreeding period. This form of migration allows birds to breed in areas that provide optimal conditions for nesting and feeding their young. Because of the way in which the continents are situated upon Earth, migration of this type takes place primarily into the higher latitudes of the Northern Hemisphere. No land birds are known to migrate into the higher latitudes of the Southern Hemisphere; only species of seabirds migrate to the Southern Hemisphere to breed.

Although most bird migration takes place between the lower and higher latitudes of the Northern Hemisphere, many species are transequatorial, living in the Northern Hemisphere during the breeding season and in the Southern Hemisphere during the remainder of the year. A well-known example of transequatorial migration is the arctic tern. This tern, which breeds in the arctic regions and winters in antarctic waters, travels 24,000 miles a year during migration.

Not all migration is long distance. Some species exhibit altitudinal migration. Their breeding areas are in higher elevations, near or at the peaks of mountains, and they spend the nonbreeding season in neighboring valleys or other nearby low country. This variety of migration is typical of many grouse species, including the ptarmigan, a type of arctic grouse. Many rock ptarmigan never leave the high arctic tundra, spending their breeding season atop windswept arctic peaks and the winter season in nearby valleys. enduring some of the coldest conditions on Earth.

During migration, most birds fly for a limited period each day, probably about six to eight hours, typically flying distances of several hundred miles. Some birds, however, undertake much longer flights when their routes include crossing large bodies of water or other geographic features such as deserts and mountains. For example, many species regularly cross the Gulf of Mexico, a trip that requires a continuous flight of more than 1,000 miles and takes from twenty-four to thirty-six hours or longer. An extreme example of nonstop bird migration is done by the miles from Alaska to New Zealand each year. At the start of its trip, about 55 percent of its body weight is made up of the fat necessary to fuel this amazing journey.

How birds manage to unerringly travel between distant locations is one aspect that has fascinated observers for centuries. Modern-day researchers have attempted to understand this feat. Most studies have found that migratory birds all have some ability to navigate and an innate drive to travel in a particular direction. Nocturnal migrants, those species that travel at night, seem to take their navigational cues from the stars. When the stars are obscured by clouds, nocturnal migrants may become confused and return to land or stray off course. Diurnal migrants, those migrating during the day, take their cues from the location of the sun. In addition, diurnal migrants have also been shown to use geographic features such as mountain ranges or seacoasts as other cues for navigation. Because the stars and the sun move constantly over the course of twenty-four hours, this suggests that migrating birds also have some sense of time.

Word Families

noun

evolution

Our research plans have gone through many evolutions and are now quite different from our original plans.

verb

evolve

Scientists believe that birds evolved from dinosaurs.

adjective

evolutionary

Through the evolutionary process, birds have developed adaptations that allow them to survive in different environments.

 

noun

fascination

His fascination with birds is not hard to understand, because there are several bird-watchers in his family.

verb

fascinate

The study of the lives of birds fascinates many people.

adjective

fascinating

The study of birdsong is a fascinating subject.

 

noun

migration

Bird migration generally takes place twice a year, in the spring and autumn.

noun

migrant

Migrants stop to rest several times during their journey.

verb

migrate

Some birds migrate thousands of miles to reach their summer breeding grounds.

adjective

migratory

Scientists study the habits of migratory birds.

 

noun

navigation

Birds use the sun, stars, and landforms for navigation.

noun

navigator

Migratory birds are amazing navigators.

verb

navigate

Birds navigate by looking at the sun and stars.

adjective

navigational

Migratory birds are born with navigational skills; they don’t have to learn them.

 

noun

observation

We can learn a great deal about the lives of birds through simple observation.

noun

observer

If birds become aware of the presence of an observer, they quickly fly away.

verb

observe

Many people observe birds as a hobby.

adjective

observant

You have to be really observant to spot most types of birds.

Passage3 Plant life in the Taklimakan Desert

The Taklimakan Desert, second in size only to Africa’s Sahara Desert, occupies some 337,600 square kilometers (130,300 square miles) of northwestern China-an area about the size of Finland. Sqarse rainfall, daily temperature swings of up to 20℃ (68°F), and violent sandstorms make it one of the most extreme environments on Earth.

Eighty-five percent of the Taklimakan Desert consists of shifting sand dunes, some up to 250 meters tall, that are largely free of vegetation. Yet, transitional areas between the open desert and oases on the desert fringe support diverse plant forms that not only have adapted to the harsh conditions but actually thrive there.

Successful desert plants are resilient to scorching summers and frigid winters, drought, and high-salt conditions. The plants’ principal defense against these environmental stressors consists of drawing in as much water a8 possible while minimizing moisture loss. Three Taklimakan plants-Populus euphratica, Tamarix ramosissima, and Alhagi sparsifolia-- represent some of the most diverse, prolific vegetation in the area; although they share many survival strategies, each has developed unique coping mechanisms of its own.

The Euphrates poplar, Populus euphratica the only tall tree in the Taklimakan ecosystem, has an extensive root system that allows it to absorb water far from the standing tree. P. euphratica controls evaporation by opening and closing the stomata, or tiny pores, on the leaf surface in response to the amount of moisture being lost through the leaves to the surrounding air. These stomata generally remain open during the day while the plant conducts photosynthesis.

  1. euphratica can endure high-salt concentrations in the soil. It takes in unlimited amounts of salt through the roots, up the stem, and into leaves, where it dilutes the normally toxic salt by increasing the number and volume of its cells.

Tamarix ramosissima, a small tree with needlelike leaves commonly known as tamarisk or salt cedar, takes in enormous amounts of water via a far-reaching root system many times the size of the plant above ground. Like P. euphratica, tamarisk can naturally determine when to close stomata inhibit evaporation and regulate photosynthesis.

Tamarisk has a high tolerance for salty conditions and even produces its own salt, which it accumulates in special glands between the leaves and then releases onto leaf surfaces. Leaves dropping to the ground make the soil more saline, or salty, giving tamarisk a competitive advantage over less salt-tolerant plants.

Alhagi sparsifolia, a spiny shrub, thrives in the Taklimakan Desert even though it uses large amounts of water, especially during the summer months. With only a few wispy roots in the upper soil, it is unaffected by occasional flooding. Most of its roots reach down deep, where they take up water from as far as sixteen meters below ground. Unlike P. euphratica and T. ramosissima, which open and close stomata according to conditions on the leaf surface, A. sparsifolia does so according to hydraulic conductance-that is, the ease with which it takes up groundwater.

Although desert plants have adapted for their own survival, they also help protect their ecosystem by stabilizing sand dunes, preventing erosion, presenting a barrier to sandstorms, and conserving biodiversity.

Word Families

noun

adaptation

Plants in the Taklimakan Desert have adaptations that allow them to live in the dry, salty conditions.

verb

adapt

One way that plants adapt to the dry desert is by developing deep root systems.

adjective

adaptable

Most plant species are not adaptable to a desert environment.

 

noun

diversity

There is a great diversity of plant life on the fringe of the Taklimakan Desert.

noun

diversification

Change in climate can result in species diversification.

verb

diversify

As climate changes, plant species in an area may diversify if conditions improve.

adjective

diverse

The diverse ways that plants adapt to desert conditions makes a fascinating study.

 

noun

extreme

Temperatures in the Taklimakan Desert reach an extreme during hot summer days.

adjective

extreme

Many plants cannot endure the extreme heat of the desert.

adverb

extremely

The weather in a desert is usually extremely dry.

 

noun

resilience

The resilience of certain plants allows them to thrive in the desert.

adjective

resilient

Desert plants are resilient to heat and dryness.

adverb

resiliently

Desert plants grow resiliently in the heat.

 

noun

stress

A long period of dryness causes a lot of stress to plants.

noun

stressor

The main stressor in a desert is lack of rain.

verb

stress

Heat and drought both stress plants.

adverb

stressful

Certain plants thrive in the desert despite the stressful conditions.

 

noun

violence

The violence of sandstorms keeps many plants from thriving in the desert.

adjective

violent

Violent winds tear up many plants or cover them with sand.

adverb

violently

The winds blow violently during a sandstorm.

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