Ozone and the Immune System

Ozone's unique physical properties allow the ozone layer to act as our planet's sunscreen, providing an invisible filter to help protect all life forms from the Sun's damaging ultraviolet (UV) rays. Most incoming UV radiation is absorbed by ozone and prevented from reaching the Earth's surface. Without the protective effect of ozone, life on Earth would not have evolved the way it has.

The ozone layer protects us from the harmful effects of certain wavelengths of ultraviolet (UV) radiation from the Sun. The danger to humans from UV radiation comes mainly from the UV-B range of the spectrum, although UV-A poses some risk if exposure is long enough. UV radiation is harmful to the eyes, can damage the immune system and over time can lead to the development of skin cancers. If ozone in the stratosphere is destroyed, more UV radiation will reach the Earth's surface, and incidences of these health effects will increase.

OZONE AND THE IMMUNE SYSTEM

UV radiation from the Sun can benefit health, generating vitamin D production in the skin. The required amount of radiation is, however, quite small. In summer, an exposure of 15 minutes to the hands and face is adequate. Vitamin D is also found in food. A normal diet will provide enough vitamin D for people even in winter. In the treatment of some skin diseases such as psoriasis, UV radiation is being effectively exploited. Under a doctor's control, the benefit from the treatment is much greater than any consequential increase in skin cancer risk.

However, over exposure to UV radiation can impair the body's ability to fight off disease, in addition to causing cancer and a range of eye disorders. UV suppresses the immune system, irrespective of skin colour, making it easier for tumours to take hold and spread.

UV radiation suppresses allergic reactions of the skin and affects the immune system. When skin has been over-exposed to UV radiation, the activity of antibody-producing white blood cells is suppressed. These effects are not restricted to the part of skin actually subject to exposure, but may also occur on shielded parts of skin and throughout the whole immune system. As a result, the body fails to produce the antigens required for defence against a variety of diseases. This could have serious consequences, including a much-diminished effectiveness of vaccinations.

At the present time, the significance of a weakening of the immune system caused by UV radiation is not properly understood. The weakening can possibly act to promote the development of skin cancers and worsen infectious diseases stemming from bacteria, viruses and tropical parasites. It may also activate viruses already present on the skin, such as herpes, and lead to an increase in diseases like measles, malaria, tuberculosis, leprosy and fungal infections, all of which have a stage involving the skin. People carrying the herpes virus should protect their faces against strong sunlight.

Scientific research suggests that sunburn can alter the distribution and function of disease-fighting white blood cells in humans for up to 24 hours after exposure to the Sun. In addition, repeated exposure to UV radiation may cause more long-lasting damage to the body's immune system. Whilst little research has been conducted on the effects of decreasing stratospheric ozone on human immunity, it is likely that continued destruction of the ozone layer will lead to further health complications, in addition to skin cancers and eye disorders, as a result of the suppression of our ability to fight off disease.

OZONE DEPLETION

The ozone layer protects the Earth from the ultraviolet rays sent down by the sun. If the ozone layer is depleted by human action, the effects on the planet could be catastrophic.

Ozone is present in the stratosphere. The stratosphere reaches 30 miles above the Earth, and at the very top it contains ozone. The suns rays are absorbed by the ozone in the stratosphere and thus do not reach the Earth.

The Ozone Layer Over Time. Image Credit: Institute for Studies in Development, Environment, and Security.

Ozone is a bluish gas that is formed by three atoms of oxygen. The form of oxygen that humans breathe in consists of two oxygen atoms, O₂. When found on the surface of the planet, ozone is considered a dangerous pollutant and is one substance responsible for producing the greenhouse effect.

The highest regions of the stratosphere contain about 90% of all ozone.

In recent years, the ozone layer has been the subject of much discussion. And rightly so, because the ozone layer protects both plant and animal life on the planet.

The fact that the ozone layer was being depleted was discovered in the mid-1980s. The main cause of this is the release of CFCs, chlorofluorocarbons.

Antarctica was an early victim of ozone destruction. A massive hole in the ozone layer right above Antarctica now threatens not only that continent, but many others that could be the victims of Antarctica's melting icecaps. In the future, the ozone problem will have to be solved so that the protective layer can be conserved.

CAUSES OF OZONE DEPLETION

Only a few factors combine to create the problem of ozone layer depletion. The production and emission of CFCs, chlorofluorocarbons, is by far the leading cause.

Many countries have called for the end of CFC production because only a few produce the chemical. However, those industries that do use CFCs do not want to discontinue usage of this highly valuable industrial chemical.

CFCs are used in industry in a variety of ways and have been amazingly useful in many products. Discovered in the 1930s by American chemist Thomas Midgley, CFCs came to be used in refrigerators, home insulation, plastic foam, and throwaway food containers.

Only later did people realize the disaster CFCs caused in the stratosphere. There, the chlorine atom is removed from the CFC and attracts one of the three oxygen atoms in the ozone molecule. The process continues, and a single chlorine atom can destroy over 100,000 molecules of ozone.

In 1974, Sherwood Rowland and Mario Molina followed the path of CFCs. Their research proved that CFCs were entering the atmosphere, and they concluded that 99% of all CFC molecules would end up in the stratosphere.

Only in 1984, when the ozone layer hole was discovered over Antarctica, was the proof truly conclusive. At that point, it was hard to question the destructive capabilities of CFCs.

Even if CFCs were banned, problems would remain. There would still be no way to remove the CFCs that are now present in the environment. Clearly though, something must be done to limit this international problem in the future.

EFFECTS OF OZONE DEPLETION

Even minor problems of ozone depletion can have major effects. Every time even a small amount of the ozone layer is lost, more ultraviolet light from the sun can reach the Earth.

Every time 1% of the ozone layer is depleted, 2% more UV-B is able to reach the surface of the planet. UV-B increase is one of the most harmful consequences of ozone depletion because it can cause skin cancer.

The increased cancer levels caused by exposure to this ultraviolet light could be enormous. The EPA estimates that 60 million Americans born by the year 2075 will get skin cancer because of ozone depletion. About one million of these people will die.

In addition to cancer, some research shows that a decreased ozone layer will increase rates of malaria and other infectious diseases. According to the EPA, 17 million more cases of cataracts can also be expected.

The environment will also be negatively affected by ozone depletion. The life cycles of plants will change, disrupting the food chain. Effects on animals will also be severe, and are very difficult to foresee.

Oceans will be hit hard as well. The most basic microscopic organisms such as plankton may not be able to survive. If that happened, it would mean that all of the other animals that are above plankton in the food chain would also die out. Other ecosystems such as forests and deserts will also be harmed.

The planet's climate could also be affected by depletion of the ozone layer. Wind patterns could change, resulting in climatic changes throughout the world.

SOLUTIONS FOR OZONE DEPLETION

The discovery of the ozone depletion problem came as a great surprise. Now, action must be taken to ensure that the ozone layer is not destroyed.

Because CFCs are so widespread and used in such a great variety of products, limiting their use is hard. Also, since many products already contain components that use CFCs, it would be difficult if not impossible to eliminate those CFCs already in existence.

The CFC problem may be hard to solve because there are already great quantities of CFCs in the environment. CFCs would remain in the stratosphere for another 100 years even if none were ever produced again.

Despite the difficulties, international action has been taken to limit CFCs. In the Montreal Protocol, 30 nations worldwide agreed to reduce usage of CFCs and encouraged other countries to do so as well.

WHAT IS GLOBAL WARMING?

Earth heats up in global-warming frying pan

What causes global warming?

Carbon dioxide and other air pollution that is collecting in the atmosphere like a thickening blanket, trapping the sun's heat and causing the planet to warm up. Coal-burning power plants are the largest U.S. source of carbon dioxide pollution -- they produce 2.5 billion tons every year. Automobiles, the second largest source, create nearly 1.5 billion tons of CO2 annually.

Here's the good news: technologies exist today to make cars that run cleaner and burn less gas, modernize power plants and generate electricity from nonpolluting sources, and cut our electricity use through energy efficiency. The challenge is to be sure these solutions are put to use.

Is the earth really getting hotter?

Yes. Although local temperatures fluctuate naturally, over the past 50 years the average global temperature has increased at the fastest rate in recorded history. And experts think the trend is accelerating: the 10 hottest years on record have all occurred since 1990. Scientists say that unless we curb global warming emissions, average U.S. temperatures could be 3 to 9 degrees higher by the end of the century.

Are warmer temperatures causing bad things to happen?

Global warming is already causing damage in many parts of the United States. In 2002, Colorado, Arizona and Oregon endured their worst wildfire seasons ever. The same year, drought created severe dust storms in Montana, Colorado and Kansas, and floods caused hundreds of millions of dollars in damage in Texas, Montana and North Dakota. Since the early 1950s, snow accumulation has declined 60 percent and winter seasons have shortened in some areas of the Cascade Range in Oregon and Washington.

Of course, the impacts of global warming are not limited to the United States. In 2003, extreme heat waves caused more than 20,000 deaths in Europe and more than 1,500 deaths in India. And in what scientists regard as an alarming sign of events to come, the area of the Arctic's perennial polar ice cap is declining at the rate of 9 percent per decade.

Is global warming making hurricanes worse?

Global warming doesn't create hurricanes, but it does make them stronger and more dangerous. Because the ocean is getting warmer, tropical storms can pick up more energy and become more powerful. So global warming could turn, say, a category 3 storm into a much more dangerous category 4 storm. In fact, scientists have found that the destructive potential of hurricanes has greatly increased along with ocean temperature over the past 35 years.

Is there really cause for serious concern?

Yes. Global warming is a complex phenomenon, and its full-scale impacts are hard to predict far in advance. But each year scientists learn more about how global warming is affecting the planet, and many agree that certain consequences are likely to occur if current trends continue. Among these:

• Melting glaciers, early snowmelt and severe droughts will cause more dramatic water shortages in the American West.
• Rising sea levels will lead to coastal flooding on the Eastern seaboard, in Florida, and in other areas, such as the Gulf of Mexico.
• Warmer sea surface temperatures will fuel more intense hurricanes in the southeastern Atlantic and Gulf coasts.
• Forests, farms and cities will face troublesome new pests and more mosquito-borne diseases.
• Disruption of habitats such as coral reefs and alpine meadows could drive many plant and animal species to extinction.

Could global warming trigger a sudden catastrophe?

Recently, researchers -- and even the U.S. Defense Department -- have investigated the possibility of abrupt climate change, in which gradual global warming triggers a sudden shift in the earth's climate, causing parts of the world to dramatically heat up or cool down in the span of a few years.

In February 2004, consultants to the Pentagon released a report laying out the possible impacts of abrupt climate change on national security. In a worst-case scenario, the study concluded, global warming could make large areas of the world uninhabitable and cause massive food and water shortages, sparking widespread migrations and war.

While this prospect remains highly speculative, many of global warming's effects are already being observed -- and felt. And the idea that such extreme change is possible underscores the urgent need to start cutting global warming pollution.

What country is the largest source of global warming pollution?

The United States. Though Americans make up just 4 percent of the world's population, we produce 25 percent of the carbon dioxide pollution from fossil-fuel burning -- by far the largest share of any country. In fact, the United States emits more carbon dioxide than China, India and Japan, combined. Clearly America ought to take a leadership role in solving the problem. And as the world's top developer of new technologies, we are well positioned to do so -- we already have the know-how.

How can we cut global warming pollution?

It's simple: By reducing pollution from vehicles and power plants. Right away, we should put existing technologies for building cleaner cars and more modern electricity generators into widespread use. We can increase our reliance on renewable energy sources such as wind, sun and geothermal. And we can manufacture more efficient appliances and conserve energy.

Why aren't these technologies more commonplace now?

Because, while the technologies exist, the corporate and political will to put them into widespread use does not. Many companies in the automobile and energy industries put pressure on the White House and Congress to halt or delay new laws or regulations -- or even to stop enforcing existing rules -- that would drive such changes. From requiring catalytic converters to improving gas mileage, car companies have fought even the smallest measure to protect public health and the environment. If progress is to be made, the American people will have to demand it.

Do we need new laws requiring industry to cut emissions of global warming pollution?

Yes. The Bush administration has supported only voluntary reduction programs, but these have failed to stop the growth of emissions. Even leaders of major corporations, including companies such as DuPont, Alcoa and General Electric, agree that it's time for the federal government to create strong laws to cut global warming pollution. Public and political support for solutions has never been stronger. Congress is now considering fresh proposals to cap emissions of carbon dioxide and other heat-trapping pollutants from America's largest sources -- power plants, industrial facilities and transportation fuels.

Stricter efficiency requirements for electric appliances will also help reduce pollution. One example is the 30 percent tighter standard now in place for home central air conditioners anheat pumps, a Clinton-era achievement that will prevent the emission of 51 million metric tons of carbon -- the equivalent of taking 34 million cars off the road for one year. The new rule survived a Bush administration effort to weaken it when, in January 2004, a federal court sided with an NRDC-led coalition and reversed the administration's rollback.

Is it possible to cut power plant pollution and still have enough electricity?

Yes. First, we must use more efficient appliances and equipment in our homes and offices to reduce our electricity needs. We can also phase out the decades-old, coal-burning power plants that generate most of our electricity and replace them with cleaner plants. And we can increase our use of renewable energy sources such as wind and sun. Some states are moving in this direction: California has required its largest utilities to get 20 percent of their electricity from renewable sources by 2017, and New York has pledged to compel power companies to provide 25 percent of the state's electricity from renewable sources by 2013.

How can we cut car pollution?

Cost-effective technologies to reduce global warming pollution from cars and light trucks of all sizes are available now. There is no reason to wait and hope that hydrogen fuel cell vehicles will solve the problem in the future. Hybrid gas-electric engines can cut global warming pollution by one-third or more today; hybrid sedans, SUVs and trucks from several automakers are already on the market.

But automakers should be doing a lot more: They've used a legal loophole to make SUVs far less fuel efficient than they could be; the popularity of these vehicles has generated a 20 percent increase in transportation-related carbon dioxide pollution since the early 1990s. Closing this loophole and requiring SUVs, minivans and pick-up trucks to be as efficient as cars would cut 120 million tons of carbon dioxide pollution a year by 2010. If automakers used the technology they have right now to raise fuel economy standards for new cars and light trucks to a combined 40 m.p.g., carbon dioxide pollution would eventually drop by more than 650 million tons per year as these vehicles replaced older models.

What can I do to help fight global warming?

There are many simple steps you can take right now to cut global warming pollution. Make conserving energy a part of your daily routine. Each time you choose a compact fluorescent light bulb over an incandescent bulb, for example, you'll lower your energy bill and keep nearly 700 pounds of carbon dioxide out of the air over the bulb's lifetime. By opting for a refrigerator with the Energy Star label -- indicating it uses at least 15 percent less energy than the federal requirement -- over a less energy-efficient model, you can reduce carbon dioxide pollution by nearly a ton in total.

Top 10 Things You Can Do to Reduce Global Warming

Burning fossil fuels such as natural gas, coal, oil and gasoline raises the level of carbon dioxide in the atmosphere, and carbon dioxide is a major contributor to the greenhouse effect and global warming.

You can help to reduce the demand for fossil fuels, which in turn reduces global warming, by using energy more wisely. Here are 10 simple actions you can take to help reduce global warming.

1. Reduce, Reuse, Recycle

Do your part to reduce waste by choosing reusable products instead of disposables. Buying products with minimal packaging (including the economy size when that makes sense for you) will help to reduce waste. And whenever you can, recycle paper, plastic, newspaper, glass and aluminum cans. If there isn't a recycling program at your workplace, school, or in your community, ask about starting one. By recycling half of your household waste, you can save 2,400 pounds of carbon dioxide annually.

2. Use Less Heat and Air Conditioning

Adding insulation to your walls and attic, and installing weather stripping or caulking around doors and windows can lower your heating costs more than 25 percent, by reducing the amount of energy you need to heat and cool your home.

Turn down the heat while you’re sleeping at night or away during the day, and keep temperatures moderate at all times. Setting your thermostat just 2 degrees lower in winter and higher in summer could save about 2,000 pounds of carbon dioxide each year.

3. Change a Light Bulb

Wherever practical, replace regular light bulbs with compact fluorescent light (CFL) bulbs. Replacing just one 60-watt incandescent light bulb with a CFL will save you $30 over the life of the bulb. CFLs also last 10 times longer than incandescent bulbs, use two-thirds less energy, and give off 70 percent less heat.

If every U.S. family replaced one regular light bulb with a CFL, it would eliminate 90 billion pounds of greenhouse gases, the same as taking 7.5 million cars off the road.

4. Drive Less and Drive Smart

Less driving means fewer emissions. Besides saving gasoline, walking and biking are great forms of exercise. Explore your community’s mass transit system, and check out options for carpooling to work or school.

When you do drive, make sure your car is running efficiently. For example, keeping your tires properly inflated can improve your gas mileage by more than 3 percent. Every gallon of gas you save not only helps your budget, it also keeps 20 pounds of carbon dioxide out of the atmosphere.

5. Buy Energy-Efficient Products

When it's time to buy a new car, choose one that offers good gas mileage. Home appliances now come in a range of energy-efficient models, and compact florescent bulbs are designed to provide more natural-looking light while using far less energy than standard light bulbs.

Avoid products that come with excess packaging, especially molded plastic and other packaging that can't be recycled. If you reduce your household garbage by 10 percent, you can save 1,200 pounds of carbon dioxide annually.

6. Use Less Hot Water

Set your water heater at 120 degrees to save energy, and wrap it in an insulating blanket if it is more than 5 years old. Buy low-flow showerheads to save hot water and about 350 pounds of carbon dioxide yearly. Wash your clothes in warm or cold water to reduce your use of hot water and the energy required to produce it. That change alone can save at least 500 pounds of carbon dioxide annually in most households. Use the energy-saving settings on your dishwasher and let the dishes air-dry.

7. Use the "Off" Switch

Save electricity and reduce global warming by turning off lights when you leave a room, and using only as much light as you need. And remember to turn off your television, video player, stereo and computer when you're not using them.

It's also a good idea to turn off the water when you're not using it. While brushing your teeth, shampooing the dog or washing your car, turn off the water until you actually need it for rinsing. You'll reduce your water bill and help to conserve a vital resource.

8. Plant a Tree

If you have the means to plant a tree, start digging. During photosynthesis, trees and other plants absorb carbon dioxide and give off oxygen. They are an integral part of the natural atmospheric exchange cycle here on Earth, but there are too few of them to fully counter the increases in carbon dioxide caused by automobile traffic, manufacturing and other human activities. A single tree will absorb approximately one ton of carbon dioxide during its lifetime.

9. Get a Report Card fromYour Utility Company

Many utility companies provide free home energy audits to help consumers identify areas in their homes that may not be energy efficient. In addition, many utility companies offer rebate programs to help pay for the cost of energy-efficient upgrades.

10. Encourage Others to Conserve

Share information about recycling and energy conservation with your friends, neighbors and co-workers, and take opportunities to encourage public officials to establish programs and policies that are good for the environment.

These 10 steps will take you a long way toward reducing your energy use and your monthly budget. And less energy use means less dependence on the fossil fuels that create greenhouse gases and contribute to global warming.

Chapter 5 - Tropical Rain Forest

Tropical Rain Forest

The tropical rain forest is a forest of tall trees in a region of year-round warmth. An average of 50 to 260 inches (125 to 660 cm.) of rain falls yearly.

Rain forests belong to the tropical wet climate group. The temperature in a rain forest rarely gets higher than 93 °F (34 °C) or drops below 68 °F (20 °C); average humidity is between 77 and 88%; rainfall is often more than 100 inches a year. There is usually a brief season of less rain. In monsoonal areas, there is a real dry season. Almost all rain forests lie near the equator.

Rainforests now cover less than 6% of Earth's land surface. Scientists estimate that more than half of all the world's plant and animal species live in tropical rain forests. Tropical rainforests produce 40% of Earth's oxygen.

A tropical rain forest has more kinds of trees than any other area in the world. Scientists have counted about 100 to 300 species in one 2 1/2-acre (1-hectare) area in South America. Seventy percent of the plants in the rainforest are trees.

About 1/4 of all the medicines we use come from rainforest plants. Curare comes from a tropical vine, and is used as an anesthetic and to relax muscles during surgery. Quinine, from the cinchona tree, is used to treat malaria. A person with lymphocytic leukemia has a 99% chance that the disease will go into remission because of the rosy periwinkle. More than 1,400 varieties of tropical plants are thought to be potential cures for cancer.

All tropical rain forests resemble one another in some ways. Many of the trees have straight trunks that don't branch out for 100 feet or more. There is no sense in growing branches below the canopy where there is little light. The majority of the trees have smooth, thin bark because there is no need to protect the them from water loss and freezing temperatures. It also makes it difficult for epiphytes and plant parasites to get a hold on the trunks. The bark of different species is so similar that it is difficult to identify a tree by its bark. Many trees can only be identified by their flowers.

Despite these differences, each of the three largest rainforests--the American, the African, and the Asian--has a different group of animal and plant species. Each rain forest has many species of monkeys, all of which differ from the species of the other two rain forests. In addition, different areas of the same rain forest may have different species. Many kinds of trees that grow in the mountains of the Amazon rain forest do not grow in the lowlands of that same forest.

The tropical rain forest can be found in three major geographical areas around the world.

• Central America in the the Amazon river basin.
• Africa - Zaire basin, with a small area in West Africa; also eastern Madagascar.
• Indo-Malaysia - west coast of India, Assam, Southeast Asia, New Guinea and Queensland, Australia.

Tropical Rainforest Layers

Tropical rainforests have four layers:

Emergent Layer
These giant trees thrust above the dense canopy layer and have huge mushroom-shaped crowns. These trees enjoy the greatest amount of sunlight but also must endure high temperatures, low humidity, and strong winds.

Canopy Layer
The broad, irregular crowns of these trees form a tight, continuous canopy 60 to 90 feet above the ground. The branches are often densely covered with other plants (epiphytes) and tied together with vines (lianas). The canopy is home to 90% of the organisms found in the rain forest; many seeking the brighter light in the treetops.

Understory
Receiving only 2-15% of the sunlight that falls on the canopy, the understory is a dark place. It is relatively open and contains young trees and leafy herbaceous plants that tolerate low light. Many popular house plants come from this layer. Only along rivers and roadways and in treefall and cut areas is sunlight sufficient to allow growth to become thick and impenetrable.

Forest Floor
The forest floor receives less than 2% of the sunlight and consequently, little grows here except plants adapted to very low light. On the floor is a thin layer of fallen leaves, seeds, fruits, and branches that very quickly decomposes. Only a thin layer of decaying organic matter is found, unlike in temperate deciduous forest.

Did you know that enough rainforests are being destroyed every minute to fill 50 football fields? We need to preserve these valuable resources because they are the lungs of our planet, and can possibly hold cures for many of our most deadly diseases. The tropical rainforests are a critical link in the ecological chains of our our earth's biosphere.

Despite covering only 2% of our planet's surface, over half of the earth's animal, insect species, and flora live there. Within a four mile square area of a tropical rainforest, you would find:

• Over 750 species of trees
• 1500 different kinds of flowering plants
• 125 species of mammals
• 400 species of birds
• 100 reptiles
• 60 amphibians
• countless insects
• 150 species of butterflies
  

**Only 1% of these species has ever been studied**

Important Facts

• Amazon rainforests produce about 40% of the world's oxygen
• One in four pharmaceuticals comes from a plant in the tropical rainforests
• 1400 rainforest plants are believed to offer cures for cancer
• 40% of tropical rainforests have already been lost in Latin America and Southeast Asia

Chapter 5 - Deciduous Forest

Deciduous biomes are located primarily in the eastern half of the United States, Canada, Europe, parts of Russia, China, and Japan.

Climate

The average temperature of the forest is about 50 degrees F. The average amount of rainfall in the forest is 30 to 60 inches a year. As the seasons change, so do the colors of the leaves of the deciduous. During the winter months water is generally not available to keep the leaves of some plants alive. Therefore, the leaves of some plants fall off and grow back in the spring. Those plants, like evergreens, keep their leaves during the winter have special adaptations to stay alive. You can learn more about the vegetation of deciduous biomes.

Animals

Precipitation in the temperate deciduous forest is spread throughout the year. However, during the winter months it is usually frozen and unavailable to animals. Animals living within this biome must adjust to cold winters and hot summers. Leaves generally fall off in the fall, leaving animals with less cover to hide themselves from predators. Also in the deciduous forests are such animals as

Black Bear

Fox

Brown Bear

Other animals found in Temperate Deciduous Forest

Ant Ants are social insects.

Bald Eagle The bald eagle is a large bird of prey. It is the symbol of the USA.

Beaver The beaver is a large rodent that builds dams and dens.

Black Bear A large, black to brown bear.

Brown Bear The Brown Bear is a large bear with a muscular hump on its shoulders.

Cardinal The cardinal is a brilliant red bird with a short, wide bill.

Collared Peccary A pig-like mammal, also known as the javelina, from deserts, chaparrals and forests of North and Central America.

Deer The deer is a shy, fast-moving plant-eater.

Dhole The dhole is a wild dog from Asia.

Earthworm An earthworm is a little animal with a long, soft body and no legs.

Fox The fox is a meat-eating mammal with a long, bushy tail.

Frog Tadpoles grow up to be frogs.

Mallard Duck The Mallard is a common wild duck that is the ancestor of most domestic ducks.

Muskrat Muskrats are rodents that often build dome-shaped houses.

Newt Newts are small, brightly-colored salamanders.

Nightingale A small songird that sings beautiful, complex songs, often at night.

Opossum The Virginia opossum is the only marsupial in North America. Over 64 species of opossum are found in South America.

Porcupine Porcupines are mammals with protective, needle-like quills on their body.

Rabbit A fast-moving mammal with long ears.

Raccoon The raccoon is a mammal with mask-like markings on its face and a ringed tail.

Red Fox The Red Fox is a meat-eating mammal with a long, bushy tail.

Red-Tailed Hawk The Red-Tailed Hawk is a bird of prey, a raptor from North America.

Scorpion A venomous arachnid with a large stinger on its tail.

Skunk Skunks are black and white mammals that can produce a terrible odor.

Squirrel Squirrels are rodents. They live in a variety of biomes, including the taiga.

Turkey Turkeys are large birds that nest on the ground.

Weasel A carnivorous mammal that has a long, slender body and short legs.

White-Tailed Deer The white-tailed deer is a shy, fast-moving plant-eater.

Vegetation

In the deciduous forest there are many flowers like the passion berry and the blue lily. There are many other flowers but those are some of the main ones.

The Deciduous forest does not have much vegetation but there are many trees that contain outrageous amounts of flowers. Animals need these trees because they provide shelter and some use them for food and even water from the leaves. The trees adapt to this forest by having thick bark barriers on the trees to keep the animals out and the trees from dying.

Chapter 5 - Taiga

Taiga is the Russian word for coniferous forest and is the largest biome in the world. It stretches over Eurasia and North America. The taiga is located near the top of the world, just below the tundra biome. The winters in the taiga are very cold with only snowfall. The summers are warm, rainy, and humid. A lot of coniferous trees grow in the taiga.

The taiga is also known as the boreal forest. Did you know that Boreal was the Greek goddess of the North Wind?

The taiga doesn't have as many plant and animal species as the tropical or the deciduous forest biomes. It does have millions of insects in the summertime. Birds migrate there every year to nest and feed.

CLIMATE/LOCATION

The taiga is located in the northern parts of Alaska, Canada, Asia, and Europe. The taiga is wrapped in a band around the world and has the tundra above it and the deciduous forest in the parts below it. This means that the tundra is at a latitude that is farther away from the equator then the taiga is and the deciduous forest is closer to the equator then the taiga is.

The climate of the taiga is very cold and dry but not as much as the tundra is. The taiga gets between 25-75 cm of rain per year. The taiga has cold snowy winters and warm summers. Also most of the precipitation comes in the summer months. Some other things about the climate of the taiga is that the average temperature is below freezing for six months of the year.

VEGETATION

The coniferious forest has few species of vegetation compared to most of the other biomes. In some parts of Canada only eight species of trees exist. Trees and plants aren't the only part of the vegetation though.

Other things that make up parts of the area of the vegetation are bogs and marshes. These are in the coniferious forest because of the wet rainy weather year round. Forest fires are another major part of the vegetation cycle. Forest fires clear old vegetation pretty much every month allowing the new vegetation sunlight so that the new vegetation may grow.

Snow is the final essential part of vegetation. The weight of the snow breaks off old tree branches. The weight also bends the trees to an abnormal form.

The main trees that inhabit the coniferous forest are the pines and other trees like it. The reason that these trees are there is they have needles that stay on them all year round. Almost all of the trees in the taiga also produce cones, thus they have the species name conifer.

Animals

There are many different kings of animals in the taiga biome. Among them are the wolves, deer, bears, lynx, cougars, moose, and cyotes. Many of these animals are often hunted for sport and also for food. Also, some are poached, which is illegal.

The adaptations of a wolf is that it is fast, has sharp fangs, and sharp claws, which they use to catch their prey. Wolves are carnivores, so they eat mainly other animals bigger and smaller than themselves. Deer are fast and have antlers, which they use to fight off their predators. Deer are herbivores, so they eat mainly plants of all kinds. Bears have the advantage of their size, teeth, claws, and the ability to run fast. Bears are omnivores, so they will eat just about anything. Lynx are basically oversized, wild, house cats. They have speed, sharp fangs, small, sharp claws. Lynx are carnivores, so they eat mainly little animals smaller than themselves. Cougars are kind of giant cats. They have speed, sharp fangs, sharp claws, and big enough to challenge even the largest of game. Cougars are omnivores, so they will eat just about anything, but they choose to eat other animals.

Ant Ants are social insects.

Arctic Fox This small, white fox lives farther north than any other land animal.

Arctic Hare This white hare lives in the Arctic and has huge hindfeet.

Arctic Wolf Arctic wolves are carnivores that live in Northern Canada.

Badger The badger is a nocturnal mammal with a black-and-white striped face.

Bald Eagle The bald eagle is a large bird of prey. It is the symbol of the USA.

Beaver The beaver is a large rodent that builds dams and dens.

Black Bear A large, black to brown bear.

Brown Bear The Brown Bear is a large bear with a muscular hump on its shoulders.

Canada Goose The Canada goose is a large North American bird that honks.

Caribou Caribou are herbivores that live in Arctic regions.

Dall Sheep A wild, white sheep from the Arctic and sub-Arctic of North America.

Deer The deer is a shy, fast-moving plant-eater.

Earthworm An earthworm is a little animal with a long, soft body and no legs.

Ermine Also known as stoat or short-tailed weasel, this tiny, ferocious mammal lives in cold areas.

Fox The fox is a meat-eating mammal with a long, bushy tail. The red fox lives in the taiga.

Gray Wolf Gray wolves are carnivores that live in packs and howl.

Great Horned Owl A large bird of prey from North and South America.

Husky A hard-working, fast-running sled dog that was originally from Siberia.

Lemming Lemmings are small, short-tailed rodents from North America and northern Eurasia.

Lynx A powerful wild cat from Eurasia and North America.

Malamute The Alaskan malamute is a powerful sled dog from Alaska.

Moose The moose is the largest member of the deer family.

Mosquito Mosquitos are flying insects that live in moist areas and can often carry diseases.

Musk Ox Musk oxen are large, hairy mammals that live in the far north.

Muskrat Muskrats are rodents that often build dome-shaped houses.

Red-Tailed Hawk The Red-Tailed Hawk is a bird of prey, a raptor from North America.

Reindeer Reindeer are herbivores that live in Arctic regions.

Scorpion A venomous arachnid with a large stinger on its tail.

Short-tailed Weasel Also known as stoat or ermine, this tiny, ferocious mammal lives in cold areas.

Snow Goose Snow Geese are migratory birds from North America.

Snowy Owl A white owl that lives in the North American tundra.

Squirrel Squirrels are rodents. They live in a variety of biomes, including the taiga.

Weasel A carnivorous mammal that has a long, slender body and short legs.

White-Tailed Deer The white-tailed deer is a shy, fast-moving plant-eater.

Wolf Wolves are carnivores that live in packs and howl.

Wolverine The Wolverine is a large, ferocious weasel that lives in cold areas.

Woodland Caribou A rare caribou from Canada that eats lichens.