Biomes and Ecosystems

Biomes are large regions of the world with similar plants, animals, and other living things that are adapted to the climate and other conditions. Explore the links below to learn more about different biomes.

Earth's biomes are areas with similar climate, geography, and other conditions as well as similar plants, animals, and other living things.

A biome is made of many similar ecosystems. An ecosystem is often much smaller than a biome, although the size varies.

Ecosystems are the interactions between the living things and the nonliving things in a place. In an ecosystem, the plants, animals, and other organisms rely on each other and on the physical environment – the soil, water, and nutrients, for example.

Even though they are living in the same place, each species in an ecosystem has its own role to play.  This role is called a niche. The niche for one species might be to climb trees and eat their fruit, while the niche for another species might be to hunt for small rodents.  For a tree, a niche might be to grow tall and make food with the Sun’s energy through the process of photosynthesis. If the niche of two species is very similar, they might compete for food or other resources.

Sometimes ecosystems get out of balance. If, for example, it rains a lot and a type of bird that thrives with extra water increases in numbers, other species in the ecosystem might be crowded out. The birds might take food or space or other resources from other species.  They might eat all the food. Sometimes an ecosystem naturally gets back into balance. Other times an ecosystem will become more and more out of balance.  Today, human actions are having an impact on ecosystems all over the world. Making buildings and roads, fishing and farming all have an impact on ecosystems.  Pollution on land, air pollution, and water pollution is sending many ecosystems out of balance too.

Acid Rain

Acid rain is a general term used to describe different kinds of acidic air pollution. Although some acidic air pollutants return directly back to Earth, a lot of it returns in rain, snow, sleet, hail, mist or fog, which is why we call it acid rain.

When power plants, factories, houses and cars release pollution into the atmosphere, it contains chemicals known as sulfur dioxide and nitrogen oxides. Sometimes, these chemicals fall directly back to the ground. This is called dry deposition. The rest of the time, they mix with water (moisture) in the air to form acids. Once these acids have formed, they can be transported long distances by the wind before being deposited in rain, snow or hail. This is what we commonly call acid rain.

During the 1970s, scientists in Sweden and Norway began noticing that acid rain was damaging their trees and fresh water. Much of the acid rain was caused by pollution that was transported through the air from other countries, primarily the United Kingdom. After that, acid rain was understood to be an international problem.

Acid rain can have harmful impacts on the ecosystems in the environment. It acidifies the soil and water where it falls, damaging or killing plants and animals. Surface water acidification can lead to a decline in, and loss of, fish populations and other aquatic species including frogs, snails and crayfish. Acid rain affects trees, usually by weakening them through damage to their leaves. Certain types of building stone, such as limestone and marble, can be slowly dissolved in acid rain.

The Effects of Air Pollution: Acid Rain

Acid rain describes sulfuric and nitric acids deposited from the atmosphere. Often associated with precipitation, the term also applies to dry acidic materials. These acids commonly result from sulfur dioxide and nitrogen oxides reacting with moisture and other substances in the atmosphere. Although there are natural sources for these chemicals, much attention has been given to man-made sources, such as coal power plants. Acid rain is problematic due to acidification of soil, rivers, and lakes beyond the tolerance range of plants and animals. Acid rain can also erode man-made structures. 

Acidifying Waters

Water resists rapid changes to pH --- a measure of the acidity of a substance with lower numbers indicating stronger acidity. However, even this resistance is overcome by prolonged and persistent exposure to acid rain. Ecosystems within lakes and rivers may be vulnerable to acidification of the water in surprising ways. For example, mayflies die off at a pH of 5.5, while trout and perch can survive in much more acidic water. However, with the decline of mayflies and other insects, trout may have insufficient food to support their population. At pH 5 many fish eggs fail to hatch and juvenile fish tend to be more susceptible to acidity, impairing the fish population's continued health. 

Forests

Direct contact with acid rain can weaken trees and destroy their leaves. This is especially true in high altitude forests where the trees are frequently immersed in an acid cloud. Acid rain can also harm trees in a more subtle fashion by reducing nutrient levels and increasing the level of toxic substances in the soil. The buffering capacity of soil varies greatly between different soil types, resulting in greater damage to forests in some areas than others, even though the acid rain exposure may be similar. 

Cars

Many people take great pride in maintaining the appearance of their vehicle, but acid rain can literally erode the vehicle's protective coating. To counter these effects, automobile manufacturer's have begun coating new vehicles with acid-resistant paints. 

Buildings

Limestone and marble construction materials are especially damaged by acid rain. This is due to the calcite mineral content in these materials that is easily dissolved away. This damage is readily seen in older stone buildings and monuments where carvings placed in the stone have eroded. Not all stone is susceptible. Granite and sandstone have a chemical composition that does not react with acid rain, though some types of sandstone contain carbonate, which will react.

Human Health

Physical contact with acid rain, either as droplets falling from the sky or from swimming in an acidic lake, has little direct impact on the health of humans. However, the pollutants responsible for the formation of acid rain are associated with an increase in respiratory disease and other illnesses. These pollutants may even infiltrate indoor spaces causing problems ranging from asthma to premature death. Laws such as the Clean Air Act strive to reduce the amount of pollution in the air. The U.S. Environmental Protection Agency reports that between 1980 and 2009, the national average for sulfur dioxide in the air decreased by 76 percent, and nitrogen dioxide decreased by 48 percent.

Why is Acid Rain Harmful?

Acid Rain Can Cause Health Problems in People

Air pollution like sulfur dioxide and nitrogen oxides can cause respiratory diseases, or can make these diseases worse. Respiratory diseases like asthma or chronic bronchitis make it hard for people to breathe. The pollution that causes acid rain can also create tiny particles. When these particles get into people’s lungs, they can cause health problems, or can make existing health problems worse. Also, nitrogen oxides cause ground-level ozone. This ground-level ozone causes respiratory problems, like pneumonia and bronchitis, and can even cause permanent lung damage. The health effects that people have to worry about are not caused by the acid rain, but are caused when people breathe in these tiny particles or ozone. Swimming in an acidic lake or walking in an acidic puddle is no more harmful to people than swimming or walking in clean water.

Acid Rain Harms Forests

Acid rain can be extremely harmful to forests. Acid rain that seeps into the ground can dissolve nutrients, such as magnesium and calcium, that trees need to be healthy. Acid rain also causes aluminum to be released into the soil, which makes it difficult for trees to take up water. Trees that are located in mountainous regions at higher elevations, such as spruce or fir trees, are at greater risk because they are exposed to acidic clouds and fog, which contain greater amounts of acid than rain or snow. The acidic clouds and fog strip important nutrients from their leaves and needles. This loss of nutrients makes it easier for infections, insects, and cold weather to damage trees and forests.

Acid Rain Damages Lakes and Streams

Without pollution or acid rain, most lakes and streams would have a pH level near 6.5. Acid rain, however, has caused many lakes and streams in the northeast United States and certain other places to have much lower pH levels. In addition, aluminum that is released into the soil eventually ends up in lakes and streams. Unfortunately, this increase in acidity and aluminum levels can be deadly to aquatic wildlife, including phytoplankton, mayflies, rainbow trout, small mouth bass, frogs, spotted salamanders, crayfish, and other creatures that are part of the food web. 

This problem can become much worse during heavy downpours of rain or when the snow begins to melt in the spring. These types of events are known as episodic acidification.

Acid Rain Damages Buildings and Objects

Acid rain can also have a damaging effect on many objects, including buildings, statues, monuments, and cars. The chemicals found in acid rain can cause paint to peel and stone statues to begin to appear old and worn down, which reduces their value and beauty.

History on the effect of the Acid Rain

1. In Sweden, over 18,000 lakes have become so acidic due to acid rain that all the fish have died. Some success has been achieved by dumping vast quantities of rocks like limestone into the lakes, because these rocks destroy the acid, but for most of the lakes it will be many years after we stop producing acid rain before the water returns to normal.
2. In what used to be called West Germany the government discovered that more than 70,000 square kilometers of forests had died because of acid rain. In the old East Germany, the damage was even worse due to factories creating much more pollution. It is not always the country that produces the pollution that suffers from the acid rain. For example, industrial pollution from the United Kingdom is blown across the sea and falls as acid rain over Norway and Sweden.
3. Acid rain is not just a European problem; it occurs around the world. In North America thousands of lakes along the eastern coast are so acidic that fish cannot survive any longer, and at least 10 percent of the lakes in the Adirondack region have a pH value of five or less. ( A pH of 7 is neutral, pure water. Lower values are acidic, higher values are alkaline. )
4. In the Appalachian Mountains a World Resources Institute report in the late 1980's stated that the acidity of clouds on the mountains was 100 times greater than it would be if it wasn't polluted. In consequence, trees were dying.

     With all this damage, why do we still produce so much pollution and continue tolerating acid rain? Well, it's basically because governments don't consider it important enough. They believe that other things are more important, such as making sure that industry continues to grow and that the prices of goods are kept as low as possible. Making factories cleaner costs money, and unless everyone does it, the clean factories wont be able to make goods as cheaply as the dirty ones,and will make less money.

Developed countries also make huge profits from the exploitation and sale of the fuels that produce the pollution. The technology exists to run all our cars and lorries on other 'cleaner' fuels, but the oil companies wouldn't want that to happen, and neither would the governments that tax the oil companies! 

What is the relationship between Sulphuric Acid and Acid Rain?

 Acid rain takes place as a direct result of the natural cleaning process of the atmosphere. The tiny droplets of water which form clouds confine within them the suspended solid particles and gases in the atmosphere. Among these gases are sulfur oxides and nitrogen oxides which are them chemically converted into sulfuric and nitric acids. Other than this some sulfuric acid may also be formed directly in the droplets of water from the reaction of sulfur dioxide and hydrogen peroxide.

Some of the effects caused by acid rain and the sulfuric acid present in it are:

• The acid may react with buildings and marble made structure by reacting with the Calcium carbonate and this reaction forms Calcium bicarbonate which is soluble and hence causes the structures, buildings etc to deteriorate.  

• Acid rain can filter aluminum from the soil and make it get mixed with ground water, lakes or rivers. This can poison fish and many plant roots. 

•Acid rain disrupts the process of photosynthesis, hence causing damage to plant life 

•If the acid rain is highly concentrated, it slows down the production of chlorophyll and at high concentration it may kill plants.

The relationship between Acid Rain and Corrosion?

Acid rain is the mixing of different harmful gases such as sulfur and nitrogen and when they mix with rain they form acid rain.The main causes of these harmful gases are cars,various factories and powerplants.Due to the harmful emissions acid rain is formed.As population increases so do all these harmful emissions.One of the main contributors that lead to acid rain are coal powerplants.As to why the corrosion,well when sulfuric acid and the calcium compounds in various buildings and monuments mix together they lead to the creation of gypsum which eventually flakes off leading to corrosion.Acid rain also has many diverse effects on the environment.

When  petroleum burns, it  produces oxides of nitrogen and  that rise up into the atmosphere.  There they get mixed by wind and undergo chemical reactions with sunlight and moisture. After some days,  the sulfuric acid and nitric acid particles fall as acid rain. So not only sulphuric acid is involved but nitric acid also plays an important role. Due to acidic features acid rain eats into the stone surfaces at once. These particles settle into crevices and molding, and
the damage they create comes later. When rain comes in contact with the deposits  corrosion is there.

What can the Acid Rain do to the soil and water?

Soils

Soil biology and chemistry can be seriously damaged by acid rain. Some microbes are unable to tolerate changes to low pHs and are killed.The enzymes of these microbes are denatured (changed in shape so they no longer function) by the acid. The hydronium ions of acid rain also mobilize toxins, e.g. aluminium, and leach away essential nutrients and minerals.

2H⁺ (aq)+ Mg²⁺ (clay)⇌ 2H⁺ (clay)+ Mg²⁺(aq)

Soil chemistry can be dramatically changed when base cations, such as calcium and magnesium, are leached by acid rain thereby affecting sensitive species, such as sugar maple (Acer saccharum).

Acid rain has many adverse effects on plant life. It may be direct or indirect. It stunts the growth of plants. The worst adverse effect is that acid rain seriously damages the soil biology.Only a few microbes consume acids. The enzymes of there microbes change shape by the acid. To retain the pH of the soil lime stone can be used.

Surface waters and aquatic animals

Both the lower pH and higher aluminum concentrations in surface water that occur as a result of acid rain can cause damage to fish and other aquatic animals. At pHs lower than 5 most fish eggs will not hatch and lower pHs can kill adult fish. As lakes and rivers become more acidic biodiversity is reduced. Acid rain has eliminated insect life and some fish species, including the brook trout in some lakes, streams, and creeks in geographically sensitive areas, such as the Adirondack Mountains of the United States.However, the extent to which acid rain contributes directly or indirectly via runoff from the catchment to lake and river acidity (i.e., depending on characteristics of the surrounding watershed) is variable. 

WHAT IS THE ACID RAIN?

Acid rain was first described by an English man in 1872. He was a chemist and was first to note that rain that fell had a high percentage of acidity which effected man, animal and plants. It is now the most controversial form of air pollution in the developed world.

Acid rain is a form of pollution which became a serious environmental problem in the large urban and industrial areas of North America, Europe and Asia. Any precipitation that contains a heavy concentration of Sulphuric Acid (H2SO4) and Nitric Acid (HNO3) is generally called acid rain. Automobile industries, electrical power plants and some other industrial operations that burn fossil fuels and emit the gases like sulphur dioxide (SO2) and nitrogen oxide (NO2) into the environment. In the air the gases meet with water vapour available in clouds to reform Sulphuric Acid and Nitric Acid. This acid rain or highly acidic precipitation from those clouds may contaminate lakes and streams, thereby, harming the fishes and other aquatic species. It also causes a great harm to vegetation including agricultural crops and plants and trees. Now-a-days acid rain or acid precipitation has become a threatening problem for the environment and humankind.

Acid rain is rain that has been made acidic by certain pollutants in the air. Acid rain is a type of acid deposition, which can appear in many forms. Wet deposition is rain, sleet, snow, or fog that has become more acidic than normal. Dry deposition is another form of acid deposition, and this is when gases and dust particles become acidic. Both wet and dry deposition can be carried by the wind, sometimes for very long distances. Acid deposition in wet and dry forms falls on buildings, cars, and trees and can make lakes acidic. Acid deposition in dry form can be inhaled by people and can cause health problems in some people. What is acidity? Acidic and basic are two ways that we describe chemical compounds. Acidity is measured using a pH scale. A pH scale runs from zero (the most acidic) to 14 (the most basic or alkaline). A substance that is neither basic or acidic is called "neutral", and this has a pH of 7. Sources of Acid RainAcid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain. Sulfur dioxide and nitrogen oxides dissolve very easily in water and can be carried very far by the wind. As a result, the two compounds can travel long distances where they become part of the rain, sleet, snow, and fog that we experience on certain days. Human activities are the main cause of acid rain. Over the past few decades, humans have released so many different chemicals into the air that they have changed the mix of gases in the atmosphere. Power plants release the majority of sulfur dioxide and much of the nitrogen oxides when they burn fossil fuels, such as coal, to produce electricity. In addition, the exhaust from cars, trucks, and buses releases nitrogen oxides and sulfur dioxide into the air. These pollutants cause acid rain. Acid Rain is Caused by Reactions in the Environment Nature depends on balance, and although some rain is naturally acidic, with a pH level of around 5.0, human activities have made it worse. Normal precipitation—such as rain, sleet, or snow—reacts with alkaline chemicals, or non-acidic materials, that can be found in air, soils, bedrock, lakes, and streams. These reactions usually neutralize natural acids. However, if precipitation becomes too acidic, these materials may not be able to neutralize all of the acids. Over time, these neutralizing materials can be washed away by acid rain. Damage to crops, trees, lakes, rivers, and animals can result. Acid Rain Can Cause Health Problems in People Air pollution like sulfur dioxide and nitrogen oxides can cause respiratory diseases, or can make these diseases worse. Respiratory diseases like asthma or chronic bronchitis make it hard for people to breathe. The pollution that causes acid rain can also create tiny particles. When these particles get into people’s lungs, they can cause health problems, or can make existing health problems worse. Also, nitrogen oxides cause ground-level ozone. This ground-level ozone causes respiratory problems, like pneumonia and bronchitis, and can even cause permanent lung damage. The health effects that people have to worry about are not caused by the acid rain, but are caused when people breathe in these tiny particles or ozone. Swimming in an acidic lake or walking in an acidic puddle is no more harmful to people than swimming or walking in clean water. Acid Rain Harms Forests Acid rain can be extremely harmful to forests. Acid rain that seeps into the ground can dissolve nutrients, such as magnesium and calcium, that trees need to be healthy. Acid rain also causes aluminum to be released into the soil, which makes it difficult for trees to take up water. Trees that are located in mountainous regions at higher elevations, such as spruce or fir trees, are at greater risk because they are exposed to acidic clouds and fog, which contain greater amounts of acid than rain or snow. The acidic clouds and fog strip important nutrients from their leaves and needles. This loss of nutrients makes it easier for infections, insects, and cold weather to damage trees and forests. Acid Rain Damages Lakes and StreamsWithout pollution or acid rain, most lakes and streams would have a pH level near 6.5. Acid rain, however, has caused many lakes and streams in the northeast United States and certain other places to have much lower pH levels. In addition, aluminum that is released into the soil eventually ends up in lakes and streams. Unfortunately, this increase in acidity and aluminum levels can be deadly to aquatic wildlife, including phytoplankton, mayflies, rainbow trout, small mouth bass, frogs, spotted salamanders, crayfish, and other creatures that are part of the food web. This problem can become much worse during heavy downpours of rain or when the snow begins to melt in the spring. These types of events are known as episodic acidification. Acid Rain Damages Buildings and Objects Acid rain can also have a damaging effect on many objects, including buildings, statues, monuments, and cars. The chemicals found in acid rain can cause paint to peel and stone statues to begin to appear old and worn down, which reduces their value and beauty. Now that you know why acid rain is a problem, you might be wondering what’s being done to control it. Regulations and new technologies are helping reduce acid rain. EPA’s Acid Rain Program Power plants generate the electricity we use every day. Unfortunately, power plants also produce large amounts of nitrogen oxides and sulfur dioxide—the pollutants that cause acid rain—when they burn fossil fuels, especially coal, to produce energy. Congress passed a law called the Clean Air Act Amendments of 1990, and this law said that EPA should start the Acid Rain Program. The program limits, or puts a cap on, the amount of sulfur dioxide that power plants can release into the air and issues allowances to the power plants to cover their sulfur dioxide emissions. It also reduces the amount of nitrogen oxides that power plants can release. Reducing Pollution Scientists have found different ways to reduce the amount of sulfur dioxide released from coal-burning power plants. One option is to use coal that contains less sulfur. Another option is to “wash” the coal to remove some of the sulfur. The power plant can also install equipment called scrubbers, which remove the sulfur dioxide from gases leaving the smokestack. Because nitrogen oxides are created in the process of burning coal and other fossil fuels, some power plants are changing the way they burn coal. Other Sources of Energy A great way to reduce acid rain is to produce energy without using fossil fuels. Instead, people can use renewable energy sources, such as solar and wind power. Renewable energy sources help reduce acid rain because they produce much less pollution. These energy sources can be used to power machinery and produce electricity. Cleaner Cars Cars and trucks are major sources of the pollutants that cause acid rain. While one car alone does not produce much pollution, all the cars on the road added together create lots of pollution. Therefore, car manufacturers are required to reduce the amount of nitrogen oxides and other pollutants released by new cars. One type of technology used in cars is called a catalytic converter. This piece of equipment has been used for over 20 years to reduce the amount of nitrogen oxides released by cars. Some new cars can also use cleaner fuels, such as natural gas. Cars that produce less pollution and are better for the environment are often labeled as low emissions vehicles. Government agencies and scientists are not the only ones that can take action to stop acid rain. You can become part of the solution, too! Understand the Problem The first step you can take to help control acid rain is to understand the problem and its solutions. Now that you have learned about this environmental issue, you can tell others about it. By telling your classmates, parents, and teachers about what you learned on this site, you can help educate them about the problem of acid rain. You CAN make a difference! Conserve Energy Since energy production creates large amounts of the pollutants that cause acid rain, one important step you can take is to conserve energy. You can do this in a number of ways: Turn off lights, computers, televisions, video games, and other electrical equipment when you're not using them. Encourage your parents to buy equipment that uses less electricity, including lights, air conditioners, heaters, refrigerators, and washing machines. Such equipment might have the Energy Star label. Try to limit the use of air conditioning. Ask your parents to adjust the thermostat (the device used to control the temperature in your home) when you go on vacation. Minimize the Miles Driving cars and trucks also produces large amounts of nitrogen oxides, which cause acid rain. To help cut down on air pollution from cars, you can carpool or take public transportation, such as buses and trains. Also, ask your parents to walk or bike with you to a nearby store or friend’s house instead of driving.