ecology the study of the interrelationships of plants and animals with each other and with their...
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EcologyEcology
The study of the interrelationships The study of the interrelationships of plants and animals with each of plants and animals with each other and with their environmentother and with their environment
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ECOLOGYECOLOGY
• An ECOSYSTEM is how the community interacts with its physical environment.
• A COMMUNITY is all the populations of plants and animals in a particular area, such as a forest or a pond.
• A POPULATION is all of the members of the same species that inhabit a particular area.
• The BIOSPHERE is a community and its physical environment, including all of the land, water, and air on the planet where organisms live.
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Population or Community?Population or Community?
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SuccessionSuccession
• Succession on land begins on bare rock. With time, the rock is subjected to weathering by wind and rain, and then mosses start growing on it, and as they die off, they create mulch, which turns into soil.
• Then grasses come along and grow in the soil, then comes the larger plants.
• Later, trees take root. • Eventually the area reaches its climax.
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SuccessionSuccession
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EcosystemEcosystem
• An ecosystem has both nonliving and living components.
• The nonliving components include sunlight, inorganic nutrients, and weather conditions.
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Sand, MagnifiedSand, Magnified
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HabitatHabitat
• The habitat of an organism is where it can be found, such as under a log or at the bottom of the pond.
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NicheNiche• The niche of an organism is its profession or role in the community.
• A description of the niche of a tree is that they take in sunlight, carbon dioxide, and water from the environment, and have many interactions with other organisms, such as woodpeckers.
• Woodpeckers feed on grubs from a tree, which also provides a habitat for their chicks.
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OrganizationOrganization
• Producers are organisms with the capability of making their own food for themselves. On land, the main producers are green plants, and in freshwater ecosystems, the main producers are algae. Therefore, all animal life depends, directly or indirectly, on green plants, algae, or some producer for food, energy, and oxygen. Producers supply oxygen to all the others.
• Consumers are organisms that use pre-formed food. – Herbivores feed directly on plants– Carnivores feed only on animals– Omnivores feet on both plants and animals
• Decomposers feed on dead material of plants and animals
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Which group are the producers? Consumers? Decomposers?
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Energy Flow and Chemical Cycling
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Energy Flow and Chemical CyclingEnergy Flow and Chemical Cycling
• Ecosystems are characterized by two fundamental phenomena:
• Energy flow begins when producers (plants) absorb solar energy. Energy flow occurs because all the energy content of organic food is eventually converted to heat, which dissipates in the environment.
• Chemical cycling begins when producers take in nutrients from the soil. Eventually, these nutrients are returned to the soil.
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Energy FlowEnergy Flow
• Since a plant uses about 55% of its fuel to stay alive, only about 45% of the plant’s energy is available to an herbivore that eats the plant.
• When a carnivore eats the herbivore, only a portion of that energy goes into the carnivore.
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Energy FlowEnergy Flow
• A certain amount of the food eaten by a herbivore is never digested and is eliminated as feces.
• The energy from the food that was absorbed is used for respiration, and thereafter becomes heat.
• Only the excess food can increase body weight, and it is this weight that becomes available to carnivores.
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Energy FlowEnergy Flow
• The elimination of feces and the death of a body is the food made available to decomposers.
• All the solar energy that enters an ecosystem eventually becomes heat.
• Ecosystems are dependent on a continual supply of solar energy
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Laws of ThermodynamicsLaws of Thermodynamics
• Energy cannot be created or destroyed; it can only be transformed.
• When energy is transformed from one form to another, there is always a loss of some usable energy as heat.
• Eventually, all the energy that entered the system is dissipated. Since energy cannot be created, all ecosystems require constant energy input (usually from the sun).
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Food WebFood Web
• Now let’s take an actual example—a forest in New Hampshire. In this forest, the producers include sugar maple trees.
• A food web shows the complicated feeding relationships that exist in natural ecosystems, and how organisms acquire their food.
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Food WebFood Web
• Caterpillars, mice, rabbits, and deer feed on the leaves. • Birds and mice feed on fruits and nuts, plus they eat the
caterpillars.• Other predators eat the birds and mice. • The bacteria and fungi that live off the decayed material
are also food for earthworms and beetles. • These worms are then eaten by lizards, which are in
turn, eaten by birds. • It’s all connected in a web, called a food web.
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Food Web
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Trophic LevelsTrophic Levels
• A food chain is a diagram that links organisms that feed upon one another.
• For example: leaves—caterpillars—sparrows—hawks.
• Another example: algae → insect larvae → fish → humans.
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Trophic levels
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Trophic LevelsTrophic Levels
• A trophic level is all the organisms that feed at a particular link in a food chain.
• In the forest, trees, plants, and grasses are the first trophic level, the caterpillars as well as the mice and rabbits are the second trophic level, the sparrows as well as the robins and finches are the third trophic level, and so forth. Therefore, in the following food chain, what organism is at the second trophic level?
• grass → rabbits → snakes → hawks.
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What animals are at the
fourth trophic level?
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In this In this food web, food web,
what what trophic trophic
level are level are hawks?hawks?Herring?Herring?
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Ecological PyramidsEcological Pyramids
• These trophic levels can be drawn in the form of a pyramid, just like a nutrition food pyramid.
• For example, in the following food chain, hawks are at the top of the ecological pyramid:
• Weeds – insects – mice –hawks.
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Ecological PyramidsEcological Pyramids
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Ecological PyramidsEcological Pyramids
• The problem is that some organisms fit into more than one trophic level, such as mice.
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Food Chain
vs. Trophic
level
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The Water CycleThe Water Cycle
• EVAPORATION is when water changes from a liquid into a gas and is removed from plant leaves on a warm day.
• PRECIPITATION is when water falls from the sky in the form of rain, snow, hail or sleet.
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Water Cycle
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The Water CycleThe Water Cycle
• Fresh water is distilled from salt water as the sun’s rays cause fresh water to evaporate from seawater, and the salts are left behind.
• Vaporized fresh water rises into the atmosphere, cools, and falls as rain over the oceans and the land.
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The Water CycleThe Water Cycle
• Water evaporates from land, but since land lies above sea level, gravity eventually returns all fresh water to the sea.
• In the meantime, water is contained within standing waters (lakes and ponds), flowing water (streams and rivers), and groundwater.
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The Water CycleThe Water Cycle
• When rain falls, some of the water sinks into the ground and saturates the earth to a certain level, called the water table.
• About ¾ of the planet is covered in water but only about 1% is drinkable.
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The Phosphorus CycleThe Phosphorus Cycle
• On land, the weathering of rocks makes phosphate, which goes into the soil and is taken up by plants.
• Some phosphate runs into the oceans for algae to use.
• Phosphorus does not enter the atmosphere; therefore, the phosphorus cycle is called a sedimentary cycle.
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The Phosphorus CycleThe Phosphorus Cycle
• Plants use phosphate to make ATP and DNA.
• Animals that eat plants incorporate some of the phosphate into teeth, bones, and shells that take many years to decompose, but when they do, it becomes available to plants again.
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The Phosphorus CyclePhosphate Cycle
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Humans Alter Transfer RatesHumans Alter Transfer Rates
• Humans impact the phosphorus cycle by mining phosphate ores, making fertilizers, and using laundry detergent. Animal wastes, detergents, and fertilizers add excess phosphate to nearby waters.
• When there is too much phosphate in the water, too much algae can grow. Then, when algae grow in excess, a condition called an algal bloom occurs.
• Any large algal bloom has the potential to result in fish and shellfish kills by depleting the water of oxygen. Furthermore, as these large blooms die and sink to the bottom, they commonly release chemicals that can produce a foul odor and musty taste.
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FISH DEATHS FROM ALGAE BLOOMS 40
The Nitrogen CycleThe Nitrogen Cycle
• Nitrogen is an abundant element in the atmosphere as a gas (78% of the atmosphere). However, nitrogen deficiency in plants is a problem. Why?
• Plants cannot make use of nitrogen gas. They depend on various types of bacteria that live in nodules on their roots which are able to take the nitrogen gas from the atmosphere and turn it into the type of nitrogen that the plant can use (nitrates, ammonia, and urea) to make amino acids and DNA.
• Humans cause an excess of nitrogen by using it in fertilizers which run off into water bodies.
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Nitrate Cycle
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The Carbon CycleThe Carbon Cycle
• Animals that inhale oxygen will exhale carbon dioxide.
• Plants, on the other hand, will take in carbon dioxide and give off oxygen.
• Animals are dependent on plants, not only to produce food and energy, but also for a supply of oxygen.
• However, since plants can make their own food and get their own carbon dioxide, they can function independently of the animal world.
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The Carbon CycleCarbon Cycle
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The Carbon CycleThe Carbon Cycle
• In the carbon cycle, plants take up carbon dioxide from the air, and convert it into food by photosynthesis.
• The plant is then eaten by animals, and when the animal exhales, some of that carbon dioxide is returned to the atmosphere.
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Reservoirs Hold CarbonReservoirs Hold Carbon
• Living and dead organisms are one of the reservoirs for the carbon cycle.
• The world’s trees contain 800 billion tons of carbon, and dead animals and plants in the soil contain an additional 2,000 billion tons of carbon.
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Reservoirs Hold CarbonReservoirs Hold Carbon
• Some of these remains are subjected to physical processes that transform them into coal, oil, and natural gas.
• We call these materials the fossil fuels.
• Most of the fossil fuels were formed about 300 million years ago, when an exceptionally large amount of organic matter was buried before decomposing.
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GREENHOUSE EFFECTGREENHOUSE EFFECT
• This is when gases trap heat in the lower atmosphere.
• These gases (such as CO2) are mainly a result of humans burning fossil fuels and forests.
• Because of burning fossil fuels and wood, an excess of carbon is released into the air.
• The typical method of clearing a rain forest is to burn it down, thus creating even more carbon dioxide in the atmosphere, and requiring more plants to absorb it for us.
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GREENHOUSE EFFECTGREENHOUSE EFFECT• So, when we burn down forests, we are causing
two kinds of damage: we increase the carbon dioxide in the air, while decreasing the main reservoir that takes up excess carbon dioxide.
• In addition, this excess carbon dioxide (and other gases) in the atmosphere cause more global warming.
• These gases allow the sun’s rays to pass through, but they absorb and reradiate heat back to the earth, the phenomenon called the greenhouse effect.
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GREENHOUSE EFFECTGREENHOUSE EFFECT
• One consequence of global warming impacting the climate is that there will be more rain along the coasts and dryer conditions inland.
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Rain along the coasts; dry inland
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What can you do?What can you do?
• If everyone in America replaced one light bulb with an Energy Star compact Fluorescent light bulb, it would reduce greenhouse gasses equivalent to getting 2 million cars off the road.
• If one in every ten houses in America used Energy Star appliances, it would have a benefit equivalent to planting 1.7 million acres of new trees.
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Walmart Goes GreenWalmart Goes Green
• http://spiritualityhealth.com/articles/ten-lessons-wal-mart-going-green
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Ten Lessons from Wal-Mart Going Green
• apply to anyone, five aimed specifically at businesses.• Carbon = energy = money. Carbon comes from using energy. Energy costs
money, which means cutting carbon saves the planet and saves you money. So do what Wal-Mart does: use energy-efficient lighting. Plant shade trees near your house or business. Insulate your attic and, if you have a flat roof, paint it white. Clean the filters in your refrigerator, heater, and AC. Small businesses that followed Wal-Mart’s advice have had their energy bills drop 20 to 60 percent by taking just those steps.
• Waste = Money. If Wal-Mart stores in California can cut their waste by 81 percent, anything’s possible. So cut out the disposable water bottles, and use the tap and a glass. Make your own coffee instead of using all those disposable latte cups. Consider bulk foods (they’re cheaper) and products with a longer shelf life, such as organic milk, because a shocking third of our food ends up spoiled and in the trash. Compost. Recycle. Donate. Wal-Mart does all of this — and makes a cool $100 million a year from stuff it used to pay to have hauled to the landfill.
•
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Ten Lessons from Wal-Mart Going Green
• Make sustainability about health. Let’s be honest: we all say we want to be greener, but when it comes to voting with our time and our wallets, not so much. So when Wal-Mart wants to sell green, it emphasizes how sustainable choices are often healthy choices: organic baby food and clothes, for instance, are pesticide-free and therefore healthier for babies. And that does influence consumer behavior.
• Start with quick wins. Wal-Mart caught sustainability fever by reducing the packaging on a single toy — and finding it simultaneously saved a forest and $2.5 million. What can a smaller business or household do? Switching out light bulbs will garner visible savings, as will washing in cold water. Or plant a vegetable garden nurtured with your own compost — the single most sustainable thing anyone can do.
• Listen to the kids. Wal-Mart is adopting sustainable business practices for two reasons: The fi rst is because, right now, sustainability boosts profi ts. The second has to do with the customers of tomorrow — our kids. Today’s Wal-Mart shoppers are not particularly motivated to buy green. But their kids are.
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Ten Lessons from Wal-Mart Going Green
• For Businesses: Sustainability starts at the top. no matter the size of the company, CEOs have to make sustainability their priority — and make their direct reports do the same. No one else can.
• Everything is fair game. For a top-down sustainability mandate to succeed, it must “infect” thinking throughout a business. it can’t be the job of a separate sustainability team but rather the consideration of every department and line worker, from buyers to truck drivers to warehouse foremen.
• Race to the top, not the bottom: Keeping the company at the point where emissions, waste, toxins, and sprawl are legal is a race to the bottom. New thinking about the environment perceives it as an opportunity to use sustainability for competitive advantage, a tool to make a business leaner, cleaner, and less wasteful, beyond anything that regulations require — a race to the top.
• Don’t wait for the market, lead it: Wal-Mart decided to get out in front of consumer demand on sustainability and found that it served the bottom line anyway — it pays to be green. But today’s sustainability efforts mean the company will be ready when consumer demand does catch up.
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Global WarmingGlobal Warming
• One concern is that the world’s overall temperature, called the global climate will continue to warm at a rate ten times faster than any time in the past.
• There is more carbon dioxide in the air from the burning of fossil fuels and the burning and clearing of forests to make way for farmland and pasture.
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Global WarmingGlobal Warming
• The oceans are currently absorbing about one half of the carbon dioxide emitted, or else the increase would he much higher than this stated amount.
• In addition, methane gas is being given off by oil wells, rice paddies, and all sorts of organisms including domesti cated cows, and this also contributes to global warming.
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Global WarmingGlobal Warming
• These gases are known as greenhouse gases because just like the panes of a greenhouse they allow the sun’s radiation to pass through but hinder the escape of heat.
• Actually, water is also a greenhouse gas because clouds do the same thing.
• If the earth’s temperature rises due to the greenhouse effect, more water will evaporate, forming more clouds, compounding the problem.
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Global WarmingGlobal Warming
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Predicted ConsequencesPredicted Consequences
• Global warming will bring about climate changes, glaciers would melt, and sea levels will rise, evaporation will increase, and most likely there will be more rain along the coasts and dryer conditions inland.
• There will be more droughts inland, which will reduce crop yields and also cause trees to die off.
• Billions will have to be spent to keep coastal cities, like New York, Boston, and Miami from disappearing into the sea.
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Global WarmingGlobal Warming
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Acid RainAcid Rain
• Pure water has a pH of 7 but the small amount of carbon dioxide in the atmosphere combines with water to produce a weak acid.
• Therefore, we get rain with an acid pH. • In addition, coal and oil that is burned will
release sulfur dioxide into the air.
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Acid RainAcid Rain
• The oil well fires started during the Persian Gulf War released much sulfur dioxide into the atmosphere.
• Automobile exhaust puts nitrogen oxides in the air.
• Both sulfur dioxide and nitrogen oxides are converted to acids when they combine with water vapor in the atmosphere.
• That gives the rain an even more acid pH.
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Acid RainAcid Rain
• When the soil absorbs this rain, it becomes acidic too, and it causes forests to die, and the waters cannot support normal fish populations.
• The acid rain also corrodes marble, metal, and stonework, an effect that is noticeable in cities.
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Ozone layerOzone layer
• Ozone is a naturally occurring substance that is supposed to stay up high in our atmosphere and absorbs the harmful ultraviolet radiation that tries to enter our planet.
• However, we are now getting ozone forming down lower where we breathe.
• The air pollutants from fossil fuels react with one another in the presence of sunlight to produce ozone.
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OzoneOzone
• Breathing ozone affects the respiratory and nervous sys tems, resulting in respiratory distress, headache, and exhaustion.
• These symptoms are particularly apt to appear in young people; therefore, in Los Angeles, where ozone levels are often high, schoolchildren must remain inside the school building.
• Ozone also damages plants.
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Carbon MonoxideCarbon Monoxide
• Carbon monoxide from car exhaust blocks the hemoglobin in our blood from carrying oxygen.
• Breathing large quantities of automobile exhaust can even result in death because of this effect.
• Carbon monoxide is released into the air from the burning of tropical forests.
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Ozone DepletionOzone Depletion
• Normally, warm air near the ground escapes into the atmosphere. However smog keeps cold air at ground level beneath a layer of warm air above.
• This is particularly true of Los Angeles, and that’s why it’s called the “air pollution capital” of the United States.
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Ozone DepletionOzone Depletion• When the ozone in the upper part of our
atmosphere becomes depleted, UV radiation impairs crop and tree growth and also kills plankton (microscopic plant and animal life) that sustain oceanic life.
• Without an adequate ozone shield, food sources and health are threatened.
• UV radiation also causes mutations that can lead to skin cancer, cataracts, and affect our immune system.
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Soil ErosionSoil Erosion
• Wind and rain carry away about 25 bil lion tons of topsoil yearly, worldwide.
• If this rate of loss continues, the earth will lose practically all of its topsoil by the middle of the next century.
• This is compounded by increased use of fertilizers, pesticides, and fossil fuel energy.
• One solution is for farmers to use different cropping methods to control soil erosion.
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DesertificationDesertification
• Desertification the transformation of land to desert conditions because of overgrazing and over-farming.
• It is particularly a problem along the edge of the Sahara Desert in Africa, but occurs in the US as well.
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DesertificationDesertification7474
DeforestationDeforestation
• Removal of forests impacts the amount of carbon dioxide in the atmosphere, the amount of fresh water available, and the retention of soil.
• Yet, a huge number of trees have been turned into paper and wood products.
• The animals that live in these forests have been displaced.
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DeforestationDeforestation7676
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Recovery Recovery of a of a
forest forest after a after a
firefire
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Nitrate Levels After DeforestationNitrate Levels After Deforestation
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DeforestationDeforestation
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DeforestationDeforestation
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Habitat lossHabitat loss• Habitat loss is of most concern in tropical
rain forests and coral reefs. • Tropical rain forests are home to more wildlife
than temperate forests. • For example, temperate forests across the entire
United States contain about 400 tree species compared to 750 types of trees in the rain forests.
• There are about twice as many fish, frogs, and birds in a rain forest.
• A million species of plants and animals are in danger of disappearing within 20 years as a result of deforestation.
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Habitat lossHabitat loss• Many of these life-forms have never been
studied, and yet they may be useful sources of food or medicines.
• Logging occurs because people prefer furniture made from tropical woods.
• In Brazil, the government does not require citizens to own any land they clear in the Amazon forest.
• Once the cleared land is incapable of sustaining crops, the farmers move on to another part of the rain forest.
• In the meantime, cattle ranchers move in and keep the area deforested.
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ExtinctionExtinction
• Hunting causes a lot of problems. Animals are being hunted on land and water for both pleasure and profit.
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Habitat DestructionHabitat Destruction
• Another major cause of extinction is habitat destruction out right or by fragmentation into small pieces that cannot support the same species richness as before.
• By the year 2020, very little undisturbed rain forest will exist outside of National parks and other relatively small protected areas.
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Introduction of New SpeciesIntroduction of New Species
• The accidental or purposeful introduction of new species into an ecosystem can cause the extinction of another species.
• The brown tree snake somehow slipped into Guam from the Pacific islands in the late 1940s.
• Since then, it has wiped out 9 of 11 native bird species, leaving the forests eerily quiet.
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Introduction of SpeciesIntroduction of Species
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PollutionPollution
• Pollution like pesticides has caused a decrease in predatory birds and amphibians.
• The loss of entire species will most likely be detrimental to humans since they depend on them for raw materials, food, medicines, and other things.
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Natural MedicinesNatural Medicines• Great benefits can come from unlikely species.• The Gila monster has deadly saliva, but it is useful at
regulating insulin levels in diabetics. • The vampire bat has substances in its salivary glands
that prevent clotting, and are found to break up clots in stroke victims.
• The scorpion’s venom can seek out and destroy brain tumors.
• The puffer fish has poisonous spines but are effective in easing the pain of heroine withdrawal and cancer.
• The saliva of the leech can reduce the risk of blood clots during surgeries.
• The poisonous frog has deadly skin secretions, but is effective as a pain killer without being addictive.
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Coral ReefsCoral Reefs
• Like a tropical forest, coral reefs are most likely sources of new medicines yet to be discovered.
• If we lose one species, we may be losing an important, life-saving medicine.
• Not only that, a reef serves as a storm barrier that protects the shoreline and provides a safe harbor for ships.
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Coral ReefsCoral Reefs
• Reefs around the globe are being destroyed. • Tons of soil from deforested tracts of land brings
nutrients that stimulate the growth of all kinds of algae.
• This has contributed to population explosion of starfish that are devouring Australia’s Great Barrier Reef.
• Reefs are also being damaged by pollutants that seep into the sea.
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Coral ReefsCoral Reefs
• About 90 % of the coral reefs of the Philippines are dead or deteriorating due to over-fishing.
• The methods are sinister, including the use of dynamite to kill the fish, making it easier to scoop them up, and use of cyanide to stun the fish to capture them alive.
• The seaweed overgrows and kills the coral. • It is estimated that we may lose 60% of all coral
reefs in the next 50 years.
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Coral ReefsCoral Reefs
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Coral ReefsCoral Reefs
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Oil Drilling in the Arctic:Oil Drilling in the Arctic:DiscussionDiscussion
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The Harm Done by Acid Rain: The Harm Done by Acid Rain: DiscussionDiscussion
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Ecology VideosEcology Videos
• How Ecosystems Work 3 mins
• Climax Communities 3 mins• Competition, Predation, and Symbiosis 3 mins
• Exploring Oceans 7 mins
• Water Cycle 3 mins
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