Ecosystems

EcosystemsSection 15 and 16

Essential Questions•How is energy captured and used in ecosystems to counteract entropy?•How are organisms interdependent?

Ecology

• The study organisms and their relationship to their environment

• An ecosystem is made up of a community of organisms and their interactions with their environment

Producers/Autotrophs

• The Sun is the ultimate, original source of energy for most all ecosystems on the planet.

• Producers use energy directly from the sun to produce sugars that organisms use for food.

• Producer are autotrophs because they make their own food (photosynthesis)

Chemosynthesis

• Some organisms live in the absence of light.

• They build sugars by using the energy stored in chemical bonds.

• This process is called chemosynthesis instead of photosynthesis.

Comsumers/Heterotrophs

• Consumers are organisms that get their energy by eating producers or other consumers.

• They are called heterotrophs because they must depend on other organisms for their food.

Consumers/Heterotrophs

• A cow eats grass.

• The cow doesn’t make energy; it gets it from the grass.

• The cow breaks down the simple sugars made by the producers into energy to live.


• The consumer that eats the producer is called the primary consumer.

• The primary consumes are also known as herbivores.


• The consumer that eats OTHER consumers is called the secondary consumer.

• The secondary consumers are also known as carnivores.

Decomposers and Detrivores

• Decomposers are also consumers and heterotrophs.

• The difference is that they break down dead organisms into detritus.


• Detritus is eaten by detrivores which convert the organic material into inorganic material.

• When a wolf dies, bacteria and fungi are decomposers that break down dead tissue.


• Detritivores (or detrivores) are usually small invertebrates like earthworms and nematodes (round worms) that recycle nutrients back into soil that are then taken in by plants – thus completing the cycle.

• Some of the suns original energy is lost in the form of heat energy, the lowest type of energy.


• Note that they do not recycle energy.

• Energy is a one-way pathway from the sun until it is used up.

• Matter is recycled; not energy.

Food Chains and Food Webs

• A simple diagram to show the flow of energy from autotrophs to heterotrophs to decomposers is called a food chain.

• When drawing a food chain, always start with your producer.

• Draw your arrows in the DIRECTION of energy flow.


• Create a food chain using at least 3 organisms found in Mississippi and place it in the box.


• Food chains don’t always fully show the flow of energy in an ecosystem.

• The relationships between organisms are typically much more complex.

• A food web shows overlapping food chains and reflect a more complex, more accurate view of an ecosystem.


• Create a food web using at least 6 organisms found in Mississippi and place it in the box.

Trophic Levels and Energy Pryamids

• Every step in a food chain or web represents a trophic level (feeding level).

• A tropic level indicates how many times energy has been transferred.


• The first trophic level is producers.

• The second trophic level is primary consumers (herbivores).

• The third trophic level is secondary consumers.

• The fourth trophic level is tertiary (3rd) consumers.


• Stored energy is transferred from one level to another when one organism eats another.

• Some energy is used by the organism to grow, reproduce, and do all the life functions.

• Some energy is lost as heat energy and radiate out into the environment.


• These energy transfers are shown in Energy pyramids.

• Only about 10% of the energy at each level is transferred to the next higher level.

• The higher the organism is on the energy pyramid, the less energy is available for that organism.


• Producers get 100% of their energy from the sun, so they make up the base of the pyramid.

• 10% of the energy stored in the plants are transferred to second level.

• 1% of the sun’s original energy, stored in the second level organisms are transferred to the third level.


• These energy transfers create the pyramid.

Food Chains and Food Webs• Complete page 238; 1-10 in the Green Book• If you have PAID for your book, you do NOT

have to write the questions. If you have NOT PAID for your book, write all questions.

• All Green Book Pages should have this heading:– Your name– The Section Number– The Page Number

• YOU WILL BE COUNTED OFF if you don’t have these on the top of the page.

Biomes

• The Biosphere includes all the life of the Earth.

• The biosphere is divided up into Biomes.

• Biomes are characterized by their climate (abiotic factor), geography (abiotic factor), and the types of plants and animals found in the biome (biotic factors).

Biomes

• Abiotic – non-living things – Sunlight, amount of rainfall, rocks, etc.

• Biotic – Living things – Types of living things

• Terrestrial biomes are land biomes.

• Aquatic biomes are water biomes.

• Lets complete the chart together!

Terrestrial Biomes

• Tundra (next to the poles – North Canada)

• Climate – Cold winters, short cool summers. Ground is permanently frozen.

• Dominant Plants – Mosses, small grasses

• Dominant Animals – Small rodents, caribou, some birds – no reptiles.

Terrestrial Biomes

• Coniferous Forest (Northern US)

• Climate – Cold winters, mild summers. Lots of precipitation.

• Dominant Plants – Cone bearing plants

• Dominant Animals – bears, deer, elk, bobcats.

Terrestrial Biomes

• Deciduous Forest (Mississippi!!!)

• Climate – Cool winters, warm summers.

• Dominant Plants – Deciduous plants (this means they lose their leaves in the fall)

• Dominant Animals – Animals you are familiar with in Mississippi – Deer, bears, skunk, turkeys, raccoons.

Terrestrial Biomes

• Grassland (The mid-west)• Climate – Fertile soils, moderate

precipitation, cold winders and hot summers. Fires are common.

• Dominant Plants – grasses, low rain prevents large trees.

• Dominant Animals – prairie dogs, buffalo, large herbivores.

Terrestrial Biomes

• Chaparral – (Pacific coast)

• Climate – hot, dry summers; mild, cool, rainy winters

• Dominant Plants – woody shrubs

• Dominant Animals – insects, lizards, snakes, chipmunks, mice, rabbits, fox, coyotes, mountain lion, owls, birds

Terrestrial Biomes

• Desert (Mexico, North Africa, SW US)

• Climate – Hot days and cold nights

• Dominant Plants – cacti and succulents

• Dominant Animals – bobcats, mountain lions, owls, hawks, antelopes, sheep, rats, lizards, rattlesnakes

Terrestrial Biomes

• Savanna (Africa)• Climate – Warm with seasonal rainfall• Dominant Plants – grasses, small clusters

of trees and shrubs• Dominant Animals – elephants, rhinos,

antelope, zebra, giraffe, insects, ostrich, eagles, lions, leopards.

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Terrestrial Biomes

• Tropical Rainforest (Near equator, South America)

• Climate – year-around high temperatures; high rainfall

• Dominant Plants – broad leaf evergreen trees, ferns, large variety. LOTS of diversity.

• Dominant Animals – all types of animals in a large variety; most biodiversity.

Aquatic Biomes

• Aquatic Biomes are usually determined by the depth and temperature of the water as well as chemicals that are dissolved in the water (salt and oxygen).

• There are two main groups freshwater (less than 1% salt) and saltwater (marine)(about 3% salt).

Freshwater Aquatic Biomes

• Flowing Water biomes include rivers and streams.

• Rivers and streams differ by SIZE.

• In general the faster the water, the cooler, clearer the water is.

• There are fewer plants.

Freshwater Aquatic Biomes

• Many animals and plants have adaptations that help anchor them in place or streamlined bodies.

Freshwater Aquatic Biomes• Standing water biomes include lakes and

ponds.• Lakes and ponds differ by SIZE.• In general standing water is warmer and

more turbid (dirtier).• Standing water harbors many unsafe

microorganisms.• Phytoplankton are the producers of many

aquatic food chains.• The primary consumers are often

zooplankton.

Saltwater Aquatic Biomes

• The saltwater biomes includes areas called the aphotic zone, the coastal ocean, the intertidal zone, coral reefs, and estuaries.


• Aphotic zone

• Deep in the water where it is dark and no sunlight reaches.

• All producers in the aphotic zone are chemosynthetic autotrophs that do not need light.


• Photic zone

• Area of water where light does penetrate.

• Lots of photosynthetic organism live here which attract other animals to this area.

• Between the photic zone and aphotic zone is the “twilight” zone.


• Costal ocean

• Saltwater; area from the outer continental shelf to the low-tide mark

• Sunlight usually penetrates to the bottom

• Kelp grows in certain areas

• Includes lots of fishes, snails, seals, sea urchins, and whales.

Saltwater Aquatic Biomes• Intertidal zone• Area between low tide and high tide;

subject to tidal changes• Organisms live here that can stand to be

out of the water. • They spend some time in sunlight and

sometimes exposed to air and temperature.

• Because of currents, organisms are usually attached to the bottom or have ways to hold on.


• Coral Reefs

• Made of calcium carbonate formed by corals; warm saltwater; usually no deeper than 40 meters.

• Home to colorful fishes, sea anemones, starfish, and the coral.

• Most diverse aquatic biome.


• Estuaries

• Where freshwater rivers and streams merge with the oceans; varying salt concentrations

• Brackish water

• Animals and plants must be adapted to the varying salt concentrations.

Ecological Relationships

• Since plant fibers are harder to digest than animal, herbivores have evolved special adaptations to chew and digest their food.– Large, flat molar teeth– Chew the cud– Special bacteria in the stomach– Stomach chambers.


• Predator-Prey

• A predator hunts, kills, and eats prey.

• Prey is what the predator eats.

• A hawk consuming a rabbit for example.


• Predators have evolved physical and behavioral adaptations that help them catch their prey.– Keen eyesight– Sharp claws or teeth– Fur coloration


• Prey have adaptations to keep them from being eaten. – Poison frogs have bright, green color to warn

predators of the danger.– Mimicry refers to a harmless organism

mimicking the poisonous one so that predators will leave them alone.

Ecological Relationships• Competition

• Anytime organisms try to use the same resource– Light, food water, space, mates– Organisms will either adapt or die– Extinction is often the very end of natural

selection. They are out competed. – If extinction happens because they were

wiped out competely, it is known as competitive exclusion.


• A relationship between organisms living together closely is called symbiosis.

• The three types of symbiosis common in biology is mutalism, commensalism, and parasitism.


• Mutualism

• Both species benefit in the relationship.

• Flowers produce nectar to attract the bees; the bees pollinate the flowers.


• Commensalism

• One species gets the benefit of living together, but another species isn’t benefited or harmed.

• Barnacles are attached to whales. The barnacles get a place to live and the whales get no benefit.


• Parasitism

• One organism gets all the benefit and the other organism is harmed.

• Parasite infects the “host.”

• Parasites usually don’t kill the host, then only weeken the host.

• Heartworms, some nematodes like tapeworms, some fungi and bacteria.

Ecosystems

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