unit 3 ecosystems chapter 6: life systems. the web of life producers: a plant which can synthesize...

Unit 3 EcosystemsUnit 3 Ecosystems

Chapter 6: Life SystemsChapter 6: Life Systems

The Web of LifeThe Web of Life Producers:Producers:

a plant which can synthesize a plant which can synthesize carbohydrates using carbon carbohydrates using carbon dioxide and the sun’s energy. dioxide and the sun’s energy.

for example in figure for example in figure 6.3 on page 94 all the plants 6.3 on page 94 all the plants are producers and convert are producers and convert the sun's energy into the sun's energy into carbohydrates (food energy) carbohydrates (food energy) for all other organisms in the for all other organisms in the ecosystem. ecosystem.

Producers are so Producers are so named because they actually named because they actually produce the food for the produce the food for the ecosystemecosystem

The Web of LifeThe Web of Life

ConsumersConsumers All those organisms in trophic All those organisms in trophic

levels other than producers. levels other than producers. Consumers eat their food. Consumers eat their food.

For example in figure 6.3 For example in figure 6.3 on page 94 all the animals are on page 94 all the animals are consumers. consumers.

Consumers are so named Consumers are so named because they have to eat or because they have to eat or consume their food. consume their food. 1st order or primary consumers 1st order or primary consumers

eat producers eat producers 2nd order or secondary 2nd order or secondary

consumers eat primary consumers eat primary consumers consumers

3rd order or tertiary consumers 3rd order or tertiary consumers eat secondary consumers eat secondary consumers


DecomposersDecomposers Simple organisms that Simple organisms that

obtain their food from dead obtain their food from dead organisms and wastes.organisms and wastes.

For example in For example in Figure 6.3 on page 94 of Figure 6.3 on page 94 of your text, name all of the your text, name all of the decomposers. decomposers.

Decomposers are so Decomposers are so named because they are named because they are actually responsible for actually responsible for decomposing dead decomposing dead organisms.organisms.


Ecosystem:Ecosystem: the network of relationships among plants, animals the network of relationships among plants, animals

and the non-living constituents in an environment. and the non-living constituents in an environment. View figure 6.3 on page 94 of your text and View figure 6.3 on page 94 of your text and

you can see that there are a lot of living things you can see that there are a lot of living things (plants & animals) and non-living things (soil, water (plants & animals) and non-living things (soil, water sun, temperature, etc.) that affect each other. It is sun, temperature, etc.) that affect each other. It is the system of relationships between the organisms the system of relationships between the organisms and between the organisms and the non-living and between the organisms and the non-living environment that makes up the ecosystem. environment that makes up the ecosystem.


Producers, Consumers & Decomposers: SimilaritiesSimilarities

All three are terms referring to the way organisms All three are terms referring to the way organisms obtain food & energy obtain food & energy

DifferencesDifferences The way they obtain food > producers make it, The way they obtain food > producers make it,

consumers eat it, decomposers feed on wastes & consumers eat it, decomposers feed on wastes & dead material. Yum.dead material. Yum.

Food Relationships in EcosystemsFood Relationships in Ecosystems

Food ChainFood Chain Is a linear sequence representing the flow of energy & Is a linear sequence representing the flow of energy &

nutrients from the simplest plant to the top carnivore.nutrients from the simplest plant to the top carnivore. An example of a food chain from fig. 6.4. P. 95 An example of a food chain from fig. 6.4. P. 95 Tree →? →? →? Tree →? →? →?

Producer = ?Producer = ? First order consumer =?First order consumer =? second order consumer = ?second order consumer = ? third order consumer = ?third order consumer = ?


Food WebFood Web a series of a series of

interconnecting food interconnecting food chains in an chains in an ecosystem. ecosystem.

Figure 6.4 on Figure 6.4 on page 95 of your text page 95 of your text book depicts a food book depicts a food web in a temperate web in a temperate deciduous forest. deciduous forest.


Food Chain vs Food Web:Food Chain vs Food Web: Similarity Similarity

Both food chains and food webs show the flow of Both food chains and food webs show the flow of nutrients and energy in an ecosystem. nutrients and energy in an ecosystem.

Differences Differences Food web is more complex Food web is more complex Food web is composed of several food chains Food web is composed of several food chains Food web is a more realistic picture of an Food web is a more realistic picture of an

ecosystem. ecosystem.


Energy Flows in Food Chains/WebsEnergy Flows in Food Chains/Webs Using figure 6.5 on page 95 you can summarize the Using figure 6.5 on page 95 you can summarize the

main energy flows in an ecosystem. main energy flows in an ecosystem. Sun = source of all ecosystem energy Sun = source of all ecosystem energy Producers make food via photosynthesis Producers make food via photosynthesis Consumers eat plants and other consumers to get energy Consumers eat plants and other consumers to get energy Each time energy moves from one organism to another, Each time energy moves from one organism to another,

energy leaves the system in the form of heat. energy leaves the system in the form of heat.

Decomposers return nutrients to the soil but energy Decomposers return nutrients to the soil but energy is not recycled. is not recycled.

Food Relationships in EcosystemsFood Relationships in Ecosystems Food PyramidsFood Pyramids

Diagram showing each Diagram showing each trophic level as a horizontal trophic level as a horizontal bar (trophic level - an bar (trophic level - an individual layer on the food individual layer on the food pyramid which represents pyramid which represents types of organisms living at types of organisms living at parallel levels on food chains)parallel levels on food chains)

Producers are located Producers are located on bottom & higher trophic on bottom & higher trophic levels are placed on top of levels are placed on top of each other each other

Each bar is drawn in Each bar is drawn in proportion to the mass of proportion to the mass of organisms giving the triangle organisms giving the triangle shape shape


Food PyramidsFood Pyramids There are fewer There are fewer

organisms at each organisms at each increasing trophic increasing trophic level. Why?level. Why? Less energy available Less energy available

at each increasing at each increasing level level

Fewer organisms can Fewer organisms can obtain energy to live obtain energy to live

Food Relationships in EcosystemsFood Relationships in Ecosystems Pyramid of Energy Pyramid of Energy

There is a high degree of energy loss at each There is a high degree of energy loss at each trophic level. trophic level.

The producers only store 1 % of the sun's energy as The producers only store 1 % of the sun's energy as food energy. food energy.

Each consumer level loses energy for several Each consumer level loses energy for several reasons:reasons: much of the energy is lost as heatmuch of the energy is lost as heat most of the energy is used to carry out life functions. i.e. most of the energy is used to carry out life functions. i.e.

we burn many calories of energy each day just ‘living’, as we burn many calories of energy each day just ‘living’, as do all organisms.do all organisms.


Pyramid of Energy (continued)Pyramid of Energy (continued) If an organism dies without being eaten the If an organism dies without being eaten the

energy goes to the decomposers and not up energy goes to the decomposers and not up the trophic levels. the trophic levels.

Consequently only about 10-15% of the Consequently only about 10-15% of the energy is stored as usable food energy at energy is stored as usable food energy at each level.each level.

Food Relationships in EcosystemsFood Relationships in Ecosystems If we look at this in terms of units If we look at this in terms of units

of energy and we start with 1000 of energy and we start with 1000 units of energy at the producer units of energy at the producer level, then:level, then: The primary consumers would only The primary consumers would only

have 100-150 units of food energy have 100-150 units of food energy stored for the next levelstored for the next level

The secondary consumers would The secondary consumers would only have 10-15 units of food energy only have 10-15 units of food energy stored for the next trophic level.stored for the next trophic level.

The tertiary consumers would only The tertiary consumers would only have 1-1.5 units of food energy have 1-1.5 units of food energy stored as food energy. It is easy to stored as food energy. It is easy to see why we do not often see a see why we do not often see a quaternary trophic level quaternary trophic level

1000

150

15

1.5


Magnification of Toxin Magnification of Toxin Levels Levels Biological Amplification is Biological Amplification is

the term used to describe the term used to describe the fact that higher trophic the fact that higher trophic level receive a higher level receive a higher dose of food chain toxins.dose of food chain toxins. This problem has This problem has

occurred in our occurred in our environment. The most environment. The most common case was that of common case was that of DDT which was used to DDT which was used to control insect populationscontrol insect populationsDropping DDT Powder from

a helicopter, 1950s


Magnification of Toxin Magnification of Toxin Levels (continued)Levels (continued) DDT was a particularly DDT was a particularly

dangerous toxin because dangerous toxin because it is fat soluble; it stays in it is fat soluble; it stays in an animal’s fat. an animal’s fat.

Lower order organisms Lower order organisms ingest some poison ingest some poison which may or may not which may or may not affect them.affect them.

Higher order organisms Higher order organisms eat large numbers of eat large numbers of lower order organisms. A lower order organisms. A small amount in a frog small amount in a frog becomes a large in a becomes a large in a hawk that eats 100 frogshawk that eats 100 frogs

Ecosystems Throughout the WorldEcosystems Throughout the World

Climax Vegetation:Climax Vegetation: the most commonly the most commonly occurring plant in an occurring plant in an ecosystem. Over a ecosystem. Over a long time, it has long time, it has adapted to that adapted to that ecosystem’s climate, ecosystem’s climate, soil, predators and soil, predators and other plants.other plants.

Ecosystems Throughout the WorldEcosystems Throughout the World: :

Climate and EcosystemsClimate and Ecosystems

Regions in the world that Regions in the world that have have similar climatessimilar climates are classified as the are classified as the same ecosystemsame ecosystem. This . This is because climate is because climate factors determine the factors determine the type of vegetation in an type of vegetation in an area. The most area. The most important factor is important factor is sunshine/temperaturesunshine/temperature..


Climate and EcosystemsClimate and Ecosystems Mountain ecosystems are Mountain ecosystems are

different. different. As elevation increases, As elevation increases,

temperature and precipitation temperature and precipitation lowers. Depending on where lowers. Depending on where in the world a mountain range in the world a mountain range is, you might find a is, you might find a varietyvariety of of ecosystems on it.ecosystems on it.

This is why there are no This is why there are no mountains on figure 6.9, page mountains on figure 6.9, page 103.103.

Use figures 6.8, 6.9 and 6.10 Use figures 6.8, 6.9 and 6.10 to answer # 19, 20, 22 to answer # 19, 20, 22 (worksheet).(worksheet).


Adaptation in EcosystemsAdaptation in Ecosystems Coniferous (Boreal) Forests Coniferous (Boreal) Forests

The “climax vegetation” is: evergreen The “climax vegetation” is: evergreen trees with needle-like leaves, thick bark, trees with needle-like leaves, thick bark, and a conical shape and a conical shape

Dense growing which blocks sun Dense growing which blocks sun Coniferous trees are well adapted to Coniferous trees are well adapted to

lack of water in winter (it is all frozen): lack of water in winter (it is all frozen): Needle leaves reduce surface area for Needle leaves reduce surface area for

transpiration transpiration Drooping branches and conical shape Drooping branches and conical shape

allow heavy snow to fall off relieving the allow heavy snow to fall off relieving the pressure pressure

Thick bark reduces water loss. Thick bark reduces water loss.


Adaptation in EcosystemsAdaptation in Ecosystems Tundra Tundra

The “climax vegetation” in the Tundra The “climax vegetation” in the Tundra is: grasses, shrubs and low plants with is: grasses, shrubs and low plants with Shallow roots and Fast Shallow roots and Fast reproduction/flowering cycle reproduction/flowering cycle

The shrubs and bushes are well The shrubs and bushes are well adapted to the extreme climate of the adapted to the extreme climate of the north where winter is long and north where winter is long and summer is very short. summer is very short. Shallow roots are needed because 1-3 Shallow roots are needed because 1-3

meters below the surface the soil is meters below the surface the soil is completely frozen (Permafrost). completely frozen (Permafrost).

The fast flowering and reproduction cycle The fast flowering and reproduction cycle is needed because the growing season is is needed because the growing season is very short, lasting only 1-2 months.very short, lasting only 1-2 months.


Adaptation in EcosystemsAdaptation in Ecosystems

Polar Ice Caps Polar Ice Caps The “climax vegetation” in The “climax vegetation” in

the Polar Ice Cap is: the Polar Ice Cap is: Phytoplankton beneath Phytoplankton beneath the ice the ice

The adaptation of The adaptation of producers to this producers to this ecosystem is extreme. ecosystem is extreme. There is no land for the There is no land for the producers to grow in so producers to grow in so there are only small there are only small phytoplankton to form phytoplankton to form the base of the food the base of the food chain. chain.



Temperate Grasslands Temperate Grasslands The “climax vegetation” The “climax vegetation”

in Temperate in Temperate Grasslands is: grass Grasslands is: grass with shallow roots and with shallow roots and small water small water requirements requirements Grasses are well Grasses are well

adapted to lack of water. adapted to lack of water. The small size of the The small size of the

plant means that it plant means that it requires less water.requires less water.


Adaptation in EcosystemsAdaptation in Ecosystems Temperate Deciduous Forests Temperate Deciduous Forests

The “climax vegetation” in The “climax vegetation” in Temperate forests is deciduous Temperate forests is deciduous trees like oak, birch and maple trees like oak, birch and maple which lose leaves in winter which lose leaves in winter

Losing their leaves in winter helps Losing their leaves in winter helps them reduce water loss. them reduce water loss.



Tropical Rain Forests Tropical Rain Forests The “climax vegetation” is: Tall The “climax vegetation” is: Tall

Evergreen Broadleaf Trees Evergreen Broadleaf Trees with Buttress roots with Buttress roots

The tall trees are well adapted The tall trees are well adapted to the thin soil with buttress to the thin soil with buttress roots (figure 6.15 on page 108) roots (figure 6.15 on page 108) to help support their height. to help support their height. Some plants are epiphytes Some plants are epiphytes which are well adapted to the which are well adapted to the rain forest. They reach the sun rain forest. They reach the sun by lying in the canopy while by lying in the canopy while they get water through roots they get water through roots that hang in the air and absorb that hang in the air and absorb moisture. Some animals are moisture. Some animals are adapted to spend their entire adapted to spend their entire life in the canopy. life in the canopy.



Savanna Grasslands Savanna Grasslands The “climax The “climax

vegetation” in the vegetation” in the savanna is grass with: savanna is grass with: shallow roots shallow roots small water small water

requirementsrequirements



Deserts Deserts The “climax The “climax

vegetation” in the vegetation” in the Desert is Cacti and Desert is Cacti and fleshy plants with: fleshy plants with: long roots long roots water storage water storage

capability capability leaves modified as leaves modified as

needlesneedles



Mountain Ecosystems Mountain Ecosystems The changes we see in The changes we see in

ecosystems as we move ecosystems as we move north from the equator are north from the equator are generally, tropical rain generally, tropical rain forest, Temperate forest, forest, Temperate forest, Coniferous forest, shrubby Coniferous forest, shrubby tundra and then polar ice tundra and then polar ice cap. The same changes in cap. The same changes in ecosystem can be seen ecosystem can be seen as you move up a tropical as you move up a tropical mountain. mountain.

Mountain ecosystems are Mountain ecosystems are not very unique; they vary not very unique; they vary with altitude and with altitude and temperature. temperature.

unit 3 ecosystems chapter 6: life systems. the web of life producers: a plant which can synthesize...

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