Lesson 3: succession, eutrophication & deforestation

• Biologie
• Middelbare school
• vwo
• Leerjaar 4

Ecology

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Learning objectives

• Describe how human influences impact global warming
• Describe how an environment can change over time due to succession
• Describe the impact of eutrophication and bioaccumulation on a natural system

Which of the following is usually true about secondary consumers in an ecosystem?

1. They eat only plants
2. They are eaten by primary consumers
3. They are fewer in number than are primary consumers
4. They contain the greatest total biomass in the system

Which of the following best explains why there are seldom more than five trophic levels in a food chain?

1. Most carnivores function at more than one trophic level
2. Top carnivores are too few in number to hunt effectively
3. The ecosystem contains too much biomass
4. Energy is lost from each trophic level

Succession

Succession: 'The change in structure and species composition of a community over time'

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Pioneer stage (early succession)

Climax stage (late succession)

low biodiversity

high biodiversity

fluctuating abiotic factors

stable abiotic factors

Few layers

Very layered (heights of vegetation)

Closed cycles

Open cycles

Stable biomass

Increasing biomass

Scientists found, that over a period of 200 years, a mountain pond was transformed into a meadow. During that time, several communities of organisms were replaced by different communities. Which of these best explains why new communities were able to replace older communities?

1. The original species became extinct
2. Species in the older community died from old age
3. The abiotic characteristics of the habitat changed
4. Diseases that killed the older organisms disappeared

Examples of Abiotic Factors include:

1. Weather, birds, plants, and animals
2. Rocks, reptiles, shrubs, trees, and grasses
3. Weather, wind, rain, sunlight, and rocks
4. Birds, plants, animals, reptiles, shrubs, trees, and grasses

How is primary succession different from secondary succession?

1. Primary succession starts with soil
2. Secondary succession start with bare rock
3. Primary succession starts with bare rock, with lichens and moss
4. Fire is an example of primary succession

How do lichens contribute to primary succession?

1. Lichens decompose organic matter from animals and plants
2. Lichens begin to break down rock to form soil
3. Lichens are nitrogen fixing bacteria
4. Lichens convert carbohydrates into fossil fuels.

A pioneer species is...

1. a large organism
2. the first organisms to adapt to a new environment
3. The best organism
4. Abiotic organisms

What is the order of succession shown in this figure?

1. A, B, C, D
2. A, D, C, B
3. C, A, D, B
4. C, D, A, B

Deflected succession

Preventing succession from proceeding to a climax system.

Often through management of humans

Which of the following is an example of deflected succession

1. Volcanic eruption
2. Letting cattle graze in a natural park
3. Planting trees
4. Flood

What type of succession is shown going from figure A to figure B?

1. Primary succession
2. Secondary succession
3. Intermediate succession
4. Deflected succession

Explain the difference between the greenhouse effect and global warming

We need the natural greenhouse effect for Earth to be habitable.

1. True
2. False

Which 2 greenhouse gases contribute the MOST to global warming of Earth?

1. N2O and H2O
2. O3 and H2O
3. CO2 and CH4
4. CO2 and O3

Explain the effect of deforestation on global warming

What are other effects of deforestation?

What is the name for the trapping of heat by gases in the atmosphere.

1. gas shield
2. global warming
3. carbon footprint
4. greenhouse effect

Largest number of individuals of a population that the environment can support

1. carrying capacity
2. primary succession
3. limiting factor
4. density dependent factor

When fertilizers run off farmland into streams and ponds, the nitrogen content of the water increases. This can lead to rapid growth of algae in a process called eutrophication. How can this process affect other organisms in the water?

1. Oxygen is used up as algae is decomposed, reducing the amount available to other organisms.
2. The water becomes better able to support aerobic organisms.
3. The algae provide food for fishes and other organisms, leading to decreased algae populations.
4. The extra nitrogen provides additional food for the other organisms, increasing their population.

Put the steps in order

1

2

3

4

5

6

In eutrophication, what does 'algal bloom' refer to?

1. The rapid increase in the number of bacteria
2. The rapid increase in the number of plants
3. The rapid decrease in the number of fish
4. The rapid increase in the amount of nitrates in the river

In eutrophication, what directly causes the death of fish?

1. The plants use up oxygen in respiration
2. The fish are poisoned by high CO2 levels
3. Bacteria use up oxygen in respiration
4. The fish use up oxygen in respiration

Which level in the pyramid has the most energy?

1. 1 because they are autotrophs
2. 1 because they are carnivores
3. 4 because they are autotrophs
4. 4 because they are carnivores

What is bioaccumulation or biomagnification?

1. buildup of toxins in an organism
2. the total mass/amount of organisms in a given area
3. the number of different species in an area

Which organism would have the most bioaccumulation?

1. A because it consumes all the toxins from B, C, and D
2. D because energy is lost as heat
3. A because I'm not really reading what this says.
4. D because it consumes all the toxins from B, C, and D

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Steps in succession

1. Pioneer species come in 
2. Through their existence they change the abiotic factors (add nutrients to ground, create shade, block wind etc)
3. This makes the environment suitable for other species to come in
4. These new species can outcompete the previous species making them dissapear from the system
5. This creates a follow up of species over time, because the population keep on changing the environment

Homework

Complete the worksheet on Classroom