3.1.2.1 Ecosystems

Question 1

Ecosystems:

Answer 1

entire living communities of plants and animals that, although diverse in nature, share common characteristics.

Question 2

What interacts closely to produce the characteristic nature of an individual ecosystem?

Answer 2

Climate, soils and vegetation interact closely to produce the characteristic nature of an individual ecosystem.

Question 3

Abiotic:

Answer 3

elements that are non-living but affect the ecosystem e.g. water, heat, relief, the atmosphere, fire, nutrients, rocks etc.

Question 4

Biotic:

Answer 4

the living components of an ecosystem e.g. plants and animals

Question 5

What is an example of an ecosystem on a local scale?

Answer 5

a hedgerow, pond

Question 6

What is an example of an ecosystem on a regional scale?

Answer 6

The Lake District

Question 7

What is an example of an ecosystem on a global scale?

Answer 7

The Earth (biome), Tropical rainforest

Question 8

Habitat:

Answer 8

the natural home or environment of an animal, plant, or other organism

Question 9

Niche:

Answer 9

an organisms role in an ecosystem

Question 10

Food chain:

Answer 10

• shows the direct links between producers and consumers in the form of a simple diagram

Question 11

What does a food chain show the flow of?

Answer 11

a food chain shows the flow of energy from one organism (living thing) to another

Question 12

What is each level of a food chain called?

Answer 12

a trophic level

Question 13

What are losses of biomass in food chains due to?

Answer 13

• Not all the ingested material is absorbed, some is excreted as faeces
• Some absorbed material is lost as waste, such as carbon dioxide and water in respiration and water and urea in urine
• Large amounts of glucose are used in respiration

Question 14

Food web:

Answer 14

shows all the connections between producers and consumers in a more complex way

Question 15

Producers + example:

Answer 15

• Convert energy from the environment (mainly sunlight) into sugars (glucose)
• The most obvious producers are plants that convert energy from the Sun by photosynthesis

Question 16

Consumers + example:

Answer 16

• Get energy from the sugars produced by the producers
• A pond snail is a good example of a consumer because it eats plants

Question 17

Decomposers + example:

Answer 17

• Break down plant and animal material produced by the producers
• Bacteria and fungi are good examples of decomposers

Question 18

Nutrients:

Answer 18

Nutrients are foods that are used by plants or animals to grow.

Question 19

What are the two main sources of nutrients?

Answer 19

• Rainwater washes chemicals out of the atmosphere
• Weathered rock releases nutrients into the soil

Question 20

What happens when plants die?

Answer 20

• When plants or animals die, the decomposers help to recycle the nutrients making them available once again for the growth of plants or animals
• This is the nutrient cycle

Question 21

What do plants and animals depend on nutrients for?

Answer 21

health and vitality

Question 22

Where are the vast majority of nutrients stored?

Answer 22

in biomass

Question 23

What happens to nutrients in the soil?

Answer 23

nutrients in soil are rapidly absorbed by vegetation

Question 24

Why are there only a few nutrients in the litter store?

Answer 24

few nutrients in the litter store due to rapid decomposition

Question 25

Describe the transfer of nutrients between the stores:

Answer 25

there is a rapid transfer of nutrients between stores

Question 26

What weather conditions promote chemical weathering?

Answer 26

warm and wet conditions promote chemical weathering

Question 27

Leaching:

Answer 27

where heavy rainfall washes away the nutrients from the soil

Question 28

What are human causes of changes in ecosystems?

Answer 28

• Woods cut down destroying habitats for birds and affecting the nutrient cycle
• ponds may be drained to use for farming - aquatic plants will die, as will fish

Question 29

What are physical causes of changes in ecosystems?

Answer 29

extreme weather events like droughts can be devastating to pods and and lakes because they could dry out - this would change the edge-of-pond environment, so plants will dry out and die

Question 30

Global Ecosystem:

Answer 30

Very large ecological areas on the earth’s surface (or biomes), with fauna and flora (animals and plants) adapting to their environment

Question 31

Explain the Global Distribution Pattern of Biomes:

Answer 31

• climate is an important factor in influencing the natural vegetation and wildlife of a region - biomes (largest scale ecosystems) broadly match the world’s climate zones
• heat is concentrated at the equator/gets more intense sunlight because the sunlight hits at 90 degrees angle and the sunlight has less atmosphere to travel through which is why it’s so cold in the poles and so much insulation is lost through scattering, absorption, reflection etc. as it travels through the atmosphere
• At the arctic circle solar E strikes the ground at a low angle and is spread over a large area. Each m squared within the solar footprint is heated only gently
• At 0 degrees latitude solar E strikes the ground at almost a right angle. E is concentrated into a small footprint and each m squared within the solar footprint is heated quite heavily

Question 32

What are the characteristics + example of the polar biome?

Answer 32

• Cold air sinks in the N and S resulting in very low, dry temps
• Arctic, Antarctica

Question 33

What are the characteristics + example of the tropical rainforest biome?

Answer 33

• High temps
• Heavy rainfall
• Equitorial low pressure creates ideal conditions for plants to grow
• Amazon, Brazil

Question 34

What are the characteristics + example of the coniferous forest biome?

Answer 34

• Coniferous trees are cone bearing evergreens
• Keep leaves to maximise photosynthesis in Summer
• Cannada

Question 35

What are the characteristics + example of the deciduous forest biome?

Answer 35

• Deciduous trees shed leaves in Winter to retain moisture
• UK

Question 36

What are the characteristics + example of the savanna biome?

Answer 36

• Distinct wet and dry seasons
• Dry seasons = very hot, wildfires
• Wet seasons = violent thunderstorms
• Large herds of animals found
• Lions and leopards graze on grasslands
• East of Brazil
• North of Australia

Question 37

What are the characteristics + example of the temperate grassland biome?

Answer 37

• Vast areas
• Warm, dry summers
• Cold winters
• Grasses can tolerate these conditions so land is used for grazing
• Mongolia, Kazakhstan

Question 38

What are the characteristics + example of the mediterranean biome?

Answer 38

• Hot and dry summers due to high pressure
• Birds migrating N and S throughout yr
• Olive trees and fruit trees e.g. lemons and oranges
• Spain

Question 39

What are the characteristics + example of the desert biome?

Answer 39

• Sub-tropical high pressure belts
• Sinking air stops clouds from forming resulting in high daytime temps
• Cod (below freezing) nights as no clouds to keep heat in due to high pressure
• Australia, North Africa e.g. Algeria

Question 40

What are the characteristics + example of the tundra biome?

Answer 40

• Low-growing plants adapted to retain heat and moisture in cold, windy and dry conditions
• Fragile ecosystem
• Easily damaged by humans through oil exploitation
• North of Russia

Question 41

Diagram of the nutrient cycle:

Answer 41

Question 42

Diagram showing the distribution of global ecosystems in the world:

Answer 42

Question 43

Ecosystem food chain showing the amounts of biomass at each trophic level:

Answer 43