3.1.2.1 Ecosystems Flashcards
Ecosystems:
entire living communities of plants and animals that, although diverse in nature, share common characteristics.
What interacts closely to produce the characteristic nature of an individual ecosystem?
Climate, soils and vegetation interact closely to produce the characteristic nature of an individual ecosystem.
Abiotic:
elements that are non-living but affect the ecosystem e.g. water, heat, relief, the atmosphere, fire, nutrients, rocks etc.
Biotic:
the living components of an ecosystem e.g. plants and animals
What is an example of an ecosystem on a local scale?
a hedgerow, pond
What is an example of an ecosystem on a regional scale?
The Lake District
What is an example of an ecosystem on a global scale?
The Earth (biome), Tropical rainforest
Habitat:
the natural home or environment of an animal, plant, or other organism
Niche:
an organisms role in an ecosystem
Food chain:
- shows the direct links between producers and consumers in the form of a simple diagram
What does a food chain show the flow of?
a food chain shows the flow of energy from one organism (living thing) to another
What is each level of a food chain called?
a trophic level
What are losses of biomass in food chains due to?
- 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
Food web:
shows all the connections between producers and consumers in a more complex way
Producers + example:
- Convert energy from the environment (mainly sunlight) into sugars (glucose)
- The most obvious producers are plants that convert energy from the Sun by photosynthesis
Consumers + example:
- Get energy from the sugars produced by the producers
- A pond snail is a good example of a consumer because it eats plants
Decomposers + example:
- Break down plant and animal material produced by the producers
- Bacteria and fungi are good examples of decomposers
Nutrients:
Nutrients are foods that are used by plants or animals to grow.
What are the two main sources of nutrients?
- Rainwater washes chemicals out of the atmosphere
- Weathered rock releases nutrients into the soil
What happens when plants die?
- 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
What do plants and animals depend on nutrients for?
health and vitality
Where are the vast majority of nutrients stored?
in biomass
What happens to nutrients in the soil?
nutrients in soil are rapidly absorbed by vegetation
Why are there only a few nutrients in the litter store?
few nutrients in the litter store due to rapid decomposition
Describe the transfer of nutrients between the stores:
there is a rapid transfer of nutrients between stores
What weather conditions promote chemical weathering?
warm and wet conditions promote chemical weathering
Leaching:
where heavy rainfall washes away the nutrients from the soil
What are human causes of changes in ecosystems?
- 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
What are physical causes of changes in ecosystems?
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
Global Ecosystem:
Very large ecological areas on the earth’s surface (or biomes), with fauna and flora (animals and plants) adapting to their environment
Explain the Global Distribution Pattern of Biomes:
- 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
What are the characteristics + example of the polar biome?
- Cold air sinks in the N and S resulting in very low, dry temps
- Arctic, Antarctica
What are the characteristics + example of the tropical rainforest biome?
- High temps
- Heavy rainfall
- Equitorial low pressure creates ideal conditions for plants to grow
- Amazon, Brazil
What are the characteristics + example of the coniferous forest biome?
- Coniferous trees are cone bearing evergreens
- Keep leaves to maximise photosynthesis in Summer
- Cannada
What are the characteristics + example of the deciduous forest biome?
- Deciduous trees shed leaves in Winter to retain moisture
- UK
What are the characteristics + example of the savanna biome?
- 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
What are the characteristics + example of the temperate grassland biome?
- Vast areas
- Warm, dry summers
- Cold winters
- Grasses can tolerate these conditions so land is used for grazing
- Mongolia, Kazakhstan
What are the characteristics + example of the mediterranean biome?
- 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
What are the characteristics + example of the desert biome?
- 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
What are the characteristics + example of the tundra biome?
- 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
Diagram of the nutrient cycle:
Diagram showing the distribution of global ecosystems in the world:
Ecosystem food chain showing the amounts of biomass at each trophic level:
