SB9 - Ecosystems and Material cycles Flashcards
What do organisms need to stay alive?
Resources
What is an ecosystem?
An area in which all the living organisms and all the non-living physical factors form a stable relationship
–> Needs NO input in order to remain stable
Give an example of a large ecosystem:
Rainforest
Give an example of a small ecosystem:
Pond
What does interdependent mean?
When organisms in an area need each other for resources
E.g. Food & Shelter
What is Abiotic factors?
The non-living aspects of an ecosystem
Give some examples of Abiotic factors:
- Temperature
- Light intensity
- Moisture
- Pollutants
Explain how light intensity affects a community as an abiotic factor
- Light is required for photosynthesis
- Rate of photosynthesis affects the rate at which a plant grows
- Plants can be food sources or shelter for many organisms
Explain how Temperature affects a community as an abiotic factor
- Temperature affects the rate of photosynthesis
Explain how Moisture levels affects a community as an abiotic factor
- Both plants and animals need water to survive
Explain how Soil pH and mineral content affects a community as an abiotic factor
- Soil pH affects the rate of decay
—> Therefore how fast mineral ions return to soil
—> Then taken up by other plants - Different species of plants thrive in different nutrient concentration levels
Explain how Wind intensity & direction affects a community as an abiotic factor
- Wind affects the rate of transpiration in plants
- Transpiration affects the temperature of the plant + rate of
photosynthesis
—> As it transports water and mineral ions to the leaves
Explain how Carbon dioxide levels affects a community as an abiotic factor
- CO2 affects the rate of photosynthesis in plants
- It also affects the distribution of organisms as some thrive in high CO2 environments
Explain how Oxygen levels for aquatic animals affects a community as an abiotic factor
- Levels in water vary greatly, unlike oxygen levels in air
- Most fish need a high concentration of oxygen to survive
What is Biotic factors?
The living components of an ecosystem
Give some examples of Biotic factors:
- Food availability
- Competition
- New pathogens
- New predators and other species
Explain how Food availabilitycan affect a community as a biotic factor
More food = organisms can breed more successfully
—> Therefore the population can increase in numbers
Explain how New pathogenscan affect a community as a biotic factor
When a new pathogen arises the population has no resistance to it
so they can be wiped out quickly
Explain how Compeitioncan affect a community as a biotic factor
If one species is better adapted to the environment than another then it will outcompete it until the numbers of the lesser adapted species are insufficient to breed
What is a Community?
All of the populations of different species living together in a habitat
Describe the importance of interdependence within a community
Removal or addition of a species to the community can affect the populations of others greatly
–> Changes prey or predator numbers
Give some examples on how organisms can be interdependent with each other
- Food
- Shelter
- Reproduction (pollination, seed dispersal)
Describe the relationship of biotic and abiotic factors in a stable community
Biotic & Abiotic factors is balanced
Describe what the happens in result of a stable community
- The population sizes remain roughly constant
- When they are lost it is very difficult to replace them
Give some examples of a stable community
- Tropical rainforests
- Oak woodlands
- Coral reefs
What are the two types of symbiotic relationships?
- Parasitism
- Mutualistic relationships
What is a parasite?
An organism that lives on (or in a) host organism and takes food from it while it’s alive
What is parasitism?
The interaction between two organisms where only one organism, the parasite, benefits whilst the host does not
What is Mutualism?
The interaction between two organisms where both benefit as a result of their relationship
What can we use to assess pollution levels?
Indicator species
What is polluted water often identified by?
The presence of bloodworms or sludgeworms
What are sludgeworms also known as?
Sewage worms
What is clean water often identified by?
The presence of freshwater shrimps and stonefly
What is good air quality often identified by?
The presence of lichens or blackspot fungus
What is bad air quality often identified by?
The absence (or little presence) of lichens or blackspot fungus
What pollutant is present when there is an absence ( or little presence) of lichens or blackspot fungus
Sulphur dioxide
Why is the rose blackspot fungus more likely to be found in less polluted areas?
As sulphur dioxide protects plants from certain fungi
