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Ecosystems and interdependence
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Organisms depend on each other and on their surroundings. A change to one part can affect the whole ecosystem.
Levels of organisation
Individual → population (one species in an area) → community (all the populations) → ecosystem (the community plus its non-living surroundings).
Abiotic and biotic factors
Abiotic (non-living): light, temperature, water, pollutants, soil pH.
Biotic (living): food availability, predators, competition, disease.
Biotic (living): food availability, predators, competition, disease.
Interdependence
Species rely on each other for food, shelter, pollination and seed dispersal.
Mutualism: both benefit, like bees and flowers.
Parasitism: one benefits and harms the other, like fleas on a dog.
Mutualism: both benefit, like bees and flowers.
Parasitism: one benefits and harms the other, like fleas on a dog.
Rabbits in a field catch a disease and many die. Suggest what happens to the fox population.
- Foxes eat rabbits, so their food supply falls.
- Fewer foxes survive and reproduce.
Answer: The fox population decreases.
Population, community, ecosystem. Abiotic factors are non-living; biotic factors are living. Species are interdependent; mutualism benefits both, parasitism harms the host.
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