Ecology

Ecology:

Adaptations, interdependence and competition:

Communities:

• An ecosystem is the interaction between the community of living organisms and their environment.
• A community is two or more populations of organisms.
• A population is all the organisms of the same or closely-related species in an ecosystem.
• Interdependence means that all the organisms in an ecosystem are dependent upon each other.

Abiotic and biotic factors:

• The abundance and distribution of organisms in an ecosystem are affected by biotic and abiotic factors.
• Abiotic factors are non-living and include light intensity, temperature, moisture levels, soil pH and mineral content, wind intensity, direction, carbon dioxide levels and oxygen levels.
• Biotic factors are living and include availability of food, the arrival of new preadtors and pathogens and being out-competed by other species.

Competition in plants and animals:

• Competition can be between individuals of the same species which is called intraspecific or between different species which is called interspecific.
• Plants compete for light, water and minerals from the soil and for space.
• Animals compete for food, mates and territory.
• Individuals within a species that cannot effectively compete are likely to die.
• Whole species that cannot effectively compete are likely to become extinct.

Adaptations in plants and animals:

• All adaptations make organisms better suited to their ecosystem and provide them with a better chance at survival and reproduction.
• Examples of structural adaptations in plants are spines and in animals are sharp teeth and claws.
• Examples of behavioural adaptations in plants are growing towards the light and courtship in animals.
• An example of physiological adaptations in animals and plants is the production of venom or poisons.

Extremophiles:

• An extremophile is an organism that lives in an extreme environment.
• An extreme environment is one in which most organisms would find it difficult or impossible to survive such as polar regions, deserts and the deep ocean bed.
• Deep sea volcanic vents are places on the ocean floor where the volcanic gases of underground magma chambers bubble through.
• The organisms that live in these places have highly specialised adaptations.

Organisation of an ecosystem:

Levels of organisation:

• 1. Feeding relationships show the levels of organisation in an ecosystem.
• 2. Feeding relationships can be shown in food chains, which add together to make food webs for a habitat.
• 3. At the base of almost every food chain is a producer, which is usually a plant or algae which photosynthesises.
• 4. All the animals above the producer are called consumers.
• 5. Decomposers are bacteria and fungi which breakdown dead organisms and help them rot.

Predators and Prey:

• In a healthy, balanced ecosystem the numbers of predators remain fairly constant.
• The numbers of predators and prey can be seen in repeating predator-prey cycles.
• When the number of prey increases so does the number of predators because there is more food.
• The number of prey reduces when there are more predators eating them.
• Finally the number of predators decreases because there is less prey.

The Carbon Cycle:

• Carbon is an important element that can exist in different…