Geography - Living World

Abiotic

Non living things, eg. soil, rocks, water, sunlight

Biodiversity

The variety of life in an ecosystem

Biomass

Renewable organic materials that come from living or recently living organisms, such as wood, agricultural crops or waste. Can be used to generate electricity

Biome

Large areas on the earth’s surface with fauna and flora adapting to their environment

Biotic

Living things

Consumer

Creature that eats herbivores and/or plant matter

Decomposer

An organism such as bacterium or fungus, that breaks down dead tissue, which is then recycled to the environment

Ecosystem

A natural system that comprises a community of plants and animals that interact with each other and their physical environment

Food chain

The connections between different organisms (plant and animals) that rely upon eachother as their source of food

Food web

A complex hierarchy of plants and animals relying on eachother for food

Nutrient cycling

A set of processes whereby organisms extract materials necessary for growth from soil or water, before passing them on through the food chain - and ultimately back to the soil and water

Producer

An organism or plant that is able to absorb energy from the sun through photosynthesis

What are the interrelationships of biotic and abiotic components in an ecosystem?

• Physical linkages between different parts, eg. animals eating plants

• Chemical linkages, eg. acid in rainwater speeding up the decay of dead leaves

Global atmospheric circulation

The Hadley cell

• 0° - 30° latitude, found closest to the equator

• Intense sun heats the equator, causing warm air to rise, creating low pressure. As the air rises, it cools and condenses, forming heavy clouds that then cause heavy rain, creating tropical rainforests

• The cold air moves away from the equator and sinks at 30°, creating high pressure and dry conditions, creating deserts

The Ferrel cell

• 30° - 60° latitude

• Warm surface air moves from the high-pressure subtropical zones at 30° towards the poles, meeting cold polar air at 60° and rises, creating unsettled, rainy weather, climate of the UK

The Polar cell

• 60° - 90°

• Cold, dense air descends at the poles, creating high pressure and very dry conditions, cold desert

• Cold surface air flows out away from the poles toward 60° latitude, warms up slightly, meets the Ferrel cell air, and rises into the upper atmosphere before returning to the poles

Local factors that affect distribution of ecosystems