Area where non-living(abiotic) parts of the Earth’s surface and biotic (living) organisms interact
Interact in such a way that a small area may eb identified as a region
Geographers may be interested in studying this ecosystem from a variety of viewpoints
Key part of the word is ‘system’ The various parts work together just as the parts of your body or a car do
Ecosystems require ‘inputs’ to make them function
Also have ‘outputs’- waste material resulting from the processes required to keep the ecosystem functioning
Abiotic part of the ecosystem is that part of the ecosystem which is non-living.
Many abiotic components of an ecosystem
These are as follows:
Sunlight
Temperature
Wind
Rainfall
Rocks
Soil
Gas
Biotic parts of an ecosystem are its living parts and include the following
Flora
Fauna
Fungi
How do Ecosystems work?
Ecosystems are dynamic
Ecosystems are subject to change
Are driven by power of the sun
Radiation from the Sun provides heat which is essential for life on Earth
The Sun and the Abiotic environment: Weather
The sun has a major impart on the abiotic environment. Weather refers the day to day changes in the earths atmosphere in terms of:
Precipitation
Temperature
Wind speed and direction
Air pressure
Main variable it affects is temperature
Sun heats up land and water surfaces of the earth
The heating up of water bodies, leads to evaporation of water
This evaporation drives one of the major cycles on earth - the water cycle
Humidity is a reflection of this evaporation
Is a measure of the amount of water the atmosphere is capable of holding
Recorded as a percentage of the total amount of water vapour the air can hold
Because land is a solid and water is a liquid, their surfaces heat up at different rates and lose heat at different rates
These differences between the heating rates of land and water generate movement within the atmosphere too
As air is warmed, it expands and the pressure It exerts on the Earths surfaces decreases (because there are fewer molecules per cubic meters)
The Sun and the Abiotic environment: Rocks and soil
Temperature changes associated with the heat of the sun are a major cause of mechanical or physical weathering. Which is the breakdown of rocks in soil as a result of different components of rocks heating up and expanding at different rates or water in cracks and crevices in the rocks freezing during the cooler hours of the night and the rock being broken apart by the expanding ice
Granular distintegration is directly caused by the sun. Dark-coloured compounds in rocks will heat up more quickly that lighter compounds. The dark compounds expand more quickly and can cause small grains of rock to break off the parent rock
The Sun and the Biotic environment: Flora and Fauna
Sunlight generates the process of photosynthesis in plants
Plants have a number of roles in ecosystems
Some plants provide shade in which other plants will grow
Some are hosts for other plants
Around the world there are some very different areas for plants to colonise
The growth of plants in these areas requires colonising plants with very special adaptions
These plants stabilise the environment and allow other plants, plants that are not adapted to the initial conditions, to eventually move into an area
The first plants to inhabit an area are know as the colonisers
The most dominant form of vegetation in the area is known as the climax vegetation.
Climax vegetation is the major plant community that will develop in an area given the existing climatic conditions
Animal kingdom is affected by sunlight in 2 ways
Time of day can have a significant effect on when animals are active
The other way sunlight affects the animal kingdom is through is effect on vegetation. There are animals which only eat plant material. These are the primary producers in an ecosystem
On a more important level, many primary producer animals are the food for the next level of animals in the food chain - the carnivores
Interesting thing about humans is that they have an increased ability to survive because they consume all levels of the food chain, from the plants at the base to the herbivores to the carnivores
The role of the suns energy in relation to plant and animal life on earth is not over even when plants and animals die
This is where the decomposers come in. They break down the decaying life forms into nutrients which can be used again in the ecosystem. Scavengers form part of the group
For some considerable time humans have had a major impact on ecosystems on the earths surface and that impact is increasing
Introducing another variable: Humans
Humans have not always had the control over ecosystems that they have today
Fire became and important tool for humans. It provided warmth and protection. Australia’s first inhabitants used fire to modify the environment for their own use
In time humans learned which plants could be grown in certain areas and which animals could be brought under control. This knowledge resulted in the domestication of plants and animals and is the basis of agriculture in the modern world
Over time humans have become established at the top of the ecosystem. Humans can save, protect, destroy or modify an ecosystem
Humans have been altering ecosystems for thousands of years. Increasing populations required more food than could be provided by hunting and gathering
The industrial revolution placed even more pressure on ecosystems as trees were cut down and burned, and later coal and oil were extracted from the ground cities were built and spread across the countryside and communication networks of road and rail were constructed to connect them
In the desire for this kind of progress ecosystems for a long time took second place in humans thinking
Fortunately, in other places the need to save and protect ecosystems ins regarded as important