An ecosystem is a community of trees, plants, animals and insects living in a particular environment.
All living things are linked and depend on the land, water and air.
What is an ECOSYSTEM?
An ecosystem is a group of living things plus the non-living things they need.
The parts of an ecosystem are linked together.
For example: in a woodland ecosystem, rain is an input which makes the trees grow. Evaporation is an output.
Copy the diagram and add examples to each box.
Human action also affects.
At what SCALE do ecosystems operate?
There are many different ecosystems in the world.
Some are small-scale , such as a pond.
Others are large-scale and cover vast areas, such as a rainforest.
Living things in the ecosystem are linked together by the flows of energy and matter as things eat each other.
These links can be shown as food chains
FOOD CHAINS This shows a food chain in the sea. Removing one animal from this would seriously harm the system. HOW?
FOOD WEBS This shows a food web in a woodland area. What would happen if the RABBITS were removed from the ecosystem?
World ecosystems 8 types
Lets go to the rainforest and find out what its like, the types of vegetation & its soil 1.Tropical rainforest
Equatorial Ecosystem Hot all year Wet all year High annual rainfall over 2000mm Wide biodiversity Plants love the heat & humidity Trees are evergreen Trees have thin barks – no need for protection against the cold
Characteristics of vegetation in the rainforest Tall straight trunks no side branches Aerial roots of epiphytes absorb moisture from the air Shallow spreading root system Buttress roots Thick, waxy surface of leaves protects against hot sun, heavy rain, and strong winds
Rainforest Floor Dark Forest Floor
The Amazon Rainforest has been described as the "Lungs of our Planet" because it provides the essential environmental world service of continuously recycling carbon dioxide into oxygen. More than 20 percent of the world oxygen is produced in the Amazon Rainforest.
One and one-half acres of rainforest are lost every second with tragic consequences for both developing and industrial countries.
A Discontinuous Canopy of tree Crowns of the Tallest trees 40 – 50m ( Emergent) B 25 – 40m Continuous layer of Main canopy C 10 -25m Discontinuous under Canopy of D Layer of shrubs & Young trees E Herb layer with Ferns 6m+ high 5 10 15 20 25 30 35 40 45
Rainforest Floor Dark Forest Floor
Human impact on Tropical Rainforest
Organic matter decays quickly
Nutrients taken up by the trees
All rain reaches the surface
No trees left to supply nutrients
Nutrients already in the soil are washed out
Increased surface runoff
Increased soil deposited into the rivers
Making a survey of the area’s resources before using them
Selecting only a few trees per hectare
Cutting down only fully grown trees
Replanting those cut down
Checking the work is done according to the plans
Waxy leaves and thorns=espinas
Drought resistant plants, such as cacti, with very long roots to reach water supplies deep underground.
Some towns have developed in deserts around the oil and natural gas industries
Las Vegas in Mojave Desert
Evergreen woodland, such as cork and pine, thorny shrubs.
Holm oaks = Encina
Shrubs = bush
Grasses up to 2 metres tall, some trees such as willow=sauce
Prairies of tall grass
Landscapes of low grass = Steppes
6. Decidous forest or woodland
Trees which shed their leaves in winter, such as oak and ash, shrubs and short grasses.
Deciduous forests (Bosques de hoja caduca) Ash Haya Oak roble Beech Fresno
Dense evergreen trees, such as fir=abeto, pine.
Fir ( Abeto)
Short plans, such as moors, heather and lichen.
Some stunted trees
Small groups of Sami and Inuits
How are ecosystem affected by human action?
Almost all ecosystems around the world have been affected by human activity.
In some areas little remains of the orginal ecosystem.
Today large areas of untouched tropical rainforest are under threat from deforestation.
The greenhouse effect is a natural phenomenon that controls the balance of heat within the Earth's atmosphere.
What is the “greenhouse effect”?
It is the process whereby the natural layer of gases in our atmosphere trap a small percentage of the sun's radiation reflected from the earth's surface. Without the greenhouse effect, the average surface temperature would be about -18 degrees Celsius.
Global warming is caused by the increases in the amount of carbon dioxide and other gases being released into the atmosphere by the burning of fossil fuels. These gases add to the natural greenhouse effect are causing global temperatures to rise.
What problems are caused by global warming ?
Sea levels will rise due to the melting of the ice caps.
Sea temperatures will rise
Ice caps and glaciers will start to melt
Low-lying areas will be flooded
Violent storms, and extreme hot weather
Deserts will spread
Vegetation and climatic belts will move
Increasement in insect pests
Tropical diseases may spread
Global warming is thought to be due to the greenhouse effect. Climate changing gases
In 1997, the Kyoto Protocol brought agreement between countries that greenhouse gases should be reduced. So far, many European countries, including Britain, have admitted difficulty in achieving the target.