Wind affects many things in the ecosystem ie speeds up evaporation, assist in
pollination of plants and the dispersal of their seeds.
Air is composed of 78% Nitrogen, 21% Oxygen, 4% Carbon dioxide and water vapour.
Oxygen – used in cellular respiration and combustion and is returned to
the environment by the process of photosynthesis.
Carbon dioxide – is a product of cellular respiration and decayed organic
matter. It is removed from the atmosphere by plants during the process ofphotosynthesis.
Nitrogen – is needed by all living organisms for the synthesis of
proteins.
Water vapour - the amount of water vapour found in the air remains constant on
average, however, it can vary greatly from one place to another. Some parts ofthe Earth are prone to high humidity levels, why other locations have very dry
air. Much of what we consider weather is caused by water vapour. The clouds inthe sky are largely made up of it, and it is the condensation of this vapour
into droplets that creates rain and snow.
Edaphic factors:
Soil structure
Humus content is the decomposed remains of dead organic matter. It gives
the topsoil its dark colour. It supplies plants with nutrients and helps the
soil
absorb (retain) water. Soils rich in humus are fertile soils.
Texture of soil is determined by the size of the soil particles.
Soil properties
How
acid or
alkaline a soil is, can be measured by the
pH scale .
pH is a measure of the acidity or alkalinity of a solution.
The pH scale
ranges from
0 to 14. Neutral solutions have a
pH value of 7 .
Acid solutions have a
pH value of less than 7 and
alkaline solutions
greater than 7 .
Litmus paper or
universal indicator can be used to determine whether a solution is acid or alkaline.
Physiographic factors:
Aspect
Refers to the position of an area in relation to the sun or wind or wave action.
It is the
direction that the slope faces
ie North, South, East, West .
In Southern Hemisphere -
North facing habitats receive:
more solar radiation than a South facing one.
are warmer and drier
greater variety of animals
South facing habitats are:
cooler
have a higher water capacity
plant growth is luxurious
Slope
Also referred to as the gradient which represents the steepness of a slope.
Affects the rate of
water run-off
Ie Steep slope – encourages fast run-off of water and causes soil erosion.
Soils tend to be
shallow and
infertile and plant growth is reduced. Plants are small and few animals present
Gentle slope – favours slower flow of surface water, reduces erosion, and increases
availability of water to plants.
Altitude
Is the
height of the land above sea level.
At
high altitudes :
the
temperature is
lower ,
the
wind speed is greater,
and the
rainfall less and more likely to get snow.
Less plant and animal species found
Plants more
stunted than at lower elevations.
Biotic components
Living organisms in an ecosystem are usually grouped according to how they
obtain food.
Autotrophs that make their own food are known as producers, while
Heterotrophs that eat other organisms, living or dead, are known as consumers.
The producers include land and aquatic plants, algae and microscopic
phytoplankton in the ocean.
They all make their own food by using chemicals and energy sources from their
environment.
