Science: Ecosystems

• Is a self-contained system of interdependent organisms and their physical environment
• An ecosystem can also be defined as a biological community of interacting organisms and their physical environment.
• In an ecosystem a community of living organisms lives in conjunction with the nonliving components of their environment (things like air, water and mineral soil), interacting as a system.
• For example in a typical grassland ecosystem the grasses/plants and animals depend on each other
• They also depend on the soil, air and water in that area
• The plants and animals live under certain conditions
• The plants grow because they have the right amount of rainfall, light, air and soil conditions that suit them
• The animals live there because they have the right kind of food to eat and shelter to live
• The organisms (plants and animals) depend on each other and on their surroundings
• The surroundings usually act as a source of energy
• The plants and animals that are interdependent under a given set of conditions form the ecosystem
• Zimbabwe has a variety of ecosystems for example forest, lake, river and grassland ecosystems

Energy transfer in an ecosystem

• Every ecosystem depends on the energy from the sun
• The plants use solar energy to create food using the photosynthesis process
• The energy is stored/trapped in the plants until they are eaten by the animals
• Thus energy flows in an ecosystem as it is transferred from the plants to the animals for example
• The flow of energy is critical as it ensures a balanced ecosystem is maintained
• There must be adequate transfer of energy from the sun, to the plants and to the animals
• This balance can be easily upset by the interference of humans
• Typically the environmental conditions in an ecosystem include the air, water, light and heat energy
• The soil also has some physical properties such as its texture
• Soils have living organisms in them as well as organic matter
• These are biological components of an ecosystem
• The biological components of an ecosystem (plants and animals) interact with one another

To access more topics go to the Combined Science Notes page.