Students session




1.1 Basic ecological terms

1.2 Types of ecosystem and their components

Explanation of ecological terms:

ecosystem, species, population, ecology, ecosphere and community.

Natural ecosystem:
fresh water, marine, estuarine, lake, rainforest, savanna and desert.

Artificial ecosystem:
farmland, man-made lake, roads.

Components of ecosystem:

Biotic/ living (plants and animals) and abiotic/ non-living(soil, air, and water).

Effects of the components on each other.

Ecological factors:
biotic (predation and competition) and abiotic (climatic factors, salinity, altitude and slope of land)

Appropriateness of instruments used to measure abiotic factors.


Basic ecological terms


is the study of living things and their interrelationship with each other and their environment.


An ecosystem is made up of living and non-living organisms in a particular habitat and their interaction with the physical environment. The habitat could be a forest, coral reef, river etc


These are distinct kind of organisms that can interbreed to produce fertile offspring with one another but do not breed with other population.


refers to a group of organisms of the same species occupying a particular habitat. E.g., a tree could house a population of birds.


It is a population of different species living in a particular habitat or interacting with each other.
For example, the ocean could be a community for different species of fish, crabs, coral,


Is part of the earth or atmosphere that supports life.
It can also be defined as the part of the universe habitable by living things.

is interchangeable with biosphere. Biosphere can be divided into biomes.


A biome is a large natural terrestrial ecosystem which has a particular climate.
The type of vegetation in a biome is largely determined by climatic factors particularly rainfall and temperature.


This is the natural dwelling place of an organism.
The main divisions of a habitat are;
1. Aquatic habitat
2. Terrestrial Habitat
3. Arboreal Habitat.

Aquatic Habitat

This is water as the natural home of organisms
Eg; Fresh water, streams, pond, ocean etc.

Terrestrial Habitat

This is land as the natural home of organisms.
Eg Rainforest, deserts, bush etc.


Aboreal Habitat

This refers to a habitat in and on trees.

Ecological Niche

A niche is an area within an ecosystem in which a particular group of organisms live in. A niche could provide a habitat for organisms of the same or different species. For example, a pond can be a home for different species of fish.
Although organisms may live in the same habitat, each has its own living space and source of food.

Ecological Factors

Ecological factors are those factors which affects an organism’s behaviour or development in an ecosystem.
Ecological Factors are grouped into two

1. Biotic Factors

2. Abiotic Factors.

Biotic factors

are factors concern with the way living organisms interact with one another.
Or biotic Factors are living organisms in a habitat or environment.

Examples of biotic factors

1. Predator: A carnivorous animal that hunts, kills and eats other animals in order to survive, or any other organism that behaves in a similar manner. This process is known as predation.
2. Competition: When a shared resource is in short supply, organisms compete, and those that are more successful survive
3. Symbiosis: A situation in which two organisms live with and are dependent on each other, to the advantage of both.
4. Epiphytism: This occurs when epiphytes (plants that do not have roots in the soil) attach themselves to other plants for supports. Epiphytes do not take any food from their hosts, and do not harm them.

Examples of useful biotic factors

1. Bacterial fixing nitrogen in the soil.
2. Birds acting as agents of pollination.
3. Fungi and bacteria decomposing organic matter.
4. Insects acting as agents of fruits and seeds dispersal.
5. Macro-organisms aerating the soil.
6. Trees providing shade or shelter to animals

Harmful biotic factors

1. Herbivores such as goats, sheep and cattle feeding on plants
2. Carnivores (e.g. lions, tigers etc) feeding on other animals
3. Parasites living on their hosts.

Abiotic Factors

These are non-living factors which affects living things in the environment.

Examples of abiotic factors

  • Climate (rainfall, temperature, humidity, etc)
  • Salinity (measurement of the mass of dissolved solids present in a given amount of water)
  • Altitude (the height of something above sea level) slope of land etc.


Abiotic factors and  Instruments use to measure them;



Abiotic factor Instrument use to measure
Temperature Thermometer
Wind direction   Wind vane
Wind speed Anemometer
Atmospheric pressure Barometer
Amount of rain fall Rain gauge
Relative humidity Hydrometer
Acidity or alkalinity of a substance pH indicator
Light intensity on land Photometer



Some ecological equipment

Quadrat Determining the number of living organisms within a given area
Butterfly net Collecting flying insects
Pooter  or Aspirator Collecting or sampling small animals
Sweep net Collecting insects and some land vertebrates




Cold warm thermometer. Temperature weather thermometers with celsius and fahrenheit scale. Thermostat meteorology vector isolated icon

Sweep Net



Rain Gauge



Further explanations will be given during face – to – Face lesson with your Facilitator.


Search for the following instruments
1. Light meter
2. Pitfall trap
3. Barometer
4. Anemometer Sacchi disc




1. What is biotic factor?
2. Give two useful biotic factors in a forest habitat
3. Explain the following ecological concepts
i. Population
ii. Community
iii. Ecosphere

3. Study the diagrams carefully and answer the questions that follow.

a. Identify instruments A, B and C
b. Name the parts labelled I, II, III, IV, V and VI
c. State one use each of A, B and C
d. Name one function each of the parts labelled
i. II
ii. III
iii. VI
e. Describe how A could be used for measuring an abiotic factor in a field trip.
Check next lesson for corrections.


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