Ecology is the scientific study of the interactions between living organisms and their environment. It incorporates fields like biology, chemistry, physics and geology to better understand these relationships. Ecological communities consist of biotic factors like plants, animals and microbes interacting with abiotic factors such as temperature, water, soil and sunlight. Organisms are dependent on environmental conditions and also impact one another through predation, competition, symbiosis and other relationships within ecosystems.

1. An introduction to Ecology
Introduction:
 The term of Ecology was first introduced by
Ernest Haeckel (1834 – 1914)
 This term is derived from Latin words:
 Oikos means home
 Logos means to study/knowledge
 Generally, Ecology is defined as a study deals
with inter relationship between living organisms
and their environment.
 This shows that there are relationship
between ecology and other disciplines within
Biological Sciences and other Sciences.

2. Ecology Cont …
Other disciplines related to ecology:
– Morphology - Chemistry
– Physiology - Geology
– Genetics - Physics
– Evolution - Meterology
– Molecular Biology
– Developmental Biology
– Behavioral study
With the above disciplines, it is expected that the
scientists can improve their understanding on
the relationship between living organisms and
their environment.

3. Ecology cont …
 Therefore, ecology is scientific study that
incorporate hypothetico-deductive approach
 In this case it uses observation and experiments
to test hypothetical explanations of ecological
phenomena
 Therefore this discipline is a challenging that
are because of its multidisciplinary nature

4. Components of Ecology
Biotic Components
– This includes all living organisms located in a certain area
– In this area a living species becomes the environment of other
species
– This living organisms can be:
All types of bacteria
Fungi
Microalgae
Moses
Ferm
Invertebrates
Vertebrates
Human
Terrestrial plants
Etc.

5. Biotic components
Within an area mentioned above, these living
organisms possess their specific way to interact
each other and to their abiotic components to
gain energy
– Example: green plants conduct photosynthetic
process by using CO2 and H2O (abiotic components)
to produce biomass (as producer)
– Biomass of plants will subsequently be consumed by
herbivores (level 1 consumers)
– Herbivores will be eaten by carnivores (Level 2
consumers)
– All dead plants and animals will finally be
decomposed by microorganisms

6. Abiotic components
All other components excluding biotic components
These include physical and chemical components
These two components determine the characteristic of
an environment where the living organisms occur
These physicochemical components are:
– Temperature
– Light
– Water
– Air
– Humidity
– Minerals
– Soils
All of these interact each other to form the characteristic
of the environment

7. Abiotic components (cont …)
Temperature
– This is the degree of heat energy
– Important parameter that determines the rate of
biochemical reactions within the body of organisms
– Important factor for living organisms in the
reproduction process.
This is related to migration of many species of birds when
they need to reproduce
Light
– The main source is Solar radiation
– Consists of several wavelength of light
– Three component of light required by organisms; the
wavelength, light intensity, and period of exposure

8. Abiotic components (cont …)
Water
– Water is found in the solid, liquid, and gas forms
– App. 80 to 90% of the body component of living organism
consists of water
– The role of water to living organisms:
As solvent in the metabolic pathways
To maintain osmotic pressure of cells
To avoid cells from dryness
Hymidity
– This means water content of air or soils
– This is a very important factor for living organisms in order to
survive
– The humidity required by organisms varied depends on the
species of those organisms.

9. Abiotic components (cont …)
Air
– Air consists of several types of gas
Nitrogen (78.9%) as a protein component
Oxygen (20.93%) as a component in respiration process
Carbo dioxide (0.03%) as a component in the photosynthesis
Other gases (…%)
Minerals
– These include ions of nitrogen, phosphorous, Sulphur,
Calcium, Sodium (Na), etc.
– These determine the soil characteristics
– Example: the content of Na+ and Cl- determine the
salinity of soils

10. Abiotic components (cont …)
Soils
– Soil is formed as a result of rocks decomposition
– This process is due to climatic changes plus
decomposition of organic materials
– Fertile soils is needed by plants and other organisms
to live
– Soils have their specific characteristics, texture, and
mineral content that determine their fertility.

11. Inter dependency between living organisms
and their environment
Each group of organisms (either the same or
different species) will occupy a suitable area for
them to live (called the habitat)
Each species in this habitat will interact each
other
These species also interact with their abiotic
environment
An example of this interdependency can be
found in a damp soil habitat
– One possible population found in this habitat is
earthworms (Pheretima sp.)

12. Damp soil habitat (cont …)
– This species can live there, because this habitat
provides them with suitable temperature, moisture
content, and organic content of the soil (suitable
physicochemical components)
– Besides this earthworms, other living organisms, such
as millipedes, bacteria, fungi, fern, ants, and Mosses
can also be found in this habitat (this is the biotic
components of this habitat
– How these component interact (especially the biotic
components) will be discussed later