An ecosystem is characterized by the interactions between organisms and their nonliving environment. It contains biotic components like living organisms and abiotic components like energy, water, and soil conditions. Within an ecosystem, a community of interacting populations from different species occupies a habitat, which is an area that provides the necessary abiotic components for that community. One of the most important interactions is the flow of energy from producers like plants through food chains and webs to consumers at different trophic levels and ultimately decomposers, which also play an important role in the ecosystem. The abiotic and biotic factors limiting population growth are called limiting factors, and ecological collapse can occur if the balance is greatly disturbed through mass extinction of species in a community.

1. ECOSYSTEM

2. Ecosystem
- Is characterized by
relations between organisms
and how these organisms
interact with the nonliving
environment they live in.

3. Ecosystem is formed by:
• Biotic (living) components
• Abiotic (nonliving) components
- Energy, water, nutrients, temperature,
humidity, atmosphere and soil condition.

5. Ecological Structure
A community is an association or interaction of two or more
populations of different species in an area.
Community are found in place called habitats, the areas
where the abiotic components present are suited for the
needs of certain populations in a community.

6. One of the most
important interactions
between living things
in a habitat is energy
flow.

7. Plants are called producers or autotrophs because they can harness
the suns energy through the process of photosynthesis.

8. Food web – is the natural interconnection of food
chain.
Decomposers such as bacteria, fungi, and worms also
play an important role.
Trophic level – the position each organism occupies in the
chain.
Food chain – the sequencing on how energy is passed from
producers to consumers.

11. Ecological Balance
Ecological pyramid – is a representation
of the population of each species that
exist on the same ecosystem.
The abiotic and biotic components that
are in short supply and limit the
population growth of species are called
limiting factors.

12. Ecological Collapse
When the ecological balance is greatly disturbed, ecological
collapse may occur. This is characterized by the mass
extinction of different species in a community.