1. The document describes the key concepts of an ecosystem, including that an ecosystem is composed of all living and nonliving things that interact in a specific area. 2. It explains the different levels of biological organization and how biotic and abiotic factors are interconnected within an ecosystem. 3. The document defines native, nonnative, and invasive species and their roles in an ecosystem. It also describes keystone species as those that help define an entire ecosystem such that it would be drastically different without that species.

1. Interactions and
Interdependence

3. Specific Objectives
At the end of the lesson, the students should
be able to:
1. Describe the principles of the ecosystem.
2. Categorize the different biotic potential and
environmental resistance (e.g., diseases,
availability of food, and predators) that affect
population explosion.
3. Describe how the different terrestrial and
aquatic ecosystems are interlinked with one
another.

4. Activity 1:
Directions: Complete the graphic organizer with words or
phrases that are related to the word ecosystem. Then ,
correlate these terms to form your definition of ecosystem.
ECOSYSTEM

5. What is
Ecosystem?
It is composed of all living
things that interact with one
another and with the physical
and chemical factors that
compose the nonliving things in
an area.

6. You have learned that climate, soil, biodiversity of plants and animals, and availability of
food and nutrients affect the ecosystem.
Biotic Abiotic
Living Things Nonliving Things

7. Levels of Biological Organization
The levels of biological organization cover organisms from species to
population and the interconnection of biotic ( e.g., plants, animals, and
microorganisms) and abiotic (e.g., air, water, and soil) factors.
To understand the need to support ecosystem management, you
must first understand the basic concepts of the ecosystem.

8. Native, Nonnative, and Invasive
Species
Native Species are organism that originated in their habitat naturally and
without human involvement or intervention.

9. Native, Nonnative, and Invasive
Species
Nonnative species move out of their natural environment because of
human intervention or natural barrier.
Human intervention includes moving the species from one point to
another.
Natural barrier include fish migration due to a natural disaster.

10. Native, Nonnative, and Invasive
Species
Invasive species are organism that have the potential to displace the native
species and may threaten the species or the ecosystem.

11. Keystone species
It is an organism that helps define the entire ecosystem it is in, such that
without it, the ecosystem would be drastically different or even cease to
exist altogether.
Carnivorous sea star, Pisaster
ochracceus, played a key role in
maintaining the balance of all other
species in the intertidal community.
Robert T. Paine