1. What is an Ecosystem
No matter where you are, you interact with plants, animals, and other organisms. But you also interact with nonliving things (oxygen, sun, wind, rain, etc.) The environment consists of everything around an organism.
The particular place where an organism lives is its habitat. The habitat might be your local neighborhood or local community.
A community is made up of all the populations that live and interact with each other in an area.
Each individual animal within each group is a member of a population. A population is a group of individuals of the same species that live in an area at the same time.
Organisms interact with each other in communities. They also interact with nonliving things in their environment. These relationships (interactions) for an ecosystem. An ecosystem is a community of organisms interacting with one another and the environment.

2. Habitat
Green plants make their own food; therefore, they start-off every food chain.
Green plants are called producers because they use the sun’s energy to produce food.

3. Energy Flow in an Ecosystem
PRODUCTION OF ENERGY: The sun is the source of energy in most ecosystems.
THE TRANSFER OF ENERGY: Energy is transferred form the sun to plants that make their own food. The stored energy in plants is transferred to animals that eat the plants. Energy is transferred to other animals when they eat the plant-eating animals.
BREAKING DOWN OF MATERIALS: When organisms die, their bodies decompose, or break down. The chemicals are reused by other living things.
RECYCLING: The materials needed by organisms in an ecosystem are recycled, or used over and over.

4. Energy Flow in an Ecosystem
Snake