Ecology is the interactions and relationships between organisms and their environment. It includes where they live, how they get their food, how energy is passed on.
Organisms are either producers or consumers. Producers are
autotrophs and can make their own food. They are green because they have chlorophyll and they photosynthesize. They can be microscopic like algae or large like trees and grass. They are at the bottom of the food chain, a food web, or an energy pyramid.
Consumers are heterotrophs and use other organisms for their food.
They are not green. They can be herbivores (eat plants), carnivores
(eat meat), omnivores (eat both plants and meat) or they may be like fungi and absorb nutrients from dead organic material. They are in all the levels of food chains, food webs, or energy pyramids above producers.
A food chain is a “straight” line that shows what eats what. A food chain could be grass ---> deer ---> wolf or seeds ---> mouse ---> snake
---> hawk. In this food chain…..
Which are the producers? Grass & Seeds
Which are the consumers? Deer, Wolf, Mouse, Snake, & Hawk
Which are the herbivores? Deer & Mouse
Which are the carnivores? Wolf & Snake

A food web shows the interconnectedness of food sources of the organisms in their habitat. Here is an example.
Which are the producers? Corn, Carrots, Flowering Shrub, Tree
The herbivores? Mouse, Rabbit, Grasshopper, Deer
The carnivores? Shrew, Hawk, Snake, Wolf, & Frog
The omnivores?

Sometimes the relationships are shown in the form of a pyramid. A
pyramid can show the number of organisms that can be supported at each level and how much energy is available for the next higher level.
This is called an energy pyramid. The numbers on the right side are kilocalories. These are the same as food calories. Notice that as you go from the bottom of the pyramid to the top, the amount of energy available is only 10%. This is called the 10% rule. The other 90% is given off as heat, used, as energy the organism needs to live, and the undigestible parts.
Also notice that the number of individual organisms at each level as you go up gets smaller. If the bass could eat eelgrass, would more be able to live in the area? With humans, more people can live off the corn that is fed to cattle than can live off the cattle themselves.

This pyramid shows biomass or how many organisms can live at a level.
At the bottom level, 900 grams of plants can live in an area that is 1 meter square. At the top only 5 grams of animals can live or find enough food in the same size area. How many grams of ants and spiders can live in this ecosystem?