Interactions Among Living Things

I. Living Things and Their Environment  All of the living (biotic) and nonliving (abiotic) things in an environment are interconnected.

 Example: Think of a spider web. The environment’s web is the relationship among its plants, animals, soil, water, temperature, light, and other biotic and abiotic factors.

Temperature Soil Animals Light Water

 What happens when one part of a spider’s web is damaged?

The entire web falls apart.

What happens when someone contaminates the water supply to a farm?

A. Ecosystems  Consists of all the living (biotic) and nonliving (abiotic) things in a given area that interact with one another.

Abiotic factors: nonliving Air Sunlight Soil Rocks

Biotic Factors: Living Fish Flower Tree Bacteria Mushroom Flamingo Man

 Ecosystems overlap and affect one another.  Ecosystems can be as tiny as a drop of pond water or as large as an ocean.

Forest Ecosystem: Includes birds, squirrels, rabbits, trees, bushes, grass, insects, mushrooms, bacteria, dead leaves, soil, rocks, sunlight, rainwater, etc….

Desert Ecosystem: Air, sunlight, cacti, sand, pocket mice, jack rabbits, etc…

B. Communities  The living part of any ecosystem.  All the different organisms that live together in that area.  Example: Pond community – Includes fish, frogs, snails, microorganisms, and water lilies.

Pond Community Cattails Kingfisher Otter Water strider Frog Catfish

C. Populations  A group of organisms of the same type (species) living together in a community.  Example: all the rainbow trout in a lake or all the redwood trees in a forest.

Rainbow Trout Redwood Trees

What type of ecosystem do you live in?  Take a sheet of paper, divide it in half, and make a list of the biotic and abiotic factors in your ecosystem.

BioticAbiotic