Living Things and Their Home

You will learn how plants and animals stay alive by using the living and nonliving parts of their home.

Think about a pond at a park in Texas. All the living and nonliving things there work together as an ecosystem, which is a place where organisms and their surroundings interact. The pond has cattails, fish, frogs, turtles, and dragonflies. It also has water, mud, sunlight, and air.

Some parts of the pond are alive or were once alive. These are the biotic factors, the living parts of an ecosystem. Fish, frogs, algae, and cattail plants are biotic. The other parts were never alive. These are the abiotic factors, the nonliving parts of an ecosystem. Water, sunlight, air, rocks, soil, and temperature are abiotic.

Now watch how they work together. A cattail plant uses sunlight, water, and air to make its own food. That plant's leaves give a dragonfly a place to rest. A frog sits on the muddy bank and snaps up the dragonfly. When the day gets hot, the frog slides into the cool water to keep its skin wet. A turtle does the opposite. It climbs onto a warm rock to soak up sunlight and warm its body.

Every organism needs both kinds of factors. A fish needs food, which is biotic, and it needs oxygen from the water, which is abiotic. If one part changes, other parts feel it too. If the pond dries up in a long Texas summer, frogs and fish lose the water they need. In a healthy ecosystem, there is enough food, water, air, shelter, and space for the living things that make their home there.

Try it: a hawk perched on a fence post in a Texas field grabs a mouse to eat, then spreads its wings and rides the warm air. Which part of that story is biotic, and which part is abiotic?