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An introduction to how living and non-living things work together in a specific environment.
Imagine a tiny puddle in your backyard. Did you know it's actually a bustling 'city' where every resident has a specific job to do to keep the neighborhood alive?
An ecosystem is a community where living things and non-living things work together as a unit. Think of it like a sports team: the players, the field, and even the weather all affect how the game is played. In nature, these 'neighborhoods' can be as huge as the Amazon Rainforest or as small as a single rotting log. Common local examples include a pond, a city park, or a backyard garden. Every part of an ecosystem has a role to play, and if one part changes, it can affect everyone else.
Quick Check
What are the two main 'ingredients' that make up an ecosystem?
Answer
Living things and non-living things.
Scientists divide everything in an ecosystem into two groups. Biotic factors are the living parts, such as plants, animals, fungi, and bacteria. Even a dead leaf is considered biotic because it came from a living thing! Abiotic factors are the non-living parts that have never been alive. These include sunlight, temperature, water, soil, and oxygen. You can think of it as a simple equation: .
Let's sort the parts of a garden: 1. Biotic: Earthworms, tomato plants, butterflies, and weeds. 2. Abiotic: The garden hose water, the plastic fence, the sunlight, and the dirt.
Quick Check
Is the wind a biotic or abiotic factor?
Answer
Abiotic, because wind is moving air and has never been alive.
Living things cannot survive alone; they have a deep interdependence with their environment. Plants are the 'producers' because they use abiotic factors like sunlight and carbon dioxide to create energy. Animals then eat those plants for food. Animals also rely on abiotic factors for shelter and hydration—like a fish needing the dissolved oxygen in water to breathe. If the water (abiotic) becomes polluted, the fish (biotic) cannot survive. Everything is connected!
In a desert ecosystem: 1. A cactus (biotic) stores water (abiotic) in its thick stem to survive the heat. 2. A lizard (biotic) hides under a rock (abiotic) to stay cool during the day. 3. The lizard eats insects (biotic) that fed on the cactus flowers.
Imagine a forest where it hasn't rained for months. 1. The Abiotic change: Water levels drop to . 2. The Biotic result: Plants wither and die. 3. The Consequence: Deer have no food or water, so they must leave or they will perish. This shows how one abiotic factor controls the whole system.
Which of these is a 'Biotic' factor in a forest?
If a pond dries up, which factor has changed?
A dead log on the forest floor is considered an abiotic factor because it is no longer moving.
Review Tomorrow
Tomorrow morning, look out your window and try to name 3 biotic factors and 3 abiotic factors you see immediately.
Practice Activity
Draw a picture of a 'Mini-Ecosystem' in a jar. Label the plants, the soil, the water, and the sunlight to show how they work together.