- Slides: 16
Ecology and Ecosystems
What is Ecology? • Ecology is the study of living organisms and the interactions between them and their environment. • It is the study of ecosystems!
What is an Ecosystem? • A group of organisms that interact with each other and their environment – The Earth is a really big ecosystem. It is called the “biosphere”. – A large ecosystem is a biome (tundra, swamp, etc. ) – A very small ecosystem is “under a rock”. Ecosystems can be very large, very small, and any size in between. Within one ecosystem, there may be many smaller ecosystems. As long as there are organisms that interact with each other and with their environment, you can define that area as an “ecosystem.
Examples of Ecosystems Pond Ecosystem Forest Ecosystem River Ecosystem Tide Pool Ecosystem
Ecosystem Structure In this ecosystem, do you see more plants or animals? Correct…. Plants
What might eat the plants in the field ecosystem? Grasshoppers eat grass!
What will eat the grasshopper? A grasshopper sparrow (A type of bird)
Producer You just described a FOOD CHAIN. A food chain (like the one above) is a diagram that shows the feeding relationships in an ecosystem. A FOOD WEB is a diagram that shows all feeding relationships in an ecosystem. It is a really just a complicated food chain. FYI: Food chains and food webs always starts with a plant-like organism, which is called a PRODUCER.
Producer Primary Consumer Secondary Consumer Tertiary Consumer Next, any organism that eats or takes in the energy of the producer is called a CONSUMER. The grasshopper is called a PRIMARY CONSUMER because it is the first to eat the producer. Most primary consumers are herbivores (organisms that only eat plants). Any consumer that eats the primary consumer is a SECONDARY CONSUMER. Secondary consumers are either omnivores (organisms that eat plants and animals) or carnivores (organisms that only eat animals). Finally, a consumer that eats a secondary consumer is a TERTIARY CONSUMER. Tertiary consumers are primarily carnivores. FYI: The arrows in a food chain always point in the direction of where the food energy is going. The food energy in the grass is going into the stomach of the grasshopper and so on…
Other Terms to Know… • Predator: An organism that eats another organism (Bear) • Prey: A organism that gets eaten by a predator (Fish)
Another important group… ***Decomposers are organisms that break down dead things. Examples are bacteria, fungi, insects, earthworms.
Now. . Let’s Talk About Energy and Ecosystems
How Does the Sun’s Energy Get Stored in Plants? Cellulose molecule A plant absorbs the sun’s light. The light energy causes a chemical reaction to occur in the plant, called photosynthesis. During this reaction, a chemical called glucose is produced. Glucose is sugar and has a chemical formula of C 6 H 12 O 6. Because glucose is a molecule made up of atoms, the chemical bonds between the atoms store chemical energy. When another organism digests the plant, the stored chemical energy is released and is used by the animal to move, breath, and stay warm.
Energy Pyramid • Look at the pyramid below. Each level in the pyramid is called a TROPHIC LEVEL. A trophic level is a feeding level in a food chain. • Notice that the most joules (a unit of energy) of energy come from the sun. Then, some of the energy from the sun is transferred to the producer trophic level (about 10%). • What happens to the other 90%? Well, some of it stays stored as chemical energy in the plant. Some is transferred back to the atmosphere as heat. Some is transferred to the soil as chemical energy, and so on.
10% RULE • • This 10% transfer of energy from one “energy level” to the next is standard. For example, as primary consumers eat producers in an ecosystem, they get about 10% of the energy contained by all the producers in that ecosystem. When secondary consumers eat primary consumers in an ecosystem, they take in 10% of the energy contained by the primary consumers. When tertiary consumers eat secondary consumers in an ecosystem, they take in 10% of the energy contained by the secondary consumers. Remember, the remaining 90% of the energy left is “lost” to the universe to be used later.
Now that you know how ecosystems are structured and how energy moves in an ecosystem, let’s review… • Print off the review worksheet that is on the lesson 2 website. Complete.