What would happen if producers were removed from the food chain? 2. How would you describe an ecosystem?

3. What describes the relationship between a food chain and a food web?

4. What would most likely be the result of an invasive species entering an ecosystem?

5. Why are humans responsible for many invasive species?

6. What are the three main roles of an ecosystem?

7. What is the purpose of a decomposer in an ecosystem?

Answer the following questions with a pictures.

1. What is the main source of energy for ecosystems?

2. What are some natural things that can disturb ecosystems?

Write a paragraph (5-8 complete sentences) using the prompt below in purple:
An ecosystem has many living and nonliving things. Choose one producer, one consumer, and one decomposer. Explain how they work together.

An ecosystem is made up of all the living and nonliving things in an area. The living parts include plants, animals and insects. The nonliving parts include water, rocks, soil and sand. Swamps, prairies, oceans and forests are all examples of ecosystems. There are usually many different kinds of life in a single ecosystem. A grassland ecosystem, for example, contains much more than just grass. It includes other plants, mammals, insects and earthworms. It also includes many tiny living things in the soil. Three Roles For Living Things Each living thing in an ecosystem has a role to play. The three main roles are producer, consumer and decomposer. Green plants are producers. They make their own food through a process called photosynthesis. Animals, including humans, are consumers. They eat, or consume, plants or other animals. By Encyclopaedia Britannica,
Bacteria and other living things that cause decay are decomposers. Decomposers break down the waste products and dead tissue of plants and animals. They return nutrients to the soil. These nutrients help new plants grow. Producers, consumers and decomposers depend on one another and provide nutrients for one another. This is called a food chain. Feeding Levels A food chain describes the order in which matter and energy move through the feeding levels of an ecosystem. The levels of a food chain are basically the same across all ecosystems. The first level is the producers. After that is the consumers. Sometimes consumers are further divided into primary consumers, secondary consumers and tertiary consumers. The final link in all food chains is the decomposers. The decomposers break down dead organisms and natural waste. The consumers at the top feeding level of a food chain are called top predators. They have no predators hunting and trying to eat them. Instead, their population size is controlled through competition. They have to compete with one another for food and other resources. Energy FlowThe main source of energy in almost all ecosystems is the sun's energy. As energy moves through the ecosystem, much of it is lost at each feeding level. Itescapes as heat. That is the main reason why few food chains have more than five feeding levels. Diagrams called energy pyramids are used to show the flow of energy from one feeding level to the next in a food chain. Most ecosystems have more than one food chain. Food chains overlap. They connect to form a food web. Recycling Nutrients Many nutrients are constantly cycling through an ecosystem. These include water, carbon and nitrogen. A nutrient is something that helps living things grow. Nutrients from soil enter into plant tissues. When consumers eat the plants, the nutrients enter the consumers' tissues. Consumers that are eaten transfer the nutrients on to the predator at the next feeding level. Consumers that are not eaten die and transfer nutrients in their decaying tissues to the decomposers that feed on them. The decomposers recycle these nutrients back into the ecosystem. They transfer the nutrients back into the soil and air, where the nutrients become available to producers. A Delicate Balance
an ecosystem's health depends on a delicate balance. This balance must exist between all of the members of the ecosystem, and their surrounding environment. If something disturbs the balance, the ecosystem and all its members might suffer. Natural things that can disturb ecosystems include a changing climate and natural disasters. Human activities that can disturb ecosystems include polluting and clearing land for farms or buildings. Humans also are responsible for many invasive species. An invasive species is a living thing that spreads through an ecosystem where it did not exist before. Invasive species can threaten the plants and animals that originally made up the ecosystem. For example, Burmese pythons were brought to Florida as pets. Some pythons escaped and began reproducing in the wild. Their skill at hunting has decreased the number of wood rats and storks in the area. This upset the balance of the natural ecosystem.