Producers

Ecosystems

• An ecosystem includes biotic and abiotic factors.

13.1 Producers and Consumers

• Ecology is the study of the interactions between living things and their environment.

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Producers

• Producers are organisms that use light energy from the Sun or energy from chemical reactions to make their own food.

• Producers use carbon dioxide and water to make sugars, which they use as food.

13.1 Producers and Consumers

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Plants

• Most green plants are producers.

• Plants use light energy, water, and carbon dioxide and make simple sugars. Photosynthesis.

• These sugars are a source of energy and carbon.

13.1 Producers and Consumers

Protists and Bacteria

• Some protists and bacteria are producers.

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Chemosynthesis• Some bacteria make food using energy from chemical

reactions in a process called chemosynthesis.

• Some chemosynthetic bacteria live deep in the ocean where sunlight never reaches. (p. 552)

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13.1 Producers and Consumers

Consumers

Consumers• Consumers are organisms that cannot make their

own food.

– All animals are consumers because they eat other organisms or their wastes.

– Some consumers eat producers, and some eat other consumers.

– Some consumers, such as protozoans, are single-celled.

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Types of Consumers

• Herbivores are animals that eat only plants.

• Carnivores are animals that only eat other animals.

• Omnivores are animals that eat other animals and plants.

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Types of Consumers (cont.)

• Scavengers are organisms that eat dead animals.

• Decomposers break down dead organisms, and animal droppings, and other wastes produced by living things. (page 556)

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Energy in Ecosystems

Energy Through the Ecosystems

• Organisms do not create or destroy energy; they change it from one form to another.

• Energy moves one way through an ecosystem—from producers to consumers and decomposers.

13.2 Energy in Ecosystems

• Energy passes through ecosystems as food.

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Food Chains• A food chain is an illustration of how energy moves

though an ecosystem.

13.2 Energy in Ecosystems

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Food Webs• An ecosystem contains more than one type of producer,

and most organisms eat more than one type of food.

• A food web is a more complicated model of the flow of energy in an ecosystem.

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Food Webs (page 560)

13.2 Energy in Ecosystems

Energy Pyramid

Energy Pyramids• An energy pyramid is a diagram that shows how much

energy is available to each type of consumer.

– The bottom layer has the most available energy and contains the producers.

– The middle layers contain primary consumers and secondary consumers.

– The small top layer has the least available energy and contains tertiary consumers.

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Energy Pyramids (cont.)

Temperate Deciduous Forest

13.2 Energy in Ecosystems

Energy Pyramids (cont.)

Desert

13.2 Energy in Ecosystems

Energy Pyramids (cont.)

Tropical Rainforest

13.2 Energy in Ecosystems

Releasing Thermal Energy• All organisms release some energy in food as thermal

energy.

• This is why less energy is available with each step up an energy pyramid. (page 564)

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Water and Nitrogen Cycles

Cycles of Matter• The amount of matter—anything that has mass and takes

up space—on Earth never changes.

• Elements that make up matter cycle among living things and between abiotic and biotic environments.

• Water, nitrogen, phosphorus and carbon cycles.

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Water Cycle• Movement of water from Earth’s surface to the

atmosphere and back.

• Three main steps:

– Evaporation: Change from liquid water to water vapor

– Condensation: Change from water vapor to liquid water. Makes clouds.

– Precipitation: Water falls back to earth as rain, snow sleet or hail

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Water Cycle

12.1 Abiotic and Biotic Factors

Nitrogen Cycle

• Nitrifying bacteria change atmospheric nitrogen into forms of nitrogen that plants can take up through their roots.

• Consumers eat the plants and get the fixed nitrogen.

• When consumers die, fixed nitrogen is returned to the soil then bacteria releases free nitrogen back to the air. (P. 568)

• The nitrogen cycle describes how nitrogen moves from the atmosphere to the soil, to living organisms, and then back to the atmosphere.

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Phosphorus and Carbon Cycles

Phosphorus Cycle• The phosphorus cycle describes how

phosphorus moves from soil to producers and consumers, and back to soil.

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The Carbon Cycle• The carbon cycle describes how carbon moves

between the living and nonliving environments.

• Carbon is the key element in sugars, proteins, starches, and many other compounds that make up living things. (page 570)

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The Carbon Cycle (cont.)13.3 Matter in Ecosystems