13-1 “Ecology: Studying Nature’s Houses” Objective: Objective: Define the term ecology. Define the term ecology. Explain ecology’s importance as a scientific field of study. Explain ecology’s importance as a scientific field of study.

Ecological Research Ecology is: Ecology is: Study of interactions between organisms Study of interactions between organisms Study of interaction between organisms and their environment Study of interaction between organisms and their environment

Observations Advantages: Often lead to valuable understanding of situations and phenomena; Often suggest connections between various events in nature. Advantages: Often lead to valuable understanding of situations and phenomena; Often suggest connections between various events in nature. Disadvantage: Alone cannot prove those links. Disadvantage: Alone cannot prove those links.

Experiments Advantages: Allow control of variables and the chance to manipulate each variable. Advantages: Allow control of variables and the chance to manipulate each variable. Disadvantage: In the lab it’s difficult to recreate complex relationships found in nature. Disadvantage: In the lab it’s difficult to recreate complex relationships found in nature.

Why Study Ecology? Gives us information necessary to understand and resolve many of the environmental and ecological issues that confront us. Gives us information necessary to understand and resolve many of the environmental and ecological issues that confront us.

Web of Interdependence Living things affect each other in many ways. Living things affect each other in many ways. The process of acquiring energy and nutrients joins all life together. The process of acquiring energy and nutrients joins all life together. Organisms need energy to power life’s processes and raw materials to build and maintain living tissue. Organisms need energy to power life’s processes and raw materials to build and maintain living tissue.

13-2 Ecology & Energy: Essential for Life’s Processes Objective: Objective: Describe how energy flows through the biosphere & different trophic levels. Describe how energy flows through the biosphere & different trophic levels. Define the terms consumer, producer, heterotroph, autotroph, carnivore, omnivore, parasite & decomposer. Define the terms consumer, producer, heterotroph, autotroph, carnivore, omnivore, parasite & decomposer.

What organisms can harness energy from sunlight? What organisms can harness energy from sunlight? Green Plants, Algae, some Bacteria Green Plants, Algae, some Bacteria By what process? By what process? Photosynthesis Photosynthesis Energy From the Sun

Primary Producers Autotrophs Autotrophs “self-feeders” “self-feeders” Create food from water, CO 2 and sunlight Create food from water, CO 2 and sunlight Produce all of the food for all organisms Produce all of the food for all organisms

Consumers Heterotrophs Heterotrophs “different food” “different food” Must consume food produced by the producers Must consume food produced by the producers

Heterotrophs Herbivores obtain energy by eating autotrophs (mostly plants) Herbivores obtain energy by eating autotrophs (mostly plants) Carnivores obtain energy by eating other animals (meats) Carnivores obtain energy by eating other animals (meats) Omnivores are animals who eat both plants and animals. Omnivores are animals who eat both plants and animals.

Heterotrophs Parasites are organisms that live in or on other organisms and obtain their nutrients from their living host. Parasites are organisms that live in or on other organisms and obtain their nutrients from their living host. Decomposers feed on the dead bodies of animals and plants or on their waste products. Decomposers feed on the dead bodies of animals and plants or on their waste products.

Energy Flow Through the Biosphere Energy can neither be created nor destroyed! (Law of Thermodynamics)

Energy Flow Through the Biosphere Energy flows from the sun to producers to consumers. All energy on Earth comes from the sun.

Trophic Levels Fig. 13-6, p.288 Each step in a food chain or food web Each step in a food chain or food web More levels = less energy More levels = less energy 90% of energy is lost at each level 90% of energy is lost at each level Usually no more than 5 trophic levels Usually no more than 5 trophic levels Decomposers fit in everywhere Decomposers fit in everywhere

Ecological Pyramids Fig. 13-7, p.290 Diagram how energy and nutrients decrease as you move up the trophic levels. Diagram how energy and nutrients decrease as you move up the trophic levels.

13-3 Nutrients: Building Blocks of Living Tissue Objectives: Objectives: What are nutrients? What are nutrients? Describe how nutrients are re-cycled in the biosphere. (Water, Nitrogen and Carbon) Describe how nutrients are re-cycled in the biosphere. (Water, Nitrogen and Carbon) Nutrient Limitation Nutrient Limitation

What are nutrients? The chemical building blocks of life. The chemical building blocks of life. The substances that organisms use to build living tissues and to grow. The substances that organisms use to build living tissues and to grow.

Autotrophs make complex substances such as carbohydrates, fats, and proteins from simple nutrients that they can easily get from their environment Autotrophs make complex substances such as carbohydrates, fats, and proteins from simple nutrients that they can easily get from their environment (ex. Water, carbon dioxide, nitrogen, phosphorus, and potassium). (ex. Water, carbon dioxide, nitrogen, phosphorus, and potassium). How do autotrophs obtain nutrients?

Heterotrophs must eat other organisms to obtain nutrients. Heterotrophs must eat other organisms to obtain nutrients. Fats and carbohydrates provide immediate energy or are stored in the animal’s body. Fats and carbohydrates provide immediate energy or are stored in the animal’s body. Proteins are broken down into amino acids, which are used to build the animal’s proteins. Proteins are broken down into amino acids, which are used to build the animal’s proteins. How do heterotrophs obtain nutrients?

Where does all energy on Earth come from? Light energy from the sun.

Heat energy. How do heterotrophs release energy?

Nutrient Cycles Matter can not be created nor destroyed. Matter can not be created nor destroyed. We only have what is present on the Earth. We only have what is present on the Earth. Nutrients must be recycled. Nutrients must be recycled.

Examples of Nutrient Cycles Water Water Carbon Carbon Nitrogen Nitrogen

Water Cycle

Carbon Cycle

Nitrogen Cycle N 2 in Atmosphere NH 3 NO 3 - and NO 2 -

Nutrient Limitation The size of a community depends on the amount of food produced by the autotrophs. The size of a community depends on the amount of food produced by the autotrophs. Certain nutrients are scarce, so they limit plant growth. Certain nutrients are scarce, so they limit plant growth. This is why farmers use fertilizer. This is why farmers use fertilizer.

13-4 Food Webs: Who Eats Whom? Describe a food web. Describe a food web.

Food Chains and Webs Food chain – simple diagram showing who eats who Food chain – simple diagram showing who eats who Food web – combination of all food chains in a community Food web – combination of all food chains in a community Shows complexity of feeding relationships Shows complexity of feeding relationships

Coastal Salt Marsh Food Web

13-5 The Carbon Cycle: A Closer Look The Greenhouse Effect The Greenhouse Effect The increase in warming effect on Earth. The increase in warming effect on Earth. Greenhouse gases (ex. Carbon dioxide) trap energy in the atmosphere as heat. Greenhouse gases (ex. Carbon dioxide) trap energy in the atmosphere as heat. Later heat radiates back into outer space. Later heat radiates back into outer space. BUT carbon dioxide and other gases absorb some of this heat energy forming a “heat trap” around the Earth. BUT carbon dioxide and other gases absorb some of this heat energy forming a “heat trap” around the Earth.

4 Major Carbon Pathways 1. Biological Pathways 1. Biological Pathways Photosynthesis, respiration, and death and decay of plants and animals. Photosynthesis, respiration, and death and decay of plants and animals. 2. Geochemical Pathways 2. Geochemical Pathways Release of carbon dioxide to atmosphere by volcanic activities, weathering of rocks, and exchange of carbon dioxide between the ocean and atmosphere. Release of carbon dioxide to atmosphere by volcanic activities, weathering of rocks, and exchange of carbon dioxide between the ocean and atmosphere. 3. Biogeochemical Pathways 3. Biogeochemical Pathways Burial and conversion of carbon from dead organisms into coal and petroleum. Burial and conversion of carbon from dead organisms into coal and petroleum.

4. Human-initiated Pathways 4. Human-initiated Pathways Mining, burning of fossil fuels, and cutting and burning of forests. Mining, burning of fossil fuels, and cutting and burning of forests.

Experimental Data Carbon flows between 3 major carbon reserviors. Carbon flows between 3 major carbon reserviors. Oceans, atmosphere, and deposits in the Earth. Oceans, atmosphere, and deposits in the Earth. Although the amount of carbon entering the atmosphere as a result of human activity is relatively small, its cumulative effect in the future can be significant. Although the amount of carbon entering the atmosphere as a result of human activity is relatively small, its cumulative effect in the future can be significant.

Atmospheric Carbon Dioxide Levels Gradual increase in atmospheric carbon dioxide levels is probably due to human activity. Gradual increase in atmospheric carbon dioxide levels is probably due to human activity. As the insulating layer of carbon dioxide gets thicker, it could have a warming effect on Earth. As the insulating layer of carbon dioxide gets thicker, it could have a warming effect on Earth.