Chapter 16: Ecosystems Ecology: study of interactions among organisms & and their environment Term first coined in 1866 by Ernst Haeckel to describe how organisms fit into their environment.Term first coined in 1866 by Ernst Haeckel to describe how organisms fit into their environment. “oikos” or house“oikos” or house “logos” or study of“logos” or study of

Questions Thinking Question #1: What evidence do you see that people in our society today are aware of the interdependence of living things? Thinking Question #2: How do animals benefit plants?

Levels of Organization Activity

Ecology: Levels of Organization 1. Organism: an individual living thing Example: You are a living thing as is an ant crawling across the floor and bacterium living in your intestines 2. Species: group of organisms that are closely related & can mate to produce fertile offspring Example: All humans belong to the same species Homo sapiens, while all black widow spiders belong to the species Latrodectus mactans

Levels of Organization Cont… 3. Population: all the members of the same species that live in the same place at the same time. Example: All the field mice in a cornfield make up one population of field mice

Levels of Organization Cont… 3. Community: group of various species that live in the same place and interact with each other. Example: A pond community includes all of the populations of plants, fish, amphibians, birds, insects, and microorganisms that live in the pond

Levels of Organization Cont 4. Ecosystem: is a community and the abiotic (nonliving) factors in the area in which a community lives. Thinking Question #3: List some abiotic factors. Thinking Question #4: Based on the definition for abiotic factors define biotic factors.

Biotic and Abiotic Factors

Levels of Organization Cont: 5. Biomes: ecosystems that cover large geographic areas Examples: tundra, coniferous forest, grassland, savanna, desert, tropical rainforest

Levels of Organization Cont 6.Biosphere: contains the combined portions of the planet on which all life exists including land, water, and air

LEVELS OF ECOLOGICAL ORGANIZATION 1. Individual (Organism) 2. Population 3. Community 4. Ecosystem 5. Biome 6. Biosphere

Levels of Organization

Biodiversity Biodiversity : variety of organisms, genetic differences, communities, and ecosystems on EarthBiodiversity : variety of organisms, genetic differences, communities, and ecosystems on Earth

Biodiversity Thinking Question #5: Discuss the importance of biodiversity within an ecosystem.

Importance of Biodiversity Gives our world beauty Brings stability to an ecosystem Provides resources to humans.

Importance of Biodiversity Species of many kinds have provided us with foods, industrial products & medicines Examples: painkillers, antibiotics, heart drugs, antidepressants, & anticancer drugs

Human Impact Thinking Question #7: Identify ways in which humans are impacting earth’s biodiversity? Why might this be a problem? What can you do about it?

Human Impact

Ecological Succession Ecological Succession: series of predictable changes that occur in an ecosystem over time One community is gradually replaced by another community Example: Pond fills up with silt and fallen leaves turns into a marsh and then into dry land

Primary Succession Primary Succession: succession that occurs on surfaces where no soil exists. Pioneer species: first organisms to colonize landPioneer species: first organisms to colonize land

Lake succession

Secondary Succession Secondary Succession: occurs when environmental disturbance changes existing community without removing the soil. Causes for secondary succession: A. Natural disasters: Ex: forest fires, floods, etc B. Human Activity: Ex: Slashing/burning, abandonment of farmland, logging

Secondary Succession

Ecological Succession

Succession Game 6-assignment-discovery-succession-in-the- environment-video.htmhttp://science.howstuffworks.com/life/ assignment-discovery-succession-in-the- environment-video.htm

Connections: Partner Activity Compare and contrast ecological succession to evolution.

Energy Flow in Ecosystems Thinking Question #8: Where does the energy come from to power Earth’s ecosystems?

Energy flow in Ecosystems Photosynthetic organisms convert the sun’s energy into useful compounds.Photosynthetic organisms convert the sun’s energy into useful compounds. Plants and bacteria are classified as the producers of an ecosystem.Plants and bacteria are classified as the producers of an ecosystem..

Primary Productivity of Ecosystem The primary productivity: measures the amount of organic material produced via photosynthesis.The primary productivity: measures the amount of organic material produced via photosynthesis.

Consumers: Organisms that eat (consume) the producers in an ecosystem. Consumers: Organisms that eat (consume) the producers in an ecosystem. Types of consumers:Types of consumers: –Herbivores - plant eaters –Carnivores - meat eaters –Omnivores - plant/meat eaters –Detritivores - organic wastes and dead organisms eaters –Decomposers - cause decay (bacteria and fungi) and recycle nutrients back into the ecosystem Consumers

Thinking Question #9: What kind of consumer are you? Explain

How Does the Energy Flow? Energy flows from the sun up through levels of organisms in an ecosystem Each level of organisms in an ecosystem in which energy flows is called a trophic level The sun is always at the beginning, so it can be said to be at trophic level 0

Energy Flow: Trophic Levels Thinking Question #10: A.In what trophic level is the snake located? A.In what trophic level are you located

Energy Flow Food ChainFood Web

Thinking Question #11 In a food web or food chain, which way does the arrow go? Why?

Energy Flow Thinking Question #12: A. Identify the differences between a food web and a food chain? B. Identify which is a more realistic representation of an ecosystem (food web or food chain). EXPLAIN

Energy Flow: Food Web Energy flow does not follow simple straight pathways like those represented in food chains as many organisms feed at several trophic levels Food web which connects numerous food chains together is a better representation of energy flow in an ecosystem

Food Web/Biodiversity Activity

Energy Pyramids Energy Pyramid: Diagram which shows how energy is lost as you move from one trophic level to the next Each trophic level is a block & blocks are stacked on top of one another with lowest trophic level on the bottom

Energy Loss As you move from one trophic level to the next only 10% of the energy is transferred. Thinking Question #13: A plant gets 100% of the sun’s energy, but when I eat the plant I only get 10% of that original 100%. Why? Where did the other 90% go?

Energy Loss The organisms in each trophic level must use the energy to nourish themselves, grow and reproduce. When I eat a plant only 10% of that initial 100% is left unused by the plant. Thinking Question #14: Do I gain more direct energy by eating a steak or eating a salad? Explain your answer

Biomass Pyramid A biomass pyramid shows the total dry weight of tissue and other organic matter found at each trophic level of an ecosystem Just like the energy pyramid only 10% of the biomass is transferred to the next trophic level

Pyramid of Numbers Pyramid of numbers shows the number of individuals at each trophic level

Pyramid Partner Activity Use the table to answer the following questions. (You may not use all the information from the table) 1.Create a food web 2.Use the table to create an energy pyramid. Include the organism name and the correct number information 3.Use the table to create a biomass pyramid. Include the organism name and the correct number information 4.Use the table to create a pyramid of numbers. Include the organism name and the correct number information Organism Name Number of Organisms on Farm Number of Calories Mass of Organisms (g) Cows grams Human Family grams Grass grams Chickens grams Corn grams

Circle of Life Thinking Question #15: The movie the Lion King demonstrated the “Circle of Life”, but in real life is an ecosystem a circle? What is cycled throughout an ecosystem and what is not? Explain

Notes: Cycles of Matter Organisms need energy but they also need water, minerals, and other compounds to survive 95 % of any organism is made up of four elements: 1.Oxygen 2.Carbon 3.Hydrogen 4.Nitrogen

Biogeochemical Cycles Unlike energy matter is recycled in an ecosystem Biogeochemical cycles: passing of matter, elements, and chemical compounds between organisms and the biosphere. Biogeochemical cycles pass the same molecules around again and again within the biosphere Carbon, nitrogen, and phosphorus are nutrient cycles

Water Cycle Water moves between the ocean, atmosphere, and land Water enters the atmosphere in two ways: A. Evaporation: water changes from a liquid to a gas B. Transpiration: water enters the atmosphere by evaporating from the leaves of plants Water returns to the earth through the process of condensation: water vapor cools into a liquid and returns to earth in the form of precipitation (rain, snow, sleet, or hail

Water Cycle What happens to the water once it returns to land? A.Runs off and is carried by a river or a stream to an ocean or a lake B.Water seeps into the soil and enters the roots of plants ***CYCLE THEN REPEATS ITSELF

Water Cycle

Water Cycle Survivor You will be working with a partner for this activity khttp:// k sHbIhttps:// sHbI

Water Facts Average person uses gallons of water per day Freshwater makes up less than 3% of water on earth, and over two-thirds of this is tied up in polar ice caps and glaciers. Freshwater lakes and rivers make up only 0.009% of water on Earth and groundwater makes up 0.28%.

Nutrient Cycles: Carbon Cycle Organisms need nutrients to build tissues and carry out essential life functions. Carbon, nitrogen, and phosphorus are nutrients that are passed like water between organisms and through the biosphere Carbon is the key ingredient in all living organisms Carbon is found in the oceans, air, and certain types of rocks

Carbon Cycle: 4 Different kinds of processes are involved in the carbon cycle: 1.Biological Processes: a. Photosynthesis: (plants take in carbon dioxide and use carbon to build carbohydrates b. Human respiration: (release CO 2 into the air) c. Decomposition of plants and animals: (releases CO 2 into the air)

Carbon Cycle Continued: 2. Geochemical Processes: release of Carbon dioxide gas to the atmosphere by volcanoes 3. Mixed Biogeochemical Processes: carbon rich organisms that are buried deep within the earth are converted into coal and oil over time through pressure 4. Human Activity: a. Mining b. Burning of fossil fuels c. Slashing and burning of forests

Carbon Cycle

Global Warming Video Clip nvironment/global-warming- environment/global-warming-101/ nvironment/global-warming- environment/global-warming-101/

Carbon Cycle gCarbon640360http://climate.nasa.gov/climate_reel/Keepin gCarbon640360

Label the Component of the Carbon Cycle

Nitrogen Cycle All organisms require nitrogen to make amino acids which are the building blocks of proteins PROBLEM: Nitrogen gas (N 2 ) makes up 78% of earth’s atmosphere, but most plants and animals cannot use this form of nitrogen.

Nitrogen Fixation Nitrogen Fixation: bacteria convert nitrogen gas (N 2 ) into ammonia (NH 3 ). Rhizobium bacteria live in the soil and on the roots of plants called legumes.

Plants Use Ammonia Ammonia (NH 3 ) can then be used by plants to make proteins. Consumers then eat the producers and reuse their nitrogen to make their own proteins.

Dentrification When plants and animals die, bacteria change their nitrogen content into ammonia (NH 3 ) or nitrites (N 2 - ) & nitrates (NO 3 - ) which can then be used again by producers OR Denitrification: Some bacteria can convert the nitrate ions back into nitrogen gas. This process releases nitrogen into the atmosphere again and the cycle continues

Nitrogen Cycle People add nitrite or nitrate into the soil when they use synthetic fertilizers Lightning forms some nitrate

Nitrogen Cycle

Nitrogen Cycle/Energy Pyramid Activity: Computer Activity

Ecology Part II: Community Interactions & Population Growth

Community Interactions Habitat: place where an organism lives out its life Ex: the habitat of a frog could be a pond Niche: all the interactions a species has with the abiotic and biotic parts of its habitat Ex: Niche includes -how an organism gets its food -what its food is -where and what it needs to survive -how it reproduces Habitat is an organism’s home “address” Niche is an organism’s occupation “profession”

Types of Niches Fundamental Niche: -The entire habitat that an organisms could live in -”Potential Niche” Realized Niche: -The part of the habitat that the organisms does live in -”Actual Niche”

Fundamental vs. Realized Niche

Thinking Question #1 With a partner come up with a paragraph explaining your fundamental and realized niche. Using the white board draw a picture of your realized niche.

Type of Community Interactions: Competition Competition occurs when organisms of the same species try to use the same resources in the same habitat Thinking Question #2: What are three resources that organisms might compete for Competitive Exclusion Principle: no two species can occupy the same niche in the same habitat at the same time

Thinking Question #3 What happens if two species try to occupy the same niche?

Community Interactions: Predation Predation: interaction that occurs when one organism captures and feeds on another organism Predator: organisms that does the killing (ex. shark) Prey: organism that becomes the food (small fish) Summary: One species benefits while the other species is disadvantaged (+/ -)

Community Interactions: Symbiosis Symbiosis is an relationship in which two species live closely together Three main types of symbiotic relationships: 1. Mutualism 2. Commensalism 3. Parasitism

Community Interactions: Commensalism Commensalism: interactions when one species benefits and the other species is neither benefited nor harmed Ex: Barnacles attach to a whale’s skin. The barnacles do not help or harm a whale, but the barnacle benefits from the food found in the constant movement of the water as the whale swims Summary: One species benefits, the other is unaffected (+/0)

Community Interactions: Mutualism Mutualism: an interaction where both species benefit Ex: Pollination (flower and bees) plant gains gamete (sperm) transfer and the animal gets nectar Summary: both benefit (+/+)

Community Interactions: Parasitism Parasitism: one organism (parasite) lives on or inside another organism (the host) and harms it. Parasite steals nutrients from the host usually weakening the host but not killing it Ex: tapeworms live in the intestines of humans and feed off of the nutrients we eat Summary: one species benefits the other is harmed (+/-) Thinking Question #4: Why do you think parasites rarely kill their hosts? The Parasite Picture Gallery

Parasitism: Tick

MULTI CELLULAR ORGANISMS are so large they can usually be seen with the naked eye. Tapeworms, for instance, can reach a length of 6 meters (20 feet).

The Monsters Inside Me

Populations Thinking Question #5: Can a population of organisms grow indefinitely? Why or why not?

Population Growth Review Population: is a term used to define all of the individuals of a single species that live together in one place at one time. Limited resources determine how quickly, if at all, the population will grow (food, water, space) Demographics refers to the study of population trends.

Thinking Question #6 Which has a better chance for survival a population of 25 squirrels (AKA rats with tails) or a population of 300 squirrels. Why? PS: I don’t like squirrels

Characteristics of Population: Population Size Population size: the number of individuals in a population Population size may determine how quickly a population may become extinct The smaller the population, the greater the chance that the population may become extinct due to some natural disturbance (fire/flood/disease) or be subject to weakening due to inbreeding.

Characteristics of Populations: Population Density Population density is defined as the number of individuals that live in a given area. The smaller the area, the larger the chance for reproduction and the potential for weakening due to inbreeding.

Characteristics of Populations: Dispersion Population dispersion: how the population is spread out or distributed, can also be studied by demographers. Three basic dispersion patterns: 1. Clumped 2. Uniform or even 3. Random

Population size, density, & dispersion

Population Models Demographers predict how populations will change using population models. A population model is a hypothetical population (pretend population) Using these hypothetical populations, demographers can change factors such as the birth and death rate and look at how these changes affect a population

Population Model: Simple Growth Population models look at the growth rate of a population Growth Rate: difference between birth and death rate Birthrate - Death rate = r

Thinking Question #7 What has to happen regarding the birth and death rate for a population to grow?

Population Model: Exponential Growth Curve When the rate of population growth is steady and the population continues to grow, exponential growth occurs

Thinking Question #8 Most populations do not grow exponentially for long. Why do you believe this is the case?

Limits to Exponential Growth Exponential growth is usually limited by predators, disease, and limited resources

Carrying Capacity The number of organisms of one species that an environment can support is called its carrying capacity.

Thinking Question #9 Has the human population reached its carrying capacity yet? Why or why not?

Logistic Growth Model When a population’ growth stabilizes because it has reached its carrying capacity, the limits imposed by the available resources, the population model is said to be logistic

Logistic vs. Exponential Growth

Thinking Question #10 A.Which is a more realistic model of population growth, logistic or exponential? Explain your answer B.Is the human population growing logistically or exponentially, why or why not?

Population Growth Lab Carrying Capacity Activity Population Growth Lab

Limiting Factors Limiting Factors: any factor that limits population growth. Limiting factors can be both abiotic and biotic. Two types of limiting factors: 1.Density- Dependent Limiting Factors 2. Density Independent Limiting Factors

Density Dependent Factors Density Dependent Factors: Factors that come into play when a population size (density) reaches a certain level (gets too big) Thinking Question #11: What are some examples of density-dependent factors?

Density-Dependent Factors 1. Competition (for resources) 2. Predation 3. Parasitism & Disease (accumulation of wastes etc)

Density Independent Factors Factors that affect a population regardless of how big or small the population is. 4 types of Density Independent Factors: 1. Unusual Weather 2. Natural Disasters 3. Seasonal Cycles 4. Human Activities