Ecosystems Chapter 30 Ecosystem An array of organisms

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Ecosystems Chapter 30

Ecosystems Chapter 30

Ecosystem An array of organisms and their physical environment, interconnected through a one-way flow

Ecosystem An array of organisms and their physical environment, interconnected through a one-way flow of energy and cycling of raw materials

Modes of Nutrition • Photoautotrophs – Capture sunlight or chemical energy – Primary producers

Modes of Nutrition • Photoautotrophs – Capture sunlight or chemical energy – Primary producers • Heterotrophs – Extract energy from other organisms or organic wastes – Consumers, decomposers, detritivores

Simple Ecosystem Model Energy input from sun Producers Autotrophs (plants and other self-feeding organisms)

Simple Ecosystem Model Energy input from sun Producers Autotrophs (plants and other self-feeding organisms) Nutrient Cycling Consumers Heterotrophs (animals, most fungi, many protists, many bacteria) Energy output (mainly metabolic heat)

Simple Ecosystem Model The role of organisms in an ecosystem

Simple Ecosystem Model The role of organisms in an ecosystem

marsh hawk crow garter snake cutworm flowering plants fifth trophic level top carnivore (fourth-level

marsh hawk crow garter snake cutworm flowering plants fifth trophic level top carnivore (fourth-level consumer) fourth trophic level carnivore (third-level consumer) third trophic level carnivore (second-level consumer) second trophic level herbivore (primary consumer) first trophic level autotroph (primary producer) Fig. 30 -3, p. 528

Tall-Grass Prairie Food Web marsh hawk sandpiper crow snake frog weasel badger coyote spider

Tall-Grass Prairie Food Web marsh hawk sandpiper crow snake frog weasel badger coyote spider sparrow earthworms, insects vole pocket gopher grasses, composites ground squirrel

marsh hawk Higher Trophic Levels Connections in a tallgrass prairie food web crow upland

marsh hawk Higher Trophic Levels Connections in a tallgrass prairie food web crow upland sandpiper garter snake frog weasel spider Second Trophic Level sparrow earthworms, insects First Trophic Level badger coyote prairie vole pocket gopher ground squirrel grasses, composites Fig. 30 -4, p. 529

Which statement about ecosystems is false? 1. 2. 3. 4. energy flows in a

Which statement about ecosystems is false? 1. 2. 3. 4. energy flows in a cycle between producers and consumers nutrients are recycled by passing from producers to consumers and back again via decomposers in most ecosystems, energy flow begins with the capture of solar energy by photosynthesizers heterotrophs include bacteria and fungi

Rain Forest Rain-forest food web

Rain Forest Rain-forest food web

Energy Losses • Energy transfers are never 100% efficient • Some energy is lost

Energy Losses • Energy transfers are never 100% efficient • Some energy is lost at each step • Limits number of trophic levels in an ecosystem

Grazing Food Web Detrital Food Web Two Types of Food Webs Energy Input: Transfers:

Grazing Food Web Detrital Food Web Two Types of Food Webs Energy Input: Transfers: Producers (photosynthesizers) energy in organic wastes, remains herbivores carnivores energy losses as metabolic heat and as net export from ecosystem energy in organic wastes, remains detritivores decomposers Energy Output energy losses as metabolic heat and as net export from ecosystem

Ecological Pyramids • Primary producers are bases for successive tiers of consumers • Biomass

Ecological Pyramids • Primary producers are bases for successive tiers of consumers • Biomass pyramid – Dry weight of all organisms • Energy pyramid – Usable energy decreases as it is transferred through ecosystem

Biomass Pyramid • Aquatic ecosystem, Silver Springs, Florida • Long-term study of a grazing

Biomass Pyramid • Aquatic ecosystem, Silver Springs, Florida • Long-term study of a grazing food web decomposers, detritivores (bacteria, crayfish) 5 1. 5 third-level carnivores (gar, large-mouth bass) 1. 1 second-level consumers (fishes, invertebrates) 37 first-level consumers (herbivorous fishes, turtles, invertebrates) 809 primary producers (algae, eelgrass, rooted plants)

Energy Pyramid • Primary producers trapped about 1. 2% of the solar energy that

Energy Pyramid • Primary producers trapped about 1. 2% of the solar energy that entered the ecosystem • 6– 16% passed on to next level 21 top carnivores herbivores producers decomposers + detritivores = 5, 080 383 3, 368 20, 810 kilocalories/square meter/year

Silver Springs Study Energy flow at Silver Springs

Silver Springs Study Energy flow at Silver Springs

Biogeochemical Cycle • Flow of an essential substance from the environment to living organisms

Biogeochemical Cycle • Flow of an essential substance from the environment to living organisms and back to the environment • Main reservoir is in the environment • Geologic processes, decomposers aid cycles

Three Categories • Hydrologic cycle – Water • Atmospheric cycles – Nitrogen and carbon

Three Categories • Hydrologic cycle – Water • Atmospheric cycles – Nitrogen and carbon • Sedimentary cycles – Phosphorus and other nutrients

Hydrologic Cycle atmosphere wind-driven water vapor 40, 000 evaporation precipitation from ocean into ocean

Hydrologic Cycle atmosphere wind-driven water vapor 40, 000 evaporation precipitation from ocean into ocean 425, 000 385, 000 precipitation onto land 111, 000 evaporation from land plants (evapotranspiration) 71, 000 surface and groundwater flow 40, 000 ocean land

Watershed • A region where precipitation is funneled into a single stream or river

Watershed • A region where precipitation is funneled into a single stream or river

Hubbard Brook Experiment • A watershed was experimentally stripped of vegetation • All surface

Hubbard Brook Experiment • A watershed was experimentally stripped of vegetation • All surface water draining from watershed was measured • Deforestation caused six-fold increase in calcium content of runoff water

Global Water Crisis • Limited amount of fresh water • Desalinization is expensive and

Global Water Crisis • Limited amount of fresh water • Desalinization is expensive and requires large amounts of energy • Aquifers are being depleted • Groundwater is contaminated • Sewage, agricultural runoff, and industrial chemicals pollute rivers

Aquifer Depletion Hawaiian Islands Alaska

Aquifer Depletion Hawaiian Islands Alaska

When the Earth's waters move from ocean to atmosphere to land back again, it

When the Earth's waters move from ocean to atmosphere to land back again, it is called the _____ cycle. 1. water 2. hydrologic 3. hydrodynamic 4. precipitation

A watershed is _____. 1. a stream or river 2. a river that discharges

A watershed is _____. 1. a stream or river 2. a river that discharges water directly into the ocean 3. a region where precipitation becomes funneled into a single stream or river 4. a region where precipitation becomes funneled into a reservoir for use in human communities

Carbon Cycle • Carbon moves through atmosphere, food webs, ocean, sediments, and rocks •

Carbon Cycle • Carbon moves through atmosphere, food webs, ocean, sediments, and rocks • Sediments and rocks are the main reservoir • Combustion of fossil fuels changes natural balance

diffusion between atmosphere and ocean bicarbonate and carbonate in ocean water photosynthesis combustion of

diffusion between atmosphere and ocean bicarbonate and carbonate in ocean water photosynthesis combustion of fossil fuels aerobic respiration marine food webs death, incorporation sedimentation into sediments uplifting sedimentation marine sediments Carbon Cycle: Marine

atmosphere combustion of fossil fuels volcanic action terrestrial rocks weathering photosynthesis aerobic combustion respiration

atmosphere combustion of fossil fuels volcanic action terrestrial rocks weathering photosynthesis aerobic combustion respiration of wood land food webs deforestation soil water leaching, runoff death, burial, compaction over geologic time Carbon Cycle: Land peat, fossil fuels

My Carbon Cycle 1. I eat carbohydrate molecules. – These are molecules of fuel

My Carbon Cycle 1. I eat carbohydrate molecules. – These are molecules of fuel which I will “burn”. – Some of the energy released when I burn them will be trapped for me to use. The rest will be lost as heat. 2. The waste products of burned fuel are carbon dioxide and water. I breathe these out. 3. Plants (or other producers) take in carbon dioxide from the atmosphere and use it to make carbohydrate.

According to the last slide, why do I eat carbohydrates? 1. Because they taste

According to the last slide, why do I eat carbohydrates? 1. Because they taste good. 2. Because they contain lots of vitamins. 3. Because they contain lots of energy. 4. Because they are low in calories.

Energy saved from burning up my fuel is saved in the form of :

Energy saved from burning up my fuel is saved in the form of : 1. 2. 3. 4. Muscle ATP Fat Heat

The only reason I need to breathe in oxygen is : 1. I need

The only reason I need to breathe in oxygen is : 1. I need oxygen to “burn” fuel molecules. 2. All living things need oxygen. 3. Oxygen + carbon = carbon dioxide. 4. Oxygen is corrosive.

Breathing out : 1. Helps me regulate my body temperature. 2. Gets rid of

Breathing out : 1. Helps me regulate my body temperature. 2. Gets rid of excess fuel molecules. 3. Burns extra calories. 4. Gets rid of the waste products of burned fuel.

The carbon in the plants I eat comes from : 1. 2. 3. 4.

The carbon in the plants I eat comes from : 1. 2. 3. 4. The atmosphere. The food they eat. The soil. Water.

The carbon in the steak I eat comes from : 1. Supplements in animal

The carbon in the steak I eat comes from : 1. Supplements in animal feed. 2. Vitamins. 3. The cow’s drinking water. 4. The plants eaten by the cow.

Greenhouse Effect • Greenhouse gases impede escape of heat from Earth’s surface

Greenhouse Effect • Greenhouse gases impede escape of heat from Earth’s surface

Global Warming Long-term increase in temperature of Earth’s lower atmosphere

Global Warming Long-term increase in temperature of Earth’s lower atmosphere

Carbon Dioxide Increase • Carbon dioxide levels fluctuate seasonally • Average level is steadily

Carbon Dioxide Increase • Carbon dioxide levels fluctuate seasonally • Average level is steadily increasing • Burning of fossil fuels and deforestation are contributing to the increase

Other Greenhouse Gases • CFCs: synthetic gases used in plastics and in refrigeration •

Other Greenhouse Gases • CFCs: synthetic gases used in plastics and in refrigeration • Methane: released by natural gas production, livestock • Nitrous oxide: released by bacteria, fertilizers, and animal wastes

Greenhouse Gases Increasing

Greenhouse Gases Increasing

Table 30 -1, p. 537

Table 30 -1, p. 537

Nitrogen Cycle • Nitrogen is used in amino acids and nucleic acids • Main

Nitrogen Cycle • Nitrogen is used in amino acids and nucleic acids • Main reservoir is nitrogen gas in the atmosphere • Nitrogen gas can’t enter food web

Fig. 30 -16, p. 538

Fig. 30 -16, p. 538

Nitrogen Fixation • Plants cannot use nitrogen gas • Nitrogen-fixing bacteria convert nitrogen gas

Nitrogen Fixation • Plants cannot use nitrogen gas • Nitrogen-fixing bacteria convert nitrogen gas into ammonia (NH 3) • Ammonia and ammonium can be taken up by plants

Air Pollution • Effects of nitrogen oxides released by burning fossil fuels

Air Pollution • Effects of nitrogen oxides released by burning fossil fuels