Ecosystems: Components, Energy Flow, and Matter Cycling G. Tyler Miller’s Living in the Environment 13 th Edition Chapter 4 G. Tyler Miller’s Living in the Environment 13 th Edition Chapter 4

Key Concepts  Basic ecological principles  Major components of ecosystems  Matter cycles and energy flow  Ecosystem studies  Ecological services

What is Ecology?

What is a species? Appearance Behavior Chemistry Genetic makeup Under natural conditions can –Actually or potentially breed –Produce fertile offspring Excluding bacteria, maybe million –Noe IE, billion

The Nature of Ecology Ecosystem organization  Organisms  Populations  Communities  Ecosystems  Biosphere Fig. 4-2 p. 66

The Earth’s Life-Support Systems  Atmosphere  Hydrosphere  Lithosphere  Biosphere Fig. 4-6 p. 68

Population, community, ecosystem What explains continuity and diversity of life on earth? What is a community? What comprises an ecosystem?

Sustaining Life of Earth  One-way flow of energy  Biogeochemical Cycles Fig. 4-7 p. 69

The Source of Energy Fig. 4-8 p. 69 Direct Conversion to Heat: 47% Evaporation:23% Photosynthesis: about.02%

Ecosystem Concepts and Components  Biomes Fig. 4-9 p. 70  Role of climate  Aquatic life zones Freshwater and Marine

Terrestrial Biomes What factors determine climate? –Temperature –Precipitation Why do temperature and precipitation vary in different regions? Latitude and altitude –Upper air flow – carries moisture –Lower level air flow –Mountains –Large bodies water –Ocean currents

Ecosystem Concepts Abiotic Factors –Determine life forms in a given area –What are key abiotic factors? Contrast aquatic vs. terrestrial Biotic

Sun Producers (rooted plants) Producers (phytoplankton) Primary consumers (zooplankton) Secondary consumers (fish) Dissolved chemicals Tertiary consumers (turtles) Sediment Decomposers (bacteria and fungi) Figure 4-11 Page 72

Sun Producer Precipitation Falling leaves and twigs Producers Primary consumer (rabbit) Secondary consumer (fox) Carbon dioxide (CO 2 ) Oxygen (O 2 ) Water Soil decomposers Soluble mineral nutrients Figure 4-12 Page 72

Human Blue whaleSperm whale Crabeater seal Killer whale Elephant seal Leopard seal Adélie penguins Petrel Fish Squid Carnivorous plankton Krill Phytoplankton Herbivorous zooplankton Emperor penguin Figure 4-19 Page 78

Ecosystem Boundaries: Ecotones Fig p. 71

What Determines Where an Organisms Lives?  Law of tolerance  Environmental Limiting factors And the related Each species has a range of tolerance to each environmental physical and chemical factor Tolerance may vary during different stages of life cycle. Example Saguaro cacti in Sonoran desert Specialist vs. generalist species

Terrestrial Ecosystems Aquatic Life Zones Sunlight Temperature Precipitation Wind Latitude (distance from equator) Altitude (distance above sea level) Fire frequency Soil Light penetration Water currents Dissolved nutrient concentrations (especially N and P) Suspended solids Salinity Figure 4-13 Page 73 – Key Abiotic Factors affecting ecosystems

The Biotic Components of Ecosystems – Flow of Energy and Materials Fig p. 75

Mushroom Wood reduced to powder Long-horned beetle holes Bark beetle engraving Carpenter ant galleries Termite and carpenter ant work Dry rot fungus Detritus feedersDecomposers Time progression Powder broken down by decomposers into plant nutrients in soil Figure 4-15 Page 75

Trophic Levels  Primary consumer (herbivore)  Secondary consumer (carnivore)  Tertiary consumer  Omnivore  Detritivores and scavengers  Decomposers

Connections: Food Webs and Energy Flow in Ecosystems Fig p. 77; Refer to Fig p. 78  Food chains  Food webs

Biodiversity  Genetic diversity  Species diversity  Ecological diversity  Functional diversity

Ecological Pyramids  Pyramid ofenergy flow  Ecological efficiency  Pyramid of biomass  Pyramid of numbers Fig p. 79

Laws of Thermodynamics (energy) First Law of Thermodynamics –“You can’t get something for nothing” Second Law of Thermodynamics –“..and you don’t even break even!”

 Pyramid ofenergy flow 10% “rule”: Where does energy go? Waste

Abandoned FieldOcean Tertiary consumers Secondary consumers Primary consumers Producers Pyramids of Biomass:Figure 4-22 Page 80 © 2004 Brooks/Cole – Thomson Learning

Grassland (summer) Temperate Forest (summer) Producers Primary consumers Secondary consumers Tertiary consumers Pyramid of Numbers: Figure 4-23 Page 80 © 2004 Brooks/Cole – Thomson Learning

Primary Productivity of Ecosystems  Gross primary productivity (GPP)  Rate at which producers make new biomass  Gross primary productivity (GPP)  Rate at which producers make new biomass  Net primary productivity (NPP)  Gross minus what producers use in cellular respiration  This is what is “leftover” for consumers  Net primary productivity (NPP)  Gross minus what producers use in cellular respiration  This is what is “leftover” for consumers What factors increase productivity What do humans to increase productivity of agricultural land

Estuaries Swamps and marshes Tropical rain forest Temperate forest Northern coniferous forest (taiga) Savanna Agricultural land Woodland and shrubland Temperate grassland Lakes and streams Continental shelf Open ocean Tundra (arctic and alpine) Desert scrub Extreme desert 8001,6002,4003,2004,0004,8005,6006,4007,2008,0008,8009,600 Average net primary productivity (kcal/m 2 /yr) Figure 4-25 Page 81 © 2004 Brooks/Cole – Thomson Learning Primary Productivity in Different Ecosystems

Connections: Matter Cycling in Ecosystems Biogeochemical cycles:  Hydrologic cycle (H 2 O)  Atmospheric cycles (C, N)  Sedimentary(mineral) cycles (P, S)

Hydrologic (Water) Cycle Fig p. 83

Key Processes in Carbon Cycle Inorganic carbon to organic carbon in biomolecules (living organisms) CO 2 + H 2 O + light Carbohydrates + O 2 Organic carbon to inorganic carbon Carbohydrates + O 2 CO 2 + H 2 O + light

Carbon Cycle Forms structural backbone of all organic and biomolecules Structural storage of carbon and energy- storage How is CO 2 removed from atmosphere? Carbon sinks: –calcium carbonate deposits –large forests and oceans (plants) –soil How is CO 2 returned to atmosphere?

Processes that Release Organic Carbon to Carbon Dioxide Burning Cellular Respiration –plants –animals Decomposition

The Carbon Cycle (Terrestrial) Fig p

The Carbon Cycle (Aquatic) Fig p

Carbon and Humans... that fossil fuel burning releases roughly 5.5 gigatons of carbon (GtC [giga=1 billion]) per year into the atmosphere and that land-use changes such as deforestation contribute roughly 1.6 GtC per year. Measurements of atmospheric carbon dioxide levels (going on since 1957) suggest that of the approximate total amount of 7.1 GtC released per year by human activities, approximately 3.2 GtC remain in the atmosphere, resulting in an increase in atmospheric carbon dioxide. In addition, approximately 2 GtC diffuses into the world’s oceans, thus leaving 1.9 GtC unaccounted for.

Nitrogen Cycle How is N removed from the atmosphere? –Role of legumes What N-compounds are usable by living organisms? –Name all steps and bacteria involved What are several ways in which N is returned to the atmosphere? How are humans altering this cycle?

The Nitrogen Cycle Fig p. 86

Human Alteration of N-Cycle Nitric oxide into atmosphere –Acid precipitation –Nitrogen compounds into soil/water ecosystems Anaerobic decomposition of livestock waste Greenhouse gas –Comes down as nitrogen inputs Removing nitrogen from topsoil –Nitrogen rich crops –Clear forests Adding nitrogen to aquatic ecosystems –Inorganic fertilizers –Animal and human waste –Runoff

Summarize Sedimentary (Mineral) Cycles What are fundamental differences between mineral cycles and atmospheric cycles? –How do the minerals enter the biotic part of ecosystem? –What important biomolecules contain P and S? How are humans altering these cycles? –What are effects?

The Phosphorus Cycle Fig p. 88

The Sulfur Cycle Fig p. 89

J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M Concentration (mg/liter -1 ) Time of deforestation Losses from disturbed watershed Losses from undisturbed watershed Loss of Nitrate Ions from Watersheds: Page 90 (read this!) © 2004 Brooks/Cole – Thomson Learning

How Do Ecologists Learn About Ecosystems?  Field research  Remote sensing  Geographic information systems (GIS)  Laboratory research  Systems analysis

GIS and Systems Analysis Fig p. 91 Fig p. 91

Ecosystem Services and Sustainability Fig p. 92