Ecosystems: Components, Energy Flow, and Matter Cycling APES 2009-10 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 10-14 million Noe IE, 1.5-1.8 billion

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

The Earth’s Life-Support Systems Biosphere Atmosphere Hydrosphere Lithosphere 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 Role of climate Aquatic life zones Freshwater and Marine Fig. 4-9 p. 70

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 Biotic Determine life forms in a given area What are key abiotic factors? Contrast aquatic vs. terrestrial Biotic

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

Soluble mineral nutrients Figure 4-12 Page 72 Oxygen (O2) Sun Producer Carbon dioxide (CO2) Secondary consumer (fox) Primary consumer (rabbit) Producers Falling leaves and twigs Precipitation Soil decomposers Water Soluble mineral nutrients

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

Ecosystem Boundaries: Ecotones Fig. 4-10 p. 71

What Determines Where an Organisms Lives? Law of tolerance And the related Environmental Limiting factors 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

Figure 4-13 Page 73 – Key Abiotic Factors affecting ecosystems Terrestrial Ecosystems Aquatic Life Zones Figure 4-13 Page 73 – Key Abiotic Factors affecting ecosystems • 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

The Biotic Components of Ecosystems – Flow of Energy and Materials Fig. 4-16 p. 75

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

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

Connections: Food Webs and Energy Flow in Ecosystems Food chains Food webs Fig. 4-18 p. 77; Refer to Fig. 4-19 p. 78

Biodiversity Genetic diversity Species diversity Ecological diversity Functional diversity

Ecological Pyramids Pyramid of energy flow Ecological efficiency Pyramid of biomass Fig. 4-20 p. 79 Pyramid of numbers

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 of energy flow 10% “rule”: Where does energy go? Waste Waste

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

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

Primary Productivity of Ecosystems 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 What factors increase productivity What do humans to increase productivity of agricultural land

Primary Productivity in Different Ecosystems © 2004 Brooks/Cole – Thomson Learning 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 Figure 4-25 Page 81 Tundra (arctic and alpine) Desert scrub Extreme desert 800 1,600 2,400 3,200 4,000 4,800 5,600 6,400 7,200 8,000 8,800 9,600 Average net primary productivity (kcal/m2/yr)

Connections: Matter Cycling in Ecosystems Biogeochemical cycles: Hydrologic cycle (H2O) Atmospheric cycles (C, N) Sedimentary(mineral) cycles (P, S)

Hydrologic (Water) Cycle Fig. 4-27 p. 83

Key Processes in Carbon Cycle Inorganic carbon to organic carbon in biomolecules (living organisms) CO2 + H2O + light Carbohydrates + O2 Organic carbon to inorganic carbon Carbohydrates + O2 CO2 + H2O + light

Carbon Cycle Forms structural backbone of all organic and biomolecules Structural storage of carbon and energy-storage How is CO2 removed from atmosphere? Carbon sinks: calcium carbonate deposits large forests and oceans (plants) soil How is CO2 returned to atmosphere?

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

The Carbon Cycle (Terrestrial) Fig. 4-28 p. 84-85

The Carbon Cycle (Aquatic) Fig. 4-28 p. 84-85

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. 4-29 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. 4-30 p. 88

The Sulfur Cycle Fig. 4-31 p. 89

Loss of Nitrate Ions from Watersheds: Page 90 (read this!) © 2004 Brooks/Cole – Thomson Learning 11 9 7 5 3 1 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 1965 1966 1967 1968 Concentration (mg/liter -1) Time of deforestation Losses from disturbed watershed undisturbed watershed

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

GIS and Systems Analysis Fig. 4-32 p. 91 Fig. 4-33 p. 91

Ecosystem Services and Sustainability Fig. 4-34 p. 92