Ecosystems: What Are They and How Do They Work? Chapter 3

Key Concepts What is ecology? What is ecology? Major components of ecosystems Major components of ecosystems Energy flow and matter cycles Energy flow and matter cycles Ecosystem studies Ecosystem studies

Importance of Insects Ecological Services Pollination Pollination Pest control Pest control Important roles in biological community Important roles in biological community

Nature of Ecology What is ecology? Study of connections in nature What is ecology? Study of connections in nature Organisms Organisms Cells Cells Species Species Microbes rule! Benefits Include: Decomposition, nutrient cycling, foods, water purification, digestion, antibiotics Microbes rule! Benefits Include: Decomposition, nutrient cycling, foods, water purification, digestion, antibiotics

Nature of Ecology Insects 751,000 Protists 57,700 Plants 248,400 Prokaryotes 4,800 Fungi 69,000 Other animals 281,000 Known species 1,412,000 Species Total? Estimated million

Levels of organization interaction Animation

See Fig. 3-4, p.42 Levels of Organization of Matter

Genetic Diversity in One Snail Species

What Sustains Life on Earth? Troposphere: Earth’s surface to 17km up- 78% N, 21% O 2 Troposphere: Earth’s surface to 17km up- 78% N, 21% O 2 Stratosphere km contains ozone layer Stratosphere km contains ozone layer Hydrosphere Hydrosphere Lithosphere = crust & upper mantle Lithosphere = crust & upper mantle Biosphere = Zone of Earth where life is found (skin of the apple) * All parts are interconnected! Biosphere = Zone of Earth where life is found (skin of the apple) * All parts are interconnected! Fig. 3-2, p. 41

Atmosphere Biosphere Crust Lower mantle Asthenosphere Upper mantle Continental crust Oceanic crust Lithosphere Vegetation and animals Soil Rock Crust (soil and rock) Atmosphere (air) Biosphere (living and dead organisms) Lithosphere (crust, top of upper mantle) Hydrosphere (water) Core Mantle What Sustains Life on Earth?

Earth’s Life-Support Systems (3 interconnected factors) One way flow of high- quality energy One way flow of high- quality energy Cycling of matter Cycling of matter Gravity - holds atmosphere, enables movement of chemicals through various spheres Gravity - holds atmosphere, enables movement of chemicals through various spheres “Energy flows, nutrients cycle.”

Biosphere Carbon cycle Phosphorus cycle Nitrogen cycle Water cycle Oxygen cycle Heat in the environment Heat Earth’s Life-Support Systems “Energy flows, nutrients cycle.”

Flow of Solar Energy to and from the Earth Greenhouse gases water vapor, CO 2, NO, CH 4, O 3 Greenhouse gases water vapor, CO 2, NO, CH 4, O 3 Greenhouse effect- Heat trapped in the troposphere to warm planet without natural greenhouse effect life would not be possible. Greenhouse effect- Heat trapped in the troposphere to warm planet without natural greenhouse effect life would not be possible. See Fig. 3-3, p. 41

Heat radiated by the earth Solar radiation Absorbed by ozone UV radiation Visible light Absorbed by the earth Reflected by atmosphere (34%) Energy in = Energy out Radiated by atmosphere as heat (66%) Lower Stratosphere (ozone layer) Troposphere Greenhouse effect Heat Flow of Solar Energy to and from the Earth Fig. 3-3, p. 41

Sun to Earth animation Animation

Why is the Earth so Favorable for Life? Liquid water Liquid water Temperature - Past 3.7 billion years average surface temp. = °F Temperature - Past 3.7 billion years average surface temp. = °F Gravity Gravity Atmosphere Atmosphere

Coniferous forest Desert Coniferous forest Prairie grassland Deciduous forest 100–125 cm (40–50 in.) 75–100 cm (30–40 in.) 50–75 cm (20–30 in.) 25–50 cm (10–20 in.) below 25 cm (0–10 in.) Average annual precipitation 4,600 m (15,000 ft.) 3,000 m (10,000 ft.) 1,500 m (5,000 ft.) Coastal mountain ranges Sierra Nevada Mountains Great American Desert Rocky Mountains Great Plains Mississippi River Valley Appalachian Mountains Coastal chaparral and scrub Major Biomes

Sun Producers (rooted plants) Producers (phytoplankton) Primary consumers (zooplankton) Secondary consumers (fish) Dissolved chemicals Tertiary consumers (turtles) Sediment Decomposers (bacteria and fungi) Major Components of Freshwater Ecosystems

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 Fig. 3-5, p. 43 Major Components of a Field Ecosystem

Matter recycling and energy flow animation Animation

ABC’s of Ecology (The study of how organisms interact with one another & their non-living environment) A= Abiotic (Non-living) B= Biotic (Living) C= Cultural (Human Interactions)

Factors Limiting Population Growth Limiting factor principle - Too much or too little of any abiotic factor can limit or prevent growth of population. Limiting factor principle - Too much or too little of any abiotic factor can limit or prevent growth of population. Limiting factors: Excess water or water shortages for terrestrial organisms Limiting factors: Excess water or water shortages for terrestrial organisms Excess or lack of soil nutrients Dissolved oxygen for aquatic organisms Salinity for aquatic organisms

Lower limit of tolerance Upper limit of tolerance TemperatureLowHigh Abundance of organisms Few organisms Few organisms No organisms No organisms Zone of intolerance Zone of physiological stress Zone of intolerance Zone of physiological stress Optimum range Population Size Range of Tolerance

Factors That Limit Population Growth Range of tolerance : range of abiotic conditions required for population to survive Range of tolerance : range of abiotic conditions required for population to survive Law of tolerance “The existence, abundance and distribution of a species in an ecosystem are determined by whether the levels of one or more physical or chemical factors fall within the range tolerated by that species.” Law of tolerance “The existence, abundance and distribution of a species in an ecosystem are determined by whether the levels of one or more physical or chemical factors fall within the range tolerated by that species.”

Consumers: Feeding and Respiration Decomposers (Fungi & Bacteria) - specialized consumers that breakdown detritus (dead stuff) into inorganic nutrients that can be reused by producers Decomposers (Fungi & Bacteria) - specialized consumers that breakdown detritus (dead stuff) into inorganic nutrients that can be reused by producers Omnivores Omnivores Detritivores- Decomposers & detritus feeders Detritivores- Decomposers & detritus feeders Aerobic respiration glucose + oxygen = carbon dioxide + water + ENERGY Aerobic respiration glucose + oxygen = carbon dioxide + water + ENERGY

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 Fig. 3-6, p. 44 Detritivores Decomposers convert organic chemicals to inorganic chemicals that can be used by producers

Fig. 3-7, p. 45 Decomposers bacteria, fungi) Solar energy Heat Abiotic chemicals (carbon dioxide, oxygen, nitrogen, minerals) Consumers (herbivores, carnivores) Producers (plants) Main Structural Components of an Ecosystem

Linked processes animation Animation

The role of organisms in an ecosystem Animation

Fig. 3-14, p. 45 Biodiversity (4 Components)

Examples of Biodiversity

Fig. 3-8, p. 46 First Trophic Level Second Trophic Level Third Trophic Level Fourth Trophic Level Producers (plants) Primary consumers (herbivores) Secondary consumers (carnivores) Tertiary consumers (top carnivores) Detritivores decomposers and detritus feeders) Solar energy Heat Model of a Food Chain

Humans Blue whale Sperm whale Crabeater seal Killer whale Elephant seal Leopard seal Petrel Fish Squid Carnivorous plankton Krill Phytoplankton Herbivorous zooplankton Emperor penguin Fig. 3-9, p. 46 Food Web in the Antarctic Adélie penguins

Energy Flow in an Ecosystem Biomass Biomass Ecological efficiency = % of usable energy transferred as biomass from one trophic level to the next (2% - 40%) 10% Rule - assumes 10% ecological efficiency Ecological efficiency = % of usable energy transferred as biomass from one trophic level to the next (2% - 40%) 10% Rule - assumes 10% ecological efficiency Pyramid of energy flow Pyramid of energy flow

See Fig. 3-10, p. 47 Secondary consumers (perch) ,000 10,000 Usable energy available at each tropic level (in kilocalories) Heat Producers (phytoplankton) Tertiary consumers (human) Primary consumers (zooplankton) Pyramid of Energy Flow Decomposers

Biomass Productivity Gross primary productivity (GPP) rate at which producers in an ecosystem convert sun into food Gross primary productivity (GPP) rate at which producers in an ecosystem convert sun into food Net primary productivity (NPP)= GPP - Respiration Net primary productivity (NPP)= GPP - Respiration NPP and populations NPP limits the number of consumers that can live on earth NPP and populations NPP limits the number of consumers that can live on earth

Energy lost and unavailable to consumers Respiration Growth and reproduction Sun Photosynthesis Gross primary production Net primary production (energy available to consumers) Differences between GPP and NPP

Fig. 3-11, p. 48 Swamps and marshes Tropical rain forest Temperate forest Northern coniferous forest (taiga) Savanna Agricultural land Woodland and shrubland Temperate grassland Tundra (arctic and alpine) Desert scrub Extreme desert Aquatic Ecosystems Estuaries Lakes and streams Continental shelf Open ocean Terrestrial Ecosystems 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/m 2 /yr) Net Primary Productivity in Major Life Zones and Ecosystems

Matter Cycling in Ecosystems: Biogeochemical Cycles Hydrologic (water) cycle Hydrologic (water) cycle Carbon cycle Carbon cycle Nitrogen cycle Nitrogen cycle Phosphorus cycle Phosphorus cycle Sulfur cycle Sulfur cycle

Precipitation to land Evaporation From ocean Ocean storage Condensation Transpiration Rain clouds Infiltration and percolation Transpiration from plants Groundwater movement (slow) Precipitation Simplified Hydrologic (Water) Cycle Surface runoff (rapid) Evaporation From ocean Rapid Precipitation to ocean Surface runoff (rapid)

Human Interventions in the Hydrologic Cycle 1. Large withdraw of surface and ground waters 2. Clearing vegetation / wetland destruction -  runoff,  infiltration,  groundwater recharge,  flood risk,  soil erosion & landslides 3. Pollution - addition of nutrients

Diffusion between atmosphere and ocean Carbon dioxide dissolved in ocean water Marine food webs Producers, consumers, decomposers, detritivores Marine sediments, including formations with fossil fuels Combustion of fossil fuels The Carbon Cycle (Marine) sedimentation uplifting over geologic time photosynthesis aerobic respiration death, sedimentation incorporatio n into sediments

Atmosphere (most carbon is in carbon dioxide) Terrestrial rocks Land food webs Producers, consumers, decomposers, detritivores Peat, fossil fuels Soil water (dissolved carbon) Combustion of fossil fuels volcanic action The Carbon Cycle (Terrestrial) photosynthesis death, burial, compaction over geologic time aerobic respiration deforestaion combustion of wood (for clearing land; or fuel) weathering leaching, runoff

Fig. 3-26, p. 56 High projection Low projection Human Interferences in the Global Carbon Cycle 1.Clearing Vegetation 2.Burning Fossil Fuels potential consequences?

Gaseous Nitrogen (N2) in Atmosphere Nitrogen Fixation by industry for agriculture Food Webs on Land Fertilizers uptake by autotrop hs excretion, death, decomposition uptake by autotrop hs Nitrogenous Wastes, Remains in Soil NO 3 – in Soil NO 2 – in Soil loss by leaching 1. Nitrification bacteria convert NH 4 + to nitrite (NO 2 – ) 2. Nitrification bacteria convert NO 2 – to nitrate (NO 3 – ) Ammonification bacteria, fungi convert the residues to NH 3 ; this dissolves to form NH 4 + NH 3, NH 4 + in Soil loss by leaching Nitrogen Fixation bacteria convert N 2 to ammonia (NH 3 ); this dissolves to form ammonium (NH 4 + ) Denitrification by bacteria The Nitrogen Cycle

Human Interferences in the Global Nitrogen Cycle 1.Add nitric oxide (NO) to atmosphere - can form acid rain 2.Add nitrous oxide N 2 O to atmosphere via anaerobic decomposition & inorganic fertilizers - greenhouse gas 3.Nitrate in inorganic fertilizers can leach thru soil & contaminate groundwater 4.Release large quantities of N into troposphere via habitat destruction 5.Upset aquatic ecosystems from excess nitrates in ag. runoff & sewage- eutrophication

Marine Sediments Rocks Marine Food Webs Dissolved in Ocean Water Dissolved in Soil Water, Lakes, Rivers Land Food Webs Guano Fertilizer excretion uptake by autotrophs death, decomposition sedimentation settling out uplifting over geologic time weathering uptake by autotrophs weathering mining leaching, runoff agriculture The Phosphorus Cycle

Human Interventions in the Phosphorus Cycle 1.Mining of phosphate rock 2. Clearing tropical forests reduces available phosphate in tropical soils 3.Phosphates from runoff of animal wastes, sewage & fertilizers disrupts aquatic ecosystems - eutrophication “Since 1900, human activities have increased the natural rate of phosphorous release to environment by about 3.7 fold”

Ocean Hydrogen sulfide Industries Volcano Oxygen Water Ammonia Sulfur trioxideSulfuric acid Acidic fog and precipitation Ammonium sulfate Plants Animals Sulfate salts Hydrogen sulfide Sulfur Decaying matter Metallic Sulfide deposits Dimethyl sulfide Sulfur dioxide The Sulfur Cycle

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