Chapter 4: Ecosystems The Living World Unit

Members of an Ecosystem Eukaryotic cells (have nucleus) Prokaryotic cells (no nucleus/bacteria) Different Species Within a specific range/distribution Direct or indirect interactions among populations ALL ecosystems make up Earth’s Biosphere

Biosphere 2 Project 3.15 acre structure built in the 1980’s in Arizona to see if a sealed, self-sustaining environment was possible. ($200 million; privately funded) Unable to control temperature Contained: Over 3,500 plant and animal species 5 biomes: desert, grassland, marsh, ocean, rainforest 8 humans (1991-1993) Outcome: After 1 year, oxygen levels dropped too much and had to be pumped in 76% of vertebrate species went extinct Ocean became too acidic Air pollution Is now owned by Columbia University

(crust, top of upper mantle) Oceanic crust Continental crust Vegetation and animals Biosphere Lithosphere Upper mantle Soil Crust Asthenosphere Rock Lower mantle “Spheres” Core Mantle Crust (soil and rock) Biosphere (Living and dead organisms) Atmosphere (air) Lithosphere (crust, top of upper mantle) Hydrosphere (water)

Biomes/Zones of Earth Terrestrial portions are called biomes Forests (conifer, deciduous, rain forest) Deserts Grasslands Aquatic Life Zones Freshwater (lakes, ponds, rivers, streams, wetlands) Marine (coral reefs, coastal regions, deep ocean)

It starts with the sun! 1 billionth of sun’s output reaches Earth Solar radiation Energy in = Energy out Reflected by atmosphere (34%) 1 billionth of sun’s output reaches Earth UV radiation Radiated by atmosphere as heat (66%) Lower stratosphere (ozone layer) Visible light Greenhouse effect Carbon dioxide, methane, NOx, H2O, O3: natural sources Absorbed by ozone Troposphere Heat Absorbed by the earth Heat radiated by the earth Earth

Photosynthesis Formula: Carbon dioxide + water + sunlight  glucose + oxygen CO2 + H2O + solar Energy  C6H12O6 + O2 Producers or autotrophs are capable of photosynthesis Chemosynthesis: photosynthesis without sunlight (specialized bacteria can do this) Autotrophs/producers are typically found at the bottom of the “food chain”

Who are you calling a Heterotroph? Scavengers Nutrients from dead and decaying animal/meat Omnivores Nutrients from both plant and animal matter Carnivores Nutrients from animals/meat Herbivore Nutrients from plant material Detritivore Nutrients from dead organic matter (plant or animal) Decomposers put nutrients back into ground

Powder broken down by decomposers into plant nutrients in soil 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 Detritivores

Respiration is more than breathing? Aerobic respiration: making energy in the presence of oxygen Glucose + oxygen  carbon dioxide + water + energy C6H12O6 + 6O2  6CO2 + H2O + energy Anaerobic respiration: energy gained in absence of oxygen. By products include methane gas, acetic acid This process was taking place in waste water treatment plant!

Variety is the Spice of Life Genetic diversity: variety of genetic material/traits within a population. Species diversity: the number of species present in an area. Ecological diversity: variety of ecosystems found in an area or on the Earth Functional diversity: Biological and chemical processes needed for survival

(decomposers and detritus feeders) First Trophic Level Second Trophic Level Third Trophic Level Fourth Trophic Level Producers (plants) Primary consumers (herbivores) Secondary consumers (carnivores) Tertiary consumers (top carnivores) Heat Heat Heat Heat Solar energy Heat Heat Heat Heat Heat Detritivores (decomposers and detritus feeders) Types of Consumers

Ecological Efficiency Ecological efficiency: useable energy that is passed along from one trophic level to the next. Typical is 10% efficient (90% of energy is lost) Top carnivores Carnivores Herbivores Producers 5,060 Decomposers/detritivores 20,810 3,368 383 21

(decomposers and detritus feeders) First Trophic Level Second Trophic Level Third Trophic Level Fourth Trophic Level Producers (plants) Primary consumers (herbivores) Secondary consumers (carnivores) Tertiary consumers (top carnivores) Heat Heat Heat Heat Solar energy Heat Heat Heat Heat Heat Detritivores (decomposers and detritus feeders) Food Chains

Food Webs Humans Blue whale Sperm whale Killer whale Elephant seal Crabeater seal Leopard seal Emperor penguin Adélie penguins Petrel Squid Fish Carnivorous plankton Herbivorous zooplankton Krill Phytoplankton

The dirt on dirt Soil horizon: a horizontal layer with a distinct texture and composition. (soil triangle) Soil profile: cross section of horizons. Can use a sampling tube to see profile. Mature, undisturbed soils have at least 3 of the 4 horizons.

Soil Profiles We will complete soil profile pictures by using text. Feel free to view these slides from the website at a later time to understand each of the horizons that make up the various profiles. Viewing them in lecture would be quite boring.

O horizon Location: very top of ground to a few inches down Composition: undecomposed leaves, partially decomposed leaves, twigs, grasses, crop waste, animal waste, fungi Color: brown or black Additional information: not very deep; some biomes have very little O horizon (desert)

A Horizon Location: Just underneath O Horizon Composition: has partially decomposed organic matter (humus), inorganic nutrients. Also known as topsoil. Color: brown or dark brown (fertile), gray, yellow, reddish (not as fertile) Additional information: Depth will varying by biome/region. Lots of life (bugs, worms, bacteria, fungi) Bottom of A Horizon is the zone of Eluviation (or E horizon). Loss of minerals and nutrients here – were pushed downward.

E Horizon Location: Underneath A horizon (sometimes is included as just a part of the A horizon) Composition: Lacking in nutrients, leaching of nutrients into B horizon occurs here Color: lighter shade of the A horizon Additional information: E horizon may be included as a part of the A horizon and not listed. Mostly found in forested area soils.

B Horizon Location: Underneath E or A horizon Composition: More dense because of fine particles from upper zones leaching down. Also called subsoil Color: yellowish to brown Additional information: Typically a dense layer with more clay content. Depth of B horizon may vary by biome/region Cool animation of leaching.

C Horizon Location: Fairly deep – 3+ feet down Composition: Chunks of rock and parent material of the upper layer soil. Mostly inorganic Color: lighter – rock. Additional information: C horizon is also referred to as the Parent material and contains clay, sand, gravel.

R Horizon Location: Under the C horizon Composition: solid bedrock Color: lighter – rock. Additional information: R horizon is not considered soil. It is solid bedrock. May not be shown on all graphics/profiles.

Profiles O Horizon A Horizon E Horizon B Horizon C Horizon

Soil Profiles - Biomes O A A E B B C C R Mosaic of closely packed pebbles, boulders O A A Alkaline, dark, and rich in humus Weak humus- mineral mixture E B Dry, brown to reddish-brown, with variable accumulations of clay, calcium carbonate, and soluble salts B Clay, calcium compounds C C R Desert Soil (hot, dry climate) Grassland Soil (semiarid climate)

Soil Profiles - Biomes O O O A A A/E E E B B B C C C R R R Tropical Rain Forest Soil (humid, tropical climate) Deciduous Forest Soil (humid, mild climate) Coniferous Forest Soil (humid, cold climate)

Soil Texture Pyramid Find: 50% clay 15% sand 35% silt

Soil Texture Pyramid 2 Find: 30% clay 35% sand 35% silt

Figure 4-28 Page 76 Water Cycle Condensation Precipitation Transpiration from plants Evaporation from land Evaporation from ocean Runoff Surface runoff Precipitation Infiltration and Percolation Surface runoff Groundwater movement Ocean Water Cycle

Carbon Cycle Diffusion Combustion of fossil fuels Carbon dioxide dissolved in ocean water photosynthesis aerobic respiration Marine food webs sediments death, sedimentation uplifting over geologic time sedimentation Marine sediments, including formations with fossil fuels

Carbon Cycle Atmosphere Combustion of fossil fuels volcanic action combustion of wood photosynthesis aerobic respiration Terrestrial rocks Land food webs sedimentation weathering Soil water (dissolved carbon) Peat, fossil fuels death, burial, compaction over geologic time leaching runoff Carbon Cycle

Nitrogen Cycle Gaseous Nitrogen (N2) in Atmosphere Nitrogen Fixation © 2004 Brooks/Cole – Thomson Learning Gaseous Nitrogen (N2) in Atmosphere Nitrogen Fixation (Legumes) Food Webs On Land uptake by autotrophs excretion, death, decomposition uptake by autotrophs Fertilizers Nitrogen Fixation bacteria convert N2 to ammonia (NH3) ; this dissolves to form ammonium (NH4+) Nitrogenous Wastes, Remains In Soil NO3 – in soil Denitrification by bacteria Ammonification bacteria, fungi convert the residues to NH3 , this dissolves to form NH4+ 2. Nitrification bacteria convert NO2- to nitrate (NO3-) NH3, NH4+ in soil 1. Nitrification bacteria convert NH4+ to nitrate (NO2–) loss by leaching NO2 – in soil loss by leaching Nitrogen Cycle

Nitrogen Ways nitrogen gets INTO ground Ways nitrogen leaves ground: Lightening Decomposition Nitrification (legumes) Fertilizer Leaching Denitrification Use by autotrophs Harvesting/removal of crops

Phosphorous Cycle mining FERTILIZER excretion GUANO agriculture weathering uptake by autotrophs uptake by autotrophs MARINE FOOD WEBS DISSOLVED IN OCEAN WATER leaching, runoff DISSOLVED IN SOIL WATER, LAKES, RIVERS LAND FOOD WEBS death, decomposition death, decomposition sedimentation settling out weathering uplifting over geologic time ROCKS MARINE SEDIMENTS Phosphorous Cycle

Phosphorous Ways phosphorous gets INTO ground Ways phosphorous leaves ground: Guano Phosphate salts Fertilizer Decompositions weathering Uptake by autotrophs Use in food chains and webs Sedimentation/rock cycle

Acidic fog and precipitation Water Acidic fog and precipitation Sulfur trioxide Sulfuric acid Ammonia Ammonium sulfate Oxygen Sulfur dioxide Hydrogen sulfide Plants Volcano Dimethyl sulfide Industries Animals Ocean Sulfate salts Death, decay Metallic sulfide deposits Sulfur Hydrogen sulfide Sulfur Cycle

Sulfur Ways sulfur gets INTO ground/atmosphere Ways phosphorous leaves ground: Fertilizer Volcanoes Hot springs Factory emissions Uptake by autotrophs Use in food chains and webs Sedimentation/rock cycle