chapter 4: ecosystems the living world unit. members of an ecosystem eukaryotic cells (have nucleus)...
TRANSCRIPT
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
Vegetationand animals
Soil
Rock
Biosphere
Crust
Core
Mantle
Lithosphere(crust, top of upper mantle) Hydrosphere
(water)
Atmosphere(air)
Biosphere(Living and dead
organisms)
Crust(soil and rock)
“Spheres”
Oceanic crust Continental crust
Lithosphere
Upper mantle
Asthenosphere
Lower mantle
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)
Solarradiation
Energy in = Energy out
Reflected byatmosphere (34%)
UV radiation
Absorbedby ozone
Absorbedby the earth
Visiblelight
Lower stratosphere(ozone layer)
Troposphere
Heat
Greenhouseeffect
Radiated byatmosphere
as heat (66%)
Earth
Heat radiatedby the earth
It starts with the sun!
1 billionth of sun’s output reaches Earth
Carbon dioxide, methane, NOx, H2O, O3: natural sources
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
MushroomWoodreduced
to powder
Long-hornedbeetle holes
Bark beetleengraving
Carpenterant
galleries
Termite andcarpenter
antwork
Dry rot fungus
Detritus feeders Decomposers
Time progression Powder broken down by decomposersinto plant nutrients in soil
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
Heat Heat Heat Heat
Heat
Heat
Heat
First TrophicLevel
Second TrophicLevel
Third TrophicLevel
Fourth TrophicLevel
Solarenergy
Producers(plants)
Primaryconsumers(herbivores)
Tertiaryconsumers
(top carnivores)
Secondaryconsumers(carnivores)
Detritivores(decomposers and detritus feeders)
Heat Heat
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
Heat Heat Heat Heat
Heat
Heat
Heat
First TrophicLevel
Second TrophicLevel
Third TrophicLevel
Fourth TrophicLevel
Solarenergy
Producers(plants)
Primaryconsumers(herbivores)
Tertiaryconsumers
(top carnivores)
Secondaryconsumers(carnivores)
Detritivores(decomposers and detritus feeders)
Heat Heat
Food Chains
Humans
Blue whale Sperm whale
Crabeater seal
Killerwhale Elephant
seal
Leopardseal
Adéliepenguins Petrel
Fish
Squid
Carnivorous plankton
Krill
Phytoplankton
Herbivorouszooplankton
Emperorpenguin
Food Webs
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.
ProfilesO Horizon
A Horizon
E Horizon
B Horizon
C Horizon
Weak humus-mineral mixture
Mosaicof closelypackedpebbles,boulders
Dry, brown toreddish-brown, with variable accumulationsof clay, calciumcarbonate, andsoluble salts
Desert Soil(hot, dry climate)
Grassland Soil(semiarid climate)
Alkaline,dark, and richin humus
Clay, calciumcompounds
Soil Profiles - Biomes
A
B
C
O
A
E
B
C
R
Tropical Rain Forest Soil(humid, tropical climate)
Deciduous Forest Soil(humid, mild climate)
Coniferous Forest Soil(humid, cold climate)
Soil Profiles - Biomes
OA
E
BC
R
OAE
B
C
R
O
B
C
R
A/E
Soil Texture PyramidFind:
50% clay
15% sand
35% silt
Soil Texture Pyramid 2Find:
30% clay
35% sand
35% silt
Figure 4-28Page 76
Precipitation Transpirationfrom plants
RunoffSurface runoff
Evaporationfrom land Evaporation
from oceanPrecipitation
Ocean
Surfacerunoff
Groundwater movement
Condensation
Infiltration andPercolation
Water Cycle
Diffusion
Carbon dioxidedissolved in ocean water
Marine food webs
Marine sediments, includingformations with fossil fuels
Combustion of fossil fuels
sediments death, sedimentation
uplifting over geologic time
sedimentation
photosynthesis aerobic respiration
Carbon Cycle
photosynthesis aerobic respirationTerrestrial
rocks
Soil water(dissolved
carbon)
Land food webs
Atmosphere
Peat,fossil fuels
combustion of wood
sedimentation
volcanic action
death, burial, compaction over geologic timeleaching
runoff
weathering
Carbon Cycle
Combustion of fossil
fuels
NO3 –
in soil
Nitrogen Fixation
(Legumes)
Fertilizers
Food Webs On Land
NH3, NH4+
in soil
1. Nitrification
bacteria convert NH4+ to
nitrate (NO2–)
loss by leaching
uptake by autotrophs
excretion, death,
decomposition
uptake by autotrophs
Nitrogen Fixationbacteria convert N2 to
ammonia (NH3) ; this
dissolves to form ammonium
(NH4+)
loss by leaching
Ammonificationbacteria, fungi convert the
residues to NH3 , this
dissolves to form NH4+
2. Nitrification
bacteria convert NO2- to
nitrate (NO3-)
Denitrificationby bacteria
Nitrogenous Wastes, Remains In Soil
Gaseous Nitrogen (N2)
in Atmosphere
NO2 –
in soil
Nitrogen Cycle
© 2004 Brooks/Cole – Thomson Learning
Nitrogen
• Ways nitrogen gets INTO ground
• Ways nitrogen leaves ground:
LighteningDecompositionNitrification (legumes)Fertilizer
LeachingDenitrificationUse by autotrophsHarvesting/removal of crops
GUANO
FERTILIZER
ROCKS
LAND FOOD WEBS
DISSOLVED IN OCEAN
WATER
MARINE FOOD WEBS
MARINE SEDIMENTS
weathering
agriculture
uptake by autotrophs
death, decomposition
sedimentation settling out weathering
leaching, runoff DISSOLVED IN SOIL WATER,
LAKES, RIVERS
uptake by autotrophs
death, decomposition
miningmining
excretionexcretion
Phosphorous Cycle
uplifting over geologic time
Phosphorous
• Ways phosphorous gets INTO ground
• Ways phosphorous leaves ground:
GuanoPhosphate saltsFertilizerDecompositionsweathering
Uptake by autotrophsUse in food chains and websSedimentation/rock cycle
Sulfur Cycle
Sulfur
Hydrogen sulfide
Sulfate salts
Plants
Acidic fog and precipitation
Ammonium sulfate
Animals
Death, decayMetallicsulfide
deposits
Ocean
Dimethyl sulfide
Sulfur dioxide Hydrogen sulfide
Sulfur trioxide Sulfuric acidWater
Ammonia
Oxygen
Volcano
Industries
Sulfur
• Ways sulfur gets INTO ground/atmosphere
• Ways phosphorous leaves ground:
FertilizerVolcanoesHot springsFactory emissions
Uptake by autotrophsUse in food chains and websSedimentation/rock cycle