Download Ecosystems - Effingham County Schools

Ecosystem Ecology
Ecosystems: What Are They and How Do
They Work?
Date: October 26, 2015
Reminders: Print out unit 5 notes & do vocabulary
Agenda:
Review FRQ Practice/Highlight & turn in tomorrow
Review Unit 4 Test & Pass papers back
Read Chapter 4 & first 20 power point slides
Ecology: Levels
• Multiple levels of ecology:
• Organisms
• Populations: groups of
individuals of same species in
same place
• Communities: populations in
same place
• **Ecosystems: community
interacting with environment
• Biosphere: parts of earth’s air,
water, and soil where life is
found
Ecology
• Ecosystems
survive on
the:
• FLOW of
energy
• CYCLING
of matter
Ecology: Three Important Factors
Life depends on 3 interconnected factors:
1. The one-way flow of energy from the sun 
organisms  the environment as heat  back
out into space as heat (open system)
Governed by laws of thermodynamics!
2. The cycling of matter through parts of the
biosphere (closed system)
3. Gravity: allows the planet to hold onto its
atmosphere and enables movement of
chemicals in their matter cycles
Ecology: Ecosystems
 Ecosystems Have Living and Nonliving
Components
 Abiotic: nonliving component
 Water
 Air
 Nutrients
 Rocks
 Heat
 Solar energy
 Biotic
 Living and once living
 Plants, animals, microbes
• Producers & Consumers Are the Living Components of
Ecosystems
• Each assigned a trophic level (feeding level)
• Producers aka autotrophs are the 1st trophic level
• Producers / autotrophs make the nutrients they
need from compounds and energy from their
environment
• Perform Photosynthesis:
• Or Chemosynthesis: make nutrients without sunlight
(specialized bacteria can do this; hydrothermal
vents)
• Autotrophs/producers are found at the bottom of
the “food chain” – have the most energy
• Types of Autotrophs:
• Terrestrial:
 Nonvascular plants: Mosses
 Vascular plants: Ferns, Gymnosperms (conifers),
Angiosperms (flowering plants)
 Some algae (not plants, are protists!)
• Aquatic:
 Phytoplankton: = floating producers
 Algae (diatoms, seaweed)
 Cyanobacteria
 Freshwater & marine plants
http://www.planktonch
ronicles.org/en/episod
e/plankton
• Consumers aka heterotrophs: must
consume other organisms for energy (and
nutrients)
• Primary consumers = eat autotrophs
• Secondary consumers = eat the autotropheaters
• Tertiary consumers = eat the eaters of the
autotroph-eaters
 Types of Heterotrophs:
 Herbivore (Ex: elephants, caterpillars, zooplankton)
 Energy/nutrients from plant/algae material
 Carnivores (Ex: spiders, lions, fish)
 Energy/nutrients from animals/meat
 Omnivores (Ex: pigs, rats, bears, humans)
 Energy/nutrients from both plant and animal matter
 Types of Heterotrophs continued:
 Scavengers (Ex: vultures, hyenas)
 Energy/nutrients from large pieces of dead and decaying
animal/meat
 Detritivore (Ex: worms, insects, small crabs)
 Energy/nutrients from medium pieces of dead organic
matter (plant or animal)
Types of Heterotrophs continued:
Decomposers: consumers that digest on a molecular
scale & release nutrients (BUT NOT ENERGY!) back
into the environment
 Includes: Bacteria & Fungi
 Are present basically at every trophic level
• Both Producers & Consumers Perform Respiration
• Aerobic respiration: making energy from sugar in
the presence of oxygen
• Anaerobic respiration/ fermentation: energy
gained in absence of oxygen. End products include
ATP
methane gas (CH4), ethyl alcohol, acetic acid, and
hydrogen sulfide
• As energy flows through ecosystems in food
chains and webs, the amount of chemical
energy available to organisms at each
succeeding trophic level decreases.
• Food Chain: One way-flow of energy (always lost has heat back out
to space)
Photosynthesis → feeding → decomposition
https://www.youtube.com/watch?v=lnAKICtJIA4
Bozeman energy flow in an ecosystem
Review
1.Where is some energy transferred to along the food chain?
2.How many trophic levels are in the diagram?
3.What is the name for the organisms in the first trophic level?
4.What is the name for the organisms on the second trophic level?
5.Where do all organisms ultimately get their energy from?
1. What are some abiotic
components in the
diagram that are
directly important to
the tree?
2. What is the primary
consumer getting
energy from?
3. How is the secondary
consumer dependent
on the producer?
 Usable Energy Decreases with Each Link in a Food Chain or Web
 Biomass: Dry weight of all organic matter of a given trophic level in a
food chain or food web
 Chemical energy is stored in biomass
 Ecological Efficiency: % of usable energy transferred as biomass from
one trophic level to the next
 Typical is 10% efficient (90% of energy is lost)
 Is diagramed as the Pyramid of Energy Flow
Ecological Pyramids
Many plants are
needed to feed fewer
snails which feed fewer
chickens which
feed fewer people
10% Law
only 10% of
the energy is
passed from
one level to
the next
Most of the energy, mass, numbers are at the bottom of the food chain
If a producer typically captures 5,000 units of energy from the sun, how
much usable energy will be available to a tertiary consumer in the
ecosystem?
• 5000 units x 0.1 = 500 units for primary consumers
• 500 units x 0.1 = 50 units for secondary consumers
• 50 units x 0.1 = 5 units for tertiary consumers
tertiary consumer 5
secondary consumer
primary consumer
producer
50
500
5000
Solve the following energy pyramid problems… [Use the 10% law across each trophic level.]
1. In this food chain, we could hypothetically
assume that for every kilogram of biomass in the
osprey eagle, it would require __________ kg of
shrimp to keep the food chain balanced.
1 kg
2. The snapping turtle lives in a small pond, where its
major prey is bass. In turn, the bass primarily eat
minnows. This snapping turtle weighs 40 pounds. If the
pond has 10 mature snapping turtles of this size, how
many pounds of minnows are required to support
them?
A snake weighs 2 lbs. Ecologists estimate
2000lbs. of grass plants exist. How many
snakes can the ecosystem support?
snakes
mice
grass plants
lbs.
10, 000,000 lbs.
100, 000, 000 lbs.
Fill in the biomass for the top trophic level in the ecological pyramid above.
At maturity a lion weighs 500 lbs. Ecologists estimate 100, 000, 000 lbs of grass plants exist in
the ecosystem. How many adult lions can the ecosystem support?
• How Fast Can Producers Produce Biomass? = Productivity
• Gross primary productivity (GPP): the rate at which
producers in an ecosystem convert solar energy into biomass
• Measured in Kcal/m2/year
• Net primary productivity (NPP): the rate at which
producers use photosynthesis to store energy minus the rate at
which they use some of this stored energy
R is the amount of energy used in respiration
APES
Monday November 2, 2015
Agenda:
Finish notes: biogeochemical cycles & watch video
Begin Study Guide
HW Learnerator Biogeochemical Cycles
Reminders:
Vocab. Quiz Wednesday Nov. 4th
Test Thursday Nov. 5th (Study 2014 FRQ #4)
• GPP vs. NPP:
• Some ecosystems have higher NPP than others:
 Matter, in the form of nutrients, cycles within and among ecosystems
and the biosphere, and human activities are altering these chemical
cycles.
 Biogeochemical cycles/ nutrient cycles
 Hydrologic (water)
 Carbon
 Nitrogen
 Phosphorus
 Sulfur
• Hydrologic Cycle
• Only cycle in which nutrient does not undergo chemical change
Evaporation
from
Water
into
Water vapor
into vapor
plant leaves
liquid
droplets
Rain, sleet, snow
Movement of water
through soil & rock to
aquifers
Surface movement
down slopes to the sea
• Alteration of the hydrologic cycle by humans:
• Withdrawal of large amounts of freshwater at rates faster
than nature can replace it
• Clearing of vegetation from land & cover it with buildings
& asphalt  increases runoff, erosion
• Draining wetlands for farming and urban development 
increases flooding
• Water Pollution
• Warmer climate  change precipitation patterns
Cycling of Carbon
• CO2 in
atmosphere
•  converted to
carbohydrates by
producers during
photosynthesis
•  producers &
consumers break
down carbs
during aerobic
respiration,
release CO2 back
into atmosphere
• Decomposers
release carbon
stored in bodies
• CO2 is also
dissolved in the
oceans (major
sink/reservoir)
•  used in
photosynthesis
by marine
producers
•  involved in
marine food
webs
• Stored in
limestone or
sediments
Ecology: Cycling of Carbon
• Over millions
of years, buried
deposits of
dead plant
matter &
bacteria are
compressed
between layers
of sediment
•  high
pressure and
heat convert
them to fossil
fuels
 Alteration of the carbon cycle by humans:
 Burn fossil fuels  releases carbon dioxide into atmosphere
 Electricity (burn coal)
 Transportation (burn oil)
 Clearing forests
 Removes carbon-absorbing trees
 Burning trees puts out CO2
 CO2 is a greenhouse gas that
traps heat in our atmosphere
http://www.youtube.com/watch?v=8oblMClD2oU
https://www.youtube.com/watch?v=2D7hZpIYlCA
Crash Course Hydrologic & Carbon
Cycling of Nitrogen
• Important
component
of proteins
& nucleic
acids
• Atmosphere
is major
reservoir for
nitrogen
(N2)
• But N2
cannot be
taken in by
organisms
 Steps:
1. Nitrogen
fixation:
nitrogenfixing
bacteria
convert N2
to ammonia
(NH3) then
dissolves to
form
ammonium
(NH4+)
 Steps:
2. Nitrification:
bacteria convert
NH4+ to nitrite
(NO2-)  nitrate
(NO3-)
3. Assimilation:
Nitrate is taken up
by plants (cycles in
food web)
 Steps:
4. Ammonification
Decomposer
bacteria convert
nitrogenous
wastes & dead
organisms back
into NH3 and NH4+
5. Denitrification:
Bacteria convert
NO3- in soil back
into N2 or N2O
(nitrous oxide)
Cycling of Nitrogen
• Since 1950, human
activities have more
than doubled the
annual release of
nitrogen from the
land into the
environment
• Alteration of the nitrogen cycle by humans:
• Add nitric oxide (NO) to atmosphere when burning
fuel
• NO  NO2 and HNO3 (nitric acid; part of acid rain)
• Add nitrous oxide (N2O) to atmosphere through
anaerobic bacteria feeding on fertilizers
• Remove nitrogen from topsoil when growing &
irrigating crops
• Alteration of the nitrogen cycle by humans:
• Add excess nitrates to aquatic systems through
agricultural runoff of fertilizers & manure or sewage
• Causes Eutrophication – growth of cyanobacteria &
phytoplankton = algal blooms
• Especially in marine ecosystems like estuaries
• Results in oxygen depletion & biodiversity loss
• Creates “Dead Zones”; examples:
• Gulf of Mexico
• Chesapeake Bay Estuary
• Can create “Red Tide” – toxic algal bloom
• Can poison fish, mammals, birds
Cycling of Phosphorus
• Does not
include the
atmosphere
• Reservoir:
salts containing
phosphate (PO43) in rock
formations &
bottom of oceans
https://www.youtube.com/watch?v=6LAT1gLMPu4
• As water
erodes rock,
phosphate ions
enter soil 
• Phosphate
taken up by
plants & enter
food web
• Important for
nucleic acids
and energy
transfer
molecules
(ATP)
• Most soils
contain little
phosphate, so
limits plant
growth
(limiting
factor!)
• That’s why
fertilizers have
phosphate
• Alteration of the phosphorus cycle by
humans:
• Removing phosphate salts from mining
• Phosphate-rich runoff enters aquatic systems (esp.
freshwater) & causes algal blooms (eutrophication)
https://www.youtube.com/watch?v=leHyY_8nRs
Crash Course N & P
Cycling of Sulfur
• Much of world’s
sulfur is in rocks
& minerals &
sulfate (SO42-)
salts in ocean
sediments
• S enters the
atmosphere from:
• Volcanoes & break
down of organic
matter by anaerobic
decomposers 
hydrogen sulfide
(H2S)
• Sulfate (SO42-)
particles come from
dust storms & forest
fires
 In atmosphere,
sulfur dioxide
(SO2)
is converted to sulfur
trioxide gas (SO3) &
sulfuric acid (H2SO4)
-Sulfate cycles
through food webs
• Alteration of the sulfur cycle by
humans:
• Factory emissions: sulfur in coal is
released into atmosphere when we
burn it
• Leads to acidic precipitation
(sulfuric acid)
• Refining petroleum
• Smelting metallic ores (copper, lead, zinc)
• Smelt: To melt or fuse (ores) in order to separate the
metallic constituents.
https://www.youtube.com/watch?v=Bn41lXKyVWQ
Bozeman biogeochemical cycles
Biomes & Aquatic Life Zones
 Large regions of similar ecosystems:
 Terrestrial areas are called biomes: large
regions characterized by a distinct climate and
specific species adapted to it
 Forests (conifer, deciduous, rain forest)
 Deserts
 Grasslands
Aquatic areas are called aquatic life zones:
 Freshwater (lakes, ponds, rivers, streams, wetlands)
 Marine (coral reefs, coastal regions, deep ocean)
Ecology: Biomes & Aquatic Life Zones
Biozone Assignments: Lab
Review for Unit 5
•
•
•
•
Primary Succession worksheet
Nitrogen Cycle page (p. 75-76)
Phosphorus Cycle (p.80)
Sulfur Cycle (p. 81)
• Once done – work on Study Guide
•Warm-Up Video: Should We All Be Eating Insects?
https://www.youtube.com/watch?v=iM8s1ch5TRw&list=UUC552Sd3nyi_tk2BudLUzA)