Download Topic 1: What is Ecology?

Topic 1: What is Ecology?
• Defined: Studying how life interacts within
the biosphere is called Ecology
• All life interacts within the biosphere
– Area within the deepest ocean trenches to the
highest mountains
Populations
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information box
• Defined: Group of one species living in the same area
• Population changes based on:
– Births, Deaths, Immigration, Emigration, Available resources
Limiting Factors
• Defined: Factors
that control
population sizes
– Disease, food,
predators, climate,
space, mates
• Carrying Capacity:
greatest number of
individuals that a
population can
sustain
• What stage is the
human population in?
Communities
• Defined: Populations of many species living in the
same area at the same time
• Each organism has it own HABITAT
– Habitat: Place where an organism lives
• Each species has its own NICHE
– Niche: The role/needs of a species
– Ex: Termites return nutrients to the soil
Ecosystems
• Defined: Community of species interacting with the
living & non-living
• Desert Biotic Factors:
– Animals: Mice, Reptiles, Insects
– Plants: Cactus, Flowers, Shrubs
• Desert Abiotic Factors: Sand, rocks, sunlight
• Ecosystem changes affect biodiversity
– Keystone species greatly alter ecosystems
What is a Biome?
• Defined:
Large area
with distinct
climate,
plant, and
animal life
• Climate
factors: sun,
rain,
topography
• Climate
determines
life
Part 2: Ecosystem Components
• Producers
– Basis of an ecosystem’s
energy
– Autotrophs: perform
photosynthesis to make
sugars
– Chemotrophs: Bacteria
which use minerals from
deep-sea vents to make
energy
• Consumers
– Heterotrophs: Consumes
others for energy
– Omnivores, herbivores,
carnivores, decomposers
• Defined: Feeding level of
an ecosystem
• Trophic levels consist of
producers, consumers, and
decomposers
• ~10% of energy is passed
to the next level
– Few trophic levels
• Defined: Organisms
that create their
energy through
photosynthesis
– AKA: Autotrophs
– Convert sunlight into
glucose (sugar)
• Bottom of food chain
(1st trophic level)
• Ex: Plants, Algae,
Cyanobacteria
• Primary Consumers
– Feed directly on
producers
– Herbivores
• Secondary Consumers
– Feed on primary
consumers
– Carnivores & omnivores
• Tertiary Consumers
– Feed on secondary
consumers
– Carnivores & omnivores
• Quaternary Consumers
– Feed on tertiary
consumers
– Carnivores & omnivores
• Decomposers: break
down dead matter into
simpler substances
• Returns nutrients to the
soil
• Feed on any trophic level
Name the tropic levels in this food pyramid
• Defined: Group
of interrelated
food chains
• Arrows show
direction
energy
(nutrients)
travel
Tertiary consumer
Secondary consumer
Primary consumer
producer
Quaternary consumer
Tertiary consumer
Secondary
consumer
Primary consumer
producer
Topic 3: Succession
Primary Succession
• Defined: Establishment and development of an
ecosystem in an uninhabited environment
• Volcanic lava creates new land
• Glaciers retreating exposing new land
Bare Rock
• Lava cools and hardens into rock
Pioneer Species
• Defined: First organisms to inhabit new land
• Moss and lichen grow on bare rock
• Dead matter accumulates with rock pieces
– Thin soil layer begins to accumulate
The Process Continues
• Seeds enter the area and grow
• Small flowers & shrubs accumulate more
organic matter
• With new plants, small animals inhabit the
area
The Process Continues
• Small trees take root in the accumulated
organic matter
• More animals use the trees as a habitat
Climax Community
• Large trees take root
– Overcrowd and out-compete original trees
• New animals inhabit new forests
Secondary Succession
• Changes that take place after a disturbance
occurs in an established ecosystem
– Forest fires, floods, tree falls…
• Faster scale (soil preexists)
Topic 4: Biogeochemical Cycles
Oxygen Cycle
O2
O2
• Autotrophs: Release O2 into atmosphere via photosynthesis
• All life: Absorbs O2 to be used during cellular respiration
– Respiration: creates ATP energy for cells
Carbon Cycle
CO2
CO2
sugars
• Carbon = (organic molecules) carbohydrates, proteins,
lipids, nucleic acids
• Plants & autotrophs:
– Intake: Absorb CO2 from atmosphere
– Output: Create carbohydrates by photosynthesis
Carbon Cycle
CO2
CO2
sugars
• Consumers
– Intake: Carbon moves up the food chain as 1 feeds on another
– Output: Release CO2 during respiration
Carbon Cycle
sugars
C
C
C
• Decomposers
– Input: Feed on dead organic matter
– Output: Release CO2 during respiration
– Output: Organic molecules returned to soil during decomposition
Carbon Cycle
CO2
• Human Industry
– Output: Release CO2 into atmosphere when fossil fuels
(coal, oil, natural gas) are burned
Nitrogen Cycle
N2
Ammonia
Nitrates
• N = 78% atmosphere (most unusable)
• Soil Bacteria
– Nitrogen fixation: convert atmospheric nitrogen into ammonia
– Nitrification: ammonia converted into nitrates
Nitrogen Cycle
Nitrates
• Plants
– Absorb nitrates through their roots
Nitrogen Cycle
Nitrates
• Animals
– Ingest nitrates through the food chain (plants eaten)
Nitrogen Cycle
Nitrates
Nitrates
Ammonia
Ammonia
Ammonia
• Decomposers
– Feed on dead organisms
– Return ammonia to soil by feeding on dead matter
Phosphorus (P) Cycle
• No
phosphorus
in
atmosphere
• Rocks
PP
– Phosphorus
released by
weathering
of rocks
Phosphorus (P) Cycle
• Plants
– Absorb P
into their
roots
P
Phosphorus (P) Cycle
• Animals
P
– Ingest P
when plants
eaten
– P continues
to move up
food chain
Phosphorus (P) Cycle
• Decomposers
– Breakdown
dead matter
and release P
into soil
P
P
Phosphorus (P) Cycle
P
P
P
P
P
P
• Human
Contribution
– Adding
excess P
from
fertilizers
– P washes
into lakes,
etc…
– Excess P
causes
extreme
algae
Topic 5: Community Interactions
• when organisms live together in an ecological
community they interact constantly.
• Three types of interactions
– Competition
– Predation
– Symbiosis
Competition
• occurs due to limited
resources
– water, nutrients, light,
food.
• Competitive exclusion
principle - no two
species can occupy the
same niche in the same
habitat at the same time
Competition
Predation
• Predation- when an
organism captures
and feeds on another
organism.
• Predator- hunter
• Prey- hunted
Symbiosis
• Symbiosis- any relationship where two
species live closely together. (3 types)
– Mutualism
– Commensalism
– Parasitism
Symbiosis
• Mutualism - both
species benefit from a
relationship
– Flower: gets pollinated
– Moth: gets nectar
Mutualism example:
Cleaner birds and Crocodiles
Symbiosis
• Commensalism – One
member of a symbiotic
relationship benefits and
the other is neither
helped or harmed
– Anemone: gains nothing
– Fish: protection
Symbiosis
• Parasitism- One
creature benefits and
one creature is harmed
– Insect larvae will feed on
the caterpillar
Topic 6: Environmental Issues
Ozone Layer Depletion
• Ozone Function:
Block UV radiation
from sun
• Problems:
– CFCs thinning the
ozone layer
– More UV radiation
reaches the surface
• Effects: Crop damage,
skin cancers, Eye
damage
• Solution: Reduce
CFCs, regrow trees
UV
UV
Ozone
layer
Ozone layer
CFCs
The Greenhouse Effect
• G.H.E. is naturally good
(it warms Earth)
• Problem: Excess heat
trapped near the earth’s
surface
• Fear: Climate patterns
change, ice caps melt
• Main Cause: CO2 from
burning of fossil fuels
(coal, oil, natural gas)
• Solutions: Reduce use
of fossil fuels, regrow
trees, alternative energy
sources
What’s in a name?
The purpose of a
greenhouse is to
trap heat year
round
Some heat
escapes into
space
Some heat
naturally trapped
by Earth’s
atmosphere
heat
Earth
Earth
Less heat
escapes into
space
More heat trapped
near Earth’s
surface
Excess CO2
in
atmosphere
Earth
The Greenhouse Effect is naturally GOOD!
Mars: No Greenhouse
Effect
Earth: Balanced
Greenhouse Effect
Little heat is trapped
by the thin CO2
atmosphere. High
temperatures can be
around 20⁰F.
Average global
temperature is 57⁰F.
Venus: The Extreme
Greenhouse Effect
Heat is trapped by
the thick CO2
atmosphere.
Temperatures
reach 750⁰F.
Deforestation
• Defined: Clearing of
forested areas
• Reasons:
– High demand for wood
products
– Create farmland
• Problems:
– Species lost
– Excess CO2 released
• Solutions:
– Recycle
– Improved farming
techniques
The Smog and Ground-Level Ozone
• Reason:
– Burning of fossil fuels &
industry
• Problems:
– Respiratory illness
– Ozone gas is poisonous
• Causes:
– Particulates rise into air
and react with sunlight to
make air pollution
• Solutions:
– Reduce use of fossil fuels
– alternative energy sources
– Plant trees
Non-native Species Introduction
• Defined: Foreign organisms
are introduced to a new habitat
• Reason:
– Pet industry, “free ride”
organisms, pest control
• Effects:
– Foreign species outcompete
native species
– Food webs unbalanced
– Economic damage
• Solutions:
– Laws preventing foreign
goods into new countries
– Introduce predators
• Defined: Precipitation with a
below normal pH
• Cause:
– Fossil fuel pollution rises
into the air & then falls as
rain
• Effect:
– Waterways more acidic
– Kills plant and animal life
• Solutions:
– Reduce fossil fuel usage
– Add buffer (base) to
waterways
The Big Problem: Overpopulation
• Over 6.7 billion people
• Many natural resources
are nonrenewable
– Fossil fuels take
millions of years to form
• More people means:
– 1) More forests
removed
– 2) More resources
consumed
– 3) More CO2 released