Transcript APES - Lemon Bay High School

APES
Chapter 5: Species Interactions &
Community Ecology
Group Work:
• In individual groups, look at each slide and
determine what it represents
• Write your answers down
• As a class we will go over each slide and
discuss answers
Resource
Partitioning:
Each Bird
Uses the
Tree for
Food,
However…
They Each
Divide up
Different
Portions of
the Trunk
Predator/Prey Paired Cycles: One
Increases, Causing the Other to
Decrease, and Vice Versa
Trophic
Levels:
The Way
in Which
Energy
Moves
Thru
Systems
Lower Level Org.
Generally Contain More
Energy, and Are in Greater
Numbers-
Food
Web
KeyStone
Species Keep
Ecosystems
in CheckSea Otters
are the
Keystone
Species in
This
Environment
Activity:
• Read the “Inferring Zebra Mussels’ Impacts on
Fish Communities”
• Answer Question #5 page 113, Seeking
Solutions.
Case Study: black and white and
spread all over
• In 1988, Zebra mussels were
accidentally introduced to
Lake St. Clair
– In discharged ballast
water
• By 2010, they had invaded
30 states
– No natural predators,
competitors, or parasites
• They cause millions of
dollars of damage to
property each year
Rap Time: Zebra Mussels
• From your reading, where are they located?
– Great Lakes
• Do you think they are located anywhere else
in the US?
– They are here in Florida!
– University of Florida News – Discovery Of Invasive
Zebra Mussel Prompts Warning From State
Officials
– Green Mussels in Florida
– Green Mussels
Problems here in Florida
• Same as in other places
– Clog pipes
– No predators
– No competition
– Damage boat engines
– FILTRATION OF PHYTOPLANKTON!!!
• Takes food from native organisms
– Starves them out
» Specifically ZOOPLANKTON
Lets Begin ;)
• List some Non-natives to Florida
– Brazilian Pepper
– Melalucca
– Cuban Tree Frogs
– Lion Fish
• Now List Some Threats They Pose to Florida
– No predators so they take over environments
– Eat all the native species (Cuban tree frog, Lion
Fish)
Lion Fish
http://www.reef.org/reef_files/Lionfish%20quickfacts.pdf
After reading the fact sheet, what do you
know about this critter?
Use knowledge learned from the last
chapter (generalist or specialist, K or r
species, what is the outlook for the native
populations, how did it get here, why is it
still here, discuss the evolution of the fish,
etc.)
Activity:
• H/W: Go home tonight and find at least 2
more non-native invasive species (plant or
animal). Include:
– Generalist or specialist
– K or r species
– What is their main source of food
– Any predators
– Short synapses of how they are affecting Florida
– Must be typed!! 12 point font, double spacced,
times new roman or arial please ;)
Video Clip
• Welcome to Discovery Education Player
Species Interactions
• 5 Major Types of Interactions Among Species
– Competition
• When organisms are seeking same limited resource(s)
– Predation
• When one organism (predator) eats another (prey)
– Parasitism
• One organism benefits, the other is harmed
– Herbivory
• An organism feeds on plant material
– Mutualism
• Both organisms benefit from the relationship
Competition
• Interspecific:
– Among members of 2 or more DIFFERENT species
(cardinals and blue jays)
• If one is more effective
– Wipe-out competitor altogether
• Through evolutionary time, co-existance is also possible
– Timing events, slightly different food sources, etc.
» RESOURCE PARTITIONING
• Intraspecific:
– Among member of the SAME species
• Cardinals
• All competition events have a negative impact
Results of interspecific competition
• Competitive exclusion = one species completely
excludes another species from using the resource
– Zebra mussels displaced native mussels in the Great
Lakes
• Species coexistence = neither species fully
excludes the other from resources, so both live
side by side
– This produces a stable point of equilibrium, with
stable population sizes
– Species minimize competition by using only a part of
the available resource (niche)
Niche: an individual’s ecological role
• Fundamental niche = the full niche of a species
• Realized niche = the portion of the fundamental
niche that is actually filled
- Due to competition or other species’ interactions
© 2011 Pearson Education, Inc.
Resource partitioning
• Resource partitioning =
species use different
resources
- Or they use shared
resources in different
ways
- Ex: one species is
active at night, another
in the day
- Ex: one species eats
small seeds, another
eats large seeds
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Character displacement
• Character displacement = competing species diverge in
their physical characteristics
- Due to the evolution of traits best suited to the
resources they use
- Results from resource partitioning
• Birds that eat larger seeds evolve larger bills
- Birds that eat smaller seeds evolve smaller bills
Competition is reduced when two species become more
different
© 2011 Pearson Education, Inc.
Predation:
• Predator/Prey relationships
• Predation can drive population dynamics
– Increase in predators will…..
– Increase in prey will ………
• These events can cycle throughout time
• Predation can also drive evolution
– Stronger adaptations become selected for
– Defense mechanisms become selected for
Zebra mussel predation on phytoplankton
• Zebra mussels eat phytoplankton and zooplankton
- Both populations decrease in lakes with zebra mussels
• Zebra mussels don’t eat cyanobacteria
- Population increases in lakes with zebra mussels
• Zebra mussels are becoming prey for some North
American predators:
- Diving ducks, muskrats, crayfish, flounder, sturgeon,
eels, carp, and freshwater drum
© 2011 Pearson Education, Inc.
Defenses against being eaten
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Parasites
• Relationships in which 1 organism depends on
another, while doing harm
– USUALLY does not result in death. Why not?
• Most live inside their host
– Disease pathogens (ex; protist that causes malaria)
– Animals (tapeworms)
• Some live externally
– Lamprey
• Parasitoids
– Eggs are laid on the backs of others, when they
hatch, use host as food source
Co-evolution
• Parasites will adapt and evolve with changes
in host
– Evolutionary Arms Race
• Host changes in order to adapt to parasite pressures
• Parasites will change in order to adapt to host pressures
Herbivore
• When animals feed on the tissues of
plants
– Insects are most wide-spread
– Doesn’t usually kill plant, but can
affect growth and reproduction
• Plants have also evolved to defend
themselves
– Chemically
– Arm themselves w/thorns, spines, or
hairs
– Critter usually evolves as well, tho
• Evolutionary Arms Race
Mutualist
• Interacting species benefit from one another
– Each provides a service or resource the other needs
• Symbiosis: two organisms live in close physical contact
– Not always the case however;
» Pollination; physical contact may only happen once
Commensalism
• One species benefits from relationship while
the other is neither harmed nor benefits
– Cattle Egret: benefits from cattle stirring up
insects, cow is neither harmed nor really benefits
• Amensalistic: hard to prove- One organism
harms or inhibits another while remaining
unaffected itself;
– Fungus Penicillium notatum which produces
penicillin- the penicillin inhibits growth of
bacteria, but it appears that the Penicillium is
unaffected
Activity
• Questions 1 &2; Testing Your Comprehension
• Seeking Solutions #1
Ecological Communities
• Community Ecologist:
– studies the way in which species co-exist
– how they relate to one another
– how communities change thru time
– why patterns exist
• Most important of these relationships is
– Who eats whom!!
• Organisms feed on one another, energy moves from
one level to the next
– Trophic Level
Energy passes through trophic levels
• One of the most important species interactions
- Who eats whom?
• Matter and energy move through the community
• Trophic levels = rank in the feeding hierarchy
- Producers (autotrophs)
- Consumers
- Detritivores and
decomposers
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
3 Major Trophic Levels
• Producer
– Autotrophs; self feeders- green plants, algaes,
cyanobacteria capture solar energy or chemical
energy and use photosynthesis or chemosynthesis
to produce sugars
• Consumer
– Primary Consumers; eat producers
– Secondary Consumers; prey on primary consumers
– Tertiary Consumers; usually top of food chain
Continued
• Detritivores/Decomposers; consumes nonliving organic matter
– Detritivores- scavenge waste products or dead
bodies (consume non-living organic matter)
• Millipedes, soil insects, vultures, hyenas
– Decomposers- break down leaf litter and other
non-living matter into simple constituents to be
taken up by plants (absorb nutrients from nonliving organic matter)
• Bacteria, fungi
10% Rule
Energy Decreases @ Higher Levels
• Most energy organisms use is lost thru
respiration as heat
• Only small amounts of E is transferred from 1
level to the next
– 10% rule; ~10% of initial energy moves to next level
• This means that there is many more
grasshoppers reqd to sustain bird pop. Etc.
• VEGETARIANS HAVE SMALLER ECOLOGICAL
FOOTPRINTS!!
Food Web vs Food Chain
• Food Chain: simple representation of energy
mvmt:
Food Web vs Food Chain
• Food Web: much more realistic representation
of how energy moves thru systems-
Roles are NOT the same
• Keystone Species: species with strong or widereaching impact far out of proportion to its
abundance
– Removal of this species will have substantial ripple
effects
– Can alter large portions of food webs
• Usually large-bodied 2nd ary or tertiary
consumers near the top of food chain
• Controls herbivores, who if left unchecked can
devastate ecosystems
Some organisms play big roles
Species can change communities
• Trophic Cascade = predators at high trophic levels
indirectly affect populations at low trophic levels
- By keeping species at intermediate trophic levels in
check
- Extermination of wolves led to increased deer
populations, which overgrazed vegetation and changed
forest structure
• Ecosystem engineers = physically modify the
environment
- Beaver dams, prairie dogs, ants, zebra mussels
© 2011 Pearson Education, Inc.
H/W
• Read Article: Urchins, Otters, and Whales
• Answer questions
- Please Type Assignment!!
- 12 pt font, double spaced, Times New Roman or
Aerial
• Due Monday, 10/22/12
© 2011 Pearson Education, Inc.
H/W; Using Question #2 of Seeking
Solutions as a Guide, Design an Intricate
Food Web (on the front) vs Food Chain
(on the back) on Poster Board. This is
an Exam Grade, and MUST be turned
into me by Wednesday of next week!!
(10/24/12)
Keep track of your data with
photographs
Be creative; make sure you use your
terminology for each organism
(producer, tertiary consumer, etc)
Communities Response
APES
Chapter 5
Disturbances
• What is a disturbance?
– Flood
– Avalanche
– Human impact
• Communities are dynamic and can respond by:
– Resisting change and remaining stable = Resistance
• It may later return to original state showing Resilience
– Become permanently modified and never return to
original state
Succession Follows Disturbance
• Disturbance eliminates all or most species,
effected site will undergo predictable changes
– Primary Succession: not even soil remains after
disturbance; new biotic community must be built
from scratch
• Glaciers retreat, lakes dry up, volcano errupts
– First colonizers = Pioneer Species;
» Lichen; breakdown rock creating substrate for plants, etc.
– Secondary Succession: Does not destroy all life or
soil, leaving some biota behind to repopulate
• Fire, hurricane, logging, farming, etc.
– Pioneer species come in, usually weeds, and eventually new
landscape arises
• Succession leads to Climax Community
Communities may undergo shifts
• The dynamics of community change are more variable
and less predictable than thought
- Conditions at one stage may promote another stage
- Competition may inhibit progression to another stage
- Chance factors also affect changes
• Phase (regime) shift = the overall character of the
community fundamentally changes
- Some crucial threshold is passed, a keystone species is
lost, or an exotic species invades
- i.e. overfishing and depletion of fish and turtles has
allowed algae to dominate corals
© 2011 Pearson Education, Inc.
Community cohesion
• Frederick Clements = viewed communities as cohesive
entities, with integrated parts
- Its members remain associated over space and time
- The community shared similar limiting factors and
evolutionary histories
• Henry Gleason = maintained that each species responds
independently to its own limiting factors
- Species join or leave communities without greatly
altering the community’s composition
- The most widely accepted view of ecologists today
© 2011 Pearson Education, Inc.
Invasive species threaten stability
• Invasive species = non-native (exotic) organisms that
spread widely and become dominant in a community
- Introduced deliberately or accidentally from
elsewhere
- Growth-limiting factors (predators, disease,
competitors, etc.) are removed or absent
- They have major ecological effects
- Chestnut blight from Asia wiped out American
chestnut trees
• Some species help people (i.e., European honeybees)
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Two invasive mussels
© 2011 Pearson Education, Inc.
Controlling invasive species
• Techniques to control invasive species
- Removing them manually
- Applying toxic chemicals
- Drying them out
- Depriving them of oxygen
- Stressing them with heat, sound, electricity,
carbon dioxide, or ultraviolet light
• Control and eradication are hard and expensive
Prevention, rather than control, is the best policy
© 2011 Pearson Education, Inc.
Altered communities can be restored
• Humans have dramatically changed ecological systems
- Severely degraded systems cease to function
• Ecological restoration = efforts to restore communities
• Restoration is informed by restoration ecology = the
science of restoring an area to an earlier condition
- To restore the system’s functionality (i.e. filtering of
water by a wetland)
- It is difficult, time-consuming, and expensive
• It is best to protect natural systems from degradation in
the first place
© 2011 Pearson Education, Inc.
Restoration efforts
• Prairie restoration = replanting native species,
controlling invasive species
• The world’s largest project = Florida Everglades
- Flood control and irrigation removed water
- Populations of wading birds dropped 90-95%
- It will take 30 years
and billions of dollars
to restore natural
water flow
© 2011 Pearson Education, Inc.
Biomes
• Activity:
• Monday and Tuesday in the 3rd Floor
Computer Lab: Rm 314
– 12 Different Biomes
– 11 Students 
– Present next week for an exam grade