DO NOW Tuesday 5/20
What did you learn about systems (specifically
ecosystems) in the Estuary Ecosystem activity
yesterday?
Stamping:
- Estuary Ecosystem Debrief WS
The Effect of:
• Japanese
Mudsnail, a
non-native,
invasive
species
• Shoreline
Development
Food Web: Yellowstone National Park
Ecosystem
1. What could happen if the elk
population was removed?
2. What could happen if the
strawberry plant was removed?
3. If the Idaho fescue was removed,
what organisms may be directly
affected? Indirectly affected?
Why?
4. What could happen if the grizzly
bear was removed?
Ecology, defined
Ecology is the study of how organisms interact
with each other and their environment.
BBECPO
Biomes
“The world's major
communities, classified
according to the
predominant vegetation
and characterized by
adaptations of
organisms to that
particular environment"
Ecosystem
All the organisms in a given area a well as the
abiotic factors with which they interact. One
more communities and the physical
environment around them.
What can affect an ecosystem?
• Abiotic Factors are non-living conditions or things
that may influence an ecosystem and the organisms
living within it.
– Examples:
• Biotic Factors are any living or once-living organisms
that may influence an ecosystem and its organisms.
– Examples:
Communities
A community refers to all populations (i.e.,
various species) living together in a shared
space.
– Think about a tropical rainforest/jungle. What are
some of the populations/species that exist there as
one community?
Community Interactions
• Predator-Prey
• Competition
• Symbiosis
– Mutualism
– Commensalism
– Parasitism
sym = together bio = life/living
Predators and Prey
Predation: an interaction between species in
which one species, the predator, eats the
other, the prey.
Predation is not to be confused with parasitism,
in which one organism feeds on the cell
contents, tissues, or body fluid of another
species (the host). Parasites harm but usually
do not kill their host.
Competition
An interaction in which 2 or more species
compete for resources due to inhabiting a
shared space. Think siblings! Both species
tend to experience some disadvantage.
Whether it be for food, living space, shelter, or
for girls attention at college parties.
Symbiotic Relationships
• Symbiotic
– “sym” = together
– “biotic” = life related
• Types
– Predation
– Commensalism
– Mutualism
– Parasitism
+
+
+
+
n/a
+
-
Mutualism
An interaction where both symbiotic organisms
benefit.
Commensalism
An interaction where one organism benefits and
the other is unaffected.
Parasitism
An interaction where one organism benefits (the
parasite) and the other is at a disadvantage
(the host).
Food Chains and Trophic Levels
• The trophic level of an organism is the
position it occupies in a food chain.
• The word trophic derives from
the Greek trophē referring to “food” or
“feeding”.
• A food chain represents a succession of
organisms that eat another organism
and are, in turn, eaten themselves.
• Explain what is being shown here.
Where might humans fit?
Connect back to…
• The Queen of Trees or Estuary Ecosystem
• List one member for each trophic level:
– Primary Producer:
– Primary Consumer:
– Secondary Consumer:
– Tertiary Consumer:
Your Task
• Read textbook excerpt, Energy Supply Limits the
Length of Food Chains
– Approximately how much energy (percentage-wise) is
used or lost as heat as we move up the food chain?
– Why are food chains limited to only 4-5 trophic levels?
What would an appropriate title be,
incorporating the terms energy and production?
Food Chains vs. Food Webs
Ecological communities with higher biodiversity form
more complex trophic paths. The greater the
biodiversity, the more stable the ecosystem. Why do
you think this is the case?
What do you notice?
The concepts of
bioaccumulation and/or toxic
magnification is shown in the
images. Make a statement that
explains this phenomenon.
Keystone Species:
a species in an ecosystem which has tremendous
importance in stabilizing an ecosystem in spite of the
fact that the species is not very abundant.
Its removal has a cascade effect
on countless other species in the
ecosystem.
Removing
the
keystone
of an arch
causes it
to
collapse.
Populations
• One “population” refers to all members of the
same species living together in a shared
space.
• Things we examine in populations
– Population Growth (graphs)
– Population Density
– Limiting Factors
– Carrying Capacity
Populations
A group of members of a certain species (i.e.,
can interbreed and reproduce fertile offspring)
that living in the same area. This is different
from community, which describes multiple
populations/species living in the same area.
“Whoa that is a huge population of Homo sapiens
hanging out at Alderwood Mall on a Saturday”
Population Density
How many organisms of one population occupy one
area.
“Whoa, the population density of Homo sapiens in Mill
Creek is far less than that of the population density of
Homo sapiens in China”
Calculate the population density of a town that is 25 square
miles and has a population of 8,341 people.
General Data
Finish Predator-Prey WS
(for #8)
Trends?
DO NOW
Observe the 2 graphs showing different populations carrying
capacity. What is the difference? What does this tell you about
carrying capacities?