Transcript Ecology Ch 18 Kaht 13

Chapter 18
Ecology
Ecology
• The study of the interactions
of organisms with one another
and within their environment
An Environment Contains…
• Biotic Factors
– “Bio” = Life
– Living factors in an environment
• Abiotic Factors
– “A” in front of a word = Non
– Non-living factors in
an environment
ABIOTIC FACTORS
1. Water• Most living things are mostly
water…mostly!
• Water is a crucial reactant
in photosynthesis
and respiration.
2. Sunlight- needed for photosynthesis
3. Air/Oxygen- Most living things need
this gas. Air breathing organisms get
it from the air. Others get it from
the water (there’s oxygen dissolved
in the water).
4. Soil
How are Environments Organized?
Five Levels of Organization
–1. Organism
–2. Population
–3. Community
–4. Ecosystem
–5. Biosphere
1. Organism
• One individual living thing.
• Ex: One individual alligator..
2. Population
• A group of individual organisms of the
same species.
• Ex: a group of alligators.
3. Community
• All species that
live and interact
in one area.
• Ex: alligators,
fish, snakes, and
trees living in a
swamp.
4. Ecosystem
• An ecosystem
contains both biotic
and abiotic factors
in an environment.
• Ex: alligators, fish,
snakes, trees, rocks,
water, dirt, etc. that
is found in a swamp.
5. Biosphere
• Contains all ecosystems. This is where
life exists on Earth.
Interaction of
Living Things Flip Book
Interactions
Between Organisms
and the Environment
Lets look at some
vocabulary
terms!
TERMS
limiting factor: environmental factor
that prevents a population from
increasing.
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food
water
space
weather
shelter
TERMS
carrying capacity: the largest
population that an environment can
support
Niche - the role an organism
plays in an ecosystem
An organism’s niche can include:
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•
•
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Type of food it eats.
How it obtains its food.
What organisms eat it.
When and how reproduction
takes place
3 Types of Interactions:
• Competition: When two or more
individuals try to use the same resource.
• Predation: One organisms hunts and kills
another.
• Symbiosis: a close relationship between
two or more species.
Competition
When two or more individuals (or
populations) try to use the same
resources.
Let’s Brainstorm!
What are some resources
that organisms might
compete for?
• Resources can be food,
water, shelter, space,
sunlight, mates, etc.
Competition
Competition can happen in
one of two ways:
1. Between individuals within a
population
2. Between populations in a community.
Competition
Individuals within a population:
Example:
The Elks in Yellowstone National Park
Elks are herbivores (what does that
mean?) and compete with each other for
the same food plants.
Competition
Competition between populations:
Example:
Different species of trees in the
forests
What do you think they compete for?
• When one organism hunts and kills another.
• Predator: the organism that kills and eats
all or part of another organism.
• Prey: an organism that is killed and eaten
by another organism.
What happens
if a predator
is suddenly
removed from a habitat?
News Flash!
Not all members of
an ecosystem are
created equal!
All organisms have important roles,
but some members are more
important to the ecosystem
as a whole.
• We call these important members
the keystone species
• Example: The sea otter in the
Pacific Ocean
• Sea otters live in
the Kelp Forests of
the Pacific Ocean.
• One of their
primary food sources
is sea urchins
• At one point, the
otters were hunted
to near extinction.
• With the otters gone, there was
nothing to eat the sea urchins
• The sea urchins exploded in
number and then ate all of the
kelp
• The kelp was home to dozens of
animals, all of which disappeared!
• Eventually, even the sea urchins
disappeared.
• Otter became protected animals,
and grew in number. Over time,
the different populations
returned!
• Organisms develop adaptations
(changes) over time in response to
their environment in order to
survive.
–This is called natural selection.
Does this apply only to predators?
Only to prey?
Or to both??
Predator Adaptations
• A predator must be able to catch
their prey!
• Predators have developed a wide
variety of methods and abilities in
order to effectively and efficiently
hunt their prey.
Examples: speed, sharp teeth, sharp
claws/talons, poisonous venom, night vision,
“radar”, coloring.
The cheetah’s speed gives it an advantage
over predators competing for the same prey!
The Goldenrod Spider
–Blends in with the goldenrod
flower.
Prey Adaptations
Prey must be able to
avoid being eaten!
Prey have developed methods and
abilities to keep from being eaten.
Prey Adaptations
Examples: speed, protective
coverings, warning coloration,
mimicry, camouflage,
false coloring, groups,
defensive chemicals,
Prey Adaptations:
• Camouflage
– Coloration that helps an organism to blend
in with its surroundings.
Examples:
• Rabbits
– Brown Rabbits, White Rabbits
• Walking Sticks
– Insect that looks just like a twig.
– Some even sway to look like they were a
stick being blown by a slight breeze!!
Prey Adaptations
• Warning Coloration
– A way to advertise their
defensive chemicals
– Predators avoid animals that have colors
and patterns they associate with pain
– Most common warning colors: bright
shades of red, yellow, orange, black, and
white.
• Fire Salamander
– Bright yellow and black
– Sprays a chemical that burns
Fire Salamander
• Pretenders
–Don’t have defensive chemicals,
but use warning coloration
–Example: Scarlet King Snake vs.
Coral Snake
Snake Rhyme–A Coral Snake Reminder - For some people a catchy rhyme is used to
remember whether a snake is poisonous or not. This is especially true of the coral
snake, one of the deadliest snakes in America. There are other colorful snakes that are
not poisonous and have the same attributes of the coral snake, hence the snake rhyme.
The Milk snake and the Scarlet King snake are the two reptiles that the rhyme is
referring to when it is said “yellow touching red: you’re dead. Red touching black: safe
for Jack. Red against yellow can kill a fellow.”
Symbiosis
Symbiosis is a close, long-term
association between two or more
species.
Symbiosis
3 types of symbiotic relationships:
1. Mutualism: both species benefit.
2. Commensalism: one species benefits, the
other species is unaffected.
3. Parasitism: one species benefits, the
other species is harmed.
Mutualism
• ants and aphids
• clownfish and sea anemones
• bees and apple trees
Ants and aphids share a well-documented relationship of mutualism. Ants feed
on the sugary honeydew left behind by aphids. In exchange, the ants protect the
aphids from predators and parasites. In fact, honey ants will go to unusual
lengths to ensure the health of the aphids in their care
Commensalism:
• Remoras and Sharks
• Cattle Egrets and Livestock
• Orchids Growing on Branches
of Trees
• A titan trigger fish (feeding
opportunities for smaller fish
by moving large rocks too big
for them to shift themselves)
Parasitism
• The parasite - organism that
benefits.
• The host - organism that is
harmed
• The parasite gets nourishment
from its host, while the host is
weakened.
Parasitism
• Tapeworms in human intestines
• Fleas on dogs
• Tick
Coevolution
• Relationships between organisms
change over time.
• Interactions between organisms can
also cause a change in the organisms
themselves!
• Coevolution is when a longterm change takes place in
two species because of their
close interactions with one
another.
• These changes happen over a
very long period of time.
Bumblebees and Flowers
• Bumblebees and the flowers they pollinate
have coevolved so that both have become
dependent on each other for survival.
• Over millions of years, flowers have changed
to attract certain pollinators!
• Flowers attract pollinators with their color,
odor, or even nectar.
Hummingbirds and Ornithophilous Flowers
Hummingbirds and ornithophilous (bird-pollinated)
flowers have evolved a mutualistic relationship.
The flowers have nectar suited to the birds' diet,
their color suits the birds' vision and their shape
fits that of the birds' bills.