Transcript Ecosystem Dynamics

Ecosystem Dynamics
Slide # 2
Important Vocabulary
1.Biotic Factors: living things
2.Abiotic Factors: nonliving, physical things such:
a.Temperature, sunlight, precipitation, soil
3.Habitat- The area in which an organism lives.
4.Niche: An organism’s place / role in the ecosystem
Abiotic
Factors
Biotic
Factors
ECOSYSTEM
Slide # 3
Five Species of Warblers and Their Niches
1.No two species can share the exact same niche in a
habitat.
2.Shaded areas show where each species feeds (one
factor that defines a niche).
Go to
Section:
Slide # 4
Descriptions of a Niche Include:
1. Its Place in the Food Web
2. Conditions Needed for Survival
Top
a. Temperature Range it has adapted to
Carnivore
b. Dependability on water
3. When and how it reproduces
A frog’s skin is moist so that
oxygen can pass through its
skin. They must also lay their
eggs in water.
Ex. Corals release eggs and sperm
on the same day every year.
Slide # 5
Community Interactions: Competition
1.Competition: occurs when
organisms of the same or
different species try to use
the same ecological
resource at the same time
and place
2.Resource: any necessity
of life
a.EX: water, nutrients,
light, food, or living
space
Uniform spacing: less competition
Clumped: more competition
Slide # 6
Competition can help define the niche.
Barnacle Species A
Barnacle
Species B
Slide # 7
More Important Vocabulary
1. Community: all populations
living in a given area.
a. Populations within
communities interact w/ one
another in their habitat.
b. These relationships are
important in maintaining the
balance in nature.
2. Symbiosis: close relationship
between 2 organisms, in which
at least one of the organisms
involved benefits.
Slide # 8
Symbiosis: Parasitism
Parasitism: One organism benefits, and the other is
harmed (host).
Filled with blood
Ticks feed on the blood of the host in which they live.
The closer together organisms live, the easier these
parasites can spread through the population.
Slide # 9
Symbiosis: Commensalism
Commensalism: One organism benefits, and the other is
neither helped nor harmed.
Barnacles live and grow on the bodies of various
ocean organisms like whales. However, they do not
help or cause any harm to them.
Slide # 10
Symbiosis: Mutualism
Mutualism: Both organisms benefit from the relationship.
This bird eats insects found on
the zebras’ body. The bird is
high above the ground and has
food, the zebra is removed of
pests.
Bees receive food (nectar),
while the flower’s pollen is
spread for reproduction.
Slide # 11
Aphids feed on
sugary sap from
the plant.
-Parasitism
Aphids are
herded and
protected by the
ants because the
ants feed on
sugary
excretions the
aphids produce.
-Mutualism
Slide # 12
Predator-Prey Relationships
1.Predation: interaction in
which one organism
captures and feeds on
another organism
2.Predator: organism that
does the killing and eating
3.Prey: organism that is
eaten (food)
Who is the predator?
Lynx
Who is the prey?
Hare
Population Ecology
Slide # 13
Populations and Their Growth
1. Growth Rate: the change
in a population’s size
2. A population’s size can
increase (positive),
decrease in size (negative)
or remain the same size
(constant)
3. Exponential growth: “J”
5. Carrying capacity:
shaped curve
largest number of
4. Logistic growth: “S”
individuals the
shaped curve
environment can support.
Slide # 14
Positive Population Growth
1. Occurs when birth rate is
higher than the death rate
2. Usually occurs when
conditions are ideal; will
increase until something
stops it
Human Population
Growth Curve
German cockroach produces 80
young every 6 months. If every
cockroach hatched survived for three
generations, kitchens might look like
this. (The Smithsonian Museum of
Natural History.)
Slide # 15
Negative Population Growth
1. Occurs when birth
rate is lower than
death rate
a. Ex. Overgrazing
and drought left
this area with out
enough resources
to sustain all of the
wildlife.
b. individuals die and
the population
decreases.
Slide # 16
Steady State -No population growth
1. Occurs when birth and death rates are about equal
Population Growth
of Rabbits
Steady State
Years
Slide # 17
Population Boom (great increase) and Population Bust
(great decrease)
Boom
Bust
The human population experienced a
boom (baby boom) after world war II.
Slide # 18
Limiting Factors: Limit Population Growth
1. Limiting factors: help stabilize population numbers
when the population reaches carrying capacity for that
ecosystem
a. Density independent: factors that affect all members
of the population equally if population is dense or not.
 Natural disasters: floods, earthquakes, wildfires,
tornadoes, mudslides, pollution, habitat
destruction
b. Density dependent: factors that affect crowed
populations
 EX: competition, predation, crowding and stress,
parasitism, and disease
Slide # 19
Density Independent Limiting Factors
Slide # 20
Density Dependent Limiting Factors
1. Competition for limited resources is
the most important limiting factor that
affects carrying capacity.
2. Predation
a. Most species serve as food for
others
Competition
b. These evolved relationships are
important for the health & survival
of predator and prey populations.
•
Removes weak & unhealthy
individuals
Predation
Slide # 21
Density Dependent Limiting Factors
3. Crowding and stress
a. Most animals have a built-in
need for a certain amount of
space & end up fighting among
themselves if they become
overcrowded
b. Increase in stress can reduce
their resistance to disease,
reduce mating, or cause low
birth weight.
c. Individuals who are stressed
may neglect, kill, or even eat
their offspring.
As the tiger’s territory is
shrinking due to habitat
destruction, they fight and
end up suffering from
stress related problems.
Slide # 22
Density Dependent Limiting Factors
4. Parasitism & Disease
a. The more crowded the
population, the easier it is
for disease and parasites to
spread.
Lyme disease – bacterial disease
transmitted by ticks; characterized by
a bulls eye shaped rash.
Slide # 23
Ecological Succession
Ecosystems are constantly changing in response
to natural and human disturbances. As an
ecosystem changes, older inhabitants gradually
die out and new organisms move in, causing
further changes in the community.
Defined as a series of predictable changes that
occurs in a community over time
Slide # 24
Primary Succession
• Occurs on surfaces where no soil exists.
– Ex: after volcanic eruption, glaciers
melting
Slide # 25
Primary Succession
First species to populate the area is called the
pioneer species.
– Lichen is the most common pioneer species
after a volcano.
• Lichen = fungus and alga capable of growing
on bare rock.
• As it grows, it helps to break up the rocks.
• When lichen die they add organic material to
help form soil to support plants.
Primary Succession
Slide # 26
Secondary Succession
Occurs when a disturbance of some kind
changes an existing community without
removing the soil.
•Ex: clearing land, plowing, wildfires.
Slide # 27
Secondary Succession
Ecologists believe that succession in a given area
proceeds in predictable stages ending with a mature,
stable community, referred to as a climax
community.
Biomes: Clusters of Similar
Ecosystems
Slide # 28
Important Vocabulary
1.Biome: complex terrestrial communities that cover a
large area
2.Characterized by a:
a.Certain climate & soil
b.Certain assemblage of plants and animals
Deserts are characterized by poor
soils and low precipitation.
Desert plants usually have
shallow, wide spreading roots
systems.
Slide # 29
Relationship Between Temperature and
Precipitation and Biome Location