Download Ecological Relationships and Succession

Ecological Relationships and
Succession
Predator/Prey
A relationship between individuals of different species in
which one individual captures and eats another individual
from a different species.
Predator–Prey Relationships
What does this information tell you about …….
A. the effect of size of prey populations on the number of predators?
B. the effect of predators on the populations of their prey?
What other factor would influence the size of the hare population in addition to
the size of the population of lynx?
Symbiotic Relationships:
close, long-term interaction between two different species
Mutualism
A symbiotic relationship between individuals of different
species in which both individuals benefit from the
association.
Example: Cleaner shrimp on sharks (both benefit)
Commensalism
A symbiotic relationship between individuals of different species
in which one individual benefits, while the other is unaffected by
the association.
Example: Barnacles on whales (barnacles benefit, whales are
unaffected)
Parasitism
A symbiotic relationship between individuals of different
species in which one individual benefits, while the other is
harmed by the association.
Example: Ticks on dogs (ticks benefit, dogs are harmed)
Niche
The role or function of an organism or species in an
ecosystem, and its interrelationships with all of the abiotic and
biotic factors affecting it.
Example: swamp grass is a shelter for some organisms and food
for other organisms, it relies on water, soil, and sunlight to
survive
Fundamental niche: the set of resources a population
is theoretically capable of using under ideal conditions
Realized niche: the resources a population actually uses
The realized niche may be smaller than the fundamental
niche because of interspecific interactions such as:
Competition
Predation
Inter-specific Competition
P. caudatum and P. aurelia are both species of Paramecium, a
microscopic protozoan. P. caudatum is the larger of the two
species.
Considering that P. caudatum is 50% larger in size than P.
aurelia, develop a hypothesis to explain why interspecific
competition has an effect on the relative population size of
P. caudatum.
Intra-specific Competition
These tadpoles are confined to a limited environment. What are they
all competing for in that environment?
Propose an explanation for why the population size affects the
number of weeks before metamorphosis of the tadpoles occurs.
What is different about this compared to the competition seen in
graph B on the previous slide?
Ecological Succession
The observed process of change in the species
structure of an ecological community over time.
Primary Succession
1. On what type of land
does primary succession
first begin to occur?
2. Why would most plants
such as shrubs and trees
find it difficult to grow
here?
3. Suggest the mechanisms
by which the first colonizers
arrived on the land.
The first colonizers are referred to as the pioneer community.
These can include lichens, mosses, ferns, and bacteria—all
organisms with low nutrient requirements.
As they colonize, they break the weathered rock surface,
which helps to create the first thin layer of soil.
Without soil other plant life cannot be sustained and
without plants no animal life can exist.
Notice the colonizers in diagrams C and D are taller and require more
nutrients than those in the pioneer community.
1. Considering what you already know about plants and
photosynthesis, why might it be a competitive advantage for a
plant to be taller?
2. What happens to the pioneer organisms once the new colonizers
become established?
As soil quality and quantity
improves, the life forms
present in the area
undergo a series of
changes, each referred to
as a seral stage. Eventually
a stable climax community
is formed.
Most climax communities are mature forests. What
features of mature forest species, such as oak trees,
make them able to dominate and compete in the
ecosystem?
What environmental factors may affect the type of
climax community that develops in an ecosystem?
As the newer colonizers begin to take over, animals will
also begin to appear so they can feed on the more diverse
food source. The pioneer plants die and decompose and
the animals leave behind manure. Both add to the thin soil
layer.
1. What effect will the
addition of animal waste and
decayed plant matter have on
the soil and land?
2. How will grazing animals
help plants to become
established?
3. How will the grazing
animals prevent or control
further colonization by other
plants?
Develop a definition for the term
primary succession, as it relates to the
colonizing of barren land.
Secondary Succession
Secondary Succession
What stage of development does diagram A
represent?
What appears to have happened in
diagram B?
What process will begin again after this
event has occurred?
What effect does an existing soil presence have on the
seral stages of secondary succession and the time it
takes to return to the climax community compared to
primary succession?
What is the MAIN difference between Primary and Secondary
succession?
Consider each event below and determine if the recovery
process for the environment will happen by primary
succession or secondary succession.
a. Melting, receding glaciers.
b Logging a wooded area.
c. Major flooding of a creek bed.
d. Volcanic eruption with lava flow.