LIMITING FACTORS
Levels of Organization Overview

Cells
 Tissues
 Organs
 Organ Systems
 Organisms
 Populations
 Communities
 Ecosystems
 Biome
Organisms-Biomes terms to know



Organism
 One individual of a single
species.
Population
 Groups of individuals that
belong to the same
species and live in the
same area.
Community
 Groups of different
populations that live
together in a defined
area


Ecosystem
 Collection of all the
organisms that live in a
particular place, together
with their abiotic (nonliving) , or physical
environment.
Biome
 Multiple ecosystems with
similar characteristics in
the same geographical
area.
Levels of Organization Examples




Organism
 Beavers, cattails, frogs, cranes,
deer, trees, owls, etc.
Population
 Groups of beavers, cattails,
kudzu, raccoons, frogs, trees,
etc.
Community
 The deer, trees, foxes, raccoons
together.
Ecosystem
 Owl, tree, kudzu, squirrel,
along with the soil, air,
temperature, rainfall, etc.
What is a population?
Population
 all the individuals of a
species that live
together in one place
at one time.
 Carrying Capacity
 The maximum
population size that an
environment can
sustain.

How is population affected?

Factors affecting
population density
 Increase:
 The number of
births
 Immigration
 Decrease
 The number of
deaths
 Emigration



Populations do not
usually grow without
limits.
Their growth is limited
by things such as
predation, disease and
availability of resources.
These factors are
grouped together as
Density-Dependent and
Density-Independent.
Density-Dependent Limiting Factors


A limiting factor that
depends on population
size is called a densitydependant limiting
factor.
Examples of densitydependent limiting
factors (DDLF) include
competition, predation,
parasitism/disease,
crowding
 Usually

Biotic Factors
 Living things
Exs.
 Competition for food,
water, shelter
 Spread of disease
(bacterial or viral)
and parasites
 Predator/prey
relationships
Examples of Density Dependent Factors


Crowding
 Organisms need a
certain amount of space
to nest and hunt, when
that space is limited it
can cause stress to the
immune system and
hormone levels
Predation
 Predator/Prey
relationships


Parasitism and Disease
 Caused by parasites
ranging from microscopic
bacteria to very large
tapeworms.
Competition
 When populations
become crowded,
organisms compete with
one another for food,
water, space, sunlight
and other essentials of
life.
Density-Independent Limiting Factors


A limiting factor that
DOES NOT depend on
population size is
called a densityindependant limiting
factor.
Examples of densitydependent limiting
factors (DILF) include
things like natural
disasters and human
interactions




Usually Abiotic Factors
 Non-Living things
Natural disasters
 Weather; hurricanes,
tornadoes, floods,
drought.
 Earthquakes, volcanoes,
avalanches, mudslides.
Fires
Human activity
 plowing, clear cutting,
slash and burn, use of
toxins on crops)