Download Ecology - Warren County Schools

Ecology
Ecology
 The study of the
interactions of
organisms with their
physical environment.
Population
 A group of individuals
on one species living
in one area who have
the ability of
interbreeding and
interacting with each
other.
Community
 Consists of all the
organisms living in one
area.
Ecosystem
 All organisms in a
given area as well as
the abiotic (nonliving)
factors with which they
interact.
Abiotic Factors
 Nonliving
 Temperature, water,
sunlight, wind, rocks,
soil
Biosphere
 Global Ecosystem
Five Properties of a Population
 Size
 Density
 Dispersion
 Survivorship Curves
 Age Structure
Diagrams
1. Size
 The total number of
individuals in a
population.
2. Density
 Number of individuals
per unit area or
volume.
 Scientists use
sampling techniques
to estimate the number
of organisms living in
one area.
 Mark and recapture.
3. Dispersion
 Pattern of spacing of
individuals within the
area the population
inhabits.
 Clumped
 Uniform
 Random
Dispersion: Clumped
 The most common
pattern.
 i.e. Fish traveling in
schools.
Dispersion: Uniform
 Even distribution of
population in
environment.
 i.e. some plants may
secrete toxins that
keep away other
plants that would
compete for limited
resources.
Dispersion: Random
 Absence of any
special attractions or
repulsions.
 i.e. trees can be
spaced randomly in a
forest.
4. Survivorship Curves
 Survivorship or
mortality curves show
the size and
composition of a
population.
 Type 1
 Type 2
 Type 3
Type 1
 Show organisms with
low death rates in
young and middle age.
 High death rates in old
age.
 Parenting accounts for
the high survival rates
of the young.
 i.e. Humans
Type 2
 Describe a species
with a death rate that
is constant over the life
span.
 i.e. Hydra, Reptiles,
Rodents
Type 3
 Very high death rate
among the young, but
then shows that death
rates decline for those
few individuals that
have survived to a
certain age.
 Fish and vertebrates
that release thousands
of eggs.
Age Structure Diagrams
 Diagrams that show the relative number of individuals
at each age.
Undeveloped Population
 “Pyramid Shape”
 Normally half the
population is under 20
years of age
 The population in 20
years will be
enormous.
Developed Population
 Stable Population
 Zero Population
Growth
 Number of people at
each age group is the
same, and the birth
and death rates are
equal.
Carrying Capacity
 The limit of the number
of individuals that can
occupy one area at a
particular time.
 Limiting factors that
limit population growth
 Density-Dependent
 Density-Independent
Density-Dependent
 Factors that increase
directly as the
population density
increases
 Competition for food,
buildup of wastes,
predation, and
disease.
Density-Independent
 Factors whose
occurrence is
unrelated to the
population density.
 Earthquakes, storms,
and naturally occurring
fires and floods.
Competition
 Competitive exclusion
principle
 Two species cannot
coexist in a community
if they share a niche
(they use the same
resources)
 One species will drive
the other to extinction.
Predation
 Refers to one animal
eating another, or an
animal eating plants.
 Plants have evolved
spines, thorns, and
chemical poisons.
 Animals have
developed active
defenses: Hiding,
fleeing, or defending
themselves
Aposematic Coloration
 “Warning Coloration”
 Very bright, often red
or orange, coloration
of poisonous animals
as a warning that
possible predators
should avoid them.
Batesian Mimicry
 “copycat” coloration
where one harmless
animal mimics the
coloration of one that
is poisonous.
 Monarch and Viceroy
Butterfly
Mullerian Mimicry
 Two or more
poisonous species
resemble each other
and gain an advantage
from their combined
numbers.
 Predators learn more
quickly to avoid prey
with that appearance.
Mutualism
 A symbiotic
relationship where
both organisms benefit
(+/+)
 i.e. bacteria that live in
the human intestine
and produce vitamins.
Commensalism
 Symbiotic relationship
where one organism
benefits and one is
unaware of the other
organism (+/0).
 i.e. barnacles that
attach to the
underbelly of whales
gain access to a
variety of food sources
as the whale swims.
Parasitism
 One organism, the
parasite, benefits while
the host is harmed.
 i.e. Tapeworm in the
intestine.
Food Chain
 Pathway along which
food is transferred
from one trophic or
feeding level to
another.
 Energy moves from
producers to
herbivores to the
carnivores.
Food Web
Producer
 Convert light energy to
chemical bond energy
 Have the greatest
biomass of any trophic
level
 Green Plants
Primary Consumers
 Herbivores
 Eat the producers
 i.e. grasshoppers,
zooplankton
Secondary Consumers
 Carnivores
 Eat the primary
consumers
 Examples: Frogs,
small fish
Tertiary Consumers
 Carnivores
 Eat Secondary
Consumers
 Top of Food Chain
 Have the smallest
biomass of any other
trophic level
 Least stable
 i.e. Hawk
Decomposers
 Bacteria and Fungi
 Recycle nutrients back
into the soil to nourish
plants.
 Without decomposers
there would be no life.