Transcript populations

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Attendance
Exam Information
Vocab Vortex
Rad Review MP3.
Exam Excitement.
Lab Love.
Packet Ponder.
Chapter 3: The
Biosphere
What is Ecology?
• Ecology is the scientific study of
interactions among organisms and
between organisms and their
environment.
• What does this mean?
• How do we study these interactions?
Levels of Organization
Organism
An individual
living thing
Population
Members of one species
that interbreed and live in
the same place at the
same time.
Population
• Compete for:
–
–
–
–
Food
Water
Shelter
Mates
Community
• Different populations that live together
in a defined area.
• Several populations interacting
together.
Ecosystem
• A collection of all of the organisms that
live in a particular place, together with
their nonliving, or physical environment.
Ecosystem
• Biotic Factors:
living organisms
within an
ecosystem
• Abiotic Factors:
nonliving factors
that help shape an
ecosystem
Biomes
• A group of ecosystems that have the
same climate and similar dominant
communities.
Biosphere
• The highest level of organization that
ecologists study is the entire biosphere
itself.
• The portion of
the Earth that
supports life.
BIOSPHERE
BIOME
ECOSYSTEM
COMMUNITY
POPULATION
ORGANISM
Ecological Methods
• Ecologists use a wide range of tools and
techniques to study the living world.
• Apply the scientific method to do
ecological research:
– Observing
– Experimenting
– Modeling
Interactions Between
Organisms
All organisms depend upon other living
things and nonliving things to meet
their needs, such as:
• Food
• Shelter
• Reproduction
• Protection
Thus, an interdependence exists
among organisms and the
environment
Energy Flow
• All living things need ENERGY to survive.
• Where does this energy ultimately come
from?
Autotrophs
• Organisms that capture energy from
sunlight or chemicals and use that
energy to produce food.
• Ex. Bacteria,
plants, and algae
Also called producers
Heterotrophs
• Rely on other organisms for
their energy and food supply
• Also called consumers
Types of Consumers
•
•
•
•
•
Herbivores
Carnivores
Omnivores
Detritivores
Decomposers
Heterotrophs that eat plants (1st
order consumers)
• Heterotrophs that eat animals
• They come in many sizes!
Eat both plants and animals
Ex: humans, raccoons, bears
Animals that feed on animal remains
and dead matter (collectively called
detritus)
EX: mites, earthworms, snails,
crabs
Break down decaying matter
Ex: bacteria and fungi
Feeding Relationships
• What happens to the energy in an
ecosystem when one organism eats
another?
– The energy moves along a one-way path.
• Energy flows through an ecosystem in
one direction, from the sun to
autotrophs and then to various
heterotrophs
Food Chains
• The energy stored by producers can be
passed through an ecosystem along a
food chain, a series of steps in which
organisms transfer energy by eating and
being eaten.
A food chain shows how matter
and energy move through an
ecosystem
Each organism represents a trophic level, a
step in the food chain.
Natural Food Chain
Sun
Grass
Rabbit
Snake
Hawk
The arrows show the direction that energy is transferred
Food Web
• Shows all of the possible feeding
relationships at each trophic level in
the community.
Tertiary consumers
Secondary consumers
Primary Consumersherbivores
Producers
• A diagram that shows the relative
amounts of energy or matter contained
within each trophic level in a food chain
or food web.
• 3 types
– Energy pyramids
– Biomass pyramids
– Pyramids of numbers
• Only part of the energy that is stored
in one trophic level is passed on to the
next10%
level….
why?
•Only
of the
energy available within
Organisms
use is
much
of the energy
one– trophic
level
transferred
to that
they consume
lifetrophic
processes
organisms
at thefor
next
level.
(reproduction, respiration, and movement).
• The total amount of living tissue within a
given trophic level is called biomass.
• A biomass pyramid represents the amount
of potential food available for each trophic
level in an ecosystem.
• Pyramid based on the numbers of
individual organisms at each trophic level.
• The water cycle is the continuous
movement of water between Earth and its
atmosphere.
• Carbon is an essential component of
proteins, fats, and carbohydrates
• The carbon cycle is a process by which
carbon is cycled between the
atmosphere, land, water, and
organisms.
• Four processes
–
–
–
–
Respiration (adds)
Combustion (adds)
Decomposition (adds)
Photosynthesis (removes)
• The carbon cycle has been operating to
keep the amount of carbon dioxide in
balance between the atmosphere and
Earth.
• HOWEVER, the burning of fossil fuels
has added more carbon dioxide than can
be removed by plants during
photosynthesis.
• Carbon dioxide is considered a
greenhouse gas …it traps heat on Earth.
• This contributes to global warming,
which has led to an overall increase in
the Earth’s average temperature.
*78% of the atmosphere is composed of nitrogen
*Living things cannot use nitrogen in the
atmospheric form
*Lightening and some bacteria convert nitrogen to
usable forms, then producers use them to make
proteins. Consumers then eat the producers and
reuse the nitrogen to make their own proteins!
*When organisms die, decomposers return nitrogen
to the soil and it is either reused or converted into
nitrogen gas and returned to the atmosphere.
Primary Productivity—rate at which an
organic matter is created by producers
Process can be limited by a lack of
nutrients
A polar bear, its fur stained with algae, stands in its cage at Higashiyama Zoo
in Nagoya, central Japan, Saturday, Sept. 6, 2008. Three polar bears at the
zoo changed their colors in July after swimming in a pond with an overgrowth
of algae, prompting many questions from visitors concerned about whether the
animals are sick or carrying mold, a zoo official said. Credit: AP Photo/Kyodo
News, Shuzo Shikano
Chapter 4
Ecosystems
&
Communities
49
4–1 The Role of Climate
• Words you need to know:
– Weather
– Climate
– The Greenhouse Effect
– Climate Zones
• polar zones (66.5° and 90° North and
South latitudes)
• temperate zones (between the polar
zones and the tropics)
• tropical zone (23.5° North and
23.5° South latitudes)
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• Heat Transport
• winds and ocean currents
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4–2
What Shapes an Ecosystem?
• Biotic & abiotic factors
• Habitat = the area where an
organism lives (biotic and abiotic
factors that affect it)
• Niche = full range of physical and
biological conditions in which an
organism lives and the way in
which the organism uses
those conditions
53
• no two species can share the same
niche in the same habitat
54
Community Interactions
• Competition = organisms of the same
or different species attempt to use an
ecological resource in the same place at
the same time
– Resource = any necessity of life (water,
nutrients, light, food, or space)
• competitive exclusion principle =
ecological rule that states that no two
species can occupy the same exact
niche in the same habitat at the
same time
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• Predation = interaction in which
one organism captures (kills) and
feeds on another organism
– Predator / Prey
58
• Symbiosis = Any relationship in
which two species live closely
together
– mutualism
– commensalism
– parasitism
59
• Mutualism = symbiotic relationship
in which both species benefit from
the relationship
60
Chapter 4
Ecosystems
&
Communities
61
4–1 The Role of Climate
• Words you need to know:
– Weather
– Climate
– The Greenhouse Effect
– Climate Zones
• polar zones (66.5° and 90° North and
South latitudes)
• temperate zones (between the polar
zones and the tropics)
• tropical zone (23.5° North and
23.5° South latitudes)
62
• Heat Transport
• winds and ocean currents
64
4–2
What Shapes an Ecosystem?
• Biotic & abiotic factors
• Habitat = the area where an
organism lives (biotic and abiotic
factors that affect it)
• Niche = full range of physical and
biological conditions in which an
organism lives and the way in
which the organism uses
those conditions
65
• no two species can share the same
niche in the same habitat
66
Community Interactions
• Competition = organisms of the same
or different species attempt to use an
ecological resource in the same place at
the same time
– Resource = any necessity of life (water,
nutrients, light, food, or space)
• competitive exclusion principle =
ecological rule that states that no two
species can occupy the same exact
niche in the same habitat at the
same time
67
68
69
• Predation = interaction in which
one organism captures (kills) and
feeds on another organism
– Predator / Prey
70
• Symbiosis = Any relationship in
which two species live closely
together
– mutualism
– commensalism
– parasitism
71
• Mutualism = symbiotic relationship
in which both species benefit from
the relationship
72
73
• Commensalism = symbiotic
relationship in which one member
of the association benefits and the
other is neither helped nor harmed
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75
• Parasitism = symbiotic relationship
in which one organism lives in or
on another organism (the host)
and consequently harms it
– Host / parasite
76
Ecological Succession
• Ecosystems are constantly changing
in response to natural and human
disturbances.
• ecological succession = gradual
change in living communities that
follows a disturbance
77
Primary Succession
• primary succession = succession
that occurs on surfaces where no
soil exists
– Volcano
– Glacier
78
• pioneer species = first species to
populate an area during primary
succession
– Often lichens
79
Secondary Succession
• secondary succession = succession
following a disturbance
that destroys a
community without
destroying the soil
– land cleared and
plowed for farming
is abandoned
– Wildfires
80
• climax community = mature, stable
community that did not undergo
further succession
– Old growth forests
81
Chapter 5
Populations
5-1
How Populations Grow
How Populations Grow
 Characteristics
of Populations
–Three important characteristics
of a population
geographic distribution
Density
growth rate
Geographic Distribution
Geographic Distribution
Geographic
distribution, or range, is
a term that describes
the area inhabited by a
population.
Population Density
 Population
density is the number of
individuals per unit area.
 The population of saguaro cactus in the
desert plant community has a low
density, whereas other plants in that
community have a relatively high
density.
Populations Growth
 Population
Growth
 Three factors can affect population size:
number of births
the number of deaths
the number of individuals that enter or
leave the population.
* Simply put, a population will increase or
decrease in size depending on how many
individuals are added to it or removed from it
Immigration & Emmigration
 Immigration
the movement of individuals into an
area, is another factor that can cause a
population to grow.
 Emigration
the movement of individuals out of an
area, can cause a population to
decrease in size.
Word Origin
 Immigration
is formed from the Latin prefix
in-, meaning “in,” and migrare, meaning “to
move from one place to another.
 If the Latin prefix e- means “out,” then
which of the following means “migration
out”?
A.) emigration
B.) migration
C.) Immigration
Exponetial Growth
 Exponential
Growth
If a population has abundant
space and food, and is protected
from predators and disease, then
organisms in that population will
multiply and the population size
will increase.
Exponential Growth
Exponential growth occurs when
the individuals in a population
reproduce at a constant rate.
Under ideal conditions with
unlimited resources, a
population will grow
exponentially.
Logistic Growth
 Logistic
growth occurs when a
population's growth slows or stops
following a period of exponential growth.
 As
resources become less available,
the growth of a population slows or
stops. The general, S-shaped curve of
this growth pattern, called logistic growth
Carrying Capacity
Carrying
Capacity
The number or the largest
number of individuals that a
given environment can support.
In the Belly of a Python
Pythons have replaced alligators as
the apex (top) predator in the
Florida Everglades
What is a Python?
• Native to grassy marshes and jungles of Southeast Asia
• Can grow up 23 feet long
• Can weigh up to 200 lbs
• Excellent swimmers – can stay submerged in
water up to 30 minutes
• Diameter can be about the same as a telephone pole
• Carnivores that kill by constriction (squeezing prey)
• On Threatened List in native lands, but not threatened in Florida
Burmese Pythons are an Invasive
Species
• An invasive species is one that “invades” a
habitat that is not its native habitat. In its
native habitat it is part of an ecosystem that
keeps its population in balance with other
organisms.
An Invasive Species can Severely
Damage an Ecosystem’s Balance
• But when it is imported into another
environment that provides the right
combination of climate and resources to live
but where its population is NOT kept in check
in the new ecosystem, it becomes an INVASIVE
SPECIES that disrupts the balance of the
ecosystem.
What are the Everglades?
• The Florida Everglades is a huge, wetland ecosystem .
• Over 4,500 miles of slow moving waters feed the sub- tropical
habitats.
• Formed over thousands of years its waters and vegetation
provides home to thousands of mammals, amphibians, birds,
fish, insects, arachnids, reptiles and plants.
• The Everglades is America's only sub-tropical wilderness and
visitors travel from all over the world over to experience its
natural beauty.
• Has diverse habitats of pine and freshwater cypress forests,
open prairie, and tropical saltwater mangrove swamps.
• Fragile ecosystems are easily disrupted by invasive species.
Images of the Everglades
Burmese Pythons Disturb the
Ecosystems of the Everglades
• The non-native python has virtually no
predators in the Everglades.
• It is a voracious eater.
• It disrupts the fragile balance of the
ecosystems in the Everglades
• The following slides show some of the very
different kinds of animals that have been
found in stomachs of captured pythons.
Bob Cats
Endangered Key Largo Woodrat
Rare – only about 100 in the wild
White-tailed Deer
White-tails have a home territory that is less than one square mile. If the deer
in an area decrease because of python predation, how does that affect the ecosystem?
Think – what else eats deer? What do deer eat? Think in both directions of the food chain.
Rabbits
Yes, Alligators in Python Digestive
Systems!
Limpkins – southern marsh bird
Feed almost exclusively on apple snails, which are voracious plant eaters. If
the limpkin population goes down from python predation, what does the apple
snail population do?
Wood Stork
Wood Storks have been on the Endangered Species List since 1984
Little Blue Heron
How Many Pythons Are in Florida?
•
•
•
•
•
•
•
•
An estimated 150,000 are slithering around the Evergaldes
So let’s see – what’s the math?
72 mice x 150,000 =
4 gators x 150,000 =
1 racoon x 150,000 =
15 rabbits x 150,00 =
And so on - you get the picture!
Now multiply the above by the fact that they can live to be
30 years old and hatch 35 to 100 eggs a year! And some
percentage of the babies live and continue eating and
hatching more snakes!
• It’s a problem, alright.
Female with 59 Eggs When Captured
and Killed
Ready to Watch Our Movie?
• What are we interested in picking up
information about?
How the invasion started
What predators they replace
What they eat
Ways that they disrupt the ecosystem
What can be done to solve the problem?
Images from The Nature Conservancy
• http://www.nature.org/ourinitiatives/regions/
northamerica/unitedstates/florida/howwewor
k/in-the-belly-of-a-python.xml
Links to videos
• http://video.pbs.org/video/1411970145/
• http://www.cbsnews.com/video/watch/?id=4
586903n