Transcript Ecology - Montgomery County Schools

Lesson 1
Abiotic and Biotic Factors
in Ecosystems
Organization of Species
Ecosystems
An ecosystem is made up of all the
organisms in an area and their
relationships with each other and
with the non-living parts of their
environment.
Biotic Factors
The living components of an
ecosystem are called biotic factors.
Examples of
Biotic Factors:
Animals
Plants
Fungi
Bacteria
Protists
Abiotic Factors
The non-living components of an
ecosystem are called abiotic
factors.
Examples of
Abiotic Factors:
Temperature
Soil and rocks
Water
Carbon
Nitrogen
A living thing is called an organism.
Example: a deer
All of the organisms of the same
species that live in an area at
the same time is called a
population.
Species is the largest group of
organisms capable of
interbreeding and producing
fertile offspring.
Example: a herd of deer
All the populations of all
species that live in an area is
called a community.
Example: deer + rabbits + bears
The place where an organism
or a biological population
normally lives - habitat.
Niche – the role an animal or plant
species plays in the environment,
the status of an organism within its
environment which affects its
survival.
All the organisms living in an
area, as well as the non-living
parts of their environment, is
called an ecosystem.
Example: deer + rabbits +
bears + water + temperature
+ sunlight + soil + air
Large geographic areas that have similar
climates and ecosystems are called
biomes.
Example: tundra, taiga, desert, etc.
The biosphere is the global ecological
system integrating all living beings and their
relationships, including their interaction with
the elements of the lithosphere, geosphere,
hydrosphere, and atmosphere.
Lesson 2
Energy Flow
Food Webs
Food Chains
Food Pyramids
Energy
• All living things need energy to grow and
to carry out their activities.
• They get this energy from their food or
directly from the Sun.
• This energy is passed from one organism
to another in an ecosystem.
Producers
Producers are living things
that can make their own
food by using energy in
sunlight. Plants are one
kind of producer and they
make their food through
photosynthesis.
Consumers
A consumer is an
organism that gets
its energy by
feeding on other
organisms.
Animals, fungi,
some protists, and
some bacteria are
consumers.
Herbivores
• Herbivores are
consumers that only
eat plants.
• They are called
primary, or first level
consumers.
Herbivores
Primary consumers eat producers.
Carnivores
Carnivores are
consumers that eat
meat. Most are
predators, but
some are
scavengers that eat
the meat of dead
animals.
Carnivores
They can be secondary (second-level)
consumers, which means they eat the
primary consumers, or…
Carnivores
…tertiary (third-level) consumers,
which means they eat the secondary
consumers.
Omnivores
• Omnivores eat
both plants
and animals.
• Humans are
omnivores.
Decomposers
Decomposers are consumers
that get energy by breaking
down dead plants and
animals. They return
materials stored in dead
plants and animals to the
soil, water, and air. Then
green plants use the
materials to make food.
Food Chains & Food Webs
• As organisms eat other organisms, they
get energy. Food chains and food webs
show us how that energy moves from one
organism to another in an ecosystem.
Food Chain
A food chain is a
model that shows
how energy flows
from one
organism to
another.
Food Chain
The arrows show
how energy flows
from the plant to
the mouse,from
the mouse to the
snake, and so on.
Food Chain
But, mice are not
the only organisms
that get their
energy from
plants, and snakes
are not the only
organisms that get
their energy from
eating mice.
Food Web
• So, we have food
webs to show us
more of these
relationships.
• Food webs show
overlapping food
chains in an
ecosystem.
A Food Web
Review Questions
• What do the arrows in a food
chain or food web represent?
• What is the difference between a
food chain and a food web?
• Where does the energy for all
living things ultimately originate?
• What is always the last step in a
food chain or food web?
Bell Work
What tertiary
level should
the grouse
(bird in the
middle) be
labeled as?
Why?
NOTES
Set-Up
Energy
• Energy is needed for all life processes,
such as breathing, moving, growing,
etc.
• The ultimate source of energy for
almost every living thing is the sun.
The Movement of Energy
• Living things do not create energy.
• Energy is just passed from one
organism to another.
• It is released from food through the
process of cellular respiration.
From the Sun to Producers
• Plants (producers) use the sun’s
energy to make food
(photosynthesis).
• They use most (~90%) of the energy
stored in their food to grow,
reproduce, etc.
• The food that is not used by the plant
(~10%) is stored in the plant to be
used later.
From Producers to
Primary Consumers
• When primary consumers eat plants,
they receive the energy that was
stored in the plant.
• They use this energy (~90%) to move,
grow and for all of the other processes
necessary to stay alive.
• The energy that is not used up (~10%)
is stored in their bodies.
From Primary Consumers
to Secondary Consumers
• When secondary consumers eat
primary consumers, they receive the
energy that was stored in those
organisms.
• They use this energy (~90%) to move
and grow and for all of the other
processes necessary to stay alive.
• The energy that is not used (~10%) up
is stored in their bodies.
…and so on.
• This energy is eventually passed on to
tertiary consumers, when the tertiary
consumers eat them.
Energy Pyramid
• An energy pyramid is a diagram that
shows the amount of energy that flows
through an ecosystem.
HowStuffWorks Videos "Assignment Discovery:
Energy Flow“
Energy Pyramid
• The shape of the energy pyramid
represents two things:
– the decrease in the amount of
energy moving from producers to
primary consumers to secondary
consumers to tertiary consumers
– the decrease in the number of
organisms in an ecosystem as you
move up the food chain.
Energy Pyramid
Questions
1. Why would there be less energy
available to move from one level to
the next?
2. Why would an ecosystem have fewer
organisms as you move up the food
chain?
Lesson 3
Limiting Factors
Carrying Capacity
Limiting Factors
Anything that limits the number
of individuals that can live in
ecosystem is a limiting factor.
Examples of
Limiting Factors:
Food
Water
Climate
Disease
Shelter
Predators
Carrying Capacity
The largest number of
individuals of the same species
that an area can support is
called its carrying capacity.
Example
The woods around Cave Run
only has enough food, water,
and living space for a certain
number of deer, rabbits, and
squirrels.
Lesson 4
Symbiotic Relationships
There are different
kinds of relationships
between the organisms
in an ecosystem.
Predator/Prey
An organism that hunts and eats
another organism is called a
predator.
The organism that the predator
hunts and eats is called prey.
Which one is the predator and
which one is the prey?
zebra
lioness
Which one is the predator and
which one is the prey?
snake
roadrunner
Which one is the predator and
which one is the prey?
fish
osprey
Which one is the predator and
which one is the prey?
fox
hare
Symbiosis
Symbiosis is when two organisms
live together, temporarily or for a
longer time, and at least one of
the organisms benefits from the
relationship.
Different kinds of
symbiosis
Mutualism
Commensalism
Parasitism
both
organisms
benefit
one
organism
benefits
one
organism is
unaffected
one
organism
benefits
one
organism is
harmed
+0
+-
++
The organism that
benefits in a parasitic
relationship is called the
parasite.
The organism that is
harmed in a parasitic
relationship is called the
host.
Identify the type of
relationships in the following
examples:
Moray Eel with
Cleaner Fish
Moray Eel gets a
clean mouth.
Cleaner Fish gets a
meal.
Mutualism
Cattle stir up insects as they eat
grass.
Egrets hang around and eat
insects.
Commensalism
Acacia plant with ant galls
Bull horn acacia
trees provide
nutrients and
housing for
acacia ants. Acacia
ants attack
herbivores that try
to eat the leaves.
Mutualism
Clown fish with anemone
Clown fish gets protection.
Anemone is unaffected.
Commensalism
Antelope with oxbird
Antelope
gets rid of
parasites.
Oxbird gets a
meal.
YouTube - JumpStart
Symbiotic Harmony Song
Mutualism
Taenia worm in human eye
Worm
infects
human
blood
stream.
Human
may go
blind.
Parasitism
Keystone Species Concept
In ecological communities there
are little players and big players.
The biggest players of all are
referred to as keystone species.
A keystone species may be
defined as one whose presence/
absence, or increase/decrease in
abundance, strongly affects other
species in the community.
Removal of the keystone in
the arch will cause the
structure to collapse.
Evidence usually comes from
addition or removal experiments.
Keystone Species
Lesson 6
Invasive Species
An introduction
Introduction Video
• https://www.youtube.com/watch?v=GJWZgjz7G0
1. Why are minx an “enemy” in Europe?
2. How did studying minx lead to breakthroughs
in methodology for studying semi-aquatic
mammals?
3. How could humans have prevented the
invasion of minx on European land?
What is a native species?
Native species are those that normally live and thrive in a
particular community. They occupy specific habitats and have
specific niches in their native environment. They have natural
predators that help to keep their populations in check.
Pink lady's slipper, Cypripedium acaule
Red fox, Vulpes vulpes
What is a non-native species?
•
A species living outside its native distributional range, which
has arrived there by human activity, either deliberate or
accidental. Non-native species are not necessarily invasive.
Multiflora rose, Rosa multiflora, was introduced
for use as an ornamental plant, to control
erosion, and to use as “living” fences for
livestock.
Zebra mussels (Dreissena polymorpha), were
accidentally introduced to North America, and
are now found in some Pennsylvanian
waterways
What is a non-native invasive species?
• A non-native species that adversely affects
habitats and biodiversity.
Emerald ash borer, Agrilus planipennis , has
killed millions of ash trees in the mid-west and
has recently been found in Pennsylvania
Japanese stilt grass, Microstegium vimineum,
becomes established on recently disturbed
areas and outcompetes native plants, reducing
biodiversity.
Common characteristics of invasive
species
Invasive species in general:
• Have few natural
predators, competitors,
parasites or diseases
• Have high reproductive
rates
• Are long-lived
• Are generalists
• Are pioneer species
Characteristics that make Zebra mussels a good
invader include its ability to tolerate a widerange of environments, and high reproduction
rate; female mussels release up to 100,000 eggs
ability to tolerate a wide-range of environments
year.
Discussion: how would these characteristics enable a species to become invasive?
What traits are common to invasive
plant species
Characteristics that make tree-of-heaven a good
invader include its ability to flower early (within
2 years), ability to spread asexually, and fast
growth rate.
• Self-compatible
• Flower early
• Produces abundant
seed
• Disperse seed widely
• Grow rapidly
• Spread asexually
• Strong competitors
Example: Japanese stilt grass
What makes Japanese stilt grass a
successful invader?
•
It can become established and live in a
wide variety of habitats
•
Each plant produces hundreds of seeds
that can remain viable in the seed bank
for upward of five years.
•
Seed can be transported long distances
by water or contaminated hay, seed mix
and soil.
•
Plants also reproduce asexually. They
form roots at the nodes, which allows for
new vegetative stem growth.
•
People can spread stilt grass by carrying
the seeds on their shoes, equipment and
vehicles.
Example: Garlic Mustard
What makes garlic mustard a successful
invader?
• It can germinate in shade
• Is capable of ballistic seed
dispersal of up to 10 feet
• Its seeds lie dormant for up to 6 years
• Its seed spread by animals and water
• It forms spreading monocultures
• It is allelopathic: it produces chemicals
that inhibit the growth of other plants
Impacts of invasive species
Displace native species:
Japanese stilt grass displaces native herbaceous plants, reducing biodiversity,
and reducing food available for wildlife species.
Monoculture of Japanese stilt grass, prevents
establishment of native herbaceous species
Diversity of herbaceous species increases
wildlife habitat
Impacts of invasive species
Reduce forest health and productivity
Monoculture of Japanese barberry prevents the
establishment tree seedlings
Impacts of invasive species
Some invasive species kill native species
About ¼ of the hardwood trees in Pennsylvania used to be American
chestnut. The invasive chestnut-blight fungus killed most American chestnut
throughout the eastern US by 1950.
American chestnut, Castanea dentata, at Grey
Towers National Historic Site in Milford, PA, circa
1905
American chestnut infected with chestnut blight
fungus, Cryphonectria parasitica
Impacts of invasive species
Indirect impacts:
Hemlock woolly adelgid is killing Eastern hemlock trees throughout
Pennsylvania and the northeast. Eastern hemlock forests play an important
role in maintaining stream temperatures and oxygen levels favorable for
brook trout. Hemlock mortality leads to increased water temperatures and
oxygen levels, and therefore reduced brook trout populations.
Hemlock woolly adelgid
Hemlock woolly adelgid
infestation
Hemlock mortality along
stream bank
Impacts of invasive species
Economic impacts:
Invasive species are responsible for tremendous
economic losses through loss in forest and
agricultural productivity, spread of diseases that
impact humans, among other impacts.
European starlings, Sturnus vulgaris, spread
diseases to wildlife, livestock, and humans,
damage agricultural crops, and displace
native birds. Their damage to agricultural
crops is estimated at $800 million annually.
What you can do
• When boating, clean your boat thoroughly before transporting it to a
different body of water.
• Clean your boots before you hike in a new area to get rid of hitchhiking
weed seeds and pathogens.
• Don’t move firewood (it can harbor forest pests like emerald ash borer).
• Don't release aquarium fish and plants, live bait or other exotic animals
into the wild. If you plan to own an exotic pet, do your research and plan
ahead to make sure you can commit to looking after it.
• Volunteer at your local park, refuge or other wildlife area to help remove
invasive species. Help educate others about the threat.