Transcript Key Terms – Copy into your journal

Changes in an Ecosystem
Ms. Newton
Changes in Ecosystems
• Many factors can cause changes in an
ecosystem including:
– Climate
– Human Activity/Interaction
– Non Native (non indigenous) Species
– Changes in populations
Change in Ecosystems - Climate
• As climate changes, some
species will relocate to new
areas creating a new
Ecosystem in new Area.
• If a population is unable to
relocate, a change in
climate could mean
extinction.
• Extinction of some species
= potential elimination of
an entire ecosystem
Change in Ecosystems- Humans
• Humans can drastically alter
an organism’s ecosystem
– Urban Development (building
new homes)
– Pollution (oil spills, burning
fossil fuels, pesticide run off)
– Deforestation – (cutting down
forests)
Ecosystem Change – Non Native
Species
• When new species are introduced to an area
(usually by humans), it can have a major
impact on the ecosystem.
• Example – Pythons in Florida – Wiping out
some ecosystems. No natural predators.
Ecosystem Changes - Populations
• Populations will grow and decrease naturally
in an ecosystem.
• Food, water, shelter, space are main factors in
population change
• When food is scarce, certain populations
decrease. When food is abundant – certain
populations increase. This is true on each
trophic level of the food chain.
Factors that impact population growth
• Limiting Factors: Limiting factors are things
that prevent a population from growing any
larger
– Availability of Food, Water, Shelter
– Space
– Competition for resources
– Predation
– Disease
Adapting to Change
• Adaptation – changing to better fit your
environment
• Populations have the ability to change in order
to survive in a changing environment.
• When change occurs animals can either adapt,
move, or become extinct.
• We will get deeper into adaptations in a few
days.
Ecosystem Cycles
• Within an Ecosystem you will find 3 main
cycles necessary for survival
– Water Cycle
– Nitrogen Cycle
– Carbon Cycle
Water Cycle
• Water Cycles through Earth
Constantly.
The water cycle involves many processes:
evaporation/transpiration 
Condensation  Precipitation 
Infiltration/Percolation  Run Off
Water Cycle
• The water cycle provides fresh water to plants
and animals in an ecosystem.
• Plants need water to conduct photosynthesis
– the process in which plants use carbon
dioxide and water to make sugar for energy.
• Animals need water for basic cellular function
as well.
Carbon Cycle
• Carbon is one of the most important elements
found on Earth. Its in every living thing.
How does carbon get cycled through
an ecosystem?
• Plants use Carbon dioxide from the air to
create food.
• When that plant is eaten, the stored carbon is
broken down and is now in the animal’s
system.
• The animal breathes out carbon dioxide and it
is released back into the atmosphere.
• If the animal dies, the carbon is broken down
and also released back into the atmosphere.
Carbon Cycle
• Carbon is also released into the atmosphere
by the burning of fossil fuels
Nitrogen Cycle
• Nitrogen is the most common gas found in the
earth's atmosphere. It is necessary for plant
growth. In fact, it's necessary for the survival
of all ecosystems
• Nitrogen is found naturally – atmosphere,
animal waste, and dead organisms.
Nitrogen Cycle
• Nitrogen fixing is when bacteria found in soil and
roots of plants convert nitrogen into a substance
that can be used (Nitrates, Nitrites, and
Ammonia).
• Once “fixed”, nitrogen can be used by plants and
then nitrogen is passed on to animals when the
plants are eaten.
• Nitrogen can also be “fixed” by lightning
Nitrogen Cycle
• Nitrogen is
“released” back into
an ecosystem in
urine/waste and
when an animal dies
Relationships
• Different organisms interact with each other
and their environment.
• Competition occurs when organisms in an
ecosystem try to get the same resources (deer
activity)
• Coexistence occurs when organisms do not
compete for the same resources since they
rely on different resources for survival.
Predator Prey Relationships
• Predation is when one animal hunts, kills, and
eats another.
•
The animal that is the hunter is the
predator.
• The animals that are killed and eaten are
called Prey.
• Predator Prey relationships balance an
ecosystem.
Other Relationships
• Symbiosis
– A close relationship between two different
species of organisms living together
• Mutualism
• Commensalism
• Parasitism
Mutualism
• Mutualism is a symbiotic relationship where
BOTH species BENEFIT.
– Example: Ox Pecker and Rhino
• Oxpeckers eat insects off the rhino. Rhino benefits by
having the insects removed.
Commensalism
• Commensalism – a symbiotic relationship
which one species benefits without benefiting
or harming the other organism.
– Barnacles on a whale. Barnacles use the whale as
transportation and do not help or harm the whale.
Parasitism
• Parasitism is a relationship between a parasite
and its host. The parasite usually harms the
host by taking away nutrients but usually does
not kill the host.
• Example: Ticks and Dogs
Key Terms – Copy into your journal
•
Autotrophs - Organisms that produce their own food through photosynthesis.
•
Consumers - Organisms that consume other organisms for food.
•
Decomposers - Organisms that break down the remains of plants and animals.
•
Energy pyramid - The flow of energy from the producer through the various
consumers.
•
Food webs - Diagrams illustrating the interaction of organisms in an ecosystem.
•
Heterotrophs - Organisms that consume autotrophs or other heterotrophs for food
and use their energy.
•
Producers - Organisms that use photosynthesis and create their own food.
•
Trophic level - Each level in an energy pyramid.