Download Abiotic or Biotic?

Interactions
of Living
Things
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What is an Ecosystem
• An ecosystem is made up of organisms
interacting with one another and with
non-living factors to form a working
unit.
– A frog eating an insect is an example of
two living things interacting in an
ecosystem.
– A frog using a stream as shelter is an
example of an interaction between a living
thing and a nonliving part of an ecosystem
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The study of the
interactions between
organisms and the
living and nonliving
components of their
environment--ECOLOGY
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Biosphere
• Part of Earth where living things can life
• Include:
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Deserts
Mountains
Rivers
Prairies
Wetlands
Forests
Plains
Oceans
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Ecology
• Ecologists spend a lot of time
outdoors, observing ecosystems up
close.
• They also conduct experiments in
laboratories.
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The Nonliving Environment
• Abiotic factors- the
nonliving parts of an
organism’s environment.
• Examples: air currents,
temperature, humidity,
light, pH, nitrogen
availability, and soil.
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The Nonliving Environment
• Light and Temperature –
determine where plants and
animals can live
• Air gases such as oxygen,
nitrogen, and carbon dioxide are
needed by most species
• Soil types determine what plants
and animals can live in an area;
made of minerals, water, air,
and organic matter
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Abiotic Factors, cont.
• Water
– Some organsims are adapted for life in water
– Water helps all living things carry out life
processes, such as digestion
– Water can also serve as shelter and a way to
move from place to place
•Sunlight
– The sun is the main source of energy for most
organisms on Earth
– Energy from the sun is used by green plants to
produce food
– Humans get energy by eating plants and other
organisms that have fed on plants
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The Living Environment
• Biotic factors- all the
living organisms that
inhabit an environment.
• All organisms depend on
others directly or
indirectly for food,
shelter, reproduction, or
protection.
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Abiotic or Biotic?
Biotic
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Abiotic or Biotic?
Abiotic
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Abiotic or Biotic?
Abiotic
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Abiotic or Biotic?
Biotic
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Levels of Organization
• Ecologists have organized the
interactions in which an organism
takes part into different levels
according to complexity.
• Ecologists organize living things into
groups to make it easier to study
ecosystems
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1st Level of Organization
• Organism:
An individual
living thing that
is made of cells,
uses energy,
reproduces,
responds, grows,
and develops
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2nd Level of Organization
• Population:
A group of organisms,
all of the same
species, which
interbreed and live in
the same place at the
same time.
• Ecologists
use
tags to study
populations of animals
that travel long
distances
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2nd Level of Organization
• Population:
Ecologists want to
know the size of a
population, where
its members live,
and how it is able
to stay alive
• Ecologists
determine
population density
by comparing the
size of a population
with its area
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3rd Level of Organization
• Biological
Community:
All the populations
of different species
that live in the
same place at the
same time and
interact (solely
biotic in terms of
composition).
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4th Level of Organization
• Ecosystem:
Populations of plants
and animals that
interact with each
other in a given
area, along with the
abiotic components
(physical and
chemical) of that
area. [terrestrial
or aquatic]
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5th Level of Organization
• Biome: Many
different
ecosystems are
found in a biome;
e.g., mountains,
tropical rain
forests, tundra
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6th Level of Organization
• Biosphere:
Broadest, most
inclusive level,
i.e., the thin
volume of Earth
and its atmosphere
that supports life
(5 to 6 miles above
surface to deepest
part of the oceans)
•Earth:apple::biosphere:skin of apple
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Energy Transfer
•Begins with the SUN
•Photosynthesis
•Energy moves through a
community as producers
and consumers interact
6CO2 + 6H2O + sunlight & chlorophyll
C6H12O6 + 6O2
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Energy Transfer
Energy moves through an
ecosystem in the form of food
Producers: autotrophs that
capture energy and use it to
make organic molecules
*Photosynthesis
*Chemosynthesis
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Energy Transfer
Consumers: heterotrophs that obtain
energy by consuming organic molecules
made by other organisms
*Herbivores: eat producers
*Carnivores: eat other consumers
*Omnivores: eat both producers
and consumers
*Detritivores/Scavengers: feed on
the “garbage” of an ecosystem
Decomposer: Organisms that get energy
by breaking down dead organisms
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Living things use energy!
Living things are divided groups by how they
get their energy.
– Producers: gets energy from sunlight
– Consumers: gets energy from other things
• Herbivore: eats only plants
• Carnivore: eats only animals
• Omnivore: eats plants and animals
– Decomposers: get energy from dead things
Living things use energy!
• Food Chain - shows energy flow from
one organism to another
Food Chains and Food Webs
Food Chain: single pathway of feeding
relationships among organisms in an
ecosystem that results in energy transfer;
matter cycle through food chains
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The amount of matter on Earth never changes
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Matter in ecosystem is recycled
Food Web: Interrelated food chains
that overlap in an ecosystem
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Food Web
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Food Chains and Food Webs
Ecological pyramids: bottom
layer of pyramid represents
ecosystem producers; top layers
represent consumers
Energy pyramid: compares the
energy available at each level of
a food chain; bottom levels have
more energy than top levels
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Living things use energy!
• Energy Pyramid – a triangular
diagram that shows the loss of energy
as it moves between organisms
In an energy pyramid, a
producer is ALWAYS on
the bottom, with a
predator on top.
90% of energy is used to
stay alive while 10% is
passed on (up the
pyramid)
Energy Pyramids Show
•Amount of available energy
decreases for higher
consumers
•Amount of available energy
decreases down the food
chain
•It takes a large number of
producers to support a small
number of primary consumers
•It takes a large number of
primary consumers to support
a small number of secondary
consumers
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Characteristics of Populations
• Populations size: number of individuals in a
population
• Population density: number of individuals in a
population that occupy a definite area
– E.g., 100 mice per square kilometer
• Population spacing: how organisms are
arranged in an area
– Evenly spaced: consistent distance between
organisms
Randomly spaced: individual location is independent
of other individuals’ locations
– Clumped spacing: organisms group together
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Limiting Factors Ch.18-3
• Populations do not have enough resources to
grow larger and larger forever
• Any biotic or abiotic factor that limits the
number of individuals, or size of a population
– E.g. drought, food, water, living space
• Carrying Capacity: the maximum population
size that can live in an environment over time
• Biotic Potential – the size a population could
reach if no limiting factors stopped its growth
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Organisms in a Changing
Environment
•Acclimation: Adjusting tolerance to
abiotic factors over the course of a
lifetime
•Adaptation: Genetic change in a
species or population that occurs from
generation to generation over time
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Symbiotic Relationships
“Living together” – close interactions
between species ~3 ways
• The most common interactions in
a community are FEEDING
interactions
• Organisms will compete for any
resource that is in limited supply
• The greater the population size
of an area, the greater the
competition for resources
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Symbiotic Relationships
“Living together” – close interactions
between species ~3 ways
1. Mutualism: both
species benefit
Ex. Ants & acacia trees (ant protect
trees, tree provides nectar & home)
Ex: When the African tickbird eats
insects off a zebra’s skin, both
organisms in the relationship benefit
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Symbiotic Relationships
• 2. Commensalism: 1 species
benefits & other is neither
harmed nor benefits
– Ex. Moss on trees (moss has place
to grow, but does not effect trees)
– A bird that builds its nest in a tree
benefits but the tree in neither
harmed nor helped
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Symbiotic Relationships
• 3. Parasitism: 1 species benefits,
the other is HARMED
– Ex. Tick on a dog (tick gets food,
dog loses blood, could get a disease)
– Insects biting a zebra’s skin harm
the zebra but benefit themselves
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Symbiotic Relationships
• Predations is also one way in
which population size is regulated
– Predation is the act of one organism
feeding on anotehr
– Predators feed on prey
• A bird of prey, such as a falcon, is an
example of a predator
• A falcon’s prey is the organism it eats
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Habitat & Niche
• Habitat is the place a
plant or animal lives
• Niche is an organism’s role in
an ecosystem, to include the
range of conditions that it can
tolerate, the resources it
uses, the methods by which it
obtains resources, the number
of offspring it has, the time
of reproduction, etc.
• Each type of organisms has a
different role to play in an
ecosystem
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