Plant & Animal Interdependency
Living Environment
Key Idea 6.1
Key Idea 6
• Plants and animals depend on each other
and their physical environment.
– Interactions of organisms and their environment
result in the flow of energy and a cycling of
materials that are essential for life.
– Competition may be for nonliving resources, or
for living resources among different species or
among the same species.
Key Idea 6.1
LE
Ecology
2
Key Idea 6 – Major
Understandings
Energy flows through the ecosystem, from Sun
through photosynthetic organisms to herbivores,
carnivores, and decomposers
Relationships between organisms may be
competitive or beneficial
Biosphere is recycled by Earth processes
Biodiversity increases the stability of the ecosystem
Chemical elements pass through food webs as
illustrated in the pyramid of energy
Biodiversity ensures a variety of genetic material,
which in turn increases chances for survival
Carrying capacity is limited by available energy,
water, oxygen, minerals and recycling
Interrelationships and interdependencies affect the
development of stable ecosystems
Competition exists for resources such as food,
space, water, air and shelter
Environmental alteration comes from both natural
and human made changes
Ecosystems are dependent on physical conditions
including light, pH, temperature, soil/rock type
Altered ecosystems may last for thousands of years
Environments and resources are finite
Damaged ecosystems will likely recover in states to
stability
Key Idea 6.1
LE
Ecology
3
Performance Indicator 6.1
• Performance Indicator 6.1 Explain factors
that limit growth of individuals and
populations.
– Abiotic factors: nonliving
– Biotic factors: living
Key Idea 6.1
LE
Ecology
4
Abiotic Factors
• Abiotic Factors (nonliving):
–
–
–
–
–
Intensity of light
Range of temperatures
Amount of moisture (H2O)
Type of substratum such as soil and rock
Availability of inorganic substances such as common
salts (NaCl)
– Supply of gases such as oxygen (O2), carbon dioxide,
(CO2), and nitrogen (N2).
– pH (such as the acidity or alkalinity of the air, water
and soil.
Key Idea 6.1
LE
Ecology
5
Limiting Factor
– Limiting Factor - the necessary resource that
an organism needs that there is the least of.
• Determines the type of organisms that may exist in
that environment.
– Some plants live well on a forest floor under tall trees, but
will not do well in an open field due to increased light.
– The low annual temperature common to the northern
latitudes determines in part what plants can exist there,
because some plant enzymes work better at higher
temperatures.
Key Idea 6.1
LE
Ecology
6
Limiting Factors (cont)
– If a body of water’s dissolved oxygen level is low, fish
that need higher oxygen levels could suffocate and die.
– The salt-laden air and water of coastal areas limit what
species can exist in those regions. Some species of fish,
shellfish, and other marine species could die in freshwater
due to an imbalance of water pressure in their tissue.
– Because of low pH caused by acid rain, more than 200
lakes in the Adirondacks (NY) have virtually no life in
them.
Key Idea 6.1
LE
Ecology
7
Material Cycles
• Process of moving and cycling materials
through the environment.
–
–
–
–
Oxygen Cycle
Carbon Cycle
Water Cycle
Nitrogen Cycle
Key Idea 6.1
LE
Ecology
8
Oxygen Cycle Diagram
Key Idea 6.1
LE
Ecology
9
Carbon Cycle Diagram
Key Idea 6.1
LE
Ecology
10
Water Cycle
• The Water Cycle
– Terms:
•
•
•
•
•
Evaporation
Transpiration
Condensation
Precipitation
Runoff, groundwater, seepage
Key Idea 6.1
LE
Ecology
11
Water Cycle Diagram
Energy From Sun
Key Idea 6.1
LE
Ecology
12
Nitrogen Cycle
– The nitrogen cycle: Recycle the nitrogen that is
necessary for the production of proteins.
• Atmospheric nitrogen is converted into nitrates by nitrogen
fixing bacteria.
• Plants use nitrates for protein synthesis.
• Animals which eat plants convert the plant protein into animal
protein.
• Nitrogenous waste and the bodies of dead plants and animals
are broken down by decomposers (bacteria of decomposition)
and ammonia is released.
• Ammonia may be converted into nitrates by nitrifying
bacteria.
• Nitrogen containing compounds may be broken down by
denitrifying bacteria, resulting in the release of nitrogen in
the atmosphere.
Key Idea 6.1
LE
Ecology
13
Nitrogen Cycle Diagram
Key Idea 6.1
LE
Ecology
14
Energy Flow & Nutritional
Relationships
– Energy Flow: Green plants convert radiant
energy from the sun into chemical energy.
• A food chain involves the transfer of energy from
plants through a series of organisms.
• Producers
– a. make their own food (autotrophs)
– plants & algae's (photosynthesis)
Key Idea 6.1
LE
Ecology
15
Consumers & Decomposers
• Consumers
– can’t make own food (heterotrophs)
» herbivores: plant eaters (primary
consumers)
» carnivores: meat eaters
predators: kill own food (prey)
scavengers: eat animals they don’t kill
omnivores: eat both plants and animals
» Decomposers: Bacteria & fungi that break
down dead bodies and wastes products. They
recycle nutrients.
Key Idea 6.1
LE
Ecology
16
Food Chain
– Food Chains and Food Webs:
• Food Chain: sequence of organisms through which
food passes in a community.
– Algae
Insect
Fish
Man
– Producer 10 Consumer
2nd Consumer Third Level
– Arrows point in direction of the flow of energy!
• Food Web: Different food chains in an area which
are interrelated to form a food network.
Key Idea 6.1
LE
Ecology
17
Food Chain Diagram
Key Idea 6.1
LE
Ecology
18
Food Web Diagram
Key Idea 6.1
LE
Ecology
19
Energy Pyramid
– Pyramids of Energy and Biomass
• All energy on the earth ultimately comes from
sun !
• Energy is lost at each link of the food chain.
– lost as heat
– approximately 10% of food energy in a given level
will become incorporated in the bodies of organisms
in the next higher level.
– as you go up a food chain or pyramid the number of
organisms decrease and the size increases. Biomass
decreases.
Key Idea 6.1
LE
Ecology
20
Energy Pyramid Diagram
• Pyramid of Energy
Final killer whales
Consumers
phytoplankton
Decrease
in
Biomass
Tertiary Consumers seals
Secondary Consumers
fish
Primary Consumers
zooplankton
plants
Producers
Key Idea 6.1
LE
Ecology
21
Nutritional & Symbiotic
Relationships
• Homeostasis of an ecosystem:
– Ex. If a rabbit population in a community
decreases there will be less food available for
foxes. This causes a decrease in the number of
foxes. With fewer foxes, the rabbit population
will increase.
Base line
Foxes
Rabbits
Key Idea 6.1
LE
Ecology
22
Symbiotic Relationships
– Symbiotic Relationships
+ = benefit to, - = expense of, 0 = not affected
• Symbiotic Relationships
– Symbiosis: When two species of organisms
interact with each other in any way.
– Mutualism: Symbiotic relationship in which both
species benefit. (+,+)
» termites & protozoa
» lichens (algae & fungi)
» cows and bacteria
Key Idea 6.1
LE
Ecology
23
Symbiotic Relationships (cont)
– Commensalism: Symbiotic relationship
in which one of the organisms benefit and
the other is not affected. (+,0)
» Remoras & Sharks
– Parasitism: Symbiotic relationship
between parasites and host. (+,-)
» tape worm & dog, fleas and dogs,
human and viruses
Key Idea 6.1
LE
Ecology
24
Predator and Prey
– Predation: Feeding relationship
between predators and prey.
» predator attacks organism for
food
» prey is the animal that serves
as food
» if the predator - prey
relationship is in balance, both
benefit as a species but not as
individuals.
Key Idea 6.1
LE
Ecology
25
Competition in an Ecosystem
– Competition in Ecosystems:
• Competition: rivalry between individuals for a
specific resource.
– Intraspecific Competition: between members of same
species.
– Interspecific Competition: Competition between
members of different species.
• Competition can be for things like:
– Habitat: Where an organism lives.
– Niche: The role of the organism in the ecosystem.
– Light, food, nesting areas, space, water, mates etc...
» Limiting Factor: the necessary resource that an
organism needs that there is the least of.
Key Idea 6.1
LE
Ecology
26