Transcript PRINCIPLES OF ECOLOGY

PRINCIPLES OF
ECOLOGY
WHAT IS ECOLOGY?
Scientific study of the interactions
among organisms and their
environments.
ASPECTS OF ECOLOGICAL STUDY
Biosphere: part of the Earth
that supports life.
Environment: non living and
living surroundings.
Abiotic factors: non living
factors, light, soil.
Biotic factors: living
organisms interactions.
Look at the picture. How do
other living organisms affect
the gold fish?
LEVELS OF ORGANIZATION IN ECOLOGY
ORGANISM
POPULATION
COMMUNITY
ECOSYSTEM
BIOSPHERE
ORGANISM
Complete
individual,
living being.
POPULATION
-A group of one
species of organisms
that live together in
the same place at the
same time
-Interbreed.
-Share and compete for
resources.
COMMUNITY
-A group of
interbreeding
populations in the
same area at the
same time.
-Changes in one
population affects
another.
ECOSYSTEM
-Composed of the
interactions between
organisms, and their
surrounding abiotic
factors.
-Types: terrestrial,
freshwater and
saltwater.
BIOSPHERE
-All portions of
Earth where life
exists.
-Relationship
between all of the
ecosystems.
ORGANISMS IN ECOSYSTEMS
-HABITAT:
Where the
organism lives.
-NICHE: The role
and position the
species has in
the
environment.
Predator prey relationship
Symbiosis
Living together of
different species
may aid survival.
LIVING RELATIONSHIPS
Commensalism (+/0) -
One is
benefited and the other is neither harmed nor
benefited.
Mutualism (+/+) –
both are benefited.
Parasitism (+/-) – One is
benefited and the other is harmed.
Feeding relationships
Autotroph –
Heterotroph –
Makes its own Food
Must eat other
organisms
Herbivore
Carnivore
Omnivore
Scavenger
Decomposer
CYCLES IN NATURE
-Energy in an ecosystem is
replenished by the sun.
-Matter in an ecosystem has
to be recycled.
-Atoms making up organisms
today are the same as those
present when life on Earth
began.
Water Cycle
The Water Cycle
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Precipitation
Evaporation
Condensation
Transpiration
Runoff
Groundwater
Liquid to vapor …
◦ Evaporation: This is when the sun
heats up water in rivers or lakes or
the ocean and turns it into vapor or
steam.
◦ Transpiration: This is kind of like
plant sweat. Transpiration is the
process by which plants lose water
out of their leaves.
◦ Respiration: When animals breathe
out they release CO2 and water
vapor.
Water turning from vapor back to liquid …
◦ Condensation: This is when the
water vapor in the air gets cold and
changes back into liquid, forming
clouds.
◦ Precipitation: Precipitation occurs
when so much water has condensed
that the air cannot hold it
anymore. The clouds get heavy and
water falls back to the earth in the
form of rain, hail, sleet or snow.
Collection of water on the ground …
◦ Infiltration: when water soaks into the soil. Once
in the ground the water can be evaporated, absorbed
by plants or continue down to the water table (kind of
like an underground river).
◦ Run off: water that doesn’t get absorbed into the
soil, or did not evaporate, and therefore made its way
from the ground surface into places that water collect.
Runoff causes erosion, and also carry chemicals and
substances on the ground surface along to the rivers
where the water ends up. It can cause water pollution
too.
◦ Only about 35% of precipitation ends up in the sea or
ocean. The other 65% is absorbed into the soil. Some
of it too is evaporated.
Water Cycle
Carbon Cycle
•Respiration (yellow lines): A byproduct of cell respiration.
You breath out carbon dioxide every time you exhale. Plants
also release carbon dioxide
•Combustion (red line): This is when organic materials are
burned. It can happen naturally in forest fires but the vast
majority of it is due to humans burning fossil fuels in our
factories and cars.
Carbon dioxide is absorbed by producers (also known as autotrophs these are organisms that make their own food e.g. plants)
•Photosynthesis (Blue line): This is when producers (like plants) take in
carbon dioxide to make sugar (carbohydrates).
•Herbivores and omnivores eat the plants and take in the carbon
that the plants used to make sugar. Most of the carbon is then
exhaled (as mentioned in step 1) but some of it is also released
as solid waste and the rest is released when the animal (or plant)
dies.
The dead organisms (dead animals and plants) are decomposed or turned
into fossil fuels.
•Decomposed: Dead organisms are broken down by decomposers (fungi and
bacteria). The carbon that was in their bodies is then returned to the atmosphere
as carbon dioxide.
•Creation of Fossil Fuels: In some circumstances the process of decomposition
is prevented. The remains of the plants and animals may then be compressed and
heated transforming it into fossil fuels (oil, coal, or natural gas) that can be used in
the future for combustion.
The Carbon Cycle
Atmosphere
Photosynthesis
Respiration
Wastes
Soil
Fuel
Pollution
Nitrogen cycle
The Nitrogen Cycle
 Amino acids and proteins
 Atmosphere
 Lightning
 Bacteria
 Waste
 Runoff
Nitrogen Fixing Nodules
-The bacteria converts the
nitrogen that can’t be
used by the plants into a
useable form.
What kind of symbiotic
relationship would this
be?
Nitrogen cycle
NUTRITION AND
ENERGY FLOW
HOW ORGANISMS OBTAIN
ENERGY
-Producers: AUTOTROPHS make their own food
-Consumers: HETEROTROPHS take their food in ready
made
◦ Carnivores: meat, hawk
◦ Herbivores: plants, rabbit
◦ Omnivores: meat and plants, bear
◦ Scavengers: carrion and refuse, buzzard
-Decomposers: breakdown and release nutrients from
dead organisms, bacteria and fungi.
MATTER AND ENERGY FLOW
IN ECOSYSTEMS
Food chain: Model used to show how matter and energy
flows through an ecosystem.
Autotrophs  Heterotrophs  Decomposers
◦ Usually 3-5 links.
◦ 10% of available energy reaches next link. Because
energy is used/lost as heat at each link.
Practice building food
chains
Click on the link below (or access build food
chain activity from the wiki ecology page) and
build all the food chains.
FEEDING LEVELS
-Trophic level: A feeding step in a food chain.
(Animal may occupy more than one trophic
level in an ecosystem.)
1st trophic level = green plant = producer
2nd trophic level = herbivore = primary consumer/1st order
3rd trophic level = carnivore = secondary consumer/2nd order
4th trophic level = carnivore = tertiary consumer/3rd order
5th trophic level = carnivore = quaternary consumer/4th order
What is wrong with this diagram?
Food Web
-Model showing all possible feeding relationships at
each trophic level in a community.
-Network of interlinked food chains.
WRITE 2 FOOD CHAINS IN THIS FOOD WEB
ECOLOGICAL PYRAMIDS
• Shows how energy flows through
an ecosystem.
• Initial energy source is the sun.
• Autotrophs/1st trophic level at
base of all pyramids.
• Three types
Pyramid of Numbers
-Based on population size at each trophic level.
-Populations decrease at each successive trophic level but
inversion is possible.
Pyramid of Energy
-Based on the amount of energy available at each trophic level.
-Only 10% of the energy is past to the next level.
Decreases at each level by 90% , this energy is used or lost as
heat.
Pyramid of Biomass
-Shows mass of living
material at each trophic
level.
-Decreases at each trophic
level