Transcript Chapter 3 Notes - Prof-desk

Chapter 3: The Biosphere
Chapter 3 Outline
3-1: What is Ecology?
3-2: Energy Flow
3-3: Cycles of Matter
3-1: What is Ecology?
 Interactions and Interdependence
 Levels of Organization
 Ecological Methods
Interactions and Interdependence
 Ecology – the scientific study of interactions among
organisms and between organisms and their
environment
 Biosphere – The combined portions of the planet
in which all life exists.
Levels of Organization in Biology
Levels of Organization
More Inclusive
 Species – groups of organisms that can breed and
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produce fertile offspring.
Population – group of organisms of the same species
that live in the same area
Community – all the living organisms found in an
area.
Ecosystem – all the organisms that live in a place,
along with their environment.
Biome – group of ecosystems that have the same
climate and similar dominant communities.
Biosphere – the combined portions on Earth where
living things are found.
Ecologists study the environment in
3 ways:
 Observing
 Experimenting
 Modeling
3-2: Energy Flow
 Producers
 Energy From the Sun
 Energy Without Light
 Consumers
 Feeding Relationships
 Food Chains
 Food Webs
 Trophic Levels
 Ecological Pyramids
Producers
Ecosystems need a source of energy to survive.
Energy!
For most ecosystems, the main source of energy is the Sun.
For a few ecosystems, it comes from chemical energy
from the earth.
Chemosynthesis:
Carbon dioxide + hydrogen sulfide
carbohydrates + sulfur
Energy!
Like at this deep sea vent!
Producers
 A producer is an organism (like plants, algae or
bacteria) that produces its own food
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Chemosynthesis – energy from inorganic chemical compounds is
used to make food (some bacteria)
Photosynthesis – energy from the Sun is used to make food (plants,
algae, some bacteria)
 Producers are autotrophs because they make their
own food.
Consumer
 A consumer is an organism that eats another
organism
 Another word for consumer: heterotroph
Types of consumers(heterotrophs):
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2.
3.
4.
5.
Herbivores obtain energy from eating
producers (autotrophs)
Carnivores eat herbivores or other
heterotrophs.
Omnivores obtain energy from eating both
autotrophs and heterotrophs.
Detritovores obtain energy from eating plant
and animal remains (detritus)
Decomposers obtain energy from organic
matter (things that were once alive).
 Energy can be tracked throughout the ecosystem
through feeding relationships
Food Chain
 A food chain is a series of
steps in which organisms
transfer energy by eating
and being eaten.
Food Web
 A food web is the
network of complex
interactions formed by
the feeding
relationships among
the various organisms
in an environment.
Food Web
 Each step in a food
chain or a food web
is called a trophic
level.
Food Web
 A food web shows all the
possible feeding
relationships in an
ecosystem.
 How are food chains and
food webs the same?
 How are they different?
Only 10% of the energy is
transferred to each trophic level.
Energy loss can be measured in biomass
of organisms.
Energy loss and biomass comparison
Energy flows one way in an ecosystem:
Producers  1st Level Consumers  2nd Level Consumers  3rd Level Consumers
3-3: Cycles of Matter
 Recycling in the Biosphere
 The Water Cycle
 Nutrient Cycles
 The Carbon Cycle
 The Nitrogen Cycle
 The Phosphorus Cycle
 Nutrient Limitation
Recycling in the Biosphere
 Unlike energy, matter is recycled within and between
ecosystems.
 Matter is passed from one organism to another and
from one part of the biosphere to another through
biogeochemical cycles.
The Water Cycle
Section 3-3
Condensation
Precipitation
Evaporation
Transpiration
Runoff
Seepage
Root
Uptake
The Water Cycle
1. Water can enter the atmosphere by evaporation and
transpiration
1.
2.
Evaporation – water changing from a liquid to a gas.
Transpiration – water evaporating through tree leaves.
2. Water cools in the air and condenses into clouds.
3. Water falls to the ground as precipitation.
4. Water makes its way to the ocean by runoff.
Nutrient Cycles
 A nutrient is a substance an organism needs to
sustain life.
 Some common nutrients are:
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Carbon (C)
Nitrogen (N)
Phosphorous (P)
Carbon
 Important for:
 Living tissue
 Animal skeletons
 Photosynthesis
 Cellular respiration
 Co2
 Released into the atmosphere by:
 Breathing, volcanoes, burning trees & fossil fuels
 Absorbed by:
 Oceans, Plants (esp. trees, algae),
The Carbon Cycle
Section 3-3
CO2 in
Atmosphere
CO2 in Ocean
Nitrogen
 Found in the air, and in dead things and poop:
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N2 = nitrogen gas – 78% of the atmosphere – unable to be used by producers
NH3 = ammonia
NO3- = nitrate
found in dead things, able to be used by living things
NO2- = nitrite
 Important for:
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Making proteins
 Some bacteria convert nitrogen gas into ammonia using nitrogen fixation,
so producers can use them.
N2  NH3
 Some bacteria convert nitrates back into nitrogen gas using denitrification.
NO3-  N2
The Nitrogen Cycle
Section 3-3
N2 in Atmosphere
NH3
NO3and NO2-
Phosphorous
 Important for:
 Making nucleic acids (DNA, RNA)
 NOT found in the atmosphere
 Mostly found in rocks and soil minerals, and in ocean
sediments.
Nutrient Limitation
 primary productivity – the rate at which organic
matter is created by producers
 When an ecosystem has low primary productivity
because it doesn’t have enough of a single nutrient,
we call that a limiting nutrient.
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A common limiting nutrient is phosphorous (P).
Limiting Nutrient