Transcript BIO CH 3 Biosphere

Chapter 3: The Biosphere
ECOLOGY-the study of
interactions among
organisms & between
organisms and their
environment or
surroundings.
LEVELS OF ORGANIZATION:
BIOSPHERE-the largest
level…to include all living
things 8 km above the Earth’s
surface & 11 km below the
surface of the ocean.
BIOME
Group of ecosystems that
have the same climate and
dominant communities.
ECOSYSTEM
*A collection of all the
organisms that live in a
particular place, together with
their non-living, physical
environment.
*Lowest level of
environmental complexity that
includes living & non-living
factors.
COMMUNITY
*The simplest group of more
than one kind of organism in
the biosphere.
*Different populations that live
together in a defined area.
POPULATION
All members of the same
species that live in one area.
SPECIES (Individual)
*Group of organisms so similar
to one another that they can
breed and produce fertile
offspring.
•Species make up _________.
•Populations make up _____.
•Communities make up _____.
•Ecosystems make up _____.
•Biomes make up the ________.
ECOLOGICAL METHODS
*Basic methods used by
ecologists to study the living
world are:
*Observing
*Experimenting
*Modeling
OBSERVING
**Simply making observations
of what the scientist is
studying.
EX: Counting populations of a
certain species.
EXPERIMENTING
*Experiments are used to
test hypotheses…these
can take place outside in
the field OR in a
laboratory.
MODELING
*Models are used when studies
involve long periods of time or
when the study involves large
complex systems.
*Ecological models may
consist of mathematical
formulas based on data
collected through observation
& experimentation.
EX: Predicting a
population
fluctuations in a
community…
3-2 Energy Flow
*Sunlight is the original
source of almost all the
energy in most
ecosystems…it is the main
energy source for life on
Earth.
In FEW ecosystems organisms
get their energy from another
source.
*Some types of organisms rely
on the energy stored in
inorganic chemical compounds.
(Inorganic = without carbon)
EX: Chemo synthetic bacteria
AUTOTROPHS
*defined…An organism that
uses energy to produce its
own food supply from
inorganic compounds.
*Autotrophs capture energy
from sunlight or chemicals to
produce food.
EXAMPLES OF AUTOTROPHS:
*Plants, some algae, & certain
bacteria;
*Autotrophs are also called
producers.
PRODUCER
Defined…organism that can
capture energy from sunlight or
chemicals & use it to produce
food from inorganic
compounds.
PRODUCERS = AUTOTROPHS
PRODUCERS ARE ESSENTIAL
TO THE FLOW OF ENERGY IN
THE BIOSPHERE.
Autotrophs use the sun’s energy
to make food through a process
called PHOTOSYNTHESIS.
PHOTOSYNTHESIS
(Photo = light)
Process by which plants &
some other organisms use light
energy to power chemical
reactions that convert water &
carbon dioxide into oxygen &
food/energy molecules.
PhotosynthesisPage 68…Figure 3-5
6 CO2 + 6 H2O --- C6H12O6 + 6 O2
Which element does each letter in
the formula stand for?
CONSUMERS
Defined…organism that
relies on other organisms
for its energy & food
supply…also called a
HETEROTROPH.
HETEROTROPH
Defined…An organism that
CANNOT MAKE its own food.
Types of Heterotrophs:
•HERBIVORE- organisms that
obtain energy by eating only
PLANTS.
•CARNIVORE- organisms that
obtain energy by eating
animals.
•OMNIVORE-organisms that
obtain energy by eating plants
& animals.
DETRIVORESOrganisms that obtain their
energy by feeding on the
remains of plants, animals, &
other dead matter.
DETRIUS- dead plant &
animal remains (& other dead
matter).
DECOMPOSER-
Heterotrophic organism that
breaks down & obtains
energy from dead matter.
*****KNOW EXAMPLES OF
ALL TYPES OF CONSUMERS!!
FEEDING RELATIONSHIPS
Energy flows through an
ecosystem in ONE
direction…from the sun or
inorganic compounds to
PRODUCERS (autotrophs) and to
various CONSUMERS
(heterotrophs).
FOOD CHAINS
Figure 3-7 Page 69
FOOD CHAIN- a series of steps
in an ecosystem in which
organisms transfer energy by
eating or by being eaten!
**Food chains show a ONE WAY
ONLY energy flow in an
ecosystem.
FOOD WEBS
•FOOD WEB- a network of
complex interactions formed by
the feeding relationships among
the various organisms in an
ecosystem.
•A food web links all the food
chains in an ecosystem…See
Figure 3-8 page 71;
Each step in a food web is
called a TROPHIC LEVEL.
A TROPHIC LEVEL…is a
“feeding level” one step in a
food chain or food web.
**Producers make up the
FIRST trophic level.
CONSUMERS MAKE UP:
*2nd Trophic Level (primary consumers)
*3rd Trophic Level (secondary consumers)
*4th Trophic Level (tertiary consumers)
*5th Trophic Level (quaternary consumers)
ECOLOGICAL PYRAMIDS
PAGE 72
Defined…A diagram that shows
relative amounts of energy or
matter contained within each
trophic level in a food chain or
food web.
3 Types of Ecological
Pyramids:
•ENERGY PYRAMIDS
•BIOMASS PYRAMIDS
•PYRAMIDS OF NUMBERS
ENERGY PYRAMID
*shows the relative amount of
energy available at each
trophic level.
*Only 10% of the energy is
passed from one trophic level
to the next. The rest is ‘lost’ as
heat.
BIOMASS PYRAMID
*Represents the amount of
living organic matter at each
trophic level.
*The greatest biomass is
usually at the bottom of the
pyramid!!
BIOMASS- the total amount of
living tissue within a given
trophic level. Biomass is
usually expressed in terms of
grams of organic matter/unit
area.
A biomass pyramid represents
the amount of potential food
available at each trophic level
in the pyramid.
PYRAMID OF NUMBERS
…shows the relative numbers
of individual organisms at
each trophic level.
Because each trophic level
harvests only about 1/10 of the
energy from the level below, it
can only support about 1/10 the
amount of living tissue.
3-3 CYCLES OF MATTER
UNLIKE the one way flow of
energy, MATTER is RECYCLED
within and between
ecosystems.
BIOGEOCHEMICAL CYCLES
Defined…process in which
elements, chemical compounds,
& other forms of matter are
passed from one organism to
another AND from one part of
the biosphere to another.
THE WATER CYCLE
EVAPORATION- process by
which water changes from a
liquid to a gas.
TRANSPIRATION-evaporation of
water from the leaves of plants.
Precipitation- rain, snow, sleet,
or hail.
RUN OFF-water that runs along
the surface of the Earth;
GROUNDWATER- water that
seeps into soil;
NUTRIENT CYCLE
*Nutrients-chemical substances
required to keep an organism
alive.
CARBON CYCLE
*Carbon is a key ingredient in
all living organisms.
*Be sure to study the carbon
cycle on page 77 for your test!!!
CARBON CYCLE
*Carbon cycles between
various components of the
biosphere….
BIOLOGICAL-Photosynthesis,
respiration, decomposition;
GEOCHEMICAL-release of CO2
by volcanoes.
(Carbon Cycle)
*Human Activity-mining,
industry, burning fossil fuels;
*MIXED BIOGEOCHEMICAL
PROCESSES-burial of
organisms that turn into
fossil fuels such as coal.
NITROGEN CYCLE
*All organisms require nitrogen
to make amino acids which in
return make PROTEINS.
*There are many different forms
of nitrogen: Nitrogen Gas (N2);
Ammonia (NH3); Nitrate Ions
(NO3-); Nitrite Ions (NO2-);
(Nitrogen Cycle)
*Nitrogen gas in the
atmosphere is very abundant
but cannot be used DIRECTLY
by most organisms.
Only certain types of bacteria
can use the “free nitrogen”.
NITROGEN FIXATION
Defined…the process of
converting nitrogen gas into
ammonia…this is carried out by
bacteria that live in “nodules”
on the roots of certain types of
plants.
Other bacteria convert
ammonia into nitrates &
nitrites.
*Once the nitrates & nitrites
are available…PRODUCERS can
use them to make proteins.
CONSUMERS eat the producers
& reuse the nitrogen to make
their OWN proteins.
(Nitrogen Cycle)
*When organisms die,
decomposers return nitrogen
to the soil as ammonia. Plants
are able to use ammonia
(fertilizer!!);
DENITRIFICATION
Defined…the conversion of
nitrates into nitrogen gas (with
the help of certain bacteria!)
*This process releases nitrogen
into the atmosphere.
PHOSPHORUS CYCLE
*Phosphorus is important to
living things because it forms
important life sustaining
molecules such as DNA & RNA.
(phosphorus cycle)
*Phosphorus does not enter
the atmosphere like carbon,
water, & nitrogen.
It remains mostly on land and
in oceans.
NUTRIENT LIMITATION
PRIMARY PRODUCTIVITY-the
rate at which organic matter is
created by producers.
LIMITING NUTRIENT-
Defined…a substance that
is scarce or cycles very
slowly and therefore limits
the ecosystem…in terms of
an organism’s growth.