Download Unit 2 Principals of Ecology Chapter 2 Section 2.1 Organisms and

Unit 2
Principals of Ecology
Chapter 2
Section 2.1 Organisms and their relationshipos
Ecology = the study of the interactive relationships of living
things with their environment.
A. Biosphere = the parts of the earth, oceans and air that
are inhabited by organisms. (8 km deep in the
ocean and 8 km high in the atmosphere)
B.
Biome = (Unit of the biosphere) group of ecosystems with the
same type of climax communities. Can be classified
as terrestrial or aquatic.
C.
Ecosystem = (unit of biosphere) Interaction of living
and nonliving (wind, fire, climate,
oxygen, carbon, etc.) things within a
given environment
Ex: forest
An ecosystem can sustain itself by performing the
following processes:
1.
2.
3.
4.
produce chemical energy from the sun
transfer energy
decompose matter
reuse nutrients (ex: nitrogen gas)
An ecosystem can be large or small, but it is
concerned with two types of environmental factors:
1.
biotic factors -
living organisms(plants
& animals)
2. abiotic factors - nonliving parts (light
& temperature, and water
and soil)
Organisms can move from one ecosystem to
another
(ex: a bird of prey)
D.
Communities =
interacting communities make up an
and ecosystem)
A group of organisms that coexist
with one another.
(Ex: all of the organisms within a
meadow)
E.
Population =
(A community is made of interacting
populations) A group of individuals of
a single species that live together
and share resources.
Some communities have hundreds of
populations like a coral reef. Some
have only a few populations like
a desert.
F.
Habitat =
Surroundings in which any particular species
can be found. The part of the ecosystem in
which an organism lives.
G.
Niche =
The role or way of life a species pursues
within its habitat.
(How much it eats, and what it eats, what
its moisture requirements are, what
temperature it requires or how much space
it occupies)
(You could think of a niche as an organism's
occupation and its habitat as its address)
Its total way of life.
Level of organization from smallest to largest:
Organism
Population
Community
Ecosystem
Biome
Biosphere
BIOTIC RELATIONSHIPS
Competition and Predation
Food, water and space are limited within an ecosystem and
organisms compete for them constantly.
1.
Competition = struggle for limited natural resources
a.
Intraspecific competition =
b.
Interspecific competition =
competition between
members of the same
species.
competition between
members of one or
more different species
Competition resulted in the evolution of animals with distinct patterns of consumption .
2.
Predation =
One organism preying upon or eating another
organism.
Prey = heterotrophs consumed by predators
SYMBIOSIS
Symbiosis means "Living Together"
A symbiotic relationship is a permanent , close relationship
Between two organisms of different species that benefits at
least one of them.
1. Mutualism =
both organism benefit
(ex: lichen [algae and fungi])
2. Commensalism = one benefits, the other is unaffected
(ex: Spanish moss on trees)
3. Parasiticism = one benefits at the expense of the other
(ex: tick on a dog)
Section 2.2 FLOW OF ENERGY WITHIN THE ECOSYSTEM
Plants and algae are the chief producers. They are able to fix carbon as
they convert solar energy into chemical energy in the form of food
(glucose). This energy passes from one organism to another.
Tropic Levels
Various feeding levels of organisms. Organisms that are able to convert
solar energy or inorganic compounds into chemical energy that can be used
by the organism are called autotrophs. Organisms that cannot do this and
rely on those autotrophs for food are called heterotrophs.
Ex: plant, rabbit, bobcat
Plants are the first or lowest trophic level in an ecosystem, and
contain the most available energy. The tropic levels are:
1.
2.
3.
4.
Primary Producer – Plants, algae (autotrophs)
Primary Consumer - Plant eater (heterotroph)
Secondary Consumer - Primary consumer eater
Tertiary Consumer - Secondary consumer
Ex: plant (1) – grasshopper (2) – mole (3) – bobcat (4)
Consumers are classified according to what they eat
1.
2.
3.
4.
5.
Herbivores –
Carnivores –
Omnivores –
Scavenger –
Decomposers –
plant eaters
meat eaters
plant and animal eaters
eats dead organisms
breaks down dead plant and
animal tissue and return the
the nutrients to the soil.
Food Chain
A food chain is the pathway of food through the ecosystem.
i.e., one organism feeding on another)
Food Web
Network of interacting food chains)
Ecosystems have more than one food chain. Chains overlap because
organisms eat more than one type of food. (See page 43, Glencoe)
Ecological Pyramids
The energy available for use by organisms at each trophic level is only
about 10% of the preceding level.
Ex: Plant gets energy from the sun (uses some of the energy for q
food making and metabolism - about 90%.)
Rabbit eats the plant (gets only about 10% of what the plant did.)
Bobcat eats the rabbit (gets only about 10% of what the rabbit
gets.)
Use of Ecological Pyramids
Ecological Pyramids are diagrams used to show a
decrease of available energy in the ecosystem.
Ex: energy pyramid or pyramid of biomass
(See pages 44 Glencoe)
Biomass = weight of an organism after all of the
water is removed
Section 2.3 Cycling of Matter
The major elements needed for life are:
carbon, hydrogen, oxygen and nitrogen.
** Other chemical requirements include sulfur,
phosphorus and various other trace elements.
When death occurs, these chemical materials are returned to the earth and
atmosphere. This is RECYCLING.
MAJOR CYCLES:
A. Water Cycle
1.
2.
3.
4.
5.
the sun evaporates water from the oceans, lakes,
streams, etc.
water is lost through the stomata of plants via
transpiration
water seeps from soil to underground springs, streams
and rivers
water molecules are carried to the atmosphere via
wind or air currents
water droplets condense around dust and are returned
to the atmosphere as rain, snow, hail or fog.
B.
Oxygen/Carbon Cycles
Without carbon molecules, life could not exist.
1.
carbon and oxygen make up most of the body's carbohydrates, proteins and fats and are also involved
in the majority of chemical reactions.
2.
3.
These cycles are driven by photosynthesis and
respiration: (i.e., autotrophs such as plants, algae
and photosynthetic bacteria take in carbon dioxide and
release oxygen as they fix carbon to make glucose
[food]. As food is metabolized by heterotrophs such
as animals, fungi, bacteria and protozoa, oxygen is
taken in and the unused carbon from above is released
as carbon dioxide in the air or as solid waste.
Decomposers break down these wastes and dead tissue
which releases more carbon dioxide into the air.)
In addition to the above, carbon is recycled during
the burning of fossil fuels.
Oxygen Cycle
Carbon Cycle
C.
Nitrogen Cycle
Proteins and DNA have nitrogen within them.
78 percent of the air is nitrogen gas but it is useless to
plants in this gaseous form.
Nitrogen must be used as n i t r a t e s , n i t r i t e s o r a m m o n i a .
Nitrogen fixation = conversion of nitrogen gas (N2)
into nitrate (N03-)
Nitrogen fixing bacteria found in the roots of legumes fix
nitrogen gas into nitrates for plants to use.
When plants and animals excrete waste or die, bacteria
convert nitrogen into ammonia. This is called
AMMONIFICATION.
Plants cannot use ammonia, so bacteria convert
it into Nitrite (NITRIFICATION) This is a twostep process.
** some bacteria convert ammonia into
nitrite then others convert nitrites
into nitrates.
Some bacteria convert ammonia, nitrite and nitrates back
into nitrogen gas. (DENITRIFICATION). This returns nitrogen
gas to the atmosphere.
D.
Phosphorus Cycle
Phosphorus is essential for growth and development of organism
Phosphorus is in ATP, DNA, RNA,
Short term and long term cycles.
Short term: SoilProducersconsumers, when organisms die or produce
waste decomposers return phosphorus to soil.
Long term: Weathering of rock and soil that contains phosphorus will
slowly add phosphorus to the soil.