Transcript Ecology Notes

*Plants take radiant
energy and change
inorganic into organic
compounds
*Food energy
is then transformed
to the consumers (animals)
*This transfer of energy and matter in a community is
called a trophic level
A. Producers - (autotrophs) make their own food;
convert inorganic to organic compounds.
B. Consumers - (heterotrophs) obtain nutrients from other
organisms.
C. Decomposers - organisms that feed on and break down
organic matter.
A. Herbivore - primary consumer, feed only on plants
B. Carnivore - animals that feed on other animals.
C. Omnivore - animals that feed on both plants and animals.
D. Scavenger - feed on dead organisms.
E. Saprobes - obtain food from breaking down the remains
of dead plants and animals
Trophic Levels - Producers
2oconsumers
1oconsumers
3oconsumers
Biomass - the total mass of organic matter at each trophic
level.
*Each trophic level contains stored energy and a
fraction of the biomass is passed on to the next
trophic level.
*Is used to represent the amount of biomass at each trophic level.
Up pyramid
Energy
Trophic levels
Biomass
Food Chains - a series of organisms through which food
energy is passed.
Food Web - multiple food chains and feeding relationships
Chain
Hawk
Mouse
Wheat
Web
Fox
Hawk
Rabbit
Mouse
Snake
Wheat
*Decomposers are the final consumer in every food chain
and food web.
Biosphere - region of earth that supports all living things.
Ecology - study of organisms and their interactions with the
environment (both living and nonliving).
Ecologist - a scientist who studies Ecology.
* Ecology is also known as Conservation which deals
with the preservation, protection, management and renewal
of natural resources.
Biotic Factors -
Abiotic Factors -
Levels of Organization- organism, population, community,
ecosystem, and biosphere (pg41 Fig 2.4)
Ecosystem - combination of the communities of organisms
and the abiotic factors in an area.
Organisms in Ecosystems
Habitat - where an organism resides or lives out its life, a
habitat can disappear from an area or change.
Niche - the role that an organism plays in its environment.
-How does it survive, reproduce, find food,
and interact with the parts of its surroundings.
I. Symbiosis - a relationship in which 2 different organisms
live closely together; it can be either beneficial
or harmful to the organisms.
Exp: bacteria in your mouth are in a symbiotic
relationship with you.
A. Mutualism - both organisms benefit from each other.
Exp: bacteria in digestive tract of cows, sheep and
horses help digest cellulose. Animals
benefit by getting the nutrients they need
and bacteria have a source of food and
a place to live.
B. Commensalism - one species benefits and the other is neither
harmed nor benefited.
Exp - pilotfish live with sharks. It eats scraps left
over from the sharks feeding; giving it food.
C. Parasitism - one benefits and the other is harmed.
Exp - tick, tapeworm, heartworm, lamprey, roundworm
parasite - benefits
host - harmed
*In a balanced ecosystem, each species occupies its own
niche and its own habitat or territory.
A. Interspecific competition - competition between 2 different species
due to niche overlap.
B. Intraspecific competition - competition between members
of the same species.
* influenced by population density and the availability
of resources. *Assignment: p39 1-5, p47 1-5
CO2 and O2 Cycle
Nitrogen fixation - N2 gas is made into useable nitrogen
compds (bacteria in roots, soil, and
fixation by lightening).
Nitrification - NH3 (ammonia) changed into nitrates
(NO2 and NO3).
Ammonification - decomposers break down nitrogen
compds in waste into NH3.
Denitrification - bacteria converts NH3, NO2 or NO3 into
free nitrogen gas.
A. Communities
Community - a particular area and all the organisms
living in it.
I. Living in a Community
A. Limiting factors
- carrying capacity - the # of organisms that
can be supported by a particular
area.
B. Range of Tolerance - resources become limited and
members in a community will
compete for food, shelter, etc. This
competition may eliminate one or
more populations (move/die).
Succession - (over time) a community change in which
populations of organisms gradually replace
the existing ones.
* Things that lead to succession: natural disasters, mining,
logging, building, farming, etc.
I. Primary Succession - change that begins in an area
where there is NO existing community
(follows avalanches, volcanic eruptions because all soil and
living organisms are destroyed).
Pioneer Community - 1st group of organisms to occupy
an area undergoing primary succession
(lichens
soil
grass
shrubs
pines)
II. Secondary Succession - change that begins in an area
that has been partially destroyed.
*Succession will slow down and eventually a stable
community will take over called a Climax Community.
Read about Biomes on pg 72-87