Download Ecology terms

Ecology terms
• Ecology- the scientific study of interactions
among organisms and between organisms
and their physical environment
• Biosphere- consists of all life on Earth and
all parts of the Earth in which life exists.
– Includes land, water, and the atmosphere
• Ecosystem- all the interacting
species and the abiotic factors
in a geographic area
• Ex- forest
• Community- collection of
interacting organisms
• Abiotic factor- nonliving parts
of ecosystem
• Ex- water, rocks
• Biotic factor- living parts of
ecosystem
• Ex- humans, trees
3 Symbiotic relationships
• Mutualism- relationship where
both organisms benefit
• Ex- bees and flowers, lichens
• Commensalism
- one benefits
and the other is
unaffected
• Ex- barnacles
on whales
• Parasitism- one benefits and
one is harmed
• Ex- ticks and dogs, tapeworm
and humans
• Ecological
successionseries of changes
in a community in
which new
populations
gradually replace
existing ones.
• Ex-Pond-> bog->
meadow-> forest
• 2 types:
• Primary succession- when succession
starts with no soil (volcano, glacier)
• Secondary succession- when a
disturbance destroys an existing
community, but leaves soil. (fire,
hurricane)
• Pioneer community- the initial
stage of succession
• Climax community- when
succession slows down and a
stable community is established
• Ex- VA: oak, hickory hardwood
forest
• Nutrient cycle- substances pass
through both living and nonliving
things in the environment
• Ex-
• Food chainflow of energy
through
organisms of
an ecosystem
• https://www.youtube.com/watch?v=puVDF
Ul4WTY
• Food web- many food
chains combined and
overlapping
Autotrophs
• Autotroph (producer)- organism that is
able to capture energy from sunlight or
chemicals to produce its own food from
inorganic compounds.
• Primary producers are the first producers
of energy-rich compounds that are later
used by other organisms
2 ways to capture energy
• Photosynthesis: process used by plants
and other autotrophs to capture light
energy and uses it to power chemical
reactions
• Chemosynthesis: process by which
chemical energy is used to produce
carbohydrates
Heterotrophs
• Heterotroph (consumer)- organisms that
require other organisms for energy and
nutrients
• Primary consumer: an animal that feeds
on plants; a herbivore.
• Secondary consumer: a carnivore that
feeds only upon herbivores.
Decomposers
• Decomposer: an organism that breaks
down and obtains energy from dead
organic matter Ex: bacteria and fungi
• http://www.mhhe.com/biosci/genbio/virtual
_labs/BL_02/BL_02.html
Pyramid of energy- shows the
amount of energy moving
through food chain; decreases
as you move up. As energy
passes up the food chain,
about 90% of the usable
energy is lost.
How many Joules do we need
to survive?
• Figure out the minimum Calorie diet
needed to survive (say 500 or something).
• 1 food Calorie = 1,000 calories
• 1 calorie=4.18 Joules.
• Doing the math you get roughly 2,000,000
Joules daily or 730,000,000 Joules yearly
• Pyramid of biomass- same as
pyramid of energy except that it
shows that there is less biomass
at each level. (biomass is the
weight of organisms)
• Pyramid of numbers- same
as pyramid of energy except
that it shows that there are
fewer organisms at each
level.
• Niche- everything an
organism does and needs in
its habitat
• Ex- deer- eats grass, lives in
forest, prey for humans,
mountain lions
Population Growth Curve
• Population growth curves exhibit many
characteristics, such as
– initial growth stage
– exponential growth
– steady state
– decline
– extinction.
• As any population of organisms grows, it is
held in check by interactions among a
variety of biotic and abiotic factors.
Carrying capacity
• The largest number of individuals of a
population that an ecosystem can support.
Human Population Growth
Curve
Population-Age Pyramids
Limiting factor
• Something in the
environment that limits
the population of a
species.
• Ex- predators, food
• Density-independent limiting
factor Any limiting factor whose effect is
not dependent on the number of
individuals in the population. Ex: an
earthquake
• Density-dependent limiting factor Any
limiting factor whose effect
is dependent on the number of individuals
in the population. Ex disease