Download Ecology Keynote (BIO)2016 copy 2

Populations
Population = all the individuals of a species living in one place
at the same time
-limited resources in the environment can limit (reduce) a
population’s size
-smaller populations affected more by natural disaster, like
fire, flood, drought than larger populations. They also
experience more inbreeding, which increases harmful
recessive traits
Populations don’t continue to grow unchecked. The population
size that an environment can sustain is called the carrying
capacity.
-population growth is affected by predators, disease, how many
resources available (food, water, space) weather and climate
-population size is directly affected by:
death -birth +
immigration +
emigration --
“Ecology”
Ecology = the study of interactions of living organisms with their
environment
“oikos” = house
“logos” = study of
habitat = where a species lives
community = the many different species living together
ecosystem = made up of a community and all the physical factors of
the community like soil, water, and weather
abiotic factors = physical aspects
biotic factors = living organisms
biodiversity = refers to all the living organisms in an ecosystem ex. think of a forest
ecosystem
-generally the greater biodiversity an ecosystem has, the more stable (resists change)
it is, and the easier it is for it to bounce-back from environmental changes
succession = the gradual regrowth of species in an area (one plant type replaces
another)
Order ---> pioneer species (lichen, weeds) ---> taller plants and shrubs ---> pine forest --->
hardwood forest (oak)
“The amount of energy available to an ecosystem is very important”
Producers = green plants, bacteria, algae (need energy from sun)-- “Autotrophs”
Consumers = eat the producers
ex. sun ---> grass (producer) ----> rabbit ( 10 consumer) ---->
------> hawk ( 2 0 consumer) this is an example of a trophic level which is a visual way
to show how energy moves through an ecosystem
Lichen
(Fungus & Algae)
“Pioneer species”
Food chain = shows one path of energy flow through an ecosystem (straight path)
-see p.408
Food web = shows a more complete picture of the feeding relationships within an ecosystem
(like a spider’s web) -see p.410
Energy Transfer = the amount of useful energy available to organisms
decreases as energy passes through an ecosystem
At every link in a food web, energy is transferred to the next level, but, only about 10% of the
energy from the previous level is passed on to the next level, so each level contains about
90% less energy than the level below it
-most of the energy that is lost is in the form of “heat”
Energy pyramid = is a diagram with each trophic level shown as blocks stacked on top of
each other, with the lowest trophic level on the bottom. The width of the block shows the
amount of energy stored in the organisms at that level
Herbivores = animals that eat plants or producers also called primary
consumers
ex. cows,ducks,rabbits,caterpillars
Carnivores = animals that eat herbivores also called secondary
consumers
ex. tigers, wolves, snakes
Omnivore = animals which are both an herbivore and carnivore
ex. bears, humans
Decomposers = bacteria and fungi which cause decay. They help
breakdown dead animal and plant material. They are
very important because they release nutrients back into
the ecosystem so they can be used again - so help
recycle nutrients.
“Herbivores”
“Carnivores”
“Carnivores”
“Omnivores”
“Decomposers”
Symbiosis : is a relationship between two or more species within
a community ---------> 5 types
predation, parasitism, competition, mutualism and commensalism
Predation : the predator captures, kills and eats another individual called
the prey
Parasitism : one individual is harmed (host) while the other benefits
(parasite) ex. ticks, fleas, lice, leeches, mosquitoes and tapeworms
Competition : results when two species use the same resource, like food,
living space, sunlight
Mutualism : a relationship where both species benefit ex. some ants get
liquid “honeydew” from aphids, which are in
turn protected by the ants
-- also pollination, bees. butterflies and flowering plants
Commensalism : a relationship in which one species benefits and the
other is neither harmed nor helped ex.clown fish “Nemo” and the sea
anemone, the fish gets protection without being stung and the sea anemone
isn’t affected