Download Chap. 16 Ecosystems

What is an Ecosystem?
Section 1
Interactions of Organisms and Their
Environment
 Ecology – the study of
the interactions of
living organisms with
one another and with
their physical
environment
 Habitat – the place
where a particular
population of a species
lives
Levels of Organization
 Organism – an
individual living thing
 Population – a group
of the same species
that lives in one area
 Community – the
many different species
that live together in a
habitat
 Ecosystem or ecological
system – consists of a
community and all the
physical aspects of its
habitat – complex web of
connected biotic & abiotic
factors
 Biome – a major regional
or global community of
organisms
Keystone species
 Is a species that has an
unusually large effect on its
ecosystem
 Form and maintain a
complex web of life
 Affects all the other species
connected to it
 Biosphere – living globe –
that part of the Earth in
which life exists
 Extends to as far as 8
kilometers above the Earth’s
surface to as far as 8
kilometers below the
surface of the ocean
 Organisms are not
distributed uniformly
throughout the biosphere
Physical Aspects
 Terrain
 Air atmosphere
 Water
 Weather/climate
 Soil
 Minerals
 Composition
 Organic matter
 pH
 Intensity of sunlight
Ecosystem Inhabitants of a Pine forest
 Which of the six
kingdoms of organisms
would be represented
if you fenced a square
kilometer of the forest?
Ecosystem Boundaries
 Physical boundaries of
an ecosystem are not
always obvious, also
depends of ecosystem
being studied
Change of Ecosystems over Time
 Pioneer species – the first
organisms to live in a new
habitat where soil is
present
 Tend to be small, fastgrowing plants examples:
lichen, mosses – can
break down solid rock
into smaller pieces
 Make the ground more
hospitable for other
species
Succession
 Succession – regular
progression of species
replacement
 Regenerate a damaged
community or create a
community in a
previously uninhabited
area
 Primary succession
–occurs where life
has not existed
before
 Secondary succession –
occurs in areas where
there has been previous
growth
 Reestablishment of a
damaged ecosystem
 Small disturbances start
the process
Again & again
Climax Community
 which populations of
plants or animals remain
stable and exist in balance
with each other and their
environment. A climax
community is the final
stage of succession,
remaining relatively
unchanged until destroyed
by an event such as fire or
human interference
 http://glencoe.mcgraw-
hill.com/sites/0078802849/student_view0/unit1/chapt
er3/concepts_in_motion.html#
Pond Succession http://www.sabah.edu.my/c
sm07010/Form%204/pond.h
tm
 Pond succession occurs due
to the change in depth of the
pond. When submerge
plants die, it will deposit at
the bottom of pond. Over
the time, the pond becomes
shallow until finally filled in.