3.1 Community Ecology
Succession and Limiting Factors
Chapter 3
Communities, Biomes, and Ecosystems
3.1 Community Ecology
Communities
 A biological
community is a
group of
interacting
populations that
occupy the
same area at
the same time.
Oasis
Chapter 3
Communities, Biomes, and Ecosystems
3.1 Community Ecology
Limiting Factors
 Any abiotic factor or biotic factor that restricts
the numbers, reproduction, or distribution of
organisms is called a limiting factor.
 Includes sunlight, climate, temperature,
water, nutrients, fire, soil chemistry, and
space, and other living things
Chapter 3
Communities, Biomes, and Ecosystems
3.1 Community Ecology
Range of Tolerance
 An upper limit and lower limit that define the
conditions in which an organism can survive
 The ability of any organism to survive when
subjected to abiotic factors or biotic factors is called
tolerance.
3:1 Succession
The living and nonliving parts of an ecosystem may change
over a period of time.
The changes that take place in a community as it gets older
are called SUCCESSION.
Succession
Succession happens SLOWLY! So it can be
hard to see happening.
Chapter 3
Communities, Biomes, and Ecosystems
3.1 Community Ecology
Primary Succession occurs at an area of NEWLY
EXPOSED rocks that has never been occupied by any
living things (biotic factors)
Chapter 3
Communities, Biomes, and Ecosystems
Chapter 3
Communities, Biomes, and Ecosystems
3.1 Community Ecology
•Secondary Succession occurs in places where a
community has been removed (like from clear cutting a
forest or plowing a field). There used to be biotic factors
present
Succession in a Land Community
In a plowed field:
weeds invade first
worms and grasshoppers arrive
beetles and ants arrive
Succession in a Land Community
As the animals die their bodies decompose
and add nutrients to the ground. Making
the soil better for other, larger animals and
plants to move in!
Succession in a Land Community
A CLIMAX COMMUNITY is the final stage of
succession in a community.
It is the final stage because it is STABLE
and can replace itself with little change
from then on.
Succession in a Land Community
It may take 150 years or more for an area to
become a climax community.
Succession in a Water Community
Succession can occur when a lake/pond
turns into a land community.
First, only microbes are present. Then,
sediments get carried in…
Succession in a Water Community
Eventually, algae come in, then larger
plants.
Over time, the pond/lake fills in with dead
plant material and larger animals move in.
Eventually, the pond/lake completely fills in
and over 100 years becomes a terrestrial
environment.