Transcript Ecological Succession

Ecological
Succession
Science 10
Ecological succession
 refers to the series of ecological changes
that every community undergoes over
long periods of time.
 From the Latin, succedere, to follow after.
 This process begins with pioneer
organisms.
What does pioneer mean?
 The one who goes before to prepare the
way for others.
 The first one.
 Like the “pioneers” or early settlers of
Canada.
 What are the pioneers of an ecosystem?
Pioneer Organisms
 Early settlers of a new
region.
 Such as bacteria,
lichens, or fungi
 We know that they add
organic matter to the
“primitive” (crude, or
simple) soil.
 This allows the first
plants, or primitive
plants, to grow.
 They include mosses
and ferns.
Order of growth
1.
2.
3.
4.
5.
6.
Primitive plants
Grasses
Shrubs
Trees
Seedling of various
trees
Succession stops with
the formation of a
climax community.
Climax Community
 Is the final stage of
ecological succession.
Two stages of Succession
1. Primary Succession
2. Secondary Succession
Primary Succession
 Occurs when a community begins to form
in an area where there is no soil or living
material.
 Occurs in a area where a disturbance
has occurred.
Disturbance
 Is a change in environmental conditions
which causes a profound (significant, or
important) change in an ecosystem.
 There are 2 types of disturbances:
 Natural
 Man-made
Natural Disturbance
 Are “nature” made catastrophic events
such as flood, fire, volcanic activity,
climate change, species extinction.
Man-Made Disturbance
 Or human influenced such as acid rain,
ozone depletion, enhanced global
warming, pollution, habitat destruction,
monoculture farming, clear-cut logging,
over-fishing.
 In terrestrial habitats,
primary succession is a
slow process because it
begins with the formation of
soil, or Pedogenesis.
Pedogenesis
 Term to describe “making soil”
 Soil is usually made from weathering and
the action of pioneer organisms (lichens,
fungi)
Weathering
 Occurs when large rocks are broken
down into pieces through natural,
chemical, or biological processes.
 Rounded boulders in
Joshua Tree National
Monument, in
California.
 Rounded boulders
like these reflect
long-term erosion of
granitic rocks by frost
wedging and
chemical weathering.
 A bizarre form of
mechanical weathering:
Mushroom Rock, Death
Valley National Park.
 Mushroom Rock was
carved by blowing sand.
 The upper part of the
rock is relatively
uneroded because the
windblown sand is
densest a few feet above
the surface.
 This rock which was
about 2 meters tall, has
since fallen down.
Secondary Succession
 Occurs in an area where the existing
community has been destroyed such as
a manmade fire or clearcutting.
 Soil is already present so plants can
grow quite quickly (opposite of primary
succession).
Factors That Help
Ecological Succession
1. Climate
2. Soil
3. Geographical Features
Climate
Includes:
1. Temperature
2. Precipitation
3. Amount of available sunlight
Soil
1.
2.
3.
4.
Includes:
salinity (amount of dissolved salt)
fertility (how things grow)
moisture (how much H2O it can hold)
texture
Geographical Features
1. Latitude: position north or south of the
equator
2. Altitude: height above sea level
3. Proximity or nearness to mountain
ranges or bodies of water
Remediate
 To restore a disturbed or contaminated
area of land to a natural state
Phytoremediation
 The use of plants, which can collect toxic
compounds in their tissues, to clean the
soil of its contaminants.
 To collect uranium after
the Chernobyl disaster
sunflowers were used.
Bioremediation
 Using bacteria or
microbes to clean up
or remove chemicals
in the soil.
 Such as pesticides,
PCBs (polychlorinated
biphenyls),
detergents, oil (as
seen in the diagram)