chap 5 Flashcards
“Ecological Succession is the orderly process of community change over time.”
Eugene Odum
also known as a wildfire or wildland fire. It is an uncontrolled and rapid spreading fire that consumes vegetation, trees, and other flammable materials in forested or wildland areas.
Forest fire
A _________ is a sudden and violent release of molten rock,
ash, gases, and other volcanic materials from a volcano. When it occurs, it can clear vegetation in several ways.
Volcanic eruption
activities that clear forests include deforestation
for agriculture, logging, urban development, and
infrastructure expansion.
human activities
what are the three disturbances
forest fire
volcanic eruption
human activities
After a disturbance, the
community will go
through a series of
stages, each with its own
characteristic species
composition and
structure. These stages
are known as____________,
and they eventually lead
to a more stable
community known as
the __________________.
seral (intermediate) stage, climax community
involves the gradual establishment of biotic communities in an area that has not been occupied by life before
primary succession
the more common type of
succession, involves the reestablishment of a biotic community in
an area where a biotic community was previously present.
Secondary succession
Types of succession
Primary succession
secondary succession
General process of succession
- Nudation
- Invasion
- Competition and coaction
- Reaction
- Climax Community
Development of a bare area
without any form of life
Nudation
Causes of Nudation
i. topographic
ii. climatic
iii. biotic
Successful establishment of a species in a bare area
Invasion
It involves following successive stages:
i. Migration (dispersal)
ii. Ecesis (establishment)
iii. Aggregation
The seeds, spores, or other propagules of the species reach the bare
area
Migration (dispersal)
The process of successful establishment of the species
Ecesis (establishment)
As a result of reproduction, the individuals of the species increase in
number, and they come close to each other
Aggregation
This phenomenon involve struggle for existence between two or more individuals growing in an area, that makes successive demands, that are similar in nature, on the soil
As a result of competition, the weak individuals are eliminated and the stronger ones are retained
Competition and coaction
*The mechanism of the modification of the
environment through the influence of
living organisms on it
* Environment is modified, becoming
unsuitable for the existing community
which sooner or later is replaced by
another community
Reaction
- The final stage of succession, remaining
relatively unchanged until destroyed by an
event such as fire or human interference
*The community is now in equilibrium with the local climate and can sustain itself over a longer period
Climax Community
Succession Is Slow In The Early Stage Because…
- harsh environment conditions
- Limited Soil Development
- Low Nutrient Levels
- Limited Seed Dispersal
- Allelopathy and Chemical Inhibition
- Limited Water Availability
- Long Reproductive Cycles
“Natura non facit saltum”
Nature does not make a jump
