Energy flow in ecosystem and ecological succession

1. Ecology and Ecosystem
Studies

3. Functions of different ecosystem
• Productivity
• Decomposition
• Fragmentation
• Leaching
• Catabolism
• Humification
• Mineralisation
• Physical (energy flow)
• Food Chain; Grazing, detritus
• Biogeochemical (nutrient cycling)

4. Energy Flow- Carbon Cycle

5. Nitrogen cycle and Water cycle

6. Energy Flow in Ecosystem

11. Ecological Succession

12. Ecological Succession in Aquatic areas

13. The process

14. Types of Ecological Succession

17. Successional Communities Description
Pioneer
It is the one that sets first in a barren area. Examples include lichens on rock,
phytoplankton and zooplanktons in ponds. They survive in the most hostile
environment.
Climax
It is the last community in biotic succession, which is relatively stable and is
in near equilibrium with the environment of that area called a climax
community. Example: forests.
Xerosere
When succession takes place in dry areas like a rock (lithosere), sand
(psammosere) and saline conditions (halosere).
Hydrosere
When succession starts on the aquatic habitat where water is plenty and
progresses from hydric to mesic conditions.
Lithosere This ecological succession develops on bare rock surfaces.
Psammosere This ecological succession originates on the sand.
Halosere The plant succession that begins on salty soil and saline water.
Senile This succession takes place on a dead matter of microorganisms.
Eosere It shows the development of vegetation in an era.

18. Stages of Ecological Succession

19. Stages Description
Nudation
Development of bare area or nudation without any form of life. It may be caused due to several
factors like volcanic eruptions, landslides, floods, erosion, earthquake, forest fire, the spread of
disease, etc.
Invasion
It is the successful establishment of a species in a barren area. The arrival of reproductive bodies or
propagules of various species and their settlement in the new or bare area occurs by air, water, etc.,
known as migration. Adjustment of establishing species with the prevailing conditions is known
as ecesis. Then the individual species are multiplied by reproduction and increase their numbers; this
is called aggregation.
Competion and
coaction
After aggregation, the individuals of a species compete with other organisms for food, space and
other resources. The intraspecific and interspecific competition takes place along with interaction
with the environment. New invasion by plants and animals takes place.
Reaction The modification of the environment through the influence of living organisms on it is called reaction.
Stabilisation
The stage at which the final or climax community becomes more or less stabilised for a longer time in
that particular environment is known as stabilisation.