ecosystem defination and other information

1. GUIDED BY: BABITA J SINGH
PRESENTED BY: MAYANK TRIVEDI
CLASS : 12th
ROLL NO : 35

2. I would like to thank my wonderful Biology
teacher Babita ma’am for giving me this
amazing learning opportunity to work on a
topic of my choice.

3. •INTRODUCTION
•COMPONENTS OF ECOSYSTEM
•PRODUCTIVITY
•DECOMPOSITION
•ENERGY FLOW
•ECOLOGICAL PYRAMIDS
•ECOLOGICAL SUCCESSION
•SUCCESION OF PLANTS
•NUTIENT CYCLE
•ECOSYSTEM SERVICES
•BIBLOGRAPHY

5. Components of ecosystem:
 Abiotic Components: The abiotic components of an ecosystem are all of
the nonliving elements. They include the water, the air, the temperature and the rocks
and minerals that make up the soil.
 Producers at the Base: Producers are the living organisms in the ecosystem
that take in energy from sunlight and use it to transform carbon dioxide and oxygen into
sugars. Plants, algae and photosynthetic bacteria are all examples of producers.
 Consumers in the Chain: Consumers are living organisms in the
ecosystem that get their energy from consuming other organisms. Conceptually,
consumers are further subdivided by what they eat: Herbivores eat producers, carnivores
eat other animals and omnivores eat both.
 Decomposers and Nutrient Cycling: Decomposers are the
living component of the ecosystem that breaks down waste material and
dead organisms. They perform a vital recycling function, returning
nutrients incorporated into dead organisms to the soil where plants can
take them up again

6. Productivity:
 The rate of synthesis of organic matter (biomass) during a
given period of time. It is measured as weight (g-2) or as
energy (kcal m-2). It is used to compare productivity of
different ecosystems.
 Primary productivity:
It is the amount of biomass produced per unit area in a
given time period by Plants during Photosynthesis.
 Secondary productivity
It is the amount of biomass produced at any of the
Consumer levels in a given period of time.

7. Decomposition:
 It is the process of breaking down of dead organic matter into smaller
organic molecules and inorganic molecules by Decomposers
(bacteria, fungi)
 DETRITUS: Dead remains of plants and animals is called detritus.
 DETRITIVORES: Animals that feed on decaying organic matter
(detritus).
 Mechanism of Decomposition:
 Fragmentation of Detritus
 Leaching:
 Catabolism:
 Humification:

8. Energy Flow:
 SUN Main Source of energy.
 50% of incident light is PHOTOSYNTHETICALLY
ACTIVE RADIATION (PAR)
 Only a small fraction of this (stored as organic
compounds) is transferred to consumers; the rest is used
up in respiration and other lifesupporting activities of the
plants.
 As energy is transferred as food, most part is lost as heat
at each stage (10% LAW)
 Unidirectional flow of Energy:

9. Ecological Pyramids:
 Pyramids are an expression of the relationship between organisms at
different tropic levels in terms of their number, biomass or energy.
 Pyramid of Number: The relationship between producers and consumers
in an ecosystem can be represented in the form of a pyramid in terms of
number called pyramid of number.
 Pyramid of Biomass: The relationship between producers and
consumers in an ecosystem can be represented in the form of a pyramid
in terms of biomass called pyramid of biomass. It can be of two types:
 Upright (in case of grassland ecosystem)
 Inverted (in case of pond ecosystem)
 3. Pyramid of energy: The relationship between producers and consumers in
an ecosystem can be represented in terms of flow of energy called pyramid
of energy. It is always upright.

10. Ecological succession:
 Refers to predictable and orderly change in the
composition or structure of a community.
 May be initiated either by formation of new,
unoccupied habitat or by some form of disturbance
of an existing community.
 Sere – entire sequence of community that
successively change in a given area.

11.  Primary Succession :
If the development begins on an area that has not been
previously occupied by a community.
Pioneer species – lichens, phytoplankton, etc.
 Secondary Succession:
If the community development is proceeding in an area
from which a community was removed.
Pioneer species – grasses, wildflowers, algae.
Examples:an abandoned crop fieid.

12. Succession of plants:
 Hydrarch succession:It takes place in wetter areas and
the successional series progress from hydric to the mesic
conditions.
 Xerarch succession :It takes place in dry areas and the
series progress from xeric to mesic condition.
Bare rock > Lichens and mosses > Annual grasses >
Perennial grasses > Shrubs > Tall Trees

13. Nutrient Cycle:
 Also known as biogeochemical cycle.
 Environmental factors like soil, moisture, temperature,
etc. regulate the rate of release of nutrients into the
atmosphere.
 Nutrients are never lost from the ecosystem; they are
recycled time an again indefinitely.
 There are two types:
Gaseous cycle
Sedimentary cycle

14. Ecosystem Services:
 Humankind benefits from a multitude of resources and
processes that are supplied by natural ecosystems.
Collectively, these benefits are known as ecosystem services.
 Purify air and water
 Decomposition of waste materials
 Cycle nutrients
 Pollinate crops
 Maintain biodiversity .
 Researchers have put an average price tag of US $33 trillion a
year on these fundamental ecosystems services, which is
largely taken for granted because they are free.

15. A Barren Ecosystem:
 Barren vegetation describes an area of land
where plant growth is sparse, stunted, or possesses
little biodiversity. Poor growth may occur due to high
winds, climate, salt spray, infertile or toxic soil, or
heavy exploitation by humans.
 Barrens may look poor—with shrubs or moss instead
of trees—but they provide good environments
for rare plant and animal species that can't compete in
nutrient-rich environments. Many serpentine barrens host
unique assemblages of plant species. Some barrens,
such alpine barrens, are well-wooded with fairly tall trees,
though the only smaller plants present are those adapted
to a low nutrient supply.

16. Methods Of Desert Greening:
 Managed intensive rotational grazing
 Holistic management
 Landscaping methods to reduce evaporation, erosion, consolidation of topsoil,
sandstorms, temperature and more
 Permaculture in general - harvesting runoff rainwater to grow plant
communities polyculture, composting or multitrophic agriculture
 Planting trees (pioneer species) and salt-loving plants such as Salicornia
and Halophytes
 Regeneration of salty, polluted, or degenerated soils
 Floodwater retention and infiltration (flood control)[1]
 Greenhouse agriculture like the Integrated Biotectural System
 Seawater farming like done by the Seawater Foundation
 Inland agriculture
 Prevention of overgrazing and firewood use
 Training of local residents to care for plantings, water systems etc.
 Planting trees with dew and rain harvesting technology

17. Modern example:
 A modern example of desert farming is the Imperial Valley in California,
which has high temperatures and average rainfall of just76 mm per year.
The economy is heavily based on agriculture and the land is irrigated
through a network of canals and pipelines sourced entirely from
the Colorado River via the All-American Canal. The soil is deep and fertile,
being part of the river's flood plains, and what would otherwise have been
desert has been transformed into one of the most productive farming
regions in California. Another problem of growing crops in this way is the
build-up of salinity in the soil caused by evaporation of river water. The
greening of the desert remains an aspiration and was at one time viewed
as a future means for increasing food production for the world's growing
population. This prospect has proved false as it disregarded the
environmental damage caused elsewhere by the diversion of water for
desert project irrigation.

18. •GOOGLE
•WIKIPEDIA
•NCERT TEXT BOOK