Levels of organization and niche

1. UNIT 2
THE ECOSYSTEM

2. 2.1.1 COMPONENTS OF AN
ECOSYSTEM
AND
LEVELS OF ORGANIZATION

5. A group of organisms
that share similar
physical characteristic
and genetic traits that
interbreed and produce
fertile offsprings.
Sea lamprey
The basic unit of ecology ( Petromyzon marinus)
or the basic unit of an
ecosystem.

6. POPULATION
• A group of organisms of the same species
living in the same place at the same time and
which are capable of interbreeding.

7. COMMUNITY
• A group of populations living and interacting
with each other in a common habitat.
• Habitat: The environment or place where
normally or usually an individual lives.

8. ECOSYSTEM
• A community of interdependent organisms
(biotic factors) and the physical environment
(abiotic factors) they inhabit.
• The environment where biotic factors (living
things) interact and abiotic factors ( non living
things) are interconnected.

9. TYPES OF ECOSYSTEMS

10. ECOLOGICAL NICHE
• Role or funtion of the specie in its
environment.
• Where it lives ( habitat ), when and how it
lives, and what it does (predator – prey
relationship, mating, etc.)
• For example: The sea lamprey eats fish blood
(parasite) and is eaten (probably) by lake trout

11. FOOD CHAIN
• WHO EATS WHO AND HOW ENERGY FLOW.

12. KEY CONCEPTS
SPECIES-organisms with
similar characteristics
that are able to
reproduce fertile
offspring.
POPULATION-organisms
of the same specie that
live together in a place
and interact with each
other.
COMMUNITY-group of
populations living and
interacting with each
other.

13. KEY CONCEPTS
NICHE – describes the role of
an organisms or population in
its community or ecosystem.
In other words, the function
of an organisms in its living
environment.
HABITAT - is an ecological or
environmental area that is
inhabited by a particular
species of animal, plant or
other type of organism. It is
the natural environment in
which an organism lives, or
the physical environment that
surrounds (influences and is
utilized by) a species
population.

14. Key Concepts
Ecosystem - Is a
community of
interdependent organisms
and the physical (abiotic)
environment which they
inhabit.
Ecosystems may be of
varying sizes from a drop
of rainwater to a forest.
Human ecosystems may
include a household or a
school or a nation.
Ecosystems interact to
make a biosphere.

15. Key Concepts
Biome – is a
collection of
ecosystems sharing
common climatic
conditions, e.g.
tundra, desert,
tropical rain forest.

16. Key Concepts
Biosphere - is that part of the
Earth inhabited by organisms.
It is a thin layer that extends
from the upper part of the
atmosphere down to the
deepest parts of the oceans
which support life – 11 km
below sea level to 10 km
above.
From an ecological point of
view, the biosphere is the
"global ecosystem",
comprising the totality of
biodiversity on earth and
performing all manner of
biological functions, including
photosynthesis, respiration,
decomposition, nitrogen
fixation and denitrification.

17. Abiotic Factors
The non-living, physical and chemical components.
COMPONENTS
Biotic Factors Include:
The living components of an • The atmosphere: humidity, temperature range, gases,
ecosystem. clouds, air pressure, greenhouse gases, ozone layer, etc
Living organisms or their products that • Climate: light intensity or light exposure; temperature
directly or indirectly affect an range; precipitation; humidity; pressure, wind speed
organism in its environment. and direction, etc.
Includes organisms such as plants,
• Soil structure and chemistry: moisture, pH, nutrients,
animals, protista like algae, euglena,
amoebas, rotifers, diptera, etc, in
components, temperature, etc
general phytoplankton and • Water chemistry: pH; salinity; dissolved nutrients;
zooplankton. Also fungi like dissolved oxygen, turbidity, etc
mushrooms, yeasts, and molds.
• Seasonality
Bacterias and archae too. But is also
includes predation, parasitism, • Level of pollutants
commensalism, mutualism, etc.
Biotic factors interact as: producer,
consumer, detritivore, scavenger,
decomposer, parasite, host, predator,
prey, competitor, herbivore, carnivore,
omnivore, mutualist, and pathogen.

18. COMPONENTS
Biotic Factor

19. COMPONENTS
Abiotic Factors

20. • Case study in commercial
LIMITING FACTORS farming.
Factors that prevent the growth In Scotland, until the 1970´s, large areas of
or limit the size of a population, a scottish blanket blog were viewed as a place for
community or organism growing commercial forestry operations. It was too wet
larger. for Sitka Spruce, the predominant cash wood
crop to grow and too expensive to
Biotic factors such as predation or drain. Then it was discovered that if a nurse crop
competition or parasitism are of lodgepole pine was planted ahead of the Sitka,
limiting factors. even though the lodgepole pine would die in the
very wet conditions, they would dry the soilm
Abiotic factors such as nutrients, enough to allow the Sitka to succeed. Thus, the
soil chemistry, water quality, drying of the area and closing in of the canopy
dissolved oxygen, temperature, trees with trees planted very close in rows would
etc can restrict the growth of prevent growth of sphagnum moss.
population.
Lodgepole pine Sphagnum moss
Sitka spruce