2. a group of organisms of different kinds or
species living together in a particular place.
assembly of populations of different species
in a particular area of a particular time.
a community consists of all plants and
animals in a place of a particular time. It is the
biotic part of an ecosystem.

3. It is the
biotic part of
an ecosystem.
It consists
of the
producer, con
sumer and
decomposer.

4. Human
Community- refers
to all people,
buildings, roads
and others in a
town or other
political unit.

5. They possess the highest biomass, occupy
the most space, make the largest contribution to
the flow of energy, and cycling of materials, and
exert control over the other organisms in the
community.
Trees are the dominants in the forest
because they create a climate suitable for certain
groups of organisms which set the character of
the community.
Numerical abundance is the determining
factor of dominance.

6. … the fundamental role
of the organism in the
community
--- what it does, its
relation to its foods and
to is enemies…
(CHARLES ELTON)

7. • part of the environment occupied by an
organism
• the role of organism in the ecosystem as well as
its position in time and place
• the job of an organism- how it gets its supply of
energy and materials
• the means of living
• functional role- what it does for a living in a
community

9. This concept states that no two species can
occupy the same niche at the same time. According
to this principle, if two species in the same area
occupy the same niche, three things would most
likely to happen:
1. If one species has greater advantage due to
greater reproductive capacity or some other
factors, the organism will eventually be
discarded from that area.

10. 2. If two kinds of organisms which are not
completely similar or identical occupy a
habitat, one of the organisms will leave the
habitat and occupy an adjacent habitat for
as long as the organism can tolerate the
conditions of the adjacent habitat.
3. If two species occupy the same area and
are very much similar at first, they develop
differences from one another which tend to
decrease their competition. This is also
known as CHARACTER DISPLACEMENT.

12. CANOPY
consists of all tallest trees.
It is the major site of production.

13. UNDERSTOREY
 consists of tall shrubs
Those that are not able to
withstand the shade and
competition will die; others will
reach the canopy layer after
some of the older trees die or
are harvested.

14. HERB LAYER
 consist of
the plants shorter
than the shrubs.

15. forest floor
 consists of
leaves, branches, dead bodies
of plants and animals, and
other matter which have fallen
to the ground.

16. AQUATIC
RESOURCES

17. A LAKE is
stratified into:
1. Littoral
zone
2. limnetic
zone
3. Profunda
zone

18. The littoral zone is
that part of a sea, lake
or river that is close to
the shore. In coastal
environments the
littoral zone extends
from the high water
mark, which is rarely
inundated, to
shoreline areas that
are permanently
submerged.

19. The limnetic
zone is the well-
lit, open surface
waters in a
lake, away from
the shore

20. The profundal zone is a
very cold and ordinary
zone, such as an ocean or a
lake, located below the
range of effective light
penetration.

22. In the field of ecology, community composition
changes over time. The study of succession
addresses this change, which can be influenced
by the environment, biotic interactions, and
dispersal.

24. Over the course of several years, you can return to any location — whether it be
the local forest, grassland, pond, abandoned farm (or urban lot), park, or even
your backyard — and you are likely to observe changes to the organisms found in
the community.
New plants may appear and other plants disappear, and these changes may also
be reflected in the animal life. These changes may be subtle or obvious, but we
can count on communities changing over time in composition, structure, diversity,
and productivity. This principle has been exploited by human populations for
1000’s of years, with the manipulation of habitat (e.g., use of fire) to promote the
abundance of certain plant and animal species to our benefit. For over a century,
ecologists
have investigated the nature of these changes in communities, documenting the
causes and patterns of change, indentifying mechanisms for change, and
developing sets of general principles to explain this change. This change in
community composition over time is termed succession. Some definitions also
include adjectives for succession (e.g., Odum 1969) that include
“orderly”, “directional,” and “stabilizing.” However, these qualifiers have been
much disputed and do not accurately represent the process in most cases

25. TYPES OF SUCCESSION
• have investigated the nature of these changes in
communities, documenting the causes and patterns
of change, indentifying mechanisms for change, and
developing sets of general principles to explain this
change. This change in community composition over
time is termed succession. Some definitions also
include adjectives for succession (e.g., Odum 1969)
that include “orderly”, “directional,” and
“stabilizing.” However, these qualifiers have been
much disputed and do not accurately represent the
process in most cases

26. MODELS OF COMMUNITY
• Several models have been developed that describe and make
predictions about the successional process. One of the most influential
was Frederic Clements’ work from early in the twentieth century
(e.g., Clements 1936). Succession was viewed as a deterministic and
orderly sequence of serial stages that ended with the climax community.
In this view, each stage was composed of a group of species viewed as a
super-organism working together and developing on a site that was then
replaced by another stage. Ultimately, succession arrived at a climax
community, which characterizes the habitat and was viewed as the
“expression of the climate”. In contrast, Henry Gleason presented a
different view of succession that emphasized individualistic traits (a
biotic tolerances and dispersal) of species and their interactions with the
environment (Gleason 1926). Species occur together in a location as the
result of their a biotic tolerances (niche requirements), not because they
are part of an integrated “super organism.” This perspective viewed
succession as less deterministic and more reliant on chance dispersal
events. One of the consequences is the potential for different
successional trajectories resulting in alternative climax communities.

28. The reestablishment of a community in
which most, but not all organisms have been
destroyed. Lodgepole pines (a) will replace
meadows in the absence of fire. Prescribe
fires (b) burned trees in the meadow (c).

29. THE WORLDS MAJOR
COMMUNITIES
• Biomes are climatically and geographically defined as similar
climatic conditions on the Earth, such as communities of
plants, animals, and soil organisms,[1] and are often referred
to as ecosystems. Some parts of the earth have more or less
the same kind of abiotic and biotic factors spread over a large
area creating a typical ecosystem over that area. Such major
ecosystems are termed as biomes. Biomes are defined by
factors such as plant structures (such as trees, shrubs, and
grasses), leaf types (such as broadleaf and needleleaf), plant
spacing (forest, woodland, savanna), and climate. Unlike
ecozones, biomes are not defined by genetic, taxonomic, or
historical similarities. Biomes are often identified with
particular patterns of ecological succession and climax
vegetation (quasi-equilibrium state of the local ecosystem

30. – Biomes are defined as "the world's major
communities, classified according to the
predominant vegetation and characterized
by adaptations of organisms to that
particular environment" (Campbell 1996).
The importance of biomes cannot be
overestimated. Biomes have changed and
moved many times during the history of life
on Earth. More recently, human activities
have drastically altered these communities.
Thus, conservation and preservation of
biomes should be a major concern to all.

32. A DESERT BIOME

33. TUNDRA BIOME