This presentation is about community structure and properties.

1. POPULATION: GROWTH
AND REGULATION
RAYMOND C. BALDONADO

2. BIOTIC POTENTIAL
Biotic Potential is…
Ability of an organism in a population to reproduce, to become
more numerous
To migrate
The ability to invade other habitat
Has strong defense mechanism
The ability to cope with adverse condition

3. ENVIRONMENTAL RESISTANCE
The measure of difference between the maximum biotic potential
and the rate of increase
The sum total of the environmental limiting factors which prevent
the biotic potential from being realized

4. BIOTIC POTENTIAL AND ENVIRONMENTAL RESISTANCE

5. BIOLOGICAL
COMMUNITIES

6. LIMITING FACTORS, CRITICAL FACTORS AND
TOLERANCE LIMITS
 Every living organism has limits to the environmental conditions it
can endure like temperature, moisture levels, nutrient supply, soil
and water chemistry, living space and others are called Limiting
factors
 Victor Shelford states that each environmental factor has both
minimum and maximum levels called the Tolerance limits, beyond
which a particular species cannot survive or is unable to
reproduce.
 The single factor closest to these survival limits is the Critical
limiting factor that determines where a particular organism can
live

7. COMMUNITY
PROPERTIES

8. FUNDAMENTAL PROPERTIES OF BIOLOGICAL COMMUNITIES
1. Productivity
2. Diversity
3. Complexity
4. Resiliency/Stability
5. Structure

9. FUNDAMENTAL PROPERTIES OF BIOLOGICAL COMMUNITIES
 Productivity- is a measure of the rate at which photosynthesis
produces biomass made of energy-rich compounds
 Net primary productivity- is the rate at which all the plants in an
ecosystem produce net useful chemical energy
 Diversity- is a measure of the number of different species,
ecological niches or genetic variation present
 Abundance is the total number of organism in a biological
community

10. FUNDAMENTAL PROPERTIES OF BIOLOGICAL COMMUNITIES
 Complexity- refers to the number of species at each trophic level
and the number of trophic levels in a community
 Highly interconnected community can form a very elaborate food
web
3 Kinds of Stability/Resiliency in Ecosystems:
a. Constancy- lack of fluctuations in composition of functions
b. Inertia- resistance to perturbations
c. Renewal- ability to repair damage after disturbance

11. FUNDAMENTAL PROPERTIES OF BIOLOGICAL COMMUNITIES
Community Structure
 Ecological structure refers to patterns of spatial distribution of individuals and
populations within the community as well as the relation of a particular community
to its surroundings
Organisms can be distributed randomly, clumped together, or in highly regular
patterns
a. Random arranged population- individuals live wherever resources are available
b. Cluster arranged population- for protection, mutual assistance, reproduction, or to
gain access to a particular environmental resource
c. Ordered arranged population- my be determined by the physical environment but
are more often the result of biological competition

12. FUNDAMENTAL PROPERTIES OF BIOLOGICAL COMMUNITIES

13. FUNDAMENTAL PROPERTIES OF BIOLOGICAL COMMUNITIES

14. ECOLOGICAL
SUCCESSION

15. ECOLOGICAL SUCCESSION
 The process by which ecosystems change over a period of time or
a process whereby an ecosystem changes from a simple
community into a complex and relatively stable one
 The process by which organisms alter the environment in ways
that allow some species to replace others
 A particular succession progresses as a result of complex
interaction of biotic and abiotic factors
 The most significant changes are brought about by plants thus it
is sometimes called plant succession

16. ECOLOGICAL SUCCESSION
 Primary succession starts with a previously unoccupied sit
Secondary succession occurs on a site that has been disturbed by
external forces
 Often succession proceeds until a mature, diverse, climax
community is established

17. ECOLOGICAL SUCCESSION

18. KINDS OF SUCCESSION
A. Terrestrial Succession

19. KINDS OF SUCCESSION
B. Intertidal Succession

20. KINDS OF SUCCESSION
C. Aquatic Succession

21. ECOLOGICAL
GLOBAL
PROBLEMS

22. POLLUTION
Air pollution- means the presence of contaminants or materials in the
atmosphere that will adversely affect plants, animals and man
Water pollution- refers to any change in natural waters which may impair
their further use or any physical, biological or chemical change in water
quality that adversely affects living or makes water unsuitable for desired uses
Land pollution- takes place when harmful substances are introduced to the
soil so that the soil is unable to sustain life as it normally should
Noise pollution- is the presence of sound so loud or so sudden or so
unpleasant that it becomes an assault to the body, particularly the sense of
hearing, causing mental or physical harm

23. DEFORESTATION AND LOSS OF BIODIVERSITY
 Forest is a focal ecosystem
Virgin forest- uncut forests
Second-growth forests- have not been seriously disturbed for several
hundred years
Deforestation- is a massive cutting of trees without planting
Reforestation- is planting trees for every trees cut

24. BIODIVERSITY
Biodiversity- is the totality of genes, species and ecosystems in a region. The wealth
of life on earth today is the product of hundreds of millions of years of evolutionary
history
Direct Mechanisms includes the following:
1. Habitat loss and fragmentation
2. Invasion by introduced species
3. The over-exploitation of living resources
4. Pollution
5. Global climate changes
6. Industrial agriculture and forestry

25. CLIMATE CHANGE
 Significant change in the mean values of atmospheric variables

26. GREENHOUSE EFFECT
 Trace gases trapping heat near the atmosphere

27. OZONE LAYER DEPLETION
 Degradation of ozone layer-with the ability to filter out a very high proportion
of incoming UV radiation

28. ACID RAIN
 Gases like sulfur dioxide and carbon monoxide combined with atmospheric
water of water vapor which are the main ingredient of acid rain.

29. BUILDING A SUSTAINABLE SOCIETY: THE CONTEXT FOR
CONSERVING BIODIVERSITY
Respect and care for the community of life
Improve the quality of human life
Conserve Earth’s vitality and diversity
Minimize the depletion of non-renewable resources
Keep within the Earth’s carrying capacity
Change personal attitudes and practices
Enable communities to care for their own environments
Provide a national framework for integrating development and conservation
Forge a global alliance