Ecology is the scientific study of the intricate relationships between living organisms and their environment. It seeks to understand how organisms interact with one another and their surroundings, from the smallest microorganisms to the largest ecosystems. One fundamental aspect of ecology is the examination of biogeochemical cycles, which are essential processes that govern the flow of elements and compounds through the Earth's ecosystems. These cycles encompass the movement of essential elements like carbon, nitrogen, phosphorus, and water between the living and non-living components of the environment. For example, the carbon cycle involves the exchange of carbon dioxide between the atmosphere, plants, and animals, regulating the levels of this greenhouse gas in the atmosphere and influencing climate. The nitrogen cycle is another vital process, as it controls the availability of nitrogen for plants and, subsequently, for all organisms in a given ecosystem. Biogeochemical cycles are critical to maintaining the delicate balance of nutrients and elements necessary for life on Earth, and any disruptions to these cycles can have profound ecological consequences. Understanding these cycles is crucial for environmental conservation and for addressing global challenges like climate change and nutrient pollution. In sum, ecology and biogeochemical cycles are intimately linked, providing the foundation for understanding how life and the environment are intricately interconnected and interdependent.

1. Ecology

2. WHAT IS ECOLOGY?
THE STUDY OF THE RELATIONSHIP
BETWEEN AN ORGANISM AND ITS’
ENVIRONMENT IS CALLED ECOLOGY

3. WHAT DO YOU MEAN BY ENVIRONMENT?
The environment is made
up of two factors:
• Biotic factors- all living
organisms inhabiting the
Earth
• Abiotic factors- nonliving
parts of the environment
(i.e. temperature, soil,
light, moisture, air
currents)

4. 4
The Nonliving Environment
• Abiotic factors- the
nonliving parts of an
organism’s environment.
• Examples include air
currents, temperature,
moisture, light, and soil.
• Abiotic factors affect an
organism’s life.

5. 5
The Living Environment
• Biotic factors- all the
living organisms that
inhabit an environment.
• All organisms depend on
others directly or
indirectly for food,
shelter, reproduction, or
protection.

6. 6
Abiotic or Biotic?
Biotic

7. 7
Abiotic or Biotic?
Abiotic

8. 8
Abiotic or Biotic?
Abiotic

9. 9
Abiotic or Biotic?
Biotic

10. 10
Levels of
Organization

11. Organism
Population
Community
Biosphere
Ecosystem

12. 12
What are the Simplest Levels?
• Atom
• Molecule
• Organelle
• Cell
• Tissue
• Organ
• System

13. 13
Levels of Organization
• Ecologists have organized the
interactions an organism takes
part in into different levels
according to complexity.

14. 14
1st Level of Organization
• Organism:
An individual
living thing that
is made of cells,
uses energy,
reproduces,
responds, grows,
and develops

15. Organism - any unicellular or
multicellular form exhibiting all of the
characteristics of life, an individual.
•The lowest level of organization

16. 16
2nd Level of Organization
• Population:
A group of
organisms, all
of the same
species, which
interbreed and
live in the
same place at
the same time.

17. POPULATION
 a group of organisms of
one species living in the
same place at the same
time that interbreed
Produce fertile offspring
Compete with each other
for resources (food,
mates, shelter, etc.)

18. 18
3rd Level of Organization
• Biological
Community:
All the
populations of
different
species that
live in the same
place at the
same time.

19. Community - several interacting
populations that inhabit a common
environment and are interdependent.

20. 20
4th Level of Organization
• Ecosystem:
Populations of plants
and animals that
interact with each
other in a given
area with the
abiotic components
of that area.
(terrestrial or
aquatic)

22. 22
5th Level of Organization
• Biosphere:
The
portion of
Earth that
supports
life.

23. 23
The Biosphere
• Life is found in air, on
land, and in fresh and salt
water.
• The BIOSPHERE is the
portion of Earth that
supports living things.

24. •The highest level of organization

26. Habitat vs. Niche
Niche - the role a species plays in
a community; its total way of life
Habitat- the place in which an
organism lives out its life

27. Habitat vs. Niche
A niche is determined by the
tolerance limitations of an
organism, or a limiting factor.
Limiting factor- any biotic or
abiotic factor that restricts the
existence of organisms in a
specific environment.

28. Examples of limiting factors -
•Amount of water
•Amount of food
•Temperature
•Amount of space
•Availability of mates
Habitat vs. Niche

29. Feeding Relationships
• There are 3 main types of feeding
relationships
1. Producer - Consumer
2. Predator - Prey
3. Parasite - Host

30. Feeding Relationships
Producer- all
autotrophs (plants),
they trap energy
from the sun
• Bottom of the food
chain

31. Feeding Relationships
Consumer- all heterotrophs: they
ingest food containing the sun’s
energy
Herbivores
Carnivores
Omnivores
Decomposers

32. Feeding Relationships
CONSUMERS
1. Primary consumers
• Eat plants
• Herbivores
2. Secondary, tertiary
… consumers
• Prey animals
• Carnivores

33. Feeding Relationships
Consumer-Carnivores-eat meat
• Predators
– Hunt prey
animals for food.

34. Feeding Relationships
Consumer- Carnivores- eat meat
• Scavengers
– Feed on carrion,
dead animals

35. Feeding Relationships
Consumer- Omnivores -eat both plants
and animals

36. Feeding Relationships
Consumer-
Decomposers
• Breakdown the
complex compounds
of dead and
decaying plants and
animals into simpler
molecules that can
be absorbed

37. Symbiotic Relationships
Symbiosis- two species living together
3 Types of
symbiosis:
1. Commensalism
2. Parasitism
3. Mutualism

38. Symbiotic Relationships
Commensalism-
one species benefits
and the other is
neither harmed nor
helped
Ex. orchids on a tree
Epiphytes: A plant, such as a tropical
orchid or a bromeliad, that grows on another
plant upon which it depends for mechanical
support but not for nutrients. Also called
xerophyte, air plant.

39. Symbiotic Relationships
Commensalism-
one species benefits
and the other is
neither harmed nor
helped
Ex. polar bears and
cyanobacteria

40. Symbiotic Relationships
Parasitism-
one species benefits (parasite) and
the other is harmed (host)
• Parasite-Host relationship

41. Symbiotic Relationships
Parasitism- parasite-host
Ex. lampreys,
leeches, fleas,
ticks, tapeworm

42. Symbiotic Relationships
Mutualism-
beneficial to
both species
Ex. cleaning birds
and cleaner
shrimp

43. Symbiotic Relationships
Mutualism-
beneficial to both species
Ex. lichen

45. Type of
relationship
Species
harmed
Species
benefits
Species
neutral
Commensalism
Parasitism
Mutualism
= 1 species

46. Trophic Levels
• Each link in a food chain is known
as a trophic level.
• Trophic levels represent a feeding
step in the transfer of energy
and matter in an ecosystem.

47. Trophic Levels
Biomass- the amount of organic matter
comprising a group of organisms in a
habitat.
• As you move up a food chain, both
available energy and biomass
decrease.
• Energy is transferred upwards but is
diminished with each transfer.

48. Trophic Levels
Producers- Autotrophs
Primary consumers- Herbivores
Secondary consumers-
small carnivores
Tertiary
consumers- top
carnivores
E
N
E
R
G
Y

51. Trophic Levels
Food chain- simple model that
shows how matter and energy
move through an ecosystem

53. Trophic Levels
Food web- shows all possible
feeding relationships in a
community at each trophic level
• Represents a network of
interconnected food chains
video

54. Food chain Food web
(just 1 path of energy) (all possible energy paths)

59. The Biogeochemical Cycles

60. Definition:
Movement of chemical
elements in a circular pathway, from
organisms to physical environment,
back to organisms.

62. What Sustains Life on Earth?
 Solar energy, the cycling of matter, and
gravity sustain the earth’s life.

63. Carbon Cycle
 All living things are made of carbon.
Carbon is also a part of the ocean, air,
and even rocks.
 In the atmosphere, carbon is attached
to some oxygen in a gas called carbon
dioxide.

64.  Plants use carbon dioxide and
sunlight to make their own food and
grow.
 The carbon becomes part of the
plant. Plants that die and are buried
may turn into fossil fuels made of
carbon like coal and oil over millions
of years.When humans burn fossil
fuels, most of the carbon quickly
enters the atmosphere as carbon
dioxide.

65.  Carbon dioxide is a greenhouse gas and
traps heat in the atmosphere. Without it
and other greenhouse gases, Earth would
be a frozen world. But humans have burned
so much fuel that there is about 30% more
carbon dioxide in the air today than there
was about 150 years ago, and Earth is
becoming a warmer place. In fact, ice cores
show us that there is now more carbon
dioxide in the atmosphere than there has
been in the last 420,000 years.

66. Carbon cycle-
•Photosynthesis and respiration
cycle carbon and oxygen through
the environment.

67. Carbon cycle-

69. Water Cycle
 The water cycle, also known as the hydrological cycle
or H2O cycle, describes the continuous movement of
water on, above and below the surface of the Earth.
Although the balance of water on Earth remains fairly
constant over time, individual water molecules can
come and go, in and out of the atmosphere.The water
moves from one reservoir to another, such as from river
to ocean, or from the ocean to the atmosphere, by the
physical processes of evaporation, condensation,
precipitation, infiltration, runoff, and subsurface flow. In
so doing, the water goes through different phases:
liquid, solid (ice), and gas (vapor).

70.  The water cycle involves the exchange of heat, which
leads to temperature changes. For instance, when water
evaporates, it takes up energy from its surroundings and
cools the environment.When it condenses, it releases
energy and warms the environment.These heat
exchanges influence climate. By transferring water from
one reservoir to another, the water cycle purifies water,
replenishes the land with freshwater, and transports
minerals to different parts of the globe. It is also
involved in reshaping the geological features of the
Earth, through such processes as erosion and
sedimentation. Finally, the water cycle figures
significantly in the maintenance of life and ecosystems
on Earth

71. Water cycle-
•Evaporation, transpiration,
condensation, precipitation

72. Water cycle-

73. The Hydrological Cycle

76. Nitrogen Cycle
 Continuous natural cycle of biological, chemical, and
geological processes by which nitrogen is circulated
in the Earth's environment.
 Although the most plentiful element in atmosphere
(78 percent by volume, compared to 21 percent of
oxygen), nitrogen cannot be used directly by most
living things unless it is converted ('fixed,' see
nitrogen fixation) into nitrogen-compounds by
microorganism such as the bacteria present in the
root-nodules of legumes, blue-green algae, and by
the action of lightning.

77.  These compounds are taken up by plants as
nutrients from the soil and converted into
plant proteins (amino acids). Plant proteins
become animal proteins when eaten and
metabolized by herbivorous animals, and
when carnivorous animals eat the
herbivorous.

78.  These proteins return to the soil through animal
excrement and the decomposition of dead
animals and plants, and are converted into
carbon dioxide, water, and ammonia (gaseous
compound of nitrogen and hydrogen) by a set
of bacteria in the soil. A portion of this
ammonia is converted into soil nitrogen (fixed
nitrogen) by another set of bacteria and the
balance is released into the atmosphere as free
nitrogen(N2).

79. Nitrogen cycle-
Atmospheric nitrogen (N2) makes up nearly
78%-80% of air.
Organisms can not use it in that form.
Lightning and bacteria convert nitrogen into
usable forms.

80. Nitrogen cycle-
Only in certain bacteria and industrial
technologies can fix nitrogen.
Nitrogen fixation-convert atmospheric
nitrogen (N2) into ammonium (NH4
+)
which can be used to make organic
compounds like amino acids.
N2 NH4
+

81. Nitrogen cycle-
Nitrogen-fixing
bacteria:
Some live in a
symbiotic
relationship with
plants of the legume
family (e.g.,
soybeans, clover,
peanuts).

82. Nitrogen cycle-
•Some nitrogen-fixing bacteria live
free in the soil.
•Nitrogen-fixing cyanobacteria are
essential to maintaining the fertility
of semi-aquatic environments like rice
paddies.

84. Atmospheric
nitrogen
Lightning
Nitrogen
fixing bacteria
Ammonium Nitrification
by bacteria
Nitrites Nitrates
Denitrification
by bacteria
Plants
Animals
Decomposers
Nitrogen Cycle

86. Phosphorous Cycle
 The phosphorus cycle is the biogeochemical
cycle that describes the movement of phosphorus
through the lithosphere, hydrosphere, and
biosphere. Unlike many other biogeochemical
cycles, the atmosphere does not play a significant
role in the movement of phosphorus, because
phosphorus and phosphorus-based compounds
are usually solids at the typical ranges of
temperature and pressure found on Earth.

87.  Phosphorus is an essential nutrient for
plants and animals in the form of ions
PO43- and HPO42-. It is a part of DNA-
molecules, of molecules that store energy
(ATP and ADP) and of fats of cell
membranes. Phosphorus is also a building
block of certain parts of the human and
animal body, such as the bones and teeth.

90. Phosphorous Cycle Video

91. Oxygen Cycle
 The oxygen cycle is the biogeochemical cycle
that describes the movement of oxygen within
its three main reservoirs: the atmosphere (air),
the total content of biological matter within the
biosphere (the global sum of all ecosystems),
and the lithosphere (Earth's crust). Failures in
the oxygen cycle within the hydrosphere (the
combined mass of water found on, under, and
over the surface of a planet) can result in the
development of hypoxic zones.

92.  The main driving factor of the oxygen cycle is
photosynthesis, which is responsible for the
modern Earth's atmosphere and life as we
know it .

95. Sulfur cycle
 Sulphur is one of the components that make up
proteins and vitamins. Proteins consist of amino
acids that contain sulphur atoms. Sulphur is
important for the functioning of proteins and
enzymes in plants, and in animals that depend
upon plants for sulphur. Plants absorb sulphur
when it is dissolved in water.Animals consume
these plants, so that they take up enough
sulphur to maintain their health.
Read more:

97.  Most of the earth's sulphur is tied up in rocks and
salts or buried deep in the ocean in oceanic
sediments. Sulphur can also be found in the
atmosphere. It enters the atmosphere through both
natural and human sources. Natural recourses can be
for instance volcanic eruptions, bacterial processes,
evaporation from water, or decaying organisms.
When sulphur enters the atmosphere through human
activity, this is mainly a consequence of industrial
processes where sulphur dioxide (SO2) and hydrogen
sulphide (H2S) gases are emitted on a wide scale.

98. REPORTING
1. BIOGEOCHEMICAL CYCLES-WATER CYCLE
2. BIOGEOCHEMICAL CYCLES-CARBON CYCLE
3. BIOGEOCHEMICAL CYCLES-PHOSPHORUS CYCLE
4. BIOGEOCHEMICAL CYCLES-NITROGEN CYCLE
5. BIOGEOCHEMICAL CYCLES-OXYGEN CYCLE
6. ECOSYSTEMS
7. POLLUTION ENVIRONMENT-WATER ENVIRONMENT
8. POLLUTION ENVIRONMENT-AIR ENVIRONMENT
9. POLLUTION ENVIRONMENT-SOLID ENVIRONMENT
10. TOXIC AND HAZARDOUSWASTETREATMENT
11. ENVIRONMENTAL MANAGEMENT SYSTEM
12. ENVIRONMENTAL IMPACT ASSESSMENT
13. ENVIRONMENTAL CLEARANCE CERTIFICATE

99. PRELIM PERIOD
 PROJECT 1 – RECYCLING –THEME: CHRISTMAS
DECORATION-DEADLINE DEC 13
 RESEARCHWORK- DIFFERENT LEVEL OF
ORGANIZATION (individual)
DESCRIBEAND GIVE EXAMPLE FOR EACH
ORGANIZATION (LOCAL)-DEADLINE NOV 29
 FOR REPORTING-HARDCOPYAND SOFTCOPY
TO BE SUBMITTED 1WEEK BEFORETHE
ACTUAL REPORTING