1. Energy Flow
By
Dr. Md. Shafiqur Rahman
UMK

2. Energy flow
Energy flow is the capture of solar
energy through photosynthesis,
which is the process used by green
plants to convert radiant energy
from the sun into organic
compounds such as glucose.

3. Energy flow
With the known exception of
organisms that live along thermal
vents in the deep ocean floor, all
organisms--including humankind--
nurture themselves, directly or
indirectly, on the products of
photosynthesis.

4. Energy flow
Energy flow can increase in a given area by
lengthening one or more legs of the triangle
that forms the base of solar conversion of the
energy tetrahedron: length of the growing
season, volume of plants, or leaf area. All of
these factors are related to other ecosystem
processes such as the water cycle, mineral
cycles, and community dynamics.

5. Energy flow
We can increase energy flow into food crops,
fiber, and forage by lengthening the growing
season (with irrigation, for example). We can
increase the volume and leaf area of plants
(by adding nitrogen fertilizer, for example).
However, long-term solutions to low energy
flow must take into account all of the
ecosystem processes, and must enhance
biodiversity as well.

6. Energy flow
Most of the food we eat comes from
simple food chains derived from human-
controlled agricultural ecosystems. For
example, the beef we eat comes from a
cow that ate corn or grass . The corn or
grass received its energy from the sun.

7. Energy flow
In natural ecosystems, a hawk may eat a
snake that may have received its energy
from a mouse, a frog, or a rabbit. If it
ate a mouse, that mouse may have
consumed seeds from any number of
plants. None of these food chains is
exactly alike, which makes studying
energy transfer complex.

8. Energy flow
The food chain begins with producers,
organisms such as green plants, that can
make their own food. Through
photosynthesis, producers convert solar
energy to chemical energy, energy in the
chemical bonds of the food. Of all the
energy a plant receives from the sun

9. Energy flow
Plants are eaten by consumers, which are
organisms that cannot make their own food.
Herbivores are consumers that eat only
producers. Consumers that prey on other
consumers are called carnivores. If an animal
can get its energy by ingesting either
producers or consumers, it is an omnivore.

10. Energy flow
The amount of energy that is transferred from
one organism to the next varies in different
food chains. Generally, about ten
percent of the energy from one level
of a food chain makes it to the next.

11. Energy flow
Because energy is "lost" with each
successive link, there must be enough
energy in the organisms to allow for this
loss and still have enough energy
remaining for the consumers in the next
level.

12. Energy flow
Decomposers, such as, bacteria, fungi, and
small animals such as ants and worms, eat
nonliving organic matter. Decomposers cycle,
nutrients back into food chains and the
remaining potential energy in unconsumed
matter is used and eventually dissipated as
heat. Therefore, decomposers are an integral
component of all ecosystems (First and
Second Laws of Thermodynamics).

13. Energy flow
In food chains there are many alternate
routes through which energy can flow,
creating integrated, complex food webs.
Through agriculture, humans have
simplified food chains so the energy
flow is more direct

14. Energy flow
Species interactions include relationships like
pollination, mutualism, predation, and
decomposition. Plants and animals in an
environment interact with each other in
various ways. For example, plants may
depend on insects or birds to pollinate
flowers and on earthworms to aerate the
soil; animals may depend on plants for food
or shelter.

15. Energy flow
The interaction of living and nonliving
components affects the qualities and
characteristics of an ecosystem. These
interactions can influence the climate
within the area (often called a micro-
climate). For example, in a forest tall trees
block the sunlight resulting in a shady moist
under story where only certain plants can
live.

16. Energy Flow and Chemical Cycling
Every ecosystem is characterized by two fundamental
phenomena:
Energy flow:
- Begins when producers absorb solar energy
- Make organic nutrients via photosynthesis
- Organic nutrients are used by themselves & by
others
Chemical cycling- The pathways by which chemicals
circulate through the ecosystems, involve both
living (biotic) and non-living (geologic) components.

17. • A nutrient is a chemical that an organism needs to
live and grow or a substance used in an organism's
metabolism which must be taken in from its
environment.[1] They are used to build and repair
tissues, regulate body processes and are
convOrganic nutrients erted to and used as energy.
• include carbohydrates, fats, proteins (or their
building blocks, amino acids), and vitamins.
Inorganic chemical compounds such as dietary
minerals, water, and oxygen may also be considered
nutrients.[

18. Natural Organic Matter (NOM)
Natural organic matter is present throughout
the ecosystem. After degrading and reacting,
it can then move into soil and mainstream
water via waterflow. NOM forms molecules
that contain nutrients as it passes through
soil and water. It provides nutrition to living
plant and animal species. NOM acts as a
buffer, when in aqueous solution, to maintain
a less acidic pH in the environment

19. Energy flow Through an Ecosystem
Ecosystems consists of 2 parts:
biotic and abiotic component
-Energy flows from sun to producer to
consumer to decomposer
-Much energy is converted to heat as it moves
from one organism to another

20. Chemical Cycling
The pathways by which chemicals circulate
through ecosystems:
-Involve both living(biotic) and nonliving (geologic)
Components.
- Known as bio-geochemical cycle.
• The water Cycle
• Carbon Cycle
• Phosphorus Cycle
• Nitrogen Cycle

21. Chemical Cycling
The pathways by which chemicals circulate
through ecosystems:
-Involve both living(biotic) and nonliving (geologic)
Components.
- Known as bio-geochemical cycle.
• The water Cycle
• Carbon Cycle
• Phosphorus Cycle
• Nitrogen Cycle

22. The Water Cycle
Is the cycle of evaporation and
condensation that controls the
distribution Earth’s water as it
evaporates from the bodies of
water, condenses, precipitates and
returns those bodies of water

23. The Water Cycle

24. The Water Cycle

25. As water travels through the water cycle, some water will become part of The Global
Conveyer Belt and can take up to 1,000 years to complete this global circuit. It
represents in a simple way how ocean currents carry warm surface waters from the
equator toward the poles and moderate global climate.

26. The Water Cycle
The Water Cycle (also known as the
hydrologic cycle) is the journey
water takes as it circulates from the
land to the sky and back again.

27. The Water Cycle
The Sun's heat provides energy to evaporate
water from the Earth's surface (oceans, lakes,
etc.). Plants also lose water to the air (this is
called transpiration). The water vapor
eventually condenses, forming tiny droplets
in clouds. When the clouds meet cool air over
land, precipitation (rain, sleet, or snow) is
triggered, and water returns to the land (or
sea).

28. The Water Cycle
Some of the precipitation soaks into the
ground. Some of the underground water is
trapped between rock or clay layers; this is
called groundwater. But most of the water
flows downhill as runoff (above ground or
underground), eventually returning to the
seas as slightly salty water.

29. Importance of the ocean in the water cycle
Oceans cover about 70% of the Earth's
surface and contain roughly 97% of the
Earth's water supply. Ocean plays a key
role in this vital cycle of water with
holds 97% of the total water on the
planet; 78% of global precipitation
occurs over the ocean, and it is the
source of 86% of global evaporation.

30. WHY ARE THE OCEANS SALTY?
As water flows through rivers, it picks up small
amounts of mineral salts from the rocks and
soil of the river beds. This very-slightly salty
water flows into the oceans and seas. The
water in the oceans only leaves by
evaporating (and the freezing of polar ice),
but the salt remains dissolved in the ocean -
it does not evaporate. So the remaining
water gets saltier and saltier as time passes.

31. The planet is approximately 71% water and contains (5) five
oceans, including the Arctic, Atlantic, Indian, Pacific and
Southern.
Five oceans

32. Importance of Hydrological cycle (water cycle)
Earth is a truly unique in its abundance of
water. Water is necessary to sustaining life on
Earth, and helps tie together the Earth's
lands, oceans, and atmosphere into an
integrated system. Precipitation, evaporation,
freezing and melting and condensation are all
part of the hydrological cycle - a never-ending
global process of water circulation from
clouds to land, to the ocean, and back to the
clouds. Contd.

33. Importance of Hydrological cycle (water cycle)
This cycling of water is intimately linked with
energy exchanges among the atmosphere,
ocean, and land that determine the Earth's
climate and cause much of natural climate
variability. The impacts of climate change and
variability on the quality of human life occur
primarily through changes in the water cycle.
Contd.

34. Importance of Hydrological cycle (water cycle)
The fresh water that we use and its
continuous replacement is a result of
the water cycle. The earth have limited
amount of fresh water and if water that
evaporate never return back to earth,
we would not be living now. One can
live longer without food than without
water.

35. The carbon cycle
Is the bio-geochemical cycle by which
carbon is exchanged among the
biosphere, geo-sphere, hydrosphere&
atmosphere and recycled & reused
throughout the biosphere and all the
organisms.

36. The carbon cycle

37. The carbon cycle

38. The carbon cycle
Carbon is the backbone of life on Earth. We are
made of carbon, we eat carbon, and our
civilizations—our economies, our homes, our
means of transport—are built on carbon. We
need carbon, but that need is also entwined
with one of the most serious problems facing
us today: global climate change.

39. The carbon cycle
Forged in the heart of aging stars, carbon
is the fourth most abundant element in
the Universe. Most of Earth’s carbon—
about 65,500 billion metric tons—is
stored in rocks. The rest is in the ocean,
atmosphere, plants, soil, and fossil
fuels.

40. Carbon Cycle - Photosynthesis
Photosynthesis is a complex series of reactions carried
out by algae, phytoplankton, and the leaves in plants,
which utilize the energy from the sun. The simplified
version of this chemical reaction is to utilize carbon
dioxide molecules from the air and water molecules
and the energy from the sun to produce a simple
sugar such as glucose and oxygen molecules as a by
product. The simple sugars are then converted into
other molecules such as starch, fats, proteins,
enzymes, and DNA/RNA i.e. all of the other molecules
in living plants. All of the "matter/stuff" of a plant
ultimately is produced as a result of this
photosynthesis reaction.

41. Carbon Cycle - Photosynthesis

42. Nitrogen Cycle
Nitrogen is both the most abundant element in
the atmosphere and, as a building block of
proteins and nucleic acids such as DNA, a
crucially important component of all
biological life. The nitrogen cycle is a complex
biogeochemical cycle in which nitrogen is
converted from its inert atmospheric
molecular form (N2) into a form that is useful
in biological processes.

43. Nitrogen Cycle

44. Nitrogen Cycle

45. Nitrogen fixation
Atmospheric nitrogen occurs primarily in an
inert form (N2) that few organisms can use;
therefore it must be converted to an organic -
or fixed - form in a process called nitrogen
fixation. Most atmospheric nitrogen is 'fixed'
through biological processes

46. Nitrification
While ammonia can be used by some plants,
most of the nitrogen taken up by plants is
converted by bacteria from ammonia - which
is highly toxic to many organisms - into nitrite
(NO2-), and then into nitrate (NO3-). This
process is called nitrification, and these
bacteria are known as nitrifying bacteria.

47. Assimilation
Nitrogen compounds in various forms,
such as nitrate, nitrite, ammonia, and
ammonium are taken up from soils by
plants which are then used in the
formation of plant and animal proteins.

48. Ammonification
When plants and animals die, or when animals
emit wastes, the nitrogen in the organic
matter reenters the soil where it is broken
down by other microorganisms, known as
decomposers. This decomposition produces
ammonia which is then available for other
biological processes.

49. Denitrification
Nitrogen makes its way back into the
atmosphere through a process called
denitrification, in which nitrate (NO3-) is
converted back to gaseous nitrogen (N2).
Denitrification occurs primarily in wet soils
where the water makes it difficult for
microorganisms to get oxygen. Under these
conditions, certain organisms - known as
denitrifiying bacteria - will process nitrate to
gain oxygen, leaving free nitrogen gas as a
byproduct.

50. PHOSPHORUS CYCLE

51. Phosphorus enters the environment from rocks
or deposits laid down on the earth many
years ago. The phosphate rock is
commercially available form is called apatite.
Other deposits may be from fossilized bone
or bird droppings called guano

52. Phosphorus Cycle

53. Phosphorus Cycle
When plant materials and waste products
decay through bacterial action, the
phosphate is released and returned to the
environment for reuse.

54. Phosphorus Cycle
Phosphate is incorporated into many
molecules essential for life such as ATP,
adenosine triphosphate, which is
important in the storage and use of
energy. It is also in the backbone of DNA
and RNA which is involved with coding
for genetics.

55. Human Inputs to the Phosphorus Cycle

56. Human Inputs to the Phosphorus
Cycle
Plants may not be able to utilize all of the
phosphate fertilizer applied, as a consequence,
much of it is lost form the land through the
water run-off. Animal wastes or manure may
also be applied to the land as fertilizer. If
misapplied on frozen ground during the winter,
much of it may lost as run-off during the spring
thaw. In certain area very large feed lots of
animals, may result in excessive run-off of
phosphate and nitrate into streams.

57. Human Inputs to the Phosphorus
Cycle
Other human sources of phosphate are in the
out flows from municipal sewage treatment
plants. Without an expensive tertiary
treatment, the phosphate in sewage is not
removed during various treatment
operations. Again an extra amount of
phosphate enters the water.