Material Cycling, Biodegradation, Different cycles of gases and decomposition of living and dead human, animals and plants

1. Saba Shahzadi
AIOU, Islamabad

2.  Ecosystem Functioning
 BiogeochemicalCycles
(carbon, nitrogen, sulfur, phosphorus
and hydrological cycles)

3. What is ecosystem functioning?
An ecosystem is a dynamic complex of plant,
animal and microorganism communities and
their non-living environment interacting as a
functional unit. Ecosystems are not only
important in terms of the species they
contain, but also in terms of the functions
they carry out.

4.  The collective intraspecific and
interspecific interactions of the biota, such
as primary and secondary production and
mutualistic relationships.
 The interactions between organisms and
the physical environment, such
as nutrient cycling, soil
development, water budgeting, and
flammability.

6. In this section, we examine material cycles of nature:
cycles of water, carbon, sulfur, phosphorus and
nitrogen(substances central to maintaining life on
Earth).The material cycles consist of the transfer of
chemicals from biological systems to geological
systems and are therefore called biogeochemical
cycles.
 Processes that affect these transfers are biological
processes such as respiration, transpiration,
photosynthesis, and decomposition, as well as
geological processes such as weathering, soil
formation, and sedimentation.

7.  As materials cycle through, we note that the
total quantity (mass) of matter remains the
same, and energy that is put in changes to
work (often to rearrange forms of matter)
and is eventually lost to the surroundings.

8. There are three main types of biogeochemical
cycles:
 Atmospheric or Gaseous cycles (C , N)
 Sedimentary cycles (P , S )
 Those which act as both Gaseous and
Sedimentary (Hydrological H2O)

10.  All living things are made of carbon. Carbon is
also a part of the ocean, air, and even rocks.
Because the Earth is a dynamic place, carbon
does not stay still. It is on the move!

11.  There are five major steps of carbon cycle :
 Plants remove carbon dioxide from the air.
 When the plants died, they were buried in the
earth.
 After millions of years, their remains turned into
coal and oil.
 People mine the earth for coal and oil, which are
called "fossil fuels".
 When people burn fossil fuels, they send carbon
dioxide and other greenhouse gases into the air.

12. Carbon Cycle

13.  Sulfur is found in every living cell. It's part of
the molecules that form the amino acids
(protein building blocks) methionine ,
cysteine , and taurine, which are essential for
health. It's a constituent of vitamin B1 and
biotin, the antioxidant glutathione, the
anticoagulant heparin, and coenzyme A,
which drives energy production in cells. Sulfur
is an integral part of the biological cement
that forms skin, hair, nails, and the cartilage
that shapes your nose and pads your joints.

14.  There are four steps in the sulfur cycle:
 First, organic sulfur becomes mineralized into
organic hydrogen sulfide, sulfide minerals, and
elemental sulfur.
 Next, the hydrogen sulfide, sulfide minerals,
and elemental sulfur are oxidized into sulfate.
 Third, sulfate is reduced to sulfide.
 Finally, sulfide becomes incorporated into
organic compounds.This cycle represents the
way in which sulfur moves back and forth
between living systems and minerals.

15. Sulfur Cycle

16.  Phosphorus is an essential element to all living
organisms. It is part of our DNA and RNA, and
it forms the molecule ATP, which gives all living
things energy.

17.  There are five major steps involved in
phosphorus cycle:
 1. Phosphate is released by the erosion of rocks.
2. Plants and fungi take up the phosphate with
their roots.
3. Phosphorus moves from producers to
consumers via food chain.
4. Phosphorus may seep into groundwater from
soil, over time forming into rock.
5.When these rocks erode, the cycle begins
again.

18. Phosphorus Cycle

19.  Nitrogen is one of the basic building blocks
for life, and farmers require a steady supply
of nitrogen fertilizers to ensure high-quality
crop growth and yields. Nitrogen production
capacity is relatively accessible due to the
abundant supply of the main raw materials –
natural gas and air.

20. There are five major steps of nitrogen cycle:
 Nitrogen fixation: conversion of atmospheric nitrogen into
ammonia, performed by bacteria in the roots of legumes
or lightning. N2 --> NH3
 Nitrification: conversion of ammonia to nitrite to nitrate
performed by bacteria. NH3 --> NO2 --> NO3-
 Assimilation: inorganic nitrogen is uptaken by the roots of
plants and becomes part of the food chain. NO3- -->
organic nitrogen (proteins and nucleic acids)
 Ammonification: conversion of organic nitrogen into
ammonia. Performed by decomposers (bacteria, fungus)
to return nitrogen to the soil. Organic nitrogen --> NH3
 Dentrification: nitrates are returned to the atmosphere by
anaerobic bacteria. NO3- --> N2

22.  Ammonification: conversion of organic
nitrogen into ammonia. Performed by
decomposers (bacteria, fungus) to return
nitrogen to the soil. Organic nitrogen --> NH3
 Dentrification: nitrates are returned to the
atmosphere by anaerobic bacteria. NO3- -->
N2

24.  With two thirds of the earth's surface covered by
water and the human body consisting of 75
percent of it, it is evidently clear that water is
one of the prime elements responsible for life on
earth.Water circulates through the land just as it
does through the human body, transporting,
dissolving, replenishing nutrients and organic
matter, while carrying away waste material.
Further in the body, it regulates the activities of
fluids, tissues, cells, lymph, blood and glandular
secretions.

26. There are 5 steps in the water cycles:
 Evaporation :(the process of water converting to
water vapor using heat.),
 Condensation: (the vapor cools and form
droplets of water),
 Precipitation: (water falls back to Earth as rain,
snow, etc.)
 Run off: (water stays on the surface of the
Earth.)
 Percolation: ( when water on the surface seeps
into the Earth.

27. Hydrological Cycle