Thesis Seminar

1. Presenter:
Subhasis satapathy
Roll no. – 20875
Division of soil science and agricultural
chemistry
ICAR-IARI, New Delhi

2. Contents
Introduction
Different carbon pool
Climate change & soil carbon dynamics
Impacts of climate change
Future prediction
Mitigation measures
Conclusion
Path ahead

3. What is climate change ?
Climate change refers to
Change in the state of the climate which can be identified by
changes in the mean and/or variability of it’s properties
That change persists for an extended period, typically decades or
longer
It may be due to natural variability or as a result of human activity
Climate change is having and will continue to have, fundamental
impacts on the natural environment and on human well-being
IPCC (2007)
Parry et al. (2007)

4. Terms we frequently come across
studying climate change
Climatic extremes:
• In climatic extreme the occurrence of a
value of a climate variable above or
below the threshold value.
• Near the upper (or lower) ends of the
range of observed values
Many biological systems (including human societies) are more sensitive to
climate extremes than to gradual climate change, due to typically greater
response strengths and shorter response times
Hanson et al. (2006)

5. World soil constitute 3rd largest global
C pool
Different C pools Amount (Pg )
Ocean 38,100
Soil (1 m depth)
• SOC(soil organic carbon)
• SIC(soil inorganic carbon)
1550
950
Vegetation 610
Atmosphere 760
Fossil fuels 4130
Hillel (2011)
Lal (2008) Percentage of carbon pools

6. Organic carbon pool in soils of India
and the world
Soil order
India world
0-30 cm 0-150 cm 0-25 cm 0-100 cm
Alfisols 4.22 13.54 73 136
Andisols - - 38 69
Aridisols 7.67 20.30 57 110
Entisols 1.36 4.17 37 106
Histosols - - 26 390
Inceptisols 4.67 15.07 162 267
Mollisols 0.12 0.50 41 72
Oxisols 0.19 0.49 88 150
Spodosols - - 39 98
Ultisols 0.14 0.34 74 101
Vertisols 2.62 8.78 17 38
Total 20.99 63.19 652 1555
Lal (2004)

7. Intersection between different
carbon pools
Lal (2006)

8. Factors controlling the main inputs and
outputs of soil carbon stocks
Davidson and janssens (2006)

9. Contribution of soil organic carbon at
different ecosystem
Scharlemann et al. (2014)
Above- and below-ground biomass
Sub- and topsoil
400
300
200
100
0
100
200
Above- and below-ground biomass
Sub- and topsoil
400
300
200
100
0
100
200

10. Climate change & organic carbon
dynamics
SOIL ORGANIC
CARBON
QUALITATIVE
CHANGE
QUANTITATIVE
CHANGE
D.Frank et al. (2015)

11. How climate change affects SOC
quantity and quality…
Quantitative change :
1.Stock
2.Concentration
Qualitative change :
1.C/N ratio
2.Functional group
3.Acidity
D.Frank et al. (2015)

12. Elevated CO2 and SOC dynamics
Carbon storage in soil increases due to
increased input and higher residence times
Plant residues decompose slower
Carbon input into the soil increases,
and its quality alters
A shift occurs in the carbon distribution
within the plant/soil system
Net carbon uptake increases
Elevated CO2
Hypothesis I
Hypothesis II
Hypothesis III
Hypothesis IV
Gorissen (1996)

13. Experiment Species
CO2 (ppm) Increase
(%)
Condition
350 700
1
Triticum
aestivum
(N=3)
Total 7.4 11.2 +51
35 daysShoot 5.0 7.7 +54
Root 2.4 3.5 +46
2
Lalium
perenne
(N=6)
Total 11.9 13.5 +13
No N
Limitation
Shoot 8.1 7.9 -2
Root 3.9 5.6 +44
3
Lalium perene
(N=3)
Total 18.0 29.1 +62
No N
Limitation
Shoot 10.5 10.9 +4
Root 7.5 18.2 +143
4
Pseudotsuga
Menziesii
(N=6)
Total 29.4 39.2 +33
3 years
Old
Shoot 17.9 22.1 +23
Root 11.5 17.1 +49
Increase in plant dry matter production
due to doubling of atmospheric CO2
Gorissen (1996)

14. Fertilization effect of CO2 on plant
growth
Elevated atmospheric CO2 caused increase in yield and carbon uptake by all plant
parts at different stages of growth and their preferential partitioning to root.
Kant et al. (2006)

15. Experiment
Plant
Incubation
Period
CO2 (ppm) Increase
(%)
Condition
350 700
Ryegrass
(Lolium
perenne)
64 days
31.2 21.2 -32 T =𝟏𝟒 𝟎
C
40.3 27.7 -31 T = 𝟐𝟎 𝟎 C
Ryegrass
(Lolium
perenne
1 season
64.7 46.7 -28 Low nitrogen
51.6 47.3 -8 High nitrogen
2 season
70.5 61.0 -13 Low nitrogen
64.6 62.1 -4 High nitrogen
%age mass loss of added root material
of grass roots found in plant
decomposition study
Gorissen (1996)

16. Impacts of elevated CO2 on crop
residue
• Elevated CO2 produces huge amount of
residues & also decreases decomposition
rate
• Elevated CO2 decreases the quality of
residue by decreasing the N content in
biomass
• As lower N content in residue impact
lower N mineralization might increase the
dependency of crops towards fertilizer N
Vishwanath et al. (2010)

17. NMR (Relative quantitative
indicator of overall SOM
composition & sources)
𝑪 𝟏𝟑 solid state NMR (non destructive analysis
of whole soil, may not be source specific,
provides overview of SOM structure)
Solution state NMR(more detailed structure)
SOM biomarkers
(Quantification of SOM
sources and stage of
degradation)
Solvent extraction (isolate free SOM
components,
Provides source & stage of SOM degradation)
Base hydrolysis
(provides information about cuticle & suberine
derived SOM)
CuO oxidation (Provides information about
lignin source & stage of oxidation )
PLFA (provides information about active
microbial community composition)
Visualizing impact of climate change on
SOC dynamics
Feng and Simpson (2011)

18. Different types of impacts of climate
extremes and corresponding extreme
ecosystem responses
D.Frank et al. (2015)

19. Effects of climate extremes and
ecosystem carbon recovery & balance
D.Frank et al. (2015)

20. D.Frank et al. (2015)
Impacts of climate extremes on ecosystem
carbon dynamics

21. D.Frank et.al. (2015)
Global distribution of different climatic
extremes & their average reduction in gross
carbon uptake compared to a normal year

22. Reichstein et al. (2013)
Overview of how carbon flows may be
triggered, or greatly altered, by extreme
events

23. Reichstein et al. (2013)
Processes and feedbacks triggered by
extreme climate events

24. Decreasing O3 and rising UV-B exposure and
SOC dynamics
Plant tissue
chemistry and
structure
Phenolic/lignin
Cuticles features
C:N
Leaf size/thickness
Other environmental
factors
PAR, Temperature, CO2,
Rainfall
UV exposure on litter
Latitude, elevation, slope,
seasonality, canopy cover,
standing vs detaching
litter, litter depth soil
cover
Litter biotic process
Microbial growth and
activity
Microbial community
Litter abiotic process
Photochemical
mineralization
Litter decomposition, Nutrient cycling, C storage
Bornman et al. (2015)

25. Q10 value & arhenius equation
 Q10 of SOM decomposition is 2 .
 But Arrhenius noticed it is only increases by about 1.5% for every 10 degree
rise in temperature.
 Arrhenius equation
K= A exp(-Ea/RT).
 The term exp(-Ea/RT) determines the fraction of the molecules present with
energies equal to or in excess of the required activation energy.
 The Arrhenius function also shows that reactants with higher activation
energies (that is less reactive and more recalcitrant) should have higher
temperature sensitivities.
 For example, in a temperate ecosystem and under current climate conditions,
the annual decomposition of glucose (Ea = 30 kJ/mol ) would proceed 6.5
million times faster than annual decomposition of a tannin compound with an
Ea of about 70 kJ/mol (assuming equal and unlimited pool sizes).

26. Rising temperature and SOC dynamics
Carbon quality-temperature (CQT)
hypothesis predicts that the temperature
sensitivity of SOM decomposition increases
with biochemical recalcitrance.
Davidson and Janssens (2006)

27. Study of beetle attack impacts on
carbon stock
Kurtz et.al.(2008)

28. Net exchange of C (in Tg C) between the soil
and atmosphere as a result of accelerated
erosion
Kristof Van Oost et al.(2012)

29. Relations of erosion & carbon loss at a
period of 4000BC to 2000AD
Kristof Van Oost et al.(2012)

30. Soil erosion and organic carbon export
by wet snow avalanche
Most organic carbon content is contained in the size fraction < 2 mm
that we largely attribute to soil erosion .
Korup and Rixen (2014)

31. Shifting rainfall pattern and SOC dynamics
Quantity Quality
Impact of shifting rainfall pattern on SOC dynamics in a cold desert (11 years study)
Anderud et al. (2010)

32. Anthropogenic CO2 emissions from 1750-2000
and from six marker SRES scenarios from
2000 to 2100
Matthews et al.(2005)

33. The three A1 groups are distinguished by their technological emphasis such as rapid
economic growth FOR A more integrated world .
A1FI = an emphasis on fossil fuels (fossil intensive).
A1b = a balanced emphasis on all energy sources.
A1t = emphasis on nonfossil energy sources.
The A2 scenario is primarily regionally oriented i.e. more divided world. And per capita
economic growth and technological change are more fragmented and slower than in other
storylines.
A world of independently operating, self reliant nations.
Continuously increasing population.
The B1 storyline is related to the introduction of clean and resource-efficient technologies.
An emphasis on global solutions to economic, social and environmental stability
The B2 storyline and scenario family describes a world in which the emphasis is on local
solutions to economic, social, and environmental sustainability.
Continuously increasing population, but at a slower rate than in A2.
Different SRES scenarios:
IPCC,2007

34. Carbon pool Global estimates
of size (Pg)
Potential loss by 2100 due to
global warming (Pg)
Upland soil (3m depth) 2300 -
Simulated upland soil
(litter layer) 200 30
Simulated upland soil
(mineral layer to 1m depth)
Annually cycling 20 3
Decadally cycling 700 40
Millennially cycling 100 0
Peatlands (3m depth) 400-500 100
Permafrost (3m depth) 400 100
Davidson & Janssen (2006)
Sizes and vulnerabilities of belowground
carbon stock

35. Impacts of climate change on
agriculture production
 In some areas, warming may benefit the types
of crops that are typically planted there, or
allow farmers to shift to crops that are
currently grown in warmer areas. Conversely,
if the higher temperature exceeds a crop's
optimum temperature, yields will decline
 Elevated CO2 levels can increase plant growth .
but elevated CO2 has been associated with
reduced protein and nitrogen content in alfalfa
and soybean plants, resulting in a loss of
quality.
 Many weeds, pests, and fungi thrive under
warmer temperatures, wetter climates, and
increased CO2 levels. Human health is also
threatened by increased pesticide use due to
increased pest pressures and reductions in the
efficacy of pesticides.
USEPA

36. Technological options for adapting to and
mitigating atmospheric abundance of CO2
Lal (2008)

37. Different technological strategy for carbon
sequestration
Lal(2008)

38. Conclusion
Carbon content in soil is about twice as large as that of in the atmosphere and
about three times that in the vegetation.
Not all climate extremes cause extreme impacts in soil carbon stock, but they can
have indirect/direct and/or immediate/lagged effects.
Not all terrestrial carbon cycle extremes are propagated immediately into the
atmosphere.
Elevated atmospheric CO2 grown crop residue quality will be decreased due to
lowering of N content thereby widening of C:N ratio , which lower N
mineralization & might increase the dependency of crops towards fertilizer N.
The goal of mitigation strategies to enhance C sink capacity of soil and vegetation,
and reduce the net anthropogenic emissions.

39. Path ahead…….
How climate change affects symbiosis & symbiotic organisms as well as
biological nitrogen fixation ?
How can we reduce GHG gas emission from different cropping system especially
rice cropping ?
How climate change affects nutrient availability w.r.t. macronutrient & different
essential micronutrient ?
What degree of effects climate change impact on microbe-microbe (or) plant
microbial interactions with relevant for ecosystem functioning ?
How thawing of permafrost impacts on mineralization of nutrients & seasonal
productivity ?
Future experiments should address lagged effects more consistently , as well as
ecosystem response to multiple subsequent climate extremes & its impact on
plant-soil interaction & soil processes.

40. Thank