307 – Abstarct
Paper Nº: 307
Oral
3c. Secuestro de Carbono y Emisión de Gases Causantes de Efecto Invernadero / Greenhouse Gas
Emissions and Soil Carbon Sequestration
ASSESSMENT OF THE CARBON STORED IN THE TROPICAL SOILS OF SOUTHEASTERN MÉXICO
Diana Uresti Durán1 Héctor Daniel Inurreta Aguirre2 Jesús Uresti Gil3 Roberto de Jesús López Escudero4
1Instituto
Nacional de Investigaciones Forestales, Agrícolas y Pecuarias. Km. 34.5 Carretera Federal
Veracruz-Córdoba, Medellín de Bravo, Veracruz. e-mail: uresti.diana@inifap.gob.mx
2Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias. Km. 34.5 Carretera Federal
Veracruz-Córdoba, Medellín de Bravo, Veracruz. e-mail: inurreta.hector@inifap.gob.mx
3Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias. Km. 34.5 Carretera Federal
Veracruz-Córdoba, Medellín de Bravo, Veracruz. e-mail: uresti.jesus@inifap.gob.mx
4Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias. Km. 34.5 Carretera Federal
Veracruz-Córdoba, Medellín de Bravo, Veracruz. e-mail: lopez.roberto@inifap.gob.mx
Abstract:
The emission of CO2 into the atmosphere from human activities has caused its concentration to increase from
272 to 396 ppm this century, with the consequent increase of air temperature that will impact negatively on all
sectors of society. To mitigate global warming, it is necessary to reduce emissions of CO2 and to reduce its
concentration in the atmosphere through carbon sequestration. Globally, in the agricultural sector the emission
and sequestration of carbon are in balance, mainly, due to the high potential of soils to store carbon, which
accounts for more than 90%. The objective was to assess the amount of carbon stored in the tropical soils of
southeastern México. From the soil maps, scale 1:250,000, published by the Instituto Nacional de Estadística
Geografía e Informática (INEGI) covering all southeastern México; and with the support of a Geographical
Information System, 94 sub-units of soil (FAO classification) were identified and their surface area was
quantified. Each soil was characterized considering the presence of typical horizons, their thickness (and
therefore the soil depth), sand, silt, clay and organic matter content. These data were obtained from the
analytical data of 1143 soil profiles description reported by INEGI along with the soil maps. Bulk density was
estimated from soil texture. With this information, the mass of organic carbon contained in the unit volume of a
particular soil was estimated. Then, taking into account the total area or total volume of that particular soil, the
total carbon stored was estimate. This operation was repeated for the 94 soils. Results are presented and
discussed in terms of total mass of carbon stored by each soil, carbon distribution along the soil profile,
implication of land use (from soil and land use maps analysis) to carbon store and total carbon stored in the
soils
of
southeas
tern
México.
Keywords: Climate Change, Green House Gases, Carbon mitigation potential, Land use, soil description
INTRODUCTION
The Intergovernmental Panel for the Climatic Change in/at its fourth report published in 2007 confirms that the
global warming of the earth is a fact due to human causes (Solomon, et al., 2007). The increase in population,
the burning of fossil fuels for energy supply and use, agriculture, deforestation and changing land use for food
production, forestry and urbanization, are the main instigators/drivers of the emission of the main greenhouse
gas (GHG): carbon dioxide (CO2), methane (CH4) and nitrous oxide (N20). Globally, from 1970 to 2004 GHG
emissions increased from 28.7 to 49 GtCO2-eq of which/whom 77% were mainly CO2 from burning fossil fuels
and deforestation and the remaining 23% corresponded mainly to CH4 and N2O mostly from the agricultural
sector.
In 2004 26% of GHG emissions originated in the activities for the energy supply, 19% in the industry, 17% in
forestry and Iand use, 14% in agriculture, 13% in the sector transports, 8% in the residential, commercial and
services and 3% of residuals and garbage (Barker et to the., 2007).In Mexico, according to INE (2002), in that
year 24% of GHG emissions originated in the activities for the supply of energy, industry 22%, 18% in transport
sector, 14% in forestry and change in land use, agriculture 7%, 5% in residential and commercial and 10%
in residuals and garbage. Mexico contributes with 1.45% of total carbon emissions that occur on our planet
every year (IPCC, 1995).National GHG emissions by CO2 gas equivalents were as follows: 480,409 Gg (74%)
were CO2, 145,586 Gg (23%) to CH4, 12,343 Gg (2%) were of N2O and the remaining 4,845 Gg (1%)
corresponded to gases HFC, PFC and SF6.
Globally, in 2005 GHG emissions from the agricultural sector were of 6.1 GtCO2-eq, of which 3.3 GtCO2-eq
corresponded to CH4 and 2.8 GtCO2-eq to N2O.In agriculture, although the exchange of CO2 between the
atmosphere and the biosphere (soil-vegetation-crops) it is of great magnitude/large, an annual balance exists
between emission and carbon sequestration, so that in this sector the emissions of CO 2 only
corresponded/were 0.04 GtCO2-eq (Smith, 2007).
In the terrestrial ecosystem the biggest carbon stock corresponds to soil organic carbon 1.550 Pg C (Batjes,
1996 and Eswaran, 1993).The future development of CO2 emissions in the agricultural sector is uncertain,
however, the scientific community (Wright, 2001; Bellarby et al., 2008) consider that agricultural ecosystems
have potential, mainly in the soils to almost mitigate 100% of direct CO 2 emissions originated in the agriculture
and to contribute significantly to reduce the global warming.
To estimate the potential of agriculture to sequester atmospheric carbon, one of the main activities to be
performed is the evaluation of carbon sequestration in soils, due to the great capacity to sequestration
(Johnson, 1992) because it can accumulate thousands of years (Schlesinger, 1990).
The objective of this study/work was to identify and assess the amount of carbon stored in soils of southeast of
Mexico.
METHODOLOGY
Used the INEGI soil map of 1:250,000 scale with a Lambert conical projection, which uses the UNESCO-FAO
classification. In this map, the soils were separated presenting lytic phase, due to its characteristics differ
from soil without limiting depth. Whereas this is formed a total of 100 subunits, which are shown in
Table T1 with the respective soil area. Their distribution is shown in Figure F1.
Table T1. – Sub-units of soil present in the watershed for the Humid Tropics of Mexico.
Abreviación
Suelo
Abreviación
Suelo
Ah
Acrisol humico
Hh
Feozem haplico
Ah(L)
Acrisol húmico fase
litica
Hh(L)
Feozem haplico
fase litica
Ao
Acrisol ortico
Hl
Feozem luvico
Ao(L)
Acrisol ortico fase
litica
Hl(L)
Feozem luvico
I
Litosol
Ap
Acrisol plintico
Jc
Fluvisol calcarico
Bc
Cambisol cromico
Cambisol cromico
fase litica
Jd
Fluvisol districo
Bc(L)
Je
Fluvisol eutrico
Bd
Cambiso districo
Jg
Fluvisol gleyico
Bd(L)
Cambiso districo
fase litica
Kh
Castañozem haplico
Be
Cambisol eutrico
Cambisol eutrico
fase litica
Kh(L)
Be(L)
Castañozem
haplicom fase litica
Bf
Cambisol ferralico
Bg
Abreviación
Suelo
Rc(L)
Regosol calcarico
fase litica
Rd
Regosol districo
Rd(L)
Regosol districo
fase litica
Re
Regosol eutrico
Re(L)
Regosol eutrico
fase litica
Th
Andosol humico
Th(L)
Andosol húmico
fase litica
Tm
Andosol molico
Tm(L)
Andosol molico
fase litica
To
Andosol ocrico
To(L)
Andosol ocrico fase
litica
Andosol vitrico fase
litica
Kk
Castañozem calcico
Cambisol gleyico
Kk(L)
Castañozem cálcico
fase litica
Tv(L)
Bh
Cambisol humico
Kl
Castañozem luvico
U
Ranker
Bh(L)
Cambisol húmico
fase litica
La
Luvisol albico
Vc
Vertisol cromico
Bk
Cambisol calcico
Lc
Luvisol cromico
Vc(L)
Vertisol cromico
fase litica
Bk(L)
Cambisol cálcico
fase litica
Lc(L)
Luvisol cromico
fase litica
Vp
Vertisol pelico
Lf
Luvisol ferrico
Vp(L)
Lg
Luvisol gleyco
Vertisol pelico fase
litica
Lk
Luvisol calcico
We
Planosol eutrico
We(L)
Planosol eutrico
fase litica
Wh
Planosol humico
Wm
Planosol molico
Wm(L)
Planosol molico
fase litica
Xg
Xerosol gypsico
Xh
Xerosol haplico
Xh(L)
Xerosol haplico
fase litica
Xk
Xerosol calcico
Xk(L)
Xerosol cálcico fase
litica
Bv
Bv(L)
Cambisol vertico
Cambisol vertico
fase litica
Lk(L)
Luvisol cálcico fase
litica
Lo
Luvisol ortico
Gleysol eutrico
Lo(L)
Ge(L)
Gleysol eutrico
fase litica
Luvisol ortico fase
litica
Lp
Luvisol plintico
Gh
Gleysol humico
Lv
Luvisol vertico
Gm
Gleysol molico
Lv(L)
Gm(L)
Gleysol molico fase
litica
Luvisol vertico fase
litica
Nd
Nitosol districo
Gp
Gleysol plintico
Ne
Nitosol eutrico
Gv
Gleysol vertico
Ne(L)
Zg
Solonchak gleyico
Gv(L)
Gleysol vertico fase
lítica
Nitosol eutrico fase
litica
Oe
Histosol eutrico
Zm
Solonchak molico
Hc
Feozem calcarico
Oe(L)
Zo
Solonchak ortico
Hc(L)
Feozem calcarico
fase lítica
Histosol eutrico
fase litica
Qc
Arenosol cambico
Zo(L)
Solonchak ortico
fase litica
Hg
Feozem gleyico
Rc
Regosol calcarico
Zt
Solonchak takirico
Ck
Chernozem calcico
E
Rendzina
Gc
Gleysol calcarico
Ge
Figure F1. - Map pedological watershed for the Humid Tropics of Mexico.
Soil Map
Sub-units
Legend
µ
of soil
Ah
Be
Bv(L)
Gp
Hl(L)
Kk
Lk(L)
Oe
Th
Vc(L)
Xh
Ah(L)
Be(L)
Ck
Gv
I
Kk(L)
Lo
Oe(L)
Th(L)
Vp
Xh(L)
Ao
Bf
E
Gv(L)
Jc
Kl
Lo(L)
Qc
Tm
Vp(L)
Xk
Ao(L)
Bg
Gc
Hc
Jd
La
Lp
Rc
Tm(L)
We
Xk(L)
Ap
Bh
Ge
Hc(L)
Je
Lc
Lv
Rc(L)
To
We(L)
Xl(L)
Bc
Bh(L)
Ge(L)
Hg
Je(L)
Lc(L)
Lv(L)
Rd
To(L)
Wh
Zg
Bc(L)
Bk
Gh
Hh
Jg
Lf
Nd
Rd(L)
Tv(L)
Wm
Zm
Bd
Bk(L)
Gm
Hh(L)
Kh
Lg
Ne
Re
U(L)
Wm(L)
Zo
Bd(L)
Bv
Gm(L)
Hl
Kh(L)
Lk
Ne(L)
Re(L)
Vc
Xg
Zo(L)
Zt
To characterize the soils, used a database from INEGI, which consists of 1143 wells agrological with analytical
data by soil horizon, between these information include: a) subunit of soil to which it belongs; b) the presence
of physical or chemical phases, c) depth d) texture, percentage of silt clay and sand; e) the amount of organic
matter (OM).The ubication of the agrological Wells is shown in figure F2.
Figure F2. - Location of wells used to characterize soils.
Map of wells
µ
Using
this
information
proceeded
to
characterize
100 soil
subunits according
to
the
information to corresponding agrological wells. First created the typical profile of each subunit complementing
the wells information with the description of each subunit. Due to the high variation in types of horizon in
different wells belonging to the same subunit, it was necessary to unify them according to their
characteristics to match those included in the typical profile of this subunit. Within the same wells were added
the equivalent depths of the horizons and averaged values of OM content and percentage of silt, clay and
sand.
Then calculated the average value of depth,organic matter content and percentage of silt, clay and sand for
each horizon of each subunit. The bulk density was calculated using the texture, according
to Saxton et al. (1986) and the software available on http://www.pedosphere.com. The content of organic
carbon (OC) was calculated using the formula CO = 1.75 MO-1 as reported by Neitsch, (2005). Obtaining
information for each soil type, as shown for example in Table C2 Ah, Vp, Bc and I.
Table T2. - Typical profile and soil characteristics Ah, Vp, Bc and I.
Soil
Ah
Horizon
Actual depth
(cm)
OM
(%)
Texture
(% of Clay-Silt-Sand)
Bulk Density
-3
(tm )
Organic Carbon
(%)
A
160.00
10.39
(27-27-47)
1.38
6.04
B1
30.00
4.27
(38-23-39)
1.31
2.48
B2t
705.00
1.84
(44-22-44)
1.28
1.07
A
164.76
7.43
(24-25-51)
1.40
4.32
B1
63.02
3.32
(27-18-55)
1.39
1.93
B2
295.08
2.13
(28-21-51)
1.38
1.24
I
A
Ap
73.80
20.36
(22-26-52)
1.42
11.84
645.20
3.18
(44-21-36)
1.26
1.85
Vp
A1
245.00
4.71
(49-21-31)
1.28
2.74
C
496.00
1.17
(47-22-31)
1.27
0.68
Bc
Using the depth of each horizon and the area occupied by each subunit of soil volume was calculated by
horizon in the basins of the humid tropics. Then the mass was calculated using the bulk density, to
finally calculate the content of CO with the percentage of this calculated from the percentage of MO. The
information was grouped by horizon for each soil subunit.
Cartographically soils were grouped into five intervals according to the amount of stored CO, contrasting the
resulting
map with
the
map
ofcurrent
land
use (CONABIO scale 1:250,000)which were
grouped in different land uses: a) agricultural, b) grassland, c) forests and jungles, d) cities and water
bodies. Was calculated for each interaction surface.
RESULTS
The following table shows the results of stored carbon for soil subunit.
Table T3. - The amount of CO storage in soil subunit.
Soil
Area
(ha)
Total
carbon(Mt)
Soil
Area
(ha)
667.6
Rc(L)
917,147
144.9
2,082,384
327.1
Rd
177,248
34.5
248,894
56.9
Rd(L)
129,776
11.3
Re
2,138,312
280.5
Re(L)
6,156,388
649.8
1,196,469
1476.4
127,899
14.8
45,781
18.4
1,111,680
140.4
Ao(L)
327,410
24.7
Hl(L)
Ap
188,140
36.0
I
Bc
604,053
100.9
Jc
Hl
163,517
32.7
11,206,804
1390.5
45,754
1.1
Th
Th(L)
1,073,117
172.3
Jd
8,886
0.8
Bd
255,055
92.2
Je
217,518
19.6
Tm
Bd(L)
371,033
49.6
Jg
69,094
12.7
Tm(L)
1,329,679
249.1
Kh
36,712
23.8
To
Be(L)
771,259
98.7
Kh(L)
Bf
125,980
14.9
Kk
Bg
100,562
19.7
Kk(L)
Bh
78,226
32.7
Kl
86,316
18.2
La
428,420
89.0
Lc
Bc(L)
Be
Bh(L)
Bk
Total
carbon(Mt)
2,025,720
65.7
Ao
Soil
Hh(L)
321.9
681,630
Ah(L)
Total
carbon(Mt)
Hh
1,343,127
Ah
Area
(ha)
4,990
0.8
513,105
167.9
8,417
2.7
To(L)
55,382
0.6
92,584
21.7
Tv(L)
1,063
0.3
2,727
0.3
U
4,320
0.5
43,201
9.6
Vc
493,596
74.6
5,719
1.1
Vc(L)
1,898,317
576.8
Vp
Vp(L)
17,294
2.8
4,404,615
1229.6
268,627
33.9
17,454
1.5
7,843
0.6
62,793
7.2
Lc(L)
953,639
179.3
268,760
44.5
Lf
142,792
47.7
Bv(L)
23,547
1.9
Lg
27,051
4.0
We(L)
Ck
44,132
11.2
Lk
30,083
7.5
Wh
489
0.0
9,658,941
2759.6
1,227
0.1
Wm
37,150
2.9
Gc
10,029
1.2
Lo
728,218
138.7
Wm(L)
19,745
0.9
Ge
922,196
226.3
Lo(L)
217,663
78.1
Xg
60,521
4.6
3,067
0.5
Lp
157,814
44.0
Xh
81,426
5.0
Gh
33,593
4.7
Lv
89,130
13.8
Xh(L)
23
0.0
Gm
356,662
89.4
240,659
58.4
Xk
52,375
8.7
9,819
3.0
Nd
75,699
26.9
Xk(L)
Gp
122,050
21.0
Ne
568,540
99.7
Zg
Gv
2,680,074
648.3
5,003
0.9
Hc
408,558
Hc(L)
Bk(L)
Bv
E
Ge(L)
Gm(L)
Gv(L)
Hg
Lk(L)
Lv(L)
We
1,581
0.2
306,493
62.1
2,023
0.4
Zm
50,831
27.1
Oe
63,100
281.0
Zo
201,723
41.4
93.6
Oe(L)
17,840
26.6
Zo(L)
5,629
1.1
154,608
15.0
Qc
179,122
15.0
Zt
719
0.1
Rc
756,991
122.3
Ne(L)
TOTAL
12,701
0.6
63,556,071
14,041
Table T4. - Subclasses of soils grouped by depth.
Soils
Shallow
Ao(L), Bc(L), E, Gm(L), Hc(L), I, Jc, Kh(L), Lk(L), Th(L), To(L), Xh(L),
Zo(L),
Medium
Ah(L), Bc, Bd(L), Be(L), Bf, Bh(L), Bk(L), Bv(L), Gv(L), Hh(L), Hl(L), Jg,
Kk(L), Lc(L), Lo(L), Lv(L), Ne(L), Oe(L), Rc, Rc(L), Rd(L), Re(L), Tm(L),
Tv(L), U, Vc(L), Vp(L), We(L), Wh, Wm(L), Xh, Zg, Zm, Zo,
Deep
Ah, Ao, Ap, Bd, Be, Bg, Bh, Bk, Bv, Ck, Gc, Ge, Ge(L), Gh, Gm, Gp,
Gv, Hc, Hg, Hh, Hl, Jd, Je, Kh, Kk, Kl, La, Lc, Lf, Lg, Lk, Lo, Lp, Lv, Nd,
Ne, Oe, Qc, Rd, Re, Th, Tm, To, Vc, Vp, We, Wm, Xg, Xk, Xk(L), Zt
Surface (ha)
Average
depth (cm)
22,675,029.03
19
15,406,305.30
46
25,462,035.72
109
Figure F3. - Classification of the subunits by depth in the Humid Tropics.
Sub-units classification by depth
Legend
Shallow
Medium
Deep
µ
The following table shows the amount of carbon stored in soil subunit
Table T5. - Area in hectares of the various interactions between CO amount stored and current land use.
Agricultural
Forests and
jungles
Grassland
Others
3,876,586
16,070,447
3,099,361
1,274,416
Cities and
Wáter bodies
109,764
Low-Medium
6,413,197
16,297,666
7,222,487
2,261,848
182,501
Medium
1,724,796
2,477,518
871,081
220,288
61,715
424,629
621,498
154,689
8,479
5,093
3,495
27,780
753
30,003
854
12,442,703
35,494,909
11,348,370
3,795,033
359,928
Clasification by amount of
organic carbon stored
Low
Medium-High
High
TOTAL
The implications of climate change are many but the exact scenarios are still uncertain, negative effects are
expected, so it is essential that measures be taken to reduce emissions of greenhouse gases and to increase
their sequestration in soils and biomass. One option is based on carbon sequestration in soils or terrestrial
biomass, particularly on lands used for agriculture or forestry. The amount of carbon stored in soils of
southeastern Mexico, tables provide data on forests and jungles that is where the greatest amount of organic
carbon stored. Forests have the potential to mitigate greenhouse gases through carbon sequestration,
(Masera, 1996 and Ordoñez, 1999) trees assimilate and store large amounts of carbonfor life. The world's
forests capture and retain more carbon than any other terrestrial ecosystem and participate with 90% of the
annual flow of carbon between the atmosphere and land surface (Apps, 1993, Brown, 1993; Dixon, 1994).
Figure F4. - The amount of CO stored in soils of the basins of the humid tropics.
Legend
Soil
carbon storage (t ha-1)
0 - 1393 (Low)
1394 - 2857 (Low-medium)
2858 - 6483 (Medium)
6484 - 14888 (Medium-high)
14889 - 44526 (High)
µ
CONCLUSIONS
Carbon sequestration appears as a proposal that attempts to reduce the rates of releaseof CO2 into
the atmosphere, environmental consequences generated impacts to soil resources, water and atmosphere and
increase the economic and social problems. Because carbon sequestration in agricultural soils is opposed to
the process of desertification through the increased role of organic matter on the stability of the structureresistance to wind and water erosion. Carbon capture us in the long run will contribute directly to the climate
change.
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