Research Article Partitioning Carbon Dioxide Emission and...

Research ArticlePartitioning Carbon Dioxide Emission and Assessing DissolvedOrganic Carbon Leaching of a Drained Peatland Cultivated withPineapple at Saratok Malaysia

Liza Nuriati Lim Kim Choo12 and Osumanu Haruna Ahmed1

1 Department of Crop Science Faculty of Agriculture and Food Science Universiti Putra Malaysia (UPM) Bintulu CampusPO Box 39697008 Bintulu Sarawak Malaysia

2 Soil and Water Management Programme Strategic Resource Research Centre Malaysian Agricultural Research andDevelopment Institute (MARDI) PO Box 59 Roban 95300 Saratok Sarawak Malaysia

Correspondence should be addressed to Osumanu Haruna Ahmed osumanuupmedumy

Received 31 May 2014 Revised 8 July 2014 Accepted 28 July 2014 Published 19 August 2014

Academic Editor Antonio Paz Gonzalez

Copyright copy 2014 L N Lim Kim Choo and O H Ahmed This is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

Pineapples (Ananas comosus (L) Merr) cultivation on drained peats could affect the release of carbon dioxide (CO2) into the

atmosphere and also the leaching of dissolved organic carbon (DOC) Carbon dioxide emission needs to be partitioned beforedeciding onwhether cultivated peat is net sink or net source of carbon Partitioning of CO

2emission into root respirationmicrobial

respiration and oxidative peat decomposition was achieved using a lysimeter experiment with three treatments peat soil cultivatedwith pineapple bare peat soil and bare peat soil fumigated with chloroform Drainage water leached from cultivated peat and barepeat soil was also analyzed for DOC On a yearly basis CO

2emissions were higher under bare peat (2188 t CO

2hayr) than under

bare peat treated with chloroform (205 t CO2hayr) and they were the lowest (1796 t CO

2hayr) under cultivated peat Decreasing

CO2emissions under pineapple were attributed to the positive effects of photosynthesis and soil autotrophic activities An average

2357mgL loss of DOC under bare peat suggests rapid decline of peat organic carbon through heterotrophic respiration and peatdecomposition Soil CO

2emission depended on moderate temperature fluctuations but it was not affected by soil moisture

1 Introduction

Tropical peat soils are generally defined as soils formed bythe accumulation of partially decayed woody plant materialsunder waterlogged condition Tropical peatlands cover 271million hectares in Southeast Asia [1] and about 26 millionhectares in Malaysia [2] Peats of the tropics are increas-ingly being cultivated Although they store large amount oforganic carbon peat soils drained for agriculture in particularaccelerate their decomposition rates Rapid decomposition ofpeats leads to increase in CO

2release into the atmosphere

[3 4] Carbon dioxidemay be emitted from peatland throughburning by wildfires microbial respiration root respirationand physical oxidation [5 6] Carbon dioxide emissions arerelated to water table depth [7] soil temperature [8 9] ferti-lization [10] land use type [11] and peat type [12] Moreover

carbon in the form of DOC is lost through leaching due tomicrobial metabolism [13] Carbon losses through emissionand leachingmay shift the peatland carbon balance from sinkto source [14]

In Malaysia approximately 600000 hectares of peatlandare cultivated with oil palm pineapple rubber and sago[15] Presently there is scarce information on soil CO

2emis-

sion from pineapple cultivation on drained peat soils Theunderstanding of the contribution of pineapple cultivation onpeats to the greenhouse gas emission is important as 90 ofpineapples are grown on peat soils ofMalaysia [16] Althoughattempts have been made to measure CO

2emission from

cultivated tropical peats such studies are limited to a fewmeasurements The recent measurements only account fortotal soil CO

2emission as they do not partition soil respira-

tion into root respirationmicrobial respiration and oxidative

Hindawi Publishing Corporatione Scientific World JournalVolume 2014 Article ID 906021 9 pageshttpdxdoiorg1011552014906021

2 The Scientific World Journal

peat decomposition [10 17] With the growing concern aboutthe effects of greenhouse gases on the environmental qualitycoupled with the need to achieve sustainable agriculture itis essential to partition CO

2emission before deciding on

whether cultivated or degraded soils are net sinks or netsources of atmospheric greenhouse gases [5] Accounting forCO2emission from cultivated peats is needed to evaluate

future rates of increase in atmospheric greenhouse gases andtheir effect on the global environmental change processes[18 19]

Based on the above rationale the general objective of thisstudy was to quantify CO

2emission and also carbon loss

from a drained tropical peat grown with pineapple The firstspecific objective was to partition soil CO

2emission from a

cultivated peat into root respiration microbial respirationand oxidative peat decompositionThe second specific objec-tive was to estimate DOC in water drained from lysimeterswith peat soil The third specific objective was to assess theeffects of soil temperature and soil moisture on soil CO

2

emissionIn this study it was hypothesized that microbial respira-

tion and peat decomposition will cause higher loss of CO2

and DOC from the bare peat soil than from the peat soilcultivated with pineapple This hypothesis is based on theassumption that CO

2emission of drained and uncultivated

peats is mainly controlled by heterotrophic respiration How-ever CO

2andDOC release in the presence of root respiration

(cultivated peats) is expected to be lower as both processesare regulated by autotrophic respiration and photosynthesisInformation obtained from partitioning respiration compo-nents could be used to control CO

2and DOC losses from

drained tropical peats that are cultivated with pineapples andother related crops

2 Materials and Methods

21 Site Description The study was carried out at the Malay-sian Agricultural Research and Development Institute(MARDI) Peat Research Station at Saratok Sarawak Malay-sia The research station has a total area of 387 hectareslocated on a logged-over forest with a flat topography of 5to 6m above mean sea level Based on the Von Post Scaleof H7 to H9 the peat soil is classified as well decomposeddark brown to almost dark coloured sapric peat with a strongsmell The thickness of the peat soil ranges from 05 to 30m

The mean temperature of the peat area ranges from 221to 317∘C The relative humidity of the area ranges from 61to 98 The annual mean rainfall of the area is 3749mm Inthe wet season (November to January) the monthly rainfallis more than 400mm whereas in the dry season particularlyin July the mean rainfall is 189mm

22 Soil Chemical and Physical Analysis Before setting upthe lysimeter experiment peat samples were collected at apeat excavation site (05 hectares) located at MARDI PeatResearch Station The experimental area was planted withMoris pineapple from 2004 to 2005 after which it was aban-doned to lie fallow for six years Samplings were performed at

depths of 0ndash20 cm 20ndash40 cm and 40ndash 60 cm systematicallyin 12 points located over a 20mtimes 125m gridThe soil sampleswere analyzed for pH conductivity ammonium-N nitrate-Norganic carbon total nitrogen and cation exchange capacity(CEC) Soil pH and conductivity were measured based on a1 5 soil to water suspension [20] Ammonium-N and nitrate-N were determined using the steam distillation method [21]Soil organic carbon was determined using the Walkley andBlack method [22] whereas total nitrogen was determinedusing the Kjeldahl method [23] Cation exchange capacitywas determined using the Harada and Inoko method [24]Bulk density was determined using the coremethod [25] andsoil water holding capacity was determined using themethodof Dugan et al [26]

23 Characteristics of the Lysimeters Twelve cylindrical fieldlysimeters made from high density polyethylene measuring143m in diameter and 158m in height were set up in April2012 tomimic the natural condition of drained tropical peatsThe size of the lysimeters used in this study was designed toensure satisfactory growth anddevelopment of the pineapplesfor sixteen months The twelve lysimeters were used forthree peat soil treatments (Section 24) The lysimeters wereequipped with water spillage opening which was attached toclear tubes mounted on the outside of the vessel to regulateand monitor water level

Each lysimeter was filled with peat soil up to 120 cmdepth Water loss from the soil was replenished by showeringeach lysimeter with 345 litres of rainwater The amount ofrainwater added was based on the volume of the fabricatedlysimeter and the mean annual rainfall at Saratok SarawakMalaysia The lysimeters with the peat soil were left in theopen for five months to ensure that the peat soil had settledbefore beginning this study The length of this initial phasewas based on weekly determination of the peat subsidenceThe equilibrium state was achieved in September 2012 beforecarrying out the CO

2measurement Water table of the

peat was maintained at 50 to 60 cm from the soil surfacethroughout the duration of the experiment

24 Peat Soil Treatments The three treatments involved inthis lysimeter experiment were peat soil cultivated with pine-apple (A) bare peat soil (B) and bare peat soil treated withchloroform (C) Each treatment had four replications Thetreatments were arranged in completely randomized design

Treatment A represents total amount of CO2emitted

from root respirationmicrobial respiration and peat decom-position Three Moris pineapple suckers were planted in thelysimeters at a distance of 30 cm Treatment B represents CO

2

emitted by microbial respiration and peat decompositionWeed sprouting on the soil surface was controlled whennecessary Treatment C represents CO

2emitted by oxidative

peat decomposition For this treatment concentrated chloro-form was applied evenly on the peat soil surface to eliminatemicrobial respiration and 646 litres of concentrated chlo-roform was used This volume was based on the peat soilrsquoswater holding capacity After the chloroform applicationthe soil was covered with cling film and canvas to produce

The Scientific World Journal 3

Table 1 Physical and chemical properties of a drained peat soil sampled at different depths

Variable Mean (0 to 10 cm) Results per soil depth (cm) Reported standard range0 to 20 cm 20 to 40 cm 40 to 60 cm

Physical propertiesBulk density (gcm3) 014 009ndash012 [31]Water holding capacity () 402 275ndash322 [31]Moisture () 809c 849b 888a 90ndash95 [32]

Chemical propertiespH 38a plusmn 01 39a plusmn 01 39a plusmn 01 30ndash45 [31]Conductivity (120583Scm) 1785a plusmn 46 1754a plusmn 43 1727a plusmn 24 lt200 [33]

Cation exchange capacity (cmol(+)kg) 1464a plusmn 201 1376a plusmn 137 1756a plusmn 349 200 [31]

145 [33]

Total organic carbon () 400a plusmn 08 398a plusmn 14 365a plusmn 11 12ndash60 [31]204ndash384 [34]

Total nitrogen () 133a plusmn 003 118b plusmn 004 112b plusmn 003 110ndash167 [32]Ammonium-Nitrogen (mgL) 1385a plusmn 162 1000b plusmn 42 948b plusmn 77 naNitrate-Nitrogen (mgL) 720a plusmn 54 488b plusmn 63 658ab plusmn 30 naValues (mean plusmn standard error) with different letters across the column are significantly different at 119875 le 005(Note na not available)

a vacuum-like condition in the lysimeters to minimize chlo-roform volatilization The soil microbial population beforeand after the chloroform application was determined usingthe culture method With this method bacteria fungi andactinomycetes were enumerated as colony forming units(CFU) per gram of fresh soil on nutrient agar Rose Ben-gal and actinomycetes isolation agar respectively [27] Theconcentrated chloroform was used to fumigate the peat soilone week before the soil CO

2measurement was commenced

(optimum time interval achieved for the biocidal effect on soilmicroorganisms)

25 Soil CO2Emission Measurements Carbon dioxide emis-

sions from the field lysimeters were measured using theclosed chamber method [28] Extracted gas samples from thechamber were analyzed for CO

2using gas chromatography

(Agilent 7890A) equippedwith thermal conductivity detector(TCD) The CO

2results were based on the measured CO

2

from treatments A B and C in the wet and dry seasonsThe values were averaged and converted into units of thayrThe gas flux was calculated from the increase in the chamberconcentration over time using the chamber volume and soilarea covered using the following equation [28ndash30]

Flux = [119889 (CO

2)

119889119905

] times

119875119881

119860119877119879

(1)

where 119889(CO2)(119889119905) is the evolution rate of CO

2within the

chamber headspace at a given time after putting the chamberinto the soil 119875 is the atmospheric pressure 119881 is the volumeheadspace gas within the chamber 119860 is the area of soilenclosed by the chamber 119877 is the gas constant and 119879 is theair temperature

The gas fluxwasmeasured in the earlymorning (240 amto 555 am) morning (715 am to 1030 am) mid-morningto afternoon (1035 am to 150 pm) afternoon (155 pm

to 510 pm) evening (800 pm to 1115 pm) and night(1120 pm to 235 am) to obtain a 24 hour CO

2emission

The flux measurements were carried out in September 2012November 2012 and January 2013 to represent the concen-trations of CO

2in the wet season whereas April 2013 and

July 2013 flux measurements represent the concentrations ofCO2in the dry season Soil temperature and moisture were

measured using Eijkelkamp IP68 and ML3 sensors respec-tively Rainfall temperature and air humidity data were alsorecorded using a portable weather station (WatchDog 2900)installed at the experimental site

26Measurement of DOC Water draining through the open-ings of the lysimeters of treatments A and B was collectedfor determinations of DOC concentrationThewater sampleswere chilled at 10∘C before being analyzed The samples werefiltered to pass a 045 120583m cellulose nitrate membrane filterand the contents of DOCwere determined using total carbonanalyzer (Shimadzu TOC) The DOC from treatment C wasnot measured because of the high residual chloroform in thepeat water

27 Statistical Analysis Treatment effects were tested usinganalysis of variance (ANOVA) and means of treatments werecompared using Duncanrsquos New Multiple Range Test at 119875 le005 The relationships between gas flux soil temperatureand soil moisture were analyzed using Pearson correlationanalysisThe statistical software used for this analysis was theStatistical Analysis System (SAS) Version 93

3 Results and Discussion

31 Peat Physical Properties Results of peat soil propertiesare compared with the previously reported ranges (Table 1)


for tropical peats in Southeast Asia [31] and Malaysia [31ndash33] The bulk density of the sampled peat soil is within thereported range [31] whereas the water holding capacity andmoisture content of the soil are lower than the reportedrange [31 32] The bulk density at 10 cm ranged from 009 to018 gcm3 which is typical of a sapric peat The bulk densitywas determined at 10 cm due to the saturated conditionof the excavation site The water holding capacity of thepeat (402) was below the reported range [31] because thewater holding capacity determination was based on oven-dryweight method [31] The increasing moisture content withincreasing peat soil depth is related to the high water tableat the excavation site during soil sampling However thesoil moisture is lower than the reported range [32] Removalof trees and debris after land clearing may have acceleratedoxidative peat decomposition and therefore soil moisturecontent is lower

32 Peat Chemical Properties Values of pH conductivityCEC total organic carbon and total nitrogen of the peatsoil studied here are within the reported range [31ndash34] forthe peat soil at MARDI Peat Research Station (Table 1) Thesoil chemical properties showedno significant differencewithdepth except for total nitrogen ammonium-N and nitrate-N The pH of the peat soil was low suggesting a need forliming before being cultivated The low conductivity of thepeat soil also indicates that the soil is not saline as theresearch station is drained by two large tidal rivers (SebelakRiver and Nyabor River) However intrusion of salt waterat the station is prevented by a tidal gate constructed atthe main outlet drain leading to Nyabor River The CEC ofthe peat soil is high because of lignin-derivatives formedduring decomposition Ion exchange in peats relates tocarboxyl and phenolic radicals of humic substances andhemicelluloses [31] However the CEC obtained is higherthan the reported range [33] This may be attributed to thepast liming activities at the excavation site as this area wascultivated with pineapples from 2004 to 2005 The totalorganic carbon of the soil is within the reported range [3134] The high organic carbon content can be associated withthe botanical origin (woody) of the sapric peat used in thisstudy [31 32] The total nitrogen of the soil was high and itwas mostly in organic form The total nitrogen ranged from11 to 13 Ammonium-N ranged from 948 to 1385mgLwhereas nitrate-N ranged from 488 to 720mgL at thethree soil depths Total nitrogen ammonium-N and nitrate-N contents decreased with increasing soil depth (from 0ndash20 cm to 20ndash40 cm depths) because decomposition of peatsgenerally decreases (low oxidation with increasing watercontent) down the soil profile [31]

33 Soil CO2Emission TheCO

2emissions under treatments

A B and C varied in the wet and dry seasons (Figure 1) Inthe wet season the CO

2emission under treatment A was

significantly lower than under treatments B and C Howeverin the dry season the CO

2emission under treatment C was

significantly lower than under treatments A and B The CO2

Wet period Dry period0

50

100

150

200

250

300

b

a a

Peat soil cultivated with pineappleBare peat soil Bare peat soil treated with chloroform

Soil

CO2

flux

(tha

yr)

a998400

a998400

b998400

Monitoring period

Figure 1 Carbon dioxide emission (wet and dry seasons) frompeat soil cultivated with pineapple bare peat soil and chloroformfumigated peat soil (Error bars represent standard error and soilmean fluxes with different letters are significantly different at 119875 le005)

emission under treatment A was affected by root develop-ment and growth of the pineapple plants Differences in dayand night temperatures in the wet and dry seasons (Table 2)may have also impeded photosynthetic activity of the pineap-ple plants [35] Furthermore heterotrophic respiration anddecomposition of root exudates in the rhizosphere [5 36]mayhave contributed to the CO

2emission under treatment A

The CO2emission under treatment B is related to the

microbial population of the peat soil and the availability ofadequate substrate for microbial metabolism but not to plantroot activities [5 12] The CO

2emission under treatment

B was also regulated by moderate temperature fluctuation(Table 2) which is in agreement with previous studies inpeat soils [9 12] The effect of soil temperature on CO

2

emission from peat soils has been also recently studied byJauhiainen et al [8] and Paz-Ferreiro et al [37] showing thatthe rate of organic material decomposition increased withincreasing temperature of peat soils

The CO2emission under treatment C was mainly due

to oxidative peat decomposition (shrinkage and consolida-tion) as the fumigant (chloroform) used inhibited microbialrespiration Bacteria and actinomycetes populations beforeand after fumigation were statistically similar Fungi were notdetected in this present studyThese findings are in agreementwith most previous findings which demonstrate that chloro-form can effectively kill (94 to 99) microorganisms [38ndash42] The effectiveness of the fumigation is supported by thedecrease in themean soil microbial biomass carbon (Table 3)This result also corroborates previous work by Zelles et al[43] who reported 80 reduction in microbial biomasscarbon after fumigating a soil with chloroform The fact thatthe subsidence rates of the peat soil in treatments A B andC were statistically similar suggests that the chloroform used


Table 2 Day and night temperatures of the experimental site (Saratok Malaysia)

Variable Wet season Dry seasonSeptember 2012 November 2012 January 2013 April 2013 July 2013

Mean day time temperature (∘C) 267 292 296 263 270Mean night time temperature (∘C) 236 249 245 246 247Mean day and night time temperature differences (∘C) 31 43 51 17 23

Mean soil temperature (∘C)Early morning 298a 300bc 282bc 301a 287b

Morning 308a 321ab 298a 305a 295b

Mid-morning to afternoon 309a 328a 307a 305a 306b

Afternoon 297a 311abc 305a 293ab 326a

Evening 295a 301bc 294ab 287ab 292b

Night 290a 292c 279c 277b 287b

Mean values with different letters within the same column are significantly different at 119875 le 005

Table 3 Effect of fumigating drained peat soil with chloroform onsoil microbial biomass carbon

Monitoring cycleMean soil microbial biomass

carbon(120583gCg soil)

Initial before chloroformapplication 947a

September 2012 296f

November 2012 734b

January 2013 560d

April 2013 672c

July 2013 460e

Mean values with different letters are significantly different at 119875 le 005

did not affect CO2emission due to oxidative peat decom-

position This observation corroborates that of Toyota et al[40] who also found no significant effect of chloroformfumigation on soil bulk density and compaction The higherCO2emission under treatment C in the wet season was

due to the decomposition of dead microorganisms [42] Incontrast the decrease in the CO


C in the dry season was because of the adaptation of themicroorganisms towards the biocidal effect of chloroformAgain it must be stressed that the CO

2emission was mainly

because of oxidative peat decomposition [1 6] The oxidativepeat decomposition (shrinkage and consolidation)was due tothe loss ofwater in the aerobic layer of the peatOxidative peatdecomposition is a continuous process and it takes severalyears to achieve the equilibrium state of peat subsidence

The CO2emission was also affected by time of sampling

(Figure 2) In the wet season the CO2emission decreased

from morning to mid-morning to afternoon followed by anincrease in the evening In the dry season the CO

2emission

decreased from the early morning to mid-morning to after-noon followed by an increase in the evening and nightTheseobservations are consistent with the significant negativecorrelation between soil CO

2emission and soil temperature

(Table 4) These findings also suggest that the CO2emission

increased with decreasing temperature Although the CO2

a


100

200

300

400

b

cc

b

b

Early morning Morning Mid-morning to afternoon

Afternoon Evening Night

Soil

CO2

flux

(tha

yr)

c998400

d998400

d998400

a998400 a998400

b998400

Monitoring period

Figure 2 Carbon dioxide emission (at different times of the day anddifferent seasons) from peat soil cultivated with pineapple (Errorbars represent standard error and soil mean fluxes with differentletters are significantly different at 119875 le 005)

emission was negatively correlated with soil temperaturethe overall data (wet and dry seasons) showed no correla-tion between CO

2emission and soil temperature (Table 4)

This indicates that although soil temperature regulates soilCO2emission the differences in the CO

2emissions under

treatments A B and C across time rather depends on themoderate fluctuation in soil temperature (02 and 16∘C) ofthe tropics There was no correlation between CO

2emission

and soil moisture (Table 4) because the water table in thelysimeters was maintained at 50 and 60 cm This findingis further supported by the fact that the soil moisture wasnot significantly affected by time of sampling (Table 5) In arelated study Kechavarzi et al [12] found that soil moisturehad no effect on CO

2emission in humified peat surface

but higher soil moisture which constrained oxygen diffusionaffected soil respiration


Table 4 The relationship between soil CO2 emission soil temperature and soil moisture in dry and wet seasons

Weather season Monitoring period Variable Soil temperature Soil moisture

Wet seasonSeptember 2012 119903 = 02253

119875 = 01464119903 = 01955119875 = 02091

November 2012 119903 = minus05169119875 = 00001

119903 = 01127119875 = 04264

January 2013 Soil CO2 emission119903 = minus04829119875 = 00004

119903 = 02290119875 = 01135

Dry season April 2013 119903 = minus07431119875 = 00001

119903 = minus00776119875 = 05558

July 2013 119903 = minus05992119875 = 00001

119903 = minus02299119875 = 00854

Pooling data throughout the wet and dry seasons 119903 = minus01119119875 = 00710

119903 = 01027119875 = 00980

Note top values represent Pearsonrsquos correlation coefficient (119903) while bottom values represent probability level at 005 (119899 = 72 for each monitoring period 119899 =360 for pooling data throughout wet and dry seasons)

Table 5 Soil moisture during CO2 measurement at different times of the day in dry and wet seasons

TimeWet season Dry season

September 2012 November 2012 January 2013 April 2013 July 2013Mean soil moisture ()

Early morning 777a 767a 777a 773a 751a

Morning 804a 774a 787a 779a 755a

Mid-morning to afternoon 772a 783a 783a 780a 751a

Afternoon 762a 797a 775a 775a 767a

Evening 785a 776a 770a 784a 736a

Night 763a 779a 763a 781a 761a

Mean values with same letter within the same column are not significantly different at 119875 ge 005

In summary the CO2emission was estimated at about

2188 t CO2hayr under bare peat soil (B) followed by 205 t

CO2hayr under bare peat soil treated with chloroform

(C) and 1796 t CO2hayr under peat soil cultivated with

pineapple (A) The higher CO2emission from treatment B

suggests that it is controlled by heterotrophic respirationwhereas the lower CO

2emission from treatment A suggests

that it is regulated by autotrophic respiration (through pho-tosynthetic activity and respiration in the rhizosphere) TheCO2emission in this study was higher than that reported by

Jauhiainen et al [8] who found that microbial respirationcontributed with 80 t CO

2hayr whereas root respiration

contributed with 21 of the total respiration The CO2

emission rate reported in this study is not consistent with thatof Jauhiainen et al [8] because the present study was carriedout on sapric peat whereas that reported by Jauhiainen et al[8] was on fibric to hemic peat

34 Dissolved Organic Carbon TheDOCunder the bare peatsoil (B) (2357mgL) was significantly higher than under peatsoil cultivated with pineapple (A) (1946mgL) (Figure 3)because of the greater decomposition of organic substrate byheterotrophs One of the byproducts of heterotrophs is DOC[13]The lower DOC under treatment A is related to the con-sumption of carbon nitrogen and root exudates by microbesat the rhizosphere [5 44] The DOC under treatment B is

DO

C (m

gL)

0

50

100

150

200

250

300

b

a

Peat soil cultivated with pineapple

Bare peat soil

Figure 3 Dissolved organic carbon (DOC) leaching losses underpeat soil cultivated with pineapple and bare peat soil (Error barsrepresent standard error and mean DOC with different letters aresignificantly different at 119875 le 005)

in accordance with the results of our field monitoring as themean CO

2under treatment B (2188 t CO

2hayr) was higher

than under treatment A (1796 t CO2hayr)

The DOC was statistically similar irrespective of themonitoring period (Figure 4) This result was expected as


Sept 2012 Nov 2012 Jan 2013 April 2013 July 2013

Monitoring period

0

DO

C (m

gL)

50

100

150

200

250

Figure 4 Dissolved organic carbon from peat soil cultivated withpineapple in the wet and dry seasons (Error bars represent standarderror and mean DOC are not significantly different at 119875 ge 005)

the peat water table was controlled to fluctuate between50 and 60 cm in the lysimeters so as to minimize oxygenavailability for carbon decomposition in the aerobic zoneFurthermore the restriction of soil water movement in thelysimeter may have contributed to the similarity of the DOCcontent This finding is also consistent with the fact thatwet and dry seasons have no significant effect on DOCproduction in drained peats

The higher DOC in this study than the initial concentra-tion (643mgL) suggests that draining peat soils acceleratestheir chemical oxidation This buttresses the fact that carbonis not only lost as CO

2but also lost through DOC Loss of

DOC is an important indicator for carbon release becausewhen it is leached from the peat soils into rivers it posesenvironmental pollution risk This is because DOC can reactwith chlorine to form trihalomethane and haloacetic acidsAlthough these chemicals are carcinogenic they are notcompletely removed from treated water [45 46]

4 Conclusion

Peat soils drained for agriculture released 2188 t CO2hayr

under bare conditions followed by bare peat soil treatedwith chloroform (205 t CO

2hayr) and peat soil cultivated

with pineapple (1796 t CO2hayr) The lower CO

2emission

from the peat soil cultivated with pineapple was due tothe regulation by pineapple photosynthetic activity het-erotrophic respiration and decomposition of root exudatesat the rhizosphere whereas the CO

2emission from the bare

peat fumigated with chloroformwas mainly due to shrinkageand consolidation of the soil Soil CO

2emission was neither

affected by soil temperature nor by soilmoisture but the emis-sion seemed to be controlled by moderate soil temperaturefluctuation in the wet and dry seasons Draining peat soilaffected leaching ofDOCAn average 2357mgL loss ofDOCunder bare conditions arisen principally from microbialrespiration and oxidative peat decomposition suggests rapiddecline of peat organic matter through heterotrophic micro-bial activities Identification of beneficial microorganisms

that reduce peat decompositionmay help tominimize carbondioxide emission from cultivated peats Further research isneeded to assess partitioning of soil CO

2emission at the

rhizosphere as CO2emission from drained peats seems to

be influenced by heterotrophic and autotrophic respirationprocesses

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors acknowledge the financial support of the Minis-try of EducationMalaysia through Universiti PutraMalaysiaThis research was funded through Research UniversityGrants Scheme (RUGS)The facilities provided by theMalay-sian Agricultural Research and Development Institute atMARDI Saratok Peat Research Station for this study areappreciated

References

[1] AHooijer S Page J G Canadell et al ldquoCurrent and futureCO2

emissions from drained peatlands in Southeast Asiardquo Bioge-osciences vol 7 no 5 pp 1505ndash1514 2010

[2] A B Ismail and J Jamaludin ldquoLand clearing techniquesemployed at MARDI Peat Research Station Sessang Sarawakand their immediate impactsrdquo in A Case Study at MARDI PeatResearch Station Sessang Sarawak Malaysia AB Ismail HKOngMJMohamadHanif andMS UmiKalsom Eds pp 1ndash8MARDI Sarawak Malaysia 2007

[3] M Maljanen V M Komulainen J Hytonen P J Martikainenand J Laine ldquoCarbon dioxide nitrous oxide and methanedynamics in boreal organic agricultural soils with different soilcharacteristicsrdquo Soil Biology and Biochemistry vol 36 no 11 pp1801ndash1808 2004

[4] B Kloslashve T E Sveistrup and A Hauge ldquoLeaching of nutrientsand emission of greenhouse gases from peatland cultivation atBodin Northern NorwayrdquoGeoderma vol 154 no 3-4 pp 219ndash232 2010

[5] Y Kuzyakov ldquoSources of CO2efflux from soil and review of

partitioning methodsrdquo Soil Biology and Biochemistry vol 38no 3 pp 425ndash448 2006

[6] A Kasimir-Klemedtsson L Klemedtsson K Berglund P Mar-tikainen J Silvola and O Oenema ldquoGreenhouse gas emissionsfrom farmed organic soils a reviewrdquo Soil Use and Managementvol 13 no 4 pp 245ndash250 1997

[7] O Berglund and K Berglund ldquoInfluence of water table leveland soil properties on emissions of greenhouse gases from culti-vated peat soilrdquo Soil Biology and Biochemistry vol 43 no 5 pp923ndash931 2011

[8] J Jauhiainen A Hooijer and S E Page ldquoCarbon dioxide emis-sions from an Acacia plantation on peatland in Sumatra Indo-nesiardquo Biogeosciences vol 9 no 2 pp 617ndash630 2012

[9] O Berglund K Berglund and L Klemedtsson ldquoA lysimeterstudy on the effect of temperature on CO

2emission from culti-

vated peat soilsrdquo Geoderma vol 154 no 3-4 pp 211ndash218 2010


[10] A Hadi K Inubushi Y Furukawa E Purnomo M Rasmadiand H Tsuruta ldquoGreenhouse gas emissions from tropical peat-lands of Kalimantan IndonesiardquoNutrient Cycling in Agroecosys-tems vol 71 no 1 pp 73ndash80 2005

[11] A B Ismail ldquoFarm management practices for mitigation ofcarbon dioxide emission in peatland agrosystemsrdquo in Proceed-ings of the International Conference on Balanced Nutrient Man-agement for Tropical Agriculture pp 72ndash76 Pahang MalaysiaAugust 2010

[12] C Kechavarzi Q Dawson M Bartlett and P B Leeds-Harrison ldquoThe role of soil moisture temperature and nutrientamendment on CO

2efflux from agricultural peat soil micro-

cosmsrdquo Geoderma vol 154 no 3-4 pp 203ndash210 2010[13] N Fenner N J Ostle NMcNamara et al ldquoElevatedCO

2effects

on peatland plant community carbon dynamics and DOC pro-ductionrdquo Ecosystems vol 10 no 4 pp 635ndash647 2007

[14] H Vasander and J Jauhiainen ldquoLand use change in tropicalpeatlands and current uncertainties in greenhouse gas emis-sionsrdquo in Proceedings of the International Symposium andWork-shop on Tropical Peatland Peatland DevelopmentmdashWise Useand Impact Management pp 143ndash148 Sarawak MalaysiaAugust 2008

[15] A B Ismail ldquoTowards wise use of tropical peatland from agri-culture perspectiverdquo in Proceedings of the International Sympo-sium and Workshop on Tropical Peatland pp 129ndash141 SarawakMalaysia August 2008

[16] M L Raziah and A R Alam ldquoStatus and impact of pineappletechnology onmineral soilrdquo Economic and Technology Manage-ment Review vol 5 pp 11ndash19 2010

[17] K Inubushi Y Furukawa AHadi E Purnomo andH TsurutaldquoSeasonal changes of CO

2 CH4and N

2O fluxes in relation to

land-use change in tropical peatlands located in coastal area ofSouth Kalimantanrdquo Chemosphere vol 52 no 3 pp 603ndash6082003

[18] S E Page C J Rieley and J O Rieley ldquoTropical peatlandsdistribution extent and carbon storagemdashuncertainties andknowledge gapsrdquo in Proceedings of the International Symposiumand Workshop on Tropical Peatland Yogyakarta IndonesiaAugust 2007

[19] O H Ahmed M H Ahmad Husni A B Anuar and M MHanafi Sustainable Production of Pineapples on Tropical PeatSoils Universiti Putra Malaysia Press Selangor Malaysia 2013

[20] A B Ismail J Asing and M Zulkefli ldquoResidual impact ofvarious land clearing techniques on peat chemical charac-teristicsrdquo in A Case Study at MARDI Peat Research StationSessang Sarawak Malaysia A B Ismail H K Ong M JMohamad Hanif and M S Umi Kalsom Eds pp 33ndash61MARDI Sarawak Malaysia 2007

[21] J M Bremner and D R Keeney ldquoDetermination and isotope-ratio analysis of different forms of nitrogen in soils Part 3Exchangeable ammonium nitrate and nitrite by extraction-dis-tillationmethodrdquo Soil Science Society of America Journal vol 35no 5 pp 577ndash582 1966

[22] DW Nelson and L E Sommers ldquoTotal carbon organic carbonand organic matterrdquo in Methods of Soil Analysis Chemical andMicrobiological Properties Part 2 A L Page R H Miller andDR Keeney Eds pp 570ndash571 Soil Science Society of AmericaWisconsin Wis USA 1982

[23] JM Bremner ldquoNitrogen-totalrdquo inMethods of Soil Analysis Part3 ChemicalMethods D L Sparks A L Page P AHelmke et alEds pp 1085ndash1121 Soil Science Society of America MadisonWis USA 1960

[24] Y Harada and A Inoko ldquoThe measurement of the cation-exchange capacity of composts for the estimation of the degreeof maturityrdquo Soil Science and Plant Nutrition vol 26 no 1 pp127ndash134 1980

[25] E T Lim ldquoPhysical analysis determination of bulk densityrdquo inPeat Soils of Sarawak and the Analytical Methods pp 27ndash28Department of Agriculture Sarawak Malaysia 1991

[26] E Dugan A Verhoef S Robinson and S Saran ldquoBio-char fromsawdust maize stover and charcoal impact on water holdingcapacities (WHC) of three soils from Ghanardquo in Proceedingsof the 19th World Congress of Soil Science Soil Solutions for aChanging World pp 9ndash12 Brisbane Australia August 2010

[27] M Suhaimi K R Emmyrafedziawati M S Umi Kalsom A MSahilah and A B Ismail ldquoEffect of land-clearing methods ondistribution of microbial populations in peat ecosystemrdquo in ACase Study at MARDI Peat Research Station Sessang SarawakMalaysia A B Ismail H K Ong M J Mohamad Hanif andM S Umi Kalsom Eds pp 81ndash87 MARDI Selangor Malaysia2007

[28] IAEA ldquoSampling techniques and sample handlingrdquo in Manualon Measurement of Methane and Nitrous Oxide Emissions fromAgriculture IAEA-TECDOC pp 45ndash67 IAEA Vienna Austria1992

[29] M Zulkefli L K C Liza Nuriati and A B Ismail ldquoSoil CO2

flux from tropical peatland under different land clearing tech-niquesrdquo Journal of Tropical Agriculture and Food Science vol 38no 1 pp 131ndash137 2010

[30] B Widen and A Lindroth ldquoA calibration system for soil car-bon dioxide-efflux measurement chambers description andapplicationrdquo Soil Science Society of America Journal vol 67 no1 pp 327ndash334 2003

[31] J P Andriesse ldquoThe main characteristics of tropical peatsrdquoin Nature and Management of Tropical Peat Soils FAO SoilsBulletin 59 FAO Rome Italy 1988

[32] M Murtedza E Padmanabhan B L H Mei and W B SiongldquoThe peat soils of Sarawakrdquo Strapeat Status Report 2002

[33] MARDI Master Plan for Malaysian Agricultural Research andDevelopment Institute Sessang Peat Research Station MARDISelangor Malaysia 1996

[34] STRAPEAT-UNIMAS-NREB ldquoPhysico-chemical characteris-ticsrdquo in Handbook for Environmental Impact Assessment (EIA)of Development on Peatlands pp 3ndash7 UNIMAS SarawakMalaysia 2004

[35] M M Selamat ldquoBiologi tanaman dan keperluan persekitaranrdquoin Penanaman NanasmdashNanas Makan Segar dan Nanas KalengMM Selamat Ed pp 7ndash16 MARDI Selangor Malaysia 1996

[36] P Makiranta K Minkkinen J Hytonen and J Laine ldquoFactorscausing temporal and spatial variation in heterotrophic and rhi-zospheric components of soil respiration in afforested organicsoil croplands in Finlandrdquo Soil Biology and Biochemistry vol40 no 7 pp 1592ndash1600 2008

[37] J Paz-Ferreiro E Medina-Roldan N J Ostle N P McNa-mara and R D Bardgett ldquoGrazing increases the temperaturesensitivity of soil organic matter decomposition in a temperategrasslandrdquo Environmental Research Letters vol 7 Article ID014027 pp 1ndash5 2012

[38] H E Dickens and J M Anderson ldquoManipulation of soil micro-bial community structure in bog and forest soils using chloro-form fumigationrdquo Soil Biology and Biochemistry vol 31 no 14pp 2049ndash2058 1999


[39] S Hu and A H C Van Bruggen ldquoEfficiencies of chloroformfumigation in soil effects of physiological states of bacteriardquo SoilBiology and Biochemistry vol 30 no 13 pp 1841ndash1844 1998

[40] K Toyota K Ritz and I M Young ldquoSurvival of bacterial andfungal populations following chloroform-fumigation effectsof soil matric potential and bulk densityrdquo Soil Biology andBiochemistry vol 28 no 10-11 pp 1545ndash1547 1996

[41] E R Ingham and K A Horton ldquoBacterial fungal and proto-zoan responses to chloroform fumigation in stored soilrdquo SoilBiology and Biochemistry vol 19 no 5 pp 545ndash550 1987

[42] D S Jenkinson andD S Powlson ldquoThe effects of biocidal treat-ments on metabolism in soil-I Fumigation with chloroformrdquoSoil Biology and Biochemistry vol 8 no 3 pp 167ndash177 1976

[43] L Zelles A Palojarvi E Kandeler M Von Lutzow K Winterand Q Y Bai ldquoChanges in soil microbial properties andphospholipid fatty acid fractions after chloroform fumigationrdquoSoil Biology and Biochemistry vol 29 no 9-10 pp 1325ndash13361997

[44] S Saggar N Jha J Deslippe et al ldquoDenitrification and N2ON2

production in temperate grasslands processes measurementsmodelling and mitigating negative impactsrdquo Science of the TotalEnvironment vol 465 pp 173ndash195 2013

[45] A R Yallop and B Clutterbuck ldquoLand management as a factorcontrolling dissolved organic carbon release from upland peatsoils 1 spatial variation in DOC productivityrdquo Science of theTotal Environment vol 407 no 12 pp 3803ndash3813 2009

[46] F Worrall H S Gibson and T P Burt ldquoModelling the impactof drainage and drain-blocking on dissolved organic carbonrelease from peatlandsrdquo Journal of Hydrology vol 338 no 1-2pp 15ndash27 2007

Submit your manuscripts athttpwwwhindawicom

Forestry ResearchInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Environmental and Public Health

Journal of



EcosystemsJournal of


MeteorologyAdvances in

EcologyInternational Journal of


Marine BiologyJournal of


Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

Advances in


Environmental Chemistry

Atmospheric SciencesInternational Journal of



Waste ManagementJournal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal of

Geophysics


Geological ResearchJournal of

EarthquakesJournal of


BiodiversityInternational Journal of


ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OceanographyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014


ClimatologyJournal of


peat decomposition [10 17] With the growing concern aboutthe effects of greenhouse gases on the environmental qualitycoupled with the need to achieve sustainable agriculture itis essential to partition CO

2emission before deciding on

whether cultivated or degraded soils are net sinks or netsources of atmospheric greenhouse gases [5] Accounting forCO2emission from cultivated peats is needed to evaluate

future rates of increase in atmospheric greenhouse gases andtheir effect on the global environmental change processes[18 19]

Based on the above rationale the general objective of thisstudy was to quantify CO

2emission and also carbon loss

from a drained tropical peat grown with pineapple The firstspecific objective was to partition soil CO

2emission from a

cultivated peat into root respiration microbial respirationand oxidative peat decompositionThe second specific objec-tive was to estimate DOC in water drained from lysimeterswith peat soil The third specific objective was to assess theeffects of soil temperature and soil moisture on soil CO

2

emissionIn this study it was hypothesized that microbial respira-

tion and peat decomposition will cause higher loss of CO2

and DOC from the bare peat soil than from the peat soilcultivated with pineapple This hypothesis is based on theassumption that CO

2emission of drained and uncultivated

peats is mainly controlled by heterotrophic respiration How-ever CO

2andDOC release in the presence of root respiration

(cultivated peats) is expected to be lower as both processesare regulated by autotrophic respiration and photosynthesisInformation obtained from partitioning respiration compo-nents could be used to control CO

2and DOC losses from

drained tropical peats that are cultivated with pineapples andother related crops

2 Materials and Methods

21 Site Description The study was carried out at the Malay-sian Agricultural Research and Development Institute(MARDI) Peat Research Station at Saratok Sarawak Malay-sia The research station has a total area of 387 hectareslocated on a logged-over forest with a flat topography of 5to 6m above mean sea level Based on the Von Post Scaleof H7 to H9 the peat soil is classified as well decomposeddark brown to almost dark coloured sapric peat with a strongsmell The thickness of the peat soil ranges from 05 to 30m

The mean temperature of the peat area ranges from 221to 317∘C The relative humidity of the area ranges from 61to 98 The annual mean rainfall of the area is 3749mm Inthe wet season (November to January) the monthly rainfallis more than 400mm whereas in the dry season particularlyin July the mean rainfall is 189mm

22 Soil Chemical and Physical Analysis Before setting upthe lysimeter experiment peat samples were collected at apeat excavation site (05 hectares) located at MARDI PeatResearch Station The experimental area was planted withMoris pineapple from 2004 to 2005 after which it was aban-doned to lie fallow for six years Samplings were performed at

depths of 0ndash20 cm 20ndash40 cm and 40ndash 60 cm systematicallyin 12 points located over a 20mtimes 125m gridThe soil sampleswere analyzed for pH conductivity ammonium-N nitrate-Norganic carbon total nitrogen and cation exchange capacity(CEC) Soil pH and conductivity were measured based on a1 5 soil to water suspension [20] Ammonium-N and nitrate-N were determined using the steam distillation method [21]Soil organic carbon was determined using the Walkley andBlack method [22] whereas total nitrogen was determinedusing the Kjeldahl method [23] Cation exchange capacitywas determined using the Harada and Inoko method [24]Bulk density was determined using the coremethod [25] andsoil water holding capacity was determined using themethodof Dugan et al [26]

23 Characteristics of the Lysimeters Twelve cylindrical fieldlysimeters made from high density polyethylene measuring143m in diameter and 158m in height were set up in April2012 tomimic the natural condition of drained tropical peatsThe size of the lysimeters used in this study was designed toensure satisfactory growth anddevelopment of the pineapplesfor sixteen months The twelve lysimeters were used forthree peat soil treatments (Section 24) The lysimeters wereequipped with water spillage opening which was attached toclear tubes mounted on the outside of the vessel to regulateand monitor water level

Each lysimeter was filled with peat soil up to 120 cmdepth Water loss from the soil was replenished by showeringeach lysimeter with 345 litres of rainwater The amount ofrainwater added was based on the volume of the fabricatedlysimeter and the mean annual rainfall at Saratok SarawakMalaysia The lysimeters with the peat soil were left in theopen for five months to ensure that the peat soil had settledbefore beginning this study The length of this initial phasewas based on weekly determination of the peat subsidenceThe equilibrium state was achieved in September 2012 beforecarrying out the CO

2measurement Water table of the

peat was maintained at 50 to 60 cm from the soil surfacethroughout the duration of the experiment

24 Peat Soil Treatments The three treatments involved inthis lysimeter experiment were peat soil cultivated with pine-apple (A) bare peat soil (B) and bare peat soil treated withchloroform (C) Each treatment had four replications Thetreatments were arranged in completely randomized design

Treatment A represents total amount of CO2emitted

from root respirationmicrobial respiration and peat decom-position Three Moris pineapple suckers were planted in thelysimeters at a distance of 30 cm Treatment B represents CO

2

emitted by microbial respiration and peat decompositionWeed sprouting on the soil surface was controlled whennecessary Treatment C represents CO

2emitted by oxidative

peat decomposition For this treatment concentrated chloro-form was applied evenly on the peat soil surface to eliminatemicrobial respiration and 646 litres of concentrated chlo-roform was used This volume was based on the peat soilrsquoswater holding capacity After the chloroform applicationthe soil was covered with cling film and canvas to produce







145 [33]











2


Flux = [119889 (CO

2)

119889119905

] times

119875119881

119860119877119879

(1)


2within the




2emission




















50

100

150

200

250

300

b

a a


Soil

CO2

flux

(tha

yr)

a998400

a998400

b998400

Monitoring period








2









Morning 308a 321ab 298a 305a 295b




Night 290a 292c 279c 277b 287b






September 2012 296f

November 2012 734b

January 2013 560d

April 2013 672c

July 2013 460e












2emission





a


100

200

300

400

b

cc

b

b



Soil

CO2

flux

(tha

yr)

c998400

d998400

d998400

a998400 a998400

b998400

Monitoring period





2emissions under


2emission








119875 = 01464119903 = 01955119875 = 02091

November 2012 119903 = minus05169119875 = 00001

119903 = 01127119875 = 04264


119903 = 02290119875 = 01135


119903 = minus00776119875 = 05558

July 2013 119903 = minus05992119875 = 00001

119903 = minus02299119875 = 00854


119903 = 01027119875 = 00980






Morning 804a 774a 787a 779a 755a



Evening 785a 776a 770a 784a 736a

Night 763a 779a 763a 781a 761a















DO

C (m

gL)

0

50

100

150

200

250

300

b

a


Bare peat soil




2hayr) was higher





Monitoring period

0

DO

C (m

gL)

50

100

150

200

250






4 Conclusion





2emission







2emission at the





Acknowledgments


References




















2effects






2 CH4and N







































Journal of












Volume 2014

Advances in









Geophysics




















145 [33]











2


Flux = [119889 (CO

2)

119889119905

] times

119875119881

119860119877119879

(1)


2within the




2emission




















50

100

150

200

250

300

b

a a


Soil

CO2

flux

(tha

yr)

a998400

a998400

b998400

Monitoring period








2









Morning 308a 321ab 298a 305a 295b




Night 290a 292c 279c 277b 287b






September 2012 296f

November 2012 734b

January 2013 560d

April 2013 672c

July 2013 460e












2emission





a


100

200

300

400

b

cc

b

b



Soil

CO2

flux

(tha

yr)

c998400

d998400

d998400

a998400 a998400

b998400

Monitoring period





2emissions under


2emission








119875 = 01464119903 = 01955119875 = 02091

November 2012 119903 = minus05169119875 = 00001

119903 = 01127119875 = 04264


119903 = 02290119875 = 01135


119903 = minus00776119875 = 05558

July 2013 119903 = minus05992119875 = 00001

119903 = minus02299119875 = 00854


119903 = 01027119875 = 00980






Morning 804a 774a 787a 779a 755a



Evening 785a 776a 770a 784a 736a

Night 763a 779a 763a 781a 761a















DO

C (m

gL)

0

50

100

150

200

250

300

b

a


Bare peat soil




2hayr) was higher





Monitoring period

0

DO

C (m

gL)

50

100

150

200

250






4 Conclusion





2emission







2emission at the





Acknowledgments


References




















2effects






2 CH4and N







































Journal of












Volume 2014

Advances in









Geophysics

























50

100

150

200

250

300

b

a a


Soil

CO2

flux

(tha

yr)

a998400

a998400

b998400

Monitoring period








2









Morning 308a 321ab 298a 305a 295b




Night 290a 292c 279c 277b 287b






September 2012 296f

November 2012 734b

January 2013 560d

April 2013 672c

July 2013 460e












2emission





a


100

200

300

400

b

cc

b

b



Soil

CO2

flux

(tha

yr)

c998400

d998400

d998400

a998400 a998400

b998400

Monitoring period





2emissions under


2emission








119875 = 01464119903 = 01955119875 = 02091

November 2012 119903 = minus05169119875 = 00001

119903 = 01127119875 = 04264


119903 = 02290119875 = 01135


119903 = minus00776119875 = 05558

July 2013 119903 = minus05992119875 = 00001

119903 = minus02299119875 = 00854


119903 = 01027119875 = 00980






Morning 804a 774a 787a 779a 755a



Evening 785a 776a 770a 784a 736a

Night 763a 779a 763a 781a 761a















DO

C (m

gL)

0

50

100

150

200

250

300

b

a


Bare peat soil




2hayr) was higher





Monitoring period

0

DO

C (m

gL)

50

100

150

200

250






4 Conclusion





2emission







2emission at the





Acknowledgments


References




















2effects






2 CH4and N







































Journal of












Volume 2014

Advances in









Geophysics



















Morning 308a 321ab 298a 305a 295b




Night 290a 292c 279c 277b 287b






September 2012 296f

November 2012 734b

January 2013 560d

April 2013 672c

July 2013 460e












2emission





a


100

200

300

400

b

cc

b

b



Soil

CO2

flux

(tha

yr)

c998400

d998400

d998400

a998400 a998400

b998400

Monitoring period





2emissions under


2emission








119875 = 01464119903 = 01955119875 = 02091

November 2012 119903 = minus05169119875 = 00001

119903 = 01127119875 = 04264


119903 = 02290119875 = 01135


119903 = minus00776119875 = 05558

July 2013 119903 = minus05992119875 = 00001

119903 = minus02299119875 = 00854


119903 = 01027119875 = 00980






Morning 804a 774a 787a 779a 755a



Evening 785a 776a 770a 784a 736a

Night 763a 779a 763a 781a 761a















DO

C (m

gL)

0

50

100

150

200

250

300

b

a


Bare peat soil




2hayr) was higher





Monitoring period

0

DO

C (m

gL)

50

100

150

200

250






4 Conclusion





2emission







2emission at the





Acknowledgments


References




















2effects






2 CH4and N







































Journal of












Volume 2014

Advances in









Geophysics


















119875 = 01464119903 = 01955119875 = 02091

November 2012 119903 = minus05169119875 = 00001

119903 = 01127119875 = 04264


119903 = 02290119875 = 01135


119903 = minus00776119875 = 05558

July 2013 119903 = minus05992119875 = 00001

119903 = minus02299119875 = 00854


119903 = 01027119875 = 00980






Morning 804a 774a 787a 779a 755a



Evening 785a 776a 770a 784a 736a

Night 763a 779a 763a 781a 761a















DO

C (m

gL)

0

50

100

150

200

250

300

b

a


Bare peat soil




2hayr) was higher





Monitoring period

0

DO

C (m

gL)

50

100

150

200

250






4 Conclusion





2emission







2emission at the





Acknowledgments


References




















2effects






2 CH4and N







































Journal of












Volume 2014

Advances in









Geophysics
















Monitoring period

0

DO

C (m

gL)

50

100

150

200

250






4 Conclusion





2emission







2emission at the





Acknowledgments


References




















2effects






2 CH4and N







































Journal of












Volume 2014

Advances in









Geophysics




















2effects






2 CH4and N







































Journal of












Volume 2014

Advances in









Geophysics




























Journal of












Volume 2014

Advances in









Geophysics














Research Article Partitioning Carbon Dioxide Emission and...

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Transcript of Research Article Partitioning Carbon Dioxide Emission and...