Role of a Pine ( ) Plantation on Water Storage in the Doi ... · PDF fileThai J. For. () : 75-87 (2014) 77 province. No study has been conducted on the hydrologic cycle of the pine

Thai J. For. 33 (3) : 75-87 (2014) วารสารวนศาสตร์ 31 (1) : 1-8 (2556)

Original article

Role of a Pine (Pinus kesiya) Plantation on Water Storage in the Doi Tung Reforestation Royal Project, Chiang Rai Province, Northern Thailand

Soontorn Khamyong* Samart SumanochitrapornNiwat Anongrak

DepartmentofPlantScienceandNaturalResources,FacultyofAgriculture,ChiangMaiUniversity,ChiangMai50200,Thailand*Corresponding Author, E-mail: [email protected]

Received:Nov12,2013 Accepted:Jan7,2014

ABSTRACT

A 22-year-old pine (Pinus kesiya Royle ex.Gorgen) plantationunder theDoiTungReforestationRoyalProject,ChiangRaiprovince,wasinvestigatedforthepotentialofwaterstorageinplantbiomassofpineandsuccessionaltreespecies,andsoilsystem.Tensampleplots,eachofsize40×40m,wereusedforthevegetationstudy.Theplotswerelocatedrandomlywithinareasofanaltituderangingfrom953to1,444mm.s.l.Thetreestemgirthat1.30maboveground(gbh)andtreeheightofallpineandsuccessionspeciesofheight>1.5mweremeasured.Thepineandsuccessionspeciesmeandensitieswere84.0+9.3and10.0+8.0 trees plot-1, respectively. Thepineaveragestemgbhandheightwere112.29+19.46cmand28.3+2.5m,respectively.Thesuccessionalspeciesinthetenplotsvariedbetween2and13species.Thepineandsuccessionalspeciesaveragebiomasswas64.59+9.41 Mg plot-1(403.70+58.80Mgha-1), and the average amountofwaterstoredinbiomassof52.34+7.80 m3 plot-1(327.10+48.77 m3ha-1). Within 2-m soildepth, themaximumcapacityofwaterstoragewasestimatedat1,763.67+8.44 m3plot-1 (11,022.93+52.76m3ha-1).Thewater storage in the rainy season (on17thAugust 2013)wasfoundtobe 1,411.36+9.89 m3plot-1 (8,821.0+61.84m3ha-1,80.02%ofthemaximumstorage).Thetotalwaterstorageinthepineplantation(plantbiomassand2-msoildepthwas1,816.01m3 plot-1(11,350.06m3ha-1). In the rainy season (on 17thAugust2013),thetotalwaterstoragereached1,463.70m3 plot-1(9,148.13m3ha-1,80.60%).Thewaterstorageinplantbiomasswaslow(3.58%ofthetotalstand)andwashighinsoil(96.42%).Inconclusion,thepineplantationshaveanimportantroleonwaterstoragethatcanreducestreamflowandflooding.Thesuccessionalspeciesinthepinestandalsocontributetowaterstorageinbiomass. Keywords: Doi Tung Reforestation Royal Project, Pine plantation, Water storage

Thai J. For. 33 (3) : 75-87 (2014)76

INTRODUCTION

ReforestationhasbeenconductedinthedevastatedhighlandwatershedinnorthernThailandby theRoyalForestDepartment.Many Watershed Development Stations wereestablishedin1970forreforestationonwatersheds.Thetreespeciesplantedintheearlyperiod included Pinus kesiyaRoyleex.Gorgen,Prunus cerasoides D.Don, Docynia indica (Andr.) Dencne., and Betula alnoides Buch.-Ham.exG.Don.Nowadays,morebroad-leavedtree species are planted. The three needle pine (P. kesiya) is still the most common species for thehighlandreforestationbecauseitcangrowveryrapidly(Pornleesangsuwan,2012).About150,000haofthepineplantationinnorthernThailandwere reported (RFD, 1993).Thereforestation in shifting cultivation areas on thehighlandwatershedisimportanttorestorethewatershedfunctionsofnutrientcycling,particularlythecarboncycle(Nongnuanget al.,2012)andthehydrologiccycle(LandbergandGower,1997;WaringandRunning,1998;Kimmins,2004;Chang,2006).Thispinegrowsnaturallyinareasofanaltituderangingbetween1,000and1,900mm.s.l.,andcangrowwellon poor soil (Seramethakun et al., 2012). Doi Tung areas are mountainous highland with thehighest altitudeof about1,500m.Inthepast,mostforesthadbeenclearedforagriculture and opium cultivation. In the year 1988,theDoiTungdevelopmentprojectwasestablishedthroughHerRoyalHighnessthePrincessMother(HRHthePrincessMother)’sinitiative. The project area is located in Mae Fah Luang and Mae Sai districts, Chiang Rai province,andcovers93,515rai(149.624km2) inanaltituderangeof400-1,500mm.s.l.Theareaisaheadwatershedsupplyingwatertomany

streamswhicharebeneficialto27villagesofvarioushilltribes:Akha,Shan,Lahu,YunaneseChinese, Lua, Tai Lu, Lisu, Hmong, Karen andMien,aswellaslocalThaisinlowerlandcommunities.Thehilltribespeoplereceivedextraincomefromlabourwage,agriculture,handicraft and commerce during the project. Nowadays,theoverallareasofDoiTungaregreenandcoveredbydiversifiedforesttreespecies, andmanyplaces are beautiful andattractbothThaiandforeigntourists. At the beginning of theDoiTungDevelopment Project, reforestationwasconsideredanimportantworktorestorethewatershedenvironment.Theforestplantationwasbegunin1989,asimplementationoftherehabilitationplantationtocelebratethe90th year of Somdet Phra Srinagarindra Borom-arajajonani Her Royal Highness the Princess Mother (HRH the Princess Mother). The plantationareawas10,532rai(1,685.12ha).Many forest tree specieswere selected forplanting. P. kesiyawas planted in areas ofhigheraltitude,above950mm.s.l. totaling6,600 rai (1056ha),whereas teak (Tectona grandisL.f.)wasplantedintheloweraltitudeareas covering a 3,600 rai (576ha).Otherspecieswereplantedinthesmallerareas.In2011,thepineandteakplantationswere22years old. Plant succession occurred in these plantations at different levels. Littleresearchhasbeenconductedinthepine forest. The ecological roles of the natural pineforestinvolvingsoilcarbonandnutrientstorageatKalayaNiWattanadistrict,ChiangMaiprovince,werestudiedbySeramethakunet al.(2012).Nongnuanget al. (2012) investigated biomasscarbonstocksofpineandsuccessiontrees in the pine plantations atBoaKaewWatershed Development Station, Chiang Mai

Thai J. For. 33 (3) : 75-87 (2014) 77

province.No studyhas been conductedonthe hydrologic cycle of the pine plantations. Most literature about forest hydrology hasfocused on inputs of precipitation into forest ecosystem,andmovementofwaterthroughmany processes, particularly interception-evaporation by forest canopy, throughfall,stemflow,uptakebyrootstranspiration,waterflow throughvegetation, evaporation fromsoil,infiltrationintosoil,drainageandrunoff,streamflow,andsoon(LandbergandGower,1997;WaringandRunning,1998;Kimmins,2004;Chang,2006).Fewdataareavailableonthepotentialofwaterstorageinplantbiomassand soils of the forests. Brady and Weil (2010) describedthatthedataonmaximumretentivecapacitieswithintheaveragedepthofsoilsinawatershedareusefulinpredictinghowmuchrainwatercanbestoredinthesoiltemporarilyand possibly avoiding downstreamfloods.Floodinganddroughthavebecomethecriticalproblemsinthecountry.Forestconservationthrough protection of the remaining natural forests and reforestation indisturbed forestland is, thus, important.Researchonwaterstorage in the plantation forest is thought tobeimportantasthebasicinformationforwatershedmanagement. The aim of this research is to evaluate the ecological role of the 22-year-old pine plantation under the Doi Tung Development Projectonwaterstorage.Thisplantationwasestablishedtocelebratethe90th year of Somdet

Phra Srinagarindra Boromarajajonani, Her Royal Highness the Princess Mother (HRH the Princess Mother). The potential capacity ofwater storage by the plantation impliesecological benefits from the reforestationproject.

MATERIALS AND METHODS

Tree and plot data collection Sampling of forest vegetation over thepineplantationswasconductedin2011usingtensampleplots,eachofsize40×40m.Theplotswereselectedbyrandomsamplingwithinareasofaltituderangingbetween953and1,444mm.s.l.Thetreestemgirthatbreastheight (gbh, 1.3m above ground) and treeheight of all pine and succession tree species of height >1.5mweremeasuredinallplots.The plot slope gradient, slope aspect, altitude, andGPSlocations,werealsorecorded.

Biomass estimation of standing trees Biomass of all standing trees of pine and succession species in the plotswerecalculated.Thepinebiomassallocatedinstem,branchandleafcomponentsintheplantationwerecalculatedusingtheallometricequationsofthepineplantationsatBoaKaewWatershedManagement Station, Sa Moeng district, Chiang Maiprovince (Nongnuanget al., 2012) as follows:

wS(stem) = 0.0503(D2H) 0.8775 (r2 = 0.9749)

wB(branch) = 0.0012(D2H) 1.0996 (r2 = 0.4982)

wL (leaf) = 0.4536(WB) 0.7933 (r2=0.6324)

where D = diameteratbreastheightincentimeters H = tree height in meters

2

Thai J. For. 33 (3) : 75-87 (2014)78

The root biomass of pinewas notinvestigatedinthisstudy.However,therootbiomassofpineandbiomassofsuccessionaltreespecieswerecalculatedusingtheequations

developedbyTsutsumiet al.(1983)derivedfromaboutfifty treespecies inThailandasfollow:

wS(stem) = 0.0509(D2H) 0.919 (r2 = 0.9780) wB(branch) = 0.00893(D2H) 0.977 (r2 = 0.8900) wL (leaf) = 0.0140 (D2H) 0.669 (r2 = 0.9810) wR(root) = 0.0313(D2H) 0.805 (r2 = 0.7140) where D = diameteratbreastheightincentimeters H = tree height in meters

Water content and storage in plant biomass Thefreshleaf,branch,stemandrootsamplesofpinewerecollectedinplasticbagsone time in the rainy season, on 17thAugust 2013.Thesamplesweregatheredfromthreeindividuals of pine in the plantation, and carried toalaboratory.Theywereoven-driedat80oC untilattainingaconstantweight,andthenthewatercontentwasdetermined.Themeanwatercontentinvariousorgansof13dominanttreespeciesinthelowermontaneforest,studiedbySeeloy-ounkeaw et al.(2012),wereusedtocalculatewaterstorageinthesuccessiontreespecies.Themeanwatercontentinstem,branch,leafandrootorgansofthesetreespecieswere79.48+4.42, 102.49+19.50,112.11+23.01and80.01+21.03%bydryweight,respectively.

Maximum capacity and water storage in soils Since the soil is deeper than 2.0 meters, asoilpit,eachofsize1.5x2x2m,wasmadein a selected plot of the pine plantation. The collectionofsoilsamplesalongsoilprofilewas takenusing a 100 cm3 corer from13layersatthedepthsof0-5,5-10,10-20,20-30,30-40,40-60,60-80,80-100,100-120,120-140,140-160,160-180and180-200cm.Two

replicationsofsoilsamplesweregatheredinareasatabout1.5mapartfromtheleftandtherightsideofthepit.Allsoilsampleswereusedtodeterminemaximumwaterholdingcapacity,andwatercontenton17thAugust2013inalaboratory.Determinationof themaximumwaterholdingcapacitywasdeterminedfromfieldcapacity(FC)(BradyandWeil,2010).Waterwasaddedintothesoilsamplewithin100 cm3coreruntilitwascompletelysaturatedwithwater,andallowed todrainoutof themacroporesbygravity.Thesoilwasthensaidtobeatfieldcapacity,anditwaslatermeasuredforthemoisturecontentbyvolume.TheFCwascalculatedusingtheequation,FC=Vw/Vt,whereVwwasthewatervolume,andVtwasthetotalsoilvolume. Thewaterstorageineachsoillayerperunitareawasmeasured,andthenthetotalamountwithin2-msoildepthperunitareawasdetermined.

RESULTS AND DISCUSSION

Tree density, girth and height Thepinestemgirthatbreastheightandtreeheightweredifferentamongthetensampleplots.Asshownin Table1,themean

Thai J. For. 33 (3) : 75-87 (2014) 79

densitiesofpineandsuccessionspecieswere84.0+9.3and10.0+8.01 trees plot-1. The mean stemgirthandheightofpinewere112.29+19.46cmand28.3+2.5m,respectively.Thevariationinpinedensitiesamongtheplotswascausedbythedifferentsurvivalrates.Differencesinthe physiographic factors, particularly slope gradient, aspect, and altitude in these plots might affect pine growth.Plant successionoccurred in the pine plantation, and it varied amongthesampleplots.Thenumberofspeciesand densities of the succession species varied, 2-13speciesand2-26treesplot-1, respectively.

The succession species included Castanopsis acuminatissima (Blume) A.DC., Diospyros grandulosa Lace, Litsea glutinosa (Lour.)C.B.Robb.,Gluta obovataCraib,Schima wallichii (DC) Korth, Ficus ribesReiw.exBlume, Dalbergia cultrataGrahamexKurz,Mangifera indica L., Bauhinia variegata L., Gmelina arboreaRoxb.,Premna tomentosa Willd., Albizia odoratissima (L.f.) Benth., and Vitex pinnata L. Some of these species normallyexist inthelowermontaneforest,whiletheothersarecommonlyfoundinthemixeddeciduousforest.

Table 1 Tree density of pine and successional species, and tree girth and height of pine, in the ten sample plots.

Plot Tree density (trees plot-1) Mean tree GBH (Pine) (cm)

Mean tree height(Pine) (m)no. Pine Other species

1 83 18 98.30+17.90 (18.21) 28.0+3.4(12.1)

2 76 10 107.70+22.10(20.56) 28.5+2.1 (7.21)

3 84 4 101.30+21.00 (20.71) 28.9+1.5(5.29)

4 83 4 99.10+17.30(17.48) 30.8+1.4(4.55)

5 62 13 128.40+18.20(14.15) 29.8+3.5(11.70)

6 75 5 118.60+18.10(15.30) 28.9+2.1(7.39)

7 79 3 109.80+18.40(16.78) 29.3+1.8(6.16)

8 74 2 129.50+18.70 (14.48) 29.9+3.5(11.59)

9 62 26 122.00+23.10(18.94) 20.1+2.8(11.36)

10 60 17 108.15+19.84(18.34) 28.3+2.7(9.42)

Mean+S.D. 84+9.3(12.58) 10+8.01 (79.22) 112.29+19.46(17.35) 28.3+2.5(8.79)

Plant biomass and water storage In the pine plantation, the majority of plant biomasswas in pine, and a smallproportionwas in successional tree species(Table2).Theplantbiomassinthetensampleplotsvariedbetween49.32and83.17Mgplot-1 (average:64.59+9.41 Mg plot-1or403.70+58.80Mg ha-1).Theaveragebiomassallocatedin

stem,branch,leafandrootwere40.80+5.79,10.46+1.89, 1.70+0.24 and11.63+1.54Mgplot-1, respectively. Asshownin Table3,thetotalwaterstorage in plant biomass in the ten sampleplotsofthepineplantationvariedfrom39.76to67.77m3 plot-1 (average:52.34+7.80 m3

plot-1or327.10+48.77 m3 ha-1). In the stem,

Thai J. For. 33 (3) : 75-87 (2014)80

branch,leafandroot,theaverageamountofwater stored in biomasswere 32.30+4.54,12.50+2.28, 2.19+0.31, and 5.35+0.70 m3

plot-1,respectivelyItwashighestinthestem,

followedbybranch,rootandleaf.Thewaterstorage in thebiomassof successional treespeciesweresmall,andvariedbetween0.99%and6.90%ofthetotalstorageinplantbiomass.

Table 2 Biomass allocation in various organs of pine in the ten sample plots.

Sample Tree Biomass amounts (Mg plot-1)Plot no. species Stem Branch Leaf Root Total

1 PineOthersTotal

33.641.89

35.51

7.980.558.53

1.390.111.50

9.900.42

10.32

52.912.95

55.862 Pine

OthersTotal

37.192.49

39.68

9.270.76

10.03

1.530.131.66

10.780.52

11.30

58.763.91

62.673 Pine

OthersTotal

37.260.38

37.64

9.070.119.18

1.530.031.56

10.880.09

10.97

58.750.60

59.354 Pine

OthersTotal

37.382.10

38.48

9.060.339.39

1.540.061.60

10.930.23

11.16

58.901.73

60.635 Pine

OthersTotal

41.972.06

44.03

11.240.61

11.85

1.720.131.85

11.870.46

12.33

66.803.26

70.066 Pine

OthersTotal

43.281.68

44.96

11.160.52

11.68

1.780.091.87

12.400.34

12.74

68.622.63

71.257 Pine

OthersTotal

40.540.23

40.77

10.160.07

10.23

1.670.011.68

11.720.06

11.78

64.090.36

64.458 Pine

OthersTotal

51.530.68

52.21

13.920.21

14.13

2.120.032.15

14.540.14

14.68

82.111.06

83.179 Pine

OthersTotal

40.323.16

43.48

10.790.94

11.73

1.660.181.84

11.410.71

12.12

64.184.98

69.1610 Pine

OthersTotal

29.281.96

31.24

7.270.597.86

1.200.111.31

8.490.428.91

46.263.06

49.32Mean (Mg plot-1) 40.80+5.79 10.46+1.89 1.70+0.24 11.63+1.54 64.59+9.41Mean (Mg ha-1) 255.00+36.16 65.37+11.77 10.63+1.47 72.69+9.58 403.70+58.80

Thai J. For. 33 (3) : 75-87 (2014) 81

Table 3 Waterstorageinbiomassofvariousorgansoftreespeciesintensampleplots.

Sampling Tree Water storage in plant biomass (m3 plot-1)

Plot no. species Stem Branch Leaf Root Total %

1 PineOthersTotal

26.591.46

28.05

9.640.50

10.14

1.810.111.92

4.520.244.76

42.562.31

44.87

94.865.14100

2 PineOthersTotal

29.391.93

31.32

11.200.69

11.89

1.990.132.12

4.920.295.22

47.513.04

50.55

93.996.01100

3 PineOthersTotal

29.450.29

29.74

10.960.10

11.06

1.990.032.02

4.970.055.02

47.370.47

47.84

99.010.99100

4 PineOthersTotal

29.541.62

31.17

10.950.30

11.25

2.010.062.07

4.990.135.12

47.492.11

49.60

95.744.26100

5 PineOthersTotal

33.171.59

34.76

13.580.55

14.14

2.240.132.37

5.420.265.68

54.412.53

56.95

95.554.45100

6 PineOthersTotal

34.201.30

35.50

13.490.47

13.96

2.320.092.41

5.660.195.85

55.672.05

57.72

96.453.55100

7 PineOthersTotal

32.040.18

32.22

12.280.06

12.34

2.170.012.18

5.350.035.39

51.850.29

52.13

99.450.55100

8 PineOthersTotal

40.720.53

41.25

16.820.19

17.01

2.760.032.79

6.640.086.72

66.950.82

67.77

98.781.22100

9 PineOthersTotal

31.862.44

34.31

13.040.85

13.89

2.160.182.34

5.210.405.61

52.283.87

56.15

93.106.90100

10 PineOthersTotal

23.141.52

24.66

8.790.539.32

1.560.111.67

3.880.244.11

37.372.40

39.76

93.976.03100

Mean (m3 plot-1) 32.30+4.54 12.50+2.28 2.19+0.31 5.35+0.70 52.34+7.80

Mean (m3 ha-1) 201.86+28.40 78.13+14.25 13.69+1.92 33.42+4.35 327.10+48.77

Thai J. For. 33 (3) : 75-87 (2014)82

Maximum capacity and water storage in soil Sincesoilinthepineplantationwasdeep,themaximumcapacityofwaterstorageand moisture content on the sampling day (17th August2013)inrainyseasonwereinvestigatedto 2-m soil depth. The physical properties, includingmeanbulkdensityandgravelcontentalongthreesoilprofiles,werestudied(Table4). Itwasfoundthat thesoilbulkdensitiesvariedfromlowtoverylowthroughoutthesoilprofile,variedfrom0.74+0.14 to 1.17+0.02 Mg m-3.Thegravelcontentwasrelativelysmallintheupper160cmdepth,andincreasedinthedeeperhorizon. Table4showsthefieldcapacitiesofwaterindifferentlayersalongthesoilprofile.Thevalueswererelativelyhighthroughoutthe

soilprofile.Itwashigheratthe0-5cmdepththatmightbeinfluencedbythehighcontentoforganicmatterwhichcanabsorbthelargeamountofwater. InFigure1, themaximumcapacityofwaterstoragewithin2-msoildepthwas1,763.67+8.44 m3 plot-1 (11,022.93+52.76m3 ha-1). In therainyseason,waterstorageinsoilwasexaminedon17thAugust2013.Itisfoundthattheaveragewaterstorageinthe2-msoildepthwas1,411.36+9.89 m3plot-1 (8,821.0+61.84m3 ha-1).Thus, thewaterstorageonthisdaywas80.02%ofthemaximumcapacity. The heavy rainfall occurring in the middle of rainy season on the highland of Doi Tung areas caused such high soil moisture storage.

Thai J. For. 33 (3) : 75-87 (2014) 83

Tabl

e 4

Bulkdensity,gravelcontent,fieldcapacity(FC),waterco

ntenton17

thAugust2013,maximum

capacityofwaterstorage,an

dwater

stor

age

on 1

7thAugust2013alongsoilprofilesinthepineplantation.

Dep

th(c

m.)

B.D

.(M

g m

-3)

Gra

vel, %

(by

wei

ght)

F.C

. (%)

(by

volu

me)

Moi

stur

e(%

by

volu

me)

Max

imum

of w

ater

stor

age

Wat

er st

orag

e (1

7/7/

2013

)M

ore

capa

city

(m3 p

lot-1

)(m

3 ha-1

)(m

3 plo

t-1)

(m3 h

a-1)

(m3 p

lot-1

)

0-5

5-10

10-2

020-30

30-40

40-60

60-80

80-1

0010

0-12

012

0-14

0140-160

160-180

180-

200

0.74+0

.14,

L0.

90+0.03,L

0.85+0

.01,

L0.

90+0

.04,

L0.95+0

.02,

L1.

01+0

.02,

L1.03+0.06,L

1.09+0

.04,

L1.

07+0

.01,

L1.

17+0

.02,

L1.

17+0

.02,

L0.

89+0.38,L

0.98+0

.10,

L

14.06+10.6

5.34+0.75

10.54+1.62

8.44+2.86

7.45+3.77

7.62+0

.40

6.46+3.05

5.82+2

.20

6.41+1

.00

7.10+0

.10

6.37+3.05

28.16+25.4

21.95+6.41

60.56+

0.72

57.73+

1.98

57.91+

1.14

56.20+

0.99

56.96+1.32

54.73+

2.20

55.76+2.34

56.04+1.34

54.80+

0.88

56.29+

1.49

55.19+0.96

49.9

0+5.36

53.32+

0.70

44.86+2.76

42.85+

2.94

41.61+2.43

42.32+

2.84

42.7

0+4.

4944

.19+0.31

42.86+1.60

44.9

4+1.

2244

.01+0.36

47.1

9+0.

9447.13+0.23

40.26+2.26

45.22+

0.94

302.79+3.57

288.65+9

.91

579.06+1

1.40

562.00+9

.90

569.65+13.24

1094.66+43.93

1115.24+46.92

1120

.82+26.77

1096.02+

17.7

21125.84+

29.8

01103.76+

19.1

0998.05+1

07.2

21066.39+13.95

48.45+0.57

46.18+1.59

92.65+

1.82

89.9

2+1.58

91.1

4+2.

12175.15+7.03

178.

44+7.51

179.33+4

.28

175.36+2

.84

180.13+4

.77

176.60+3.06

159.69+17.15

170.62+2.23

224.32+13.82

214.

27+1

4.74

416.14+24.32

423.20+28.39

427.

01+4

4.89

883.84+6.13

857.14+32.02

898.

72+2

4.48

880.31+7

.21

943.83+18.76

942.68+4.50

805.21+45.17

904.36+18.75

35.89+

2.21

34.28+2.36

66.58+3.89

67.71+4.45

68.32+

7.18

141.

41+0

.98

137.14+5.12

143.79+3.92

140.85+1.15

151.01+3.00

150.83+0

.72

128.83+7.23

144.

70+3.00

11.56

11.9

026.07

22.2

122

.82

33.74

41.30

35.54

34.51

29.1

225.77

30.86

25.92

Tota

l11022.93+52.8

1763.67+

8.4

8821

.0+61.8

1411.36+

9.9

352.31

Not

es:1.L=low,accordingtoNongkarn(1986)mentionedbyAnongrak(2003)

2.M

orecapacity=maximum

waterstoragewaterstorageon17t

h August2013

Thai J. For. 33 (3) : 75-87 (2014)84

Figure 1 Amounts of water storage along soil profile in 22-year-old pine plantation.

( = maximum water storage, = water storage on 17th August 2013)

0

20

40

60

80

100

120

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Figure 1Amountsofwaterstoragealongsoilprofilein22-year-oldpineplantation. (●=maximumwaterstorage,○=waterstorageon17thAugust2013)

Ecosystem water storage Inthepineplantation,thewaterstoragewas containedmainly in two components,plantbiomassandsoilsystem.Theaverageamountofwaterstoredinbiomassofpineandsuccession tree specieswas52.34+7.80 m3 plot-1(327.10+48.77 m3 ha-1).Themaximumcapacityofwaterstorageinthe2-msoildepthwas1,763.67+8.44 m3 plot-1(11,022.93+52.76m3 ha-1).Therefore,thetotalamountofwaterstorage(plantbiomassandsoil)inthepineplantationwas1,816.01m3 plot-1(11,350.06m3 ha-1).Thewaterstorageinplantbiomasswasonly2.88%oftotalwaterstorageinthestand.Theremaining97.12%ofwaterwerestoredinthesoilprofile. In the rainy season (17thAugust2013),theamountofwaterstoragewithin2-msoildepthintheplantationwas1,411.36+9.89 m3 plot-1 (8,821.0+61.84m3 ha-1). Thus, the total amountofwaterstorage(plantbiomassand

soil) in thepineplantationon thisdaywas1,463.70m3 plot-1 (9,148.13m3 ha-1). The waterstorageinplantbiomassonthisdaywas3.58%ofthetotalwaterstorageinthestand,andtheremaining96.42%wereinthesoil. Thepineplantationwithatotalareaof6,600rai(1,056ha)couldstorethemaximumamountofwaterintheecosystem(2-msoildepth)ofabout11,985,666m3, and the total standwaterstorageinthemid-rainyseason(17thAugust 2013)was 9,660,420m3, and couldstoremorerainwaterof2,325,246m3. Ingeneral,thewaterstorageinthe22-year-oldpineplantationecosystemvarieswithtimeofthe year.

Discussion Thegrowthofpineinthe22-year-oldpineplantationatDoiTungareaswasbetterthan in other sites at Hot district (Khamyong, 2001)andSamoengdistrict(Pornleesangsuwan

Thai J. For. 33 (3) : 75-87 (2014) 85

et al., 2012), Chiang Mai province. In this study area, the mean stem girth and height ofpinewere112.29+19.46cmand28.3+2.5m, respectively,whereas those atHot andSamoengdistrictswere80.32cmand18.24m, and 82.80 cm and 21.20 m, respectively. ThepineplantationatDoiTungareahadbeenestablishedforrestorationofthedevastatedhighlandwatershed,notforthecommercialpurposes. In forest plantations, plant succession is usually occurs, and the stands reach the climaxstage.Khamyong(2001)reportedthatplantsuccessionispoorin7-37yearsoldpineplantations atHot district,whichhadbeencoveredbypine-drydipterocarpforest.Thepoor succession causedbyweeding in theplantations,whichwas theold silviculturalpractice employed by theRoyal ForestDepartment in the past. In some plantations, all individualsofotherbroad-leavedtreespecieswereremovedtostimulatethepinegrowth.However, the succession by broad-leavedspecies including oaks and some dipterocarp specieswereobservedinsomeplotswhichwere far from theWatershedDevelopmentStation.Pornleesangsuwanet al. (2012) found that plant succession in the pine plantations at Samoengdistrictconsistedof72broad-leavedtreespecieswhichalsoexistedinthenearbyfragmentedlowermontaneforests. Thepineplantationcanstorewaterinmainly two components, forest biomassand soil system. The organic layers on forest floorwerethinduetotherapidlitterdecomposition,and,thus,theroleonwaterstoragemightbesmall.Inplantbiomass,thewaterisstoredindifferentorgansincludingstem,branch,leafand root. Water storage varies among tree species,andevenwithinthesamespeciesthe

storageisdifferentamongtreesizesandages.In soil, thewater storage depends on soiltexture,organicmattercontentandsoildepth.Thesoilwaterretentionhasbeenimprovedsince organic matter gradually increases, as doesinfiltrationrateandwaterholdingcapacity(Brady and Weil, 2010). According to Waring and Runing (1998), a forest ecosystem is important for energy balance.The energyexchangebetweenvegetationandtheenvironmentinvolvesanumberofprocesses.Waterstoredinplantsandsoilcanabsorbheatenergyduringdaytime,andcooldownthroughevaporationand transpiration. The heat transfer is byre-radiation, convection andwind removal.Unfortunately,therearenodataonthewaterstorageinplantbiomassoftheforests.Thewaterstorageinplantbiomassofthe22-year-oldplantationwasratherhigh,52.34+7.80 m3 plot-1 (or327.10+4.54m3 ha-1). The successional treespeciescontributedslightlytothewaterstorageinbiomassinthepinestand.Theplantsuccessionseemed tobe in theearlystage,andresultedinlowcontributionofthesuccessionspeciestowaterstorage,i.e.,only0.55-6.90%of the total stand. This study did not focus on the seasonal changeover theyear. Ingeneral, thewaterstorageinsoilvariedwithtime;itishighinrainyseasonandverylowindryseason.Thewaterstorage insoilprofilewithin the2-mdepth in the mid-rainy season (on 17th August 2013)underthepineplantationwas80.02%ofthemaximumcapacity.Thestorageinforestbiomasswasratherlow(3.45%)comparedtothatinsoil(96.55%).Withawatchutikul et al. (2011) reported thatwater storage in forestsoilsweredifferent among the forests.Themontane forest (150-cm soil depth),moistevergreen forest (100-cm), dry evergreen forest

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(70-cm),mixeddeciduousforest(60-cm)anddrydipterocarpforest(30-cm)couldstorewatervolumesof9475.5,4782.0,3184.3,2611.8and1441.5m3ha-1, respectively. Further study on thewaterstorageindifferentnaturalforests,plantationforestsandagro-forestsshouldbebasedontheseasonalchangesduringtheyear.

CONCLUSION

The reforestation on devastated highlandwatershed,suchas,the22-year-oldpine plantation at the Doi Tung areas, has essential ecological roles on the hydrologic cycle in terms ofwater storage,which isimportant to the management of forests and watershed.Theconclusionsofthisstudyareasfollows: 1.ThegrowthofpineintheplantationsatDoiTung areaswasbetter than in otherareas in northern Thailand. The mean stem girthandheightofpinewere112.29+19.46cmand28.3+2.5m,respectively.Thewaterstorage in this pine plantation ecosystem was rather high, and occurredmainly intwocomponents:plantbiomassofpineandsuccession tree species, and soil system. In the mid-rainy season (17thAugust2013),theamountofwaterstoragewithin2-msoildepthintheplantationecosystemwasestimatedat8,821.0+61.84Mgha-1.Themaximumwaterstorage(plantbiomassandsoil)inthepinestandwas11,350.06m3 ha-1. 2.The amount ofwater stored inplantbiomassofthepineplantationwasmuchlowerthanthatinsoil.Thesoilprofileinpineplantationwasverydeepandcouldstorelargevolumesofwateruptomorethan90%ofthetotalwaterstorageinthestand. 3.Plantsuccessionbybroad-leaved

tree species in the pine plantation involved manyspeciesfromthelowermontaneforestandsomefromthemixeddeciduousforest.Thesespeciescontributedtowaterstorageinplantbiomass.Thisplantsuccessionimpliesthatthepinestandwilldevelopintoalowermontane forest, and then the succession species will havemore influenceon the ecosystemwaterstorageintheadvancedstagesofplantsuccession.

ACKNOWLEDGEMENTS

ThisresearchwasconductedundertheDoi Tung Development Project. The authors wouldliketothankMr.DisnadaDiskul,theMaeFhaLoungFoundation’sSecretary,theDirector-GeneralofDepartmentofNationalPark, Wildlife and Plants Conservation as wellastheRoyalForestDepartmentandallforestryofficersforfacilitiesduringthefielddata collection.

REFERENCES

Anongrak,N.2003.Highland soil catena as affected by land uses and land covers in Doi Inthanon area, Chiang Mai province. Ph.D Thesis, Kasetsart University, Bangkok.

Brady,N.C.andR.R.Weil.2010.Elements of the Nature and Properties of Soils. 3th edition, Pearson Education, Inc., publishingasPrenticeHall,NewJersey,USA.

Chang,M.2006.Forest Hydrology. 2nd edition, Taylor and Francis Group, Baca Raton, USA.

Khamyong, S. 2001. Ecological Effects of Pinus kesiya Plantations on Highland Watershed, Northern Thailand. ResearchReporttoNRCT.

Thai J. For. 33 (3) : 75-87 (2014) 87

Khamyong, S., T. Seramethakun and T. Seeloy-ounkeaw.2012.Evaluation of planted tree species and plant succession in forest plantations for land restoration in Mae Moh lignite mining area. Final Research Report to EGAT, Faculty of Agriculture, Chiang Mai University, Chiang Mai.

Kimmins, J.P. 2004. Chapter 11 Water: The material thatmakes lifepossible.pp.269-295.In Forest Ecology: A foundation for sustainable forest management and environmental ethics in forestry. PrenticeHall,UpperSaddleRiver,NewJersey, USA.

Landsberg,J.J.andS.T.Gower.1997.Chapter4 Forest Hydrology and Tree-Water Relations. pp. 89-124. In Application of Physiological Ecology to Forest Management. Academic Press, Inc., San Diego, USA.

Nongnuang,S.,S.Khamyong,K.Sri-ngernyuangandN.Anongrak.2012.Biomasscarbonstocks of trees in pine plantations at BoaKaewwatershedmanagementstation, Chiang Mai province. Thai.J.For 31(2):1-15.

Pornleesangsuwan,A.,S.Khamyong,K.Sri-ngernyuang andN.Anongrak. 2012.Growth,stemvolumeandplantsuccessionin Pinus kesiya plantations, northern watershed,ChiangMai province.Thai.J.For31(1):26-37.

RFD,RoyalForestDeoartment,1993.Forestry statistics of Thailand 1993. Data Centre, InformationOffice,RoyalForestDepartment, Bangkok. (in Thai)

Seeloy-ounkeaw,T.,S.Khamyong andN.Anongrak 2012. Ecosystem water storages of conservation and utilization community forests of Karen tribe, Chiang Mai, northern Thailand. A paper presented in the 1st Mae Fah Luang University International Conference, Chiang Rai province.

Seramethakun,T.,S.Khamyong,N.AnongrakandT.Kongkaew.1993.Soilpropertiesandcarbon-nutrientstoragesinnaturalpineforest,Kunlayaniwattanadistrict,Chiang Mai province. Journal of Agriculture28(3):205-215.

Tsutsumi, T., K. Yoda, P. Sahunaru, P. DhanmanondaandB.Prachaiyo.1983.Forest:burningandregeneration.In Shifting cultivation, an experiment at Nam Phrom, Northeast Thailand, and its implications for upland farming in the monsoon tropics. Kyuma, K and Pairintra, C. (eds.). A report of a cooperative researchbetweenThai-Japanese universities, Kyoto University, Japan.

Withawatchutikul, P., S.Pan-utai andP.Titirodchanawat.2011.Roles of forest resources and Problems about Flooding and Landslide. A Watershed Research Report. Watershed Research Division, DepartmentofNationalParks,Wildlifeand Plant Conservation. Bangkok. (in Thai)

Waring, R.H. and S.W. Running. 1998. Chapter 2WaterCycle. pp. 19-57. In Forest Ecosystems: Analysis at multiple scales. 2nd edition. Academic Press, USA.