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Name : Dr. Annamalainathan K.

Designation : Deputy Director (Physiology)

Organization : Rubber Research Institute of India

Kottayam, Kerala, India

Qualifications : M.Sc., M.Phil., Ph.D.

Areas of interest : Tree crop physiology, Photosynthesis

Stress physiology

Flux studies

Title of the papers : 1.Measurement of CO2 flux in rubber plantation using eddy covariance method 2.Seasonal Changes in Xylem Sap Flow rate in Mature Rubber Plants

K. AnnamalainathanPR. SatheeshJames Jacob

Rubber Research Institute of IndiaKottayam, India

annamalai@rubberboard.org.in

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y = 2.0956x - 3822.1

R2 = 0.9976

368370372374376378380382384

1999 2001 2003 2005 2007

Year

Atm

osp

her

ic C

O2

Con

cen

trat

ion

(ppm

)

Before industrialization, the atmospheric CO2

concentration remained more or less constant

at about 280 ppm for many centuries, but over

the past one and a half century, this rapidly

increased to well over 380 ppm.

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Deforestation contributes 17.4 % total world CO2 emission

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CO2

H2O

SOIL CO2

LITTER

ATMOSPHERE

BIOSPHERE

GEOSPHERE

RHIZOSPHERE

(Autotrophic and heterotrophic Respiration)

canopy level Net ‘A’

FLUX COMPONENTS IN RUBBER PLANTATION

Respiration

Photosynthesis

ET

• Hevea brasiliensis is relatively a fast growing tree

• Sequestering vast amounts of carbon as biomass (annual shoot biomass increment 30 – 50 /tree)

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• Natural rubber plantation helps to mitigate the

atmospheric CO2

concentration by supplying natural rubber which can be used in place

of synthetic rubber

Rubber Flux Measurements

Objectives

• To evaluate the ecosystem level CO2 and water flux in an immature rubber plantation

• To analyze the carbon sequestration potential of natural rubber plants

• Account the ecosystem services by the rubber plantations

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Description of Experiment

Experimental Site : CES, RRII, ChethackalPathanamthitta

Age of the plantation: 6-7 years old

Clones: RRII 105, PB 260, RRII 430 and ten selected ortet clones.

Plant Height : Aproximately 12 metres

Tower Height: 18 meters

Sensors were fixed at 4 metres above the canopy

EXPERIMENTAL SITE

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Eddy covariance system

Eddy covariance

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Fc in immature rubber plants during APRIL 3rd - 8th 2009

-2

-1.5

-1

-0.5

0

0.5

1

1.5

1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 193 205 217 229 241 253 265 277

0:30 hrs

CO

2 g

m/m

2/3

0 m

inDiurnal Carbon Flux in a 4-5 years old immature

rubber plantation at CES, Chethackal.

A typical diurnal flux of CO2 in immature rubber plantson April 4th 2010

-1.5

-1

-0.5

0

0.5

1

2.00

5.00

8.00

11.00

14.00

17.00

20.00

23.00

Hrs

CO

2 g

/m2 /3

0min

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Net Primary Productivity

GPP- Respiration = NPP

Ecosystem level = (NEE)

(Net ecosystem exchange)

18

CO2 Sequesteration FEBRUARY 2010

-20

-15

-10

-5

0

5

10

15

20

25

1 4 7 10 13 16 19 22 25 28

DOM

CO

2 a

ssim

ilatio

n (

g/m

2 /da

y)

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CO2 Flux (March 2009 ‐ March 2010)

‐10

‐5

0

5

10

15

20

25

30

35

01/03/20

0

01/04/200

01/05/20

0

01/06/200

01/07/20

0

01/08/200

01/09/200

01/10/2009

01/11/2009

01/12/2009

01/01/20

10

01/02/20

10

01/03/20

10

Day of the Year

CO

2 (g

m/m

2 /day

)

3600 gm/m2/year = 36 ton CO2/ha/year

CO2 sequestration potential of five years old rubber plants calculated from Eddy Covariance System

Canopy assimilation Vs Sunshine Hrs 

(July 2009)

y = 1.75x + 8.36

R2 = 0.47

‐5

0

5

10

15

20

25

0.0 2.0 4.0 6.0 8.0

Sunshine Hrs

Assim

ilation (gm/m

2/day)

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NET ECOSYSTEM EXCHANGE (NEE)(2009-2011)

NEE (net ecosystem exchange)

0

2

4

6

8

10

12

14

16

18

20

A M J J A S O N D J F M A M J J A S O N D J F M

NEE (CO

2g/m

2/day)

Month

A

I year mean 9 g CO2, II year 11 g and III year 14 gCO2 /m2/day

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E = LE / w λv

WhereE = evapotranspiration rate (mm/sec)

LE = latent heat flux

w = density of water

λv = latent heat of vaporization (2.5x 106 J kg-1)

Conversion of Latent heat flux into mass flux of water

-0.05

0

0.05

0.1

0.15

0.2

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46

mm

/30 m

in

Hrs (30 min)

Diurnal Water Vapour Flux

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H2O Flux (April 2009 - March 2010)

0

1

2

3

4

5

6

7

8

1-A

pr-2

009

21-A

pr-2

009

11-M

ay-2

009

31-M

ay-2

009

20-J

un-2

009

10-J

ul-2

009

30-J

ul-2

009

19-A

ug-2

009

8-Se

p-20

09

28-S

ep-2

009

18-O

ct-2

009

7-N

ov-2

009

27-N

ov-2

009

17-D

ec-2

009

6-Ja

n-20

10

26-J

an-2

010

15-F

eb-2

010

7-M

ar-2

010

Day of the Year

H2O

(m

m/m

2 /day

)

WATER VAPOUR FLUX

1

1.5

2

2.5

3

3.5

4

4.5

A M J J A S  O N D J F M A M J J A S  O N D J F M

Month

Evapotranspiration (mm/day)

B

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C-Sequestration potential of NR

• Annual average Reco = 3.0 g CO2/m2/day• Annual average Net ‘A’= 15.0 g CO2/m2/day• Average NEE = 12.0 g CO2/m2/day

(NET ECOSYSTEM EXCHANGE)

• Ratio between R/A = 1:5

• Carbon sequestration= 43 tonCO2/ha/year

• The current rate of atmospheric CO2 increase is approximately 2 ppm /year (IPCC). • Global NR cultivation is around 10.5 m ha• World’s NR plantations fix about 280 m T CO2/yr • 1 ppm = 2127.66 mT • So, 280 mT CO2/year is equal 0.038 ppm /year• That is, 0.038/22 x 100 = 1.9%

• Means 1.9 % of the current rate of CO2 increase in the atmosphere is reversed by the world’s NR plantation.

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This is a significant ecosystem service provided by the natural rubber plantation

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Seasonal Changes in Xylem Sap Flow rate in Mature Rubber

Plants

K. Annamalainathan,

Joby Joseph, Badre Alam and James Jacob

Email: annamalai@rubberboard.org.in

RUBBER RESEARCH INSTITUTE OF INDIA

KOTTAYAM, KERALA

INDIA

INTRODUCTION Sap flow measurement is a precise technique to study the

tree water relations

Estimation of transpirational water loss is a direct method for accounting the water use of individual tree

This technique is useful to assess the physiological response of tree to environmental factors, diseases and damages.

OBJECTIVES

To quantify the water mining rate in a mature rubber plantation using thermal dissipation probes (TDP probes).

To analyze the seasonal transpiration water loss in a traditional rubber growing area

To estimate the water use of rubber plantations

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MaterialsandMethods

Experimental site at RRII, Kottayam, Kerala, India

Clones: RRII 5 and PR 255 (three trees each)

Tree age: 18-19 years old

Sap flow was measured by Granier’s method (Granier, 1985) using thermal dissipation probes (TDP).

The data on mV signal converted to flow velocity (V)

V= 0.0119*K^ 1.231 cm/s

where K = (dTM-dT)/dT

The Sap flow velocity can be converted to sap flow rate (ml h-1)

Fs = As * V* 3600 ml h-1

where Fs is the sap flow and As is the cross-sectional area of sap conducting wood (cm2).

33

Sap flow measurement

TDP Probes (DYNAMAX, USA) Probes installed and insulated

Data logging

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Diurnal pattern of sap flow in rubber plants

0

500

1000

1500

2000

2500

3000

0:30

5:00

9:30

14:0

0

18:3

0

23:0

0

3:30

8:00

12:3

0

17:0

0

21:3

0

2:00

6:30

11:0

0

15:3

0

20:0

0

Hrs

wat

er (

ml/

hr)

RESULTS AND DISCUSSION

SAP FLOW PATTERN DURING WINTERING AND REFOLIATION PERIODS

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ANNUAL SAP FLOW PATTERN

Month Mean sap-flow rate (l/day)

RRII 5 PR 255

January 28.5 ± 1.0 30 ± 0.7

February 14 ± 0.6 5.5 ± 0.4

March 16 ± 0.7 12 ± 0.4

April 21 ± 0.7 9.5 ± 0.4

May 16 ± 0.8 17 ± 0.5

June 13 ± 0.5 13 ± 0.7

July 14 ± 0.7 19 ± 0.8

August 21.5 ± 0.8 21 ± 0.9

September 22 ± 1.4 17 ± 1.1

October 34 ± 1 30.5 ± 1.0

November 28 ± 1.3 24 ± 1.5

December 40 ± 1.5 32 ±1.1± SE indicated

Mean daily sap-flow rate (l/day) in two clones of mature Hevea brasiliensis trees at Rubber Research Institute of

India (RRII), Kottayam.

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DIURNAL SUN LIGHT INTENSITY AND SAP FLOW RATE

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CUMULATIVE LIGHT LOAD AND SAP FLOW RATE

Tmax and sap flow rate in rubber trees

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HIGHLIGHTS

• The major environmental factors which regulate the sap flow rate are solar radiation, sunshine hours, temperature variance, atmospheric vapour pressure deficit (VPD) and soil moisture conditions.

• Sunlight intensity had a direct role in regulating the sap flow rate. There was a positive relationship existing between light intensity and sap flow rate (R2=0.7-0.9).

• Significant positive relationship was existing between day time temperature and sap flow rate during pre-monsoon period only.

• By and large the Tmax (maximum temperature) did not have any influence on the rate of xylem flow very strictly throughout the year.

• Sap flow rate during the summer was smaller than post-monsoon season.

• Intensive rainy days also witnessed a sharp decline in sap flow most probably due to cloudy days leading to partial stomatal closure

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Water use of rubber plantation

• Considering the average field stand the mean water consumption of rubber plantation is

22 litre x 400 x 365 = 3. 2 x 106 l ha-1 year-1

Mean annual rainfall at RRII is 2900 mm

• The water consumed by rubber plantation as estimated from sap flow rate was around 12 % of rainfall. The amount of water transpired (T) by a mature tree was around 2 mm per day.

• Under field condition the evapotranspiration (ET) of mature rubber plants was varied from 2-6 mm as reported from different countries (Monteny et al., 1985, Jessy et al., 2004, Rodrigo et al., 2005,Isarangkool Na Ayutthaya et al., 2009).

Water use

• From the present result and previous studies with Penman-Monteithequation for water use of rubber plantation (Gururaja Rao et al., 1990) it is understood that another equal portion of sap-flow amount may be lost from the soil surface.

• Hence, the total plant and surface evapo-transpiration loss of water is about 20-25% of rainfall.

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