7 september 2010 lecture d2l3e co2 in crolands thuy le toan dragon 2 id 5319 the role of croplands...

7 September 2010 Lecture D2L3e CO2 in crolands Thuy Le Toan

Dragon 2 ID 5319The role of croplands and grasslands in

the carbon budget of China

Thuy Le ToanCentre d’Etudes Spatiales de la Biosphère (CESBIO)

Toulouse, [email protected]


Thuy Le Toan (PI),

CESBIO,Toulouse, FranceShaun Quegan (PI)CTCD,Sheffield, UK

Li Bingbai, Yang Shenbin, Wang Zhiming

Institute of Agriculture Resources and Environment, JAAS, Nanjing ( China)

Alberte BondeauInstitute for Climate Research (PIK), Potsdam (Germany)

Michael BuchwitzIUP Bremen (Germany)

Wang Xiaoqin, Wang Qinmin, Jiang Hong, Chen YunzhiFuzhou University, China

He GuojinChina RS Satellite Ground Station, Beijing, China

Huang Yao (PI), Zhang Wen, Sun Wenjuan

Institute of Atmospheric Physics, CAS, Beijing

Tan Bingxiang (PI), Ling Feilong, Bai Lina, Li Shimming, CAF, Beijing


Fossil fuel CO2 emissions in China have increased from 0.4 PgC/yr in 1980 to 1.5 PgC/yr in 2006.

According to a recent study (Piao et al., Nature, 2009) China’s terrestrial ecosystems absorbed 28–37 per cent of its cumulated fossil carbon emissions during the 1980s and 1990s.

Quantifying the carbon balance of Chinese ecosystems is necessary not only to assess the magnitude of the Northern Hemispheric and global sinks, but also to define new objectives for the management of terrestrial ecosystems to slow the rate of CO2 growth.

Background


Much attention has been paid to the contribution of forest ecosystems to the carbon sink, while less attention has been paid to the other ecosystems.

However, it is recognized that agricultural management can play an important role in mitigation climate change by increasing carbon storage in soils and reducing methane emission from rice cultivation.

Background


To contribute to understanding the role of vegetation ecosystems (croplands, grasslands and forests) in the C budget of China, by developing approach combining EO, models, in situ and historical data, to provide:

Spatial distribution of land use/land cover and their

changes over time

Seasonal and inter-annual variation of vegetation phenology, NPP, NEE

CH4 and CO2 fluxes

Project Objectives


Model estimates of C budget

Soils

EO dataLand coverLand parameters (NDVI,

phenology, crop calendar, …)

Ecological switches (Freeze-thaw, Soil moisture indicator, …)

Climate

Models

C budget


Northeast China

Jiangsu

Fujian

Qinghai-Tibet

Plateau

Test regions


Main ResultsI. EO methodology development:

- Rice monitoring at regional scale - Land cover at province scale- Phenology in cold region

II. Model development - LPJ mL: carbon- Agro-C: carbon- CH4MOD: rice and wetland methane

III. Preliminary EO-Model integration


Climate change in Qinghai-Tibet Plateau

Temperature increased, precipitation decreased

-12

-10

-8

-6

-4

-2

0

1975 1980 1985 1990 1995 2000 2005 2010

Year

Air

tem

pera

ture

(℃

)

300

400

500

600

700

800

Annual pre

cipit

ati

on (

mm

)

Temperature

Precipitation

Frost days decreased

(Liu et al., 2003, JGR)


SPOT VEGETATION DATAMean NDVI 2007

Lanzhou


Leaf appearance = date when NDWI starts to increase

In situ Leaf appearanceIn situ Leaf appearanceIn situ Snow meltIn situ Snow melt

DOYDOY

Date of greening in cold regions NIR-SWIRNIR-SWIRNDWI=--------------NDWI=-------------- NIR+SWIRNIR+SWIR

Phenology in Qinghai-Tibet


DOY


March

July

Dates of beginning of greening in Qinghai-Tibet


Phenology in cold regionsDates of beginning of greening in Qinghai Tibet


Red: October 8th ; Green: August 18th ; Blue: October 27th , Jiangsu province. ASAR WSM data

EO : Rice mapping


Magenta: 20060705 Green: 20060809Magenta: 20060702 Green: 20060806Magenta: flooded rice fieldsGreen: fields with temporary drainage

(ASAR WideSwath VV)Mapping of mid season drainageEO : monitoring of irrigation


Increase in N use promoted NPP production

Model AGRO-C: Progress and primary resultsWheat/Maize rotation in North China Plain

0.10

0.12

0.14

0.16

0.18

0.20

0.22

0.24

12

/01

12

/31

01

/30

03

/01

03

/31

04

/30

05

/30

06

/29

07

/29

08

/28

09

/27

10

/27

11

/26

12

/26

01

/25

Date (MM/DD)

ND

VI

Mean of 1996-2000Mean of 1981-1985

g C/m2

g C/m2

Hebei Province Mean of

1981-1985 Mean of

1996-2000 Increased

Accumulated >10℃ T (℃·d)

4561 4742 181

N for wheat (kg/ha) 105 198 93

Wheat NPP (tC/ha) 3.35 4.66 1.31

Simulated changes in crop NPP


Single crop in Northeastern China

0.10

0.12

0.14

0.16

0.18

0.20

0.22

0.24

12

/01

12

/31

01

/30

03

/01

03

/31

04

/30

05

/30

06

/29

07

/29

08

/28

09

/27

10

/27

11

/26

12

/26

01

/25

Date (MM/DD)N

DV

I

Mean of 1996-2000Mean of 1981-1985

g C/m2

g C/m2

Heilongjiang Province

Mean of 1981-1985

Mean of 1996-2000

Increased

Accumulated >10℃ T (℃·d)

2704 2847 143

Rice area (Mha) 0.28 1.46 1.18

Rice NPP (tC/ha) 3.3 5.5 2.2

Global warming has resulted in a significant northward expansion of rice planting in northeast China.

Simulated changes in crop NPPbetween 1980 and 2000 by using Agro-C

Model AGRO-C: Progress and primary results


CH4MOD: Progress and primary results

y = 0.167x - 325

(R 2 = 0.95)

y = 0.054x - 101

(R 2 = 0.79)

2

3

4

5

6

7

8

1950

1960

1970

1980

1990

2000

2010

CH

4 em

issi

on (

Tg/

yr)

Estimated CH4 emission from Chinese rice paddies over the

period of 1955―2005

Spatial distribution of CH4

emission from Chinese rice paddies (mean of 1990―1999)

(Wang P, Huang Y, Zhang W, Adv. Clim. Change Res.,2009)


Average over 2001-2005

SCIAMACHY CH4 and modelled rice paddy CH4

7 september 2010 lecture d2l3e co2 in crolands thuy le toan dragon 2 id 5319 the role of croplands...

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