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The carbon balance of

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Shilong Piao, Jingyun Fang, Philippe Ciais, Philippe Peylin, Yao Huang, Stephen Sitch, Tao Wang ... P, Huang Y, Sitch S, Wang T (2009), The Carbon balance of ... – PowerPoint PPT presentation

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Title: The carbon balance of


1

The carbon balance of terrestrial ecosystems in
China during the 1980s and 1990s Shilong
Piao, Jingyun Fang, Philippe Ciais, Philippe
Peylin, Yao Huang, Stephen Sitch, Tao Wang

April 2009
2
Regional C budget (hi)story
  • in 1998, a very controversial study by Fan et
    al. finds a huge NA sink seen from the
    atmosphere (1.7 Pg C / yr)
  • in 2001, Pacala et al. estimate C budget in USA
    (0.3-0.58 Pg C / yr)
  • in 2003, Janssen et al. estimate C budget in
    Europe (0.14-0.21 PgC/yr)
  • in 2007, Stephens et al. Estimate a NH sink of
    1.5 1.5 Pg C / yr much smaller than in prevous
    inversions studies -gt this call for an assessment
    using bottom up data
  • China?

3
Spatial distribution climae
Mean annual temperature
Annual Precipitaion
4
Distribution of vegetation types in China
5
Distribution of NPP in China
6
Afforestation/reforestation projects
  • China contributed about one quarter of the global
    plantation area.
  • Forest plantation benefit net carbon uptake

Kauppi et al., (2006)
7
Significant climate change
Temperature change
Precipitation change
  • During the past two decades, mean annual
    temperature over China increased by more than 0.5
    ºC/decade.
  • Warmer-dryer in the North and warmer-wetter in
    the South where most productive ecosystems are
    distributed.

Based on CRU climate data (Mitchell et al., 2003)
8
HOW DID CARBON STORAGE RESPOND TO CLIMATE AND
HUMAN DISTURBANCE OVER THE PAST 20-YEARS?
9
Methods used in this study
1000 km
Atmospheric inverse Model
10 km
Upscaling Prediction
ha
dm
Downscaling Verification
Integration by modeling (Moses-Triffid LPJ
Sheffield-DGVM Hyland ORCHIDEE)
10
Datasets
1. Forest inventories and field biomass data
200,000 permanent and temporary sample plots,
5 periods 1977-81, 1984-88, 1989-93, 1994-98,
1999-2004 2. Grassland biomass inventory data 3.
Cropland SOC survey data, statistics for crop
yield, area, and others 4. NDVI datasets
The NDVI data were from the GIMMS (Global
Inventory Monitoring and Modeling Study) group
derived from NOAA/AVHRR land dataset, with 8 km
resolution for each 15 days from 1981 to 1999.
11
Inventory and satellite based estimation
7535 Tg C/yr
131 Tg C/yr
2210 Tg C/yr
73 Tg C/yr
vegetation
61 Tg C/yr
44 Tg C/yr
2611 Tg C/yr
399 Tg C/yr
Soil
Bamboo
Fire
Total net C balance
- 3 Tg C/yr
11 Tg C/yr
(?)
12
Inventory and satellite based estimation
7535 Tg C/yr
73 Tg C/yr
131 Tg C/yr
2210 Tg C/yr
vegetation
61 Tg C/yr
44 Tg C/yr
2611 Tg C/yr
399 Tg C/yr
Soil
Bamboo
Fire
17773 Tg C/yr

- 3 Tg C/yr
11 Tg C/yr
Limitations Not included wetland trees out
forests (four-side trees and individual tress)
13
Atmospheric inversion estimation
Prior flux information
LMDZ transport model
observations
Optimized fluxes
The mean result of the inversion ensemble over
the period 1996 2004 is a net CO2 uptake of
0.35 Pg C/yr.
Limitations scarce atmospheric netwrork (only 9
sites in North Asia) and uncertainty from
transport model
14
The link between inventory and atmospheric
inversion estimation
15
Carbon balance of Chinese terrestrial ecosystems
16
Spatial distribution of the C balance in China
17
Comparison of C balance in different regions
18
NEP vs. fossile fule CO2 emission
Raupach et al., (2007)
19
Why large C sinks?
? large-scale reforestation ? changes of energy
consumption structure and vegetation
recovery ? intensive agriculture practices ?
regional climate changes
20
(i) Reforestation and afforestation
China is the largest country with planted
forests, about 1/4 of total global plantations
(FAO, 2001)
FAO (2001)
21
(ii) Change of energy consumption strucure and
recovery of vegetation
In the last 30 yrs, firewood, charcoals, and
crop straws that had been used as major energy
sources in the most rural areas have been
steadily replaced with fossil fuels. This on the
one hand has increased the consumption of fossil
fuels, but it accelerated the recovery of
vegetation, especially of scrubs. Movement
of rural residents to cities reduced pressure to
nature.
22
(iii) Intensive agriculture practices
expansion of straw incorporation, shallow
plowing, irrigation, and no-till farming have
increased C sequestration in agricultural soils.
23
(iv) Regional climate changes
Inter-annual changes in seasonal precipitation
Despite no significant change in annual rainfall,
summer precipitation in China has significantly
increased by 2.5 mm each year over the last 2
decades.
24
Conclusions
  • Comprehensive estimate of Chinese ecosystems
    carbon budget
  • A carbon sink of 0.19 to 0.26 Pg C / yr
  • Offsets 28-37 of emissions over
    1980-2000
  • Offsets 16-22 of emissions over
    2001-2005
  • 50 forest up to 30 in shrublands
  • More than 65 of the sinks are distributed in
    southern China owing to regional climate change,
    reforestation and afforestatioin programmes
    acive, and shrubland recovery.
  • Recent trends in agricultural practice also cause
    an increase in carbon sequestration.

25
References
  • Janssens IA. et al. (2003), Europe's terrestrial
    biosphere absorbs 7 to 12 of European
    anthropogenic CO2 emissions. Science, 300,
    1538-1542.
  • Kauppi PE, Ausuble JH, Fang JY, Mather A, Sedjo
    RA, Waggoner PE (2006), Returning forest analyzed
    with the forest identity. PNAS, 103, 17574-17579
  • Mitchell TD, Jones PD (2005), An improved method
    of constructing a database of monthly climate
    observations and associated high-resolution
    grids. Int. J. Climatol, 25, 693-712
  • Pacala SW et al. (2001), Consistent land- and
    atmosphere-based US carbon sink estimates.
    Science, 292, 2316-2320.
  • Piao SL, Fang JY, Ciais P, Peylin P, Huang Y,
    Sitch S, Wang T (2009), The Carbon balance of
    terrestrial ecosystems in China. Nature,
    doil10.1038/nature07944 in press
  • Raupach MR, Marland G, Ciais P, LeQuere C,
    Canadell JG, Klepper G, Field CB (2007), Global
    and regional drivers of accelarating CO2
    emissions. PNAS, 104, 10288-10293

26
Thank you!
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