MAPPING NPP AND BIOMASS IN WEST SIBERIAN WETLANDS
Description:
The objective of this study is to provide
improved estimation of the area extent for major mire types within West Siberia
(WS) and determine the spatial variability of NPP and biomass in relation to
macro/micro landscape and site position within the bioclimatic division. Our
approach relies upon scaling up available field survey and literature data to
provide wetland net primary production (NPP) and biomass inventory maps for West Siberia. Both, satellite images and aerial
photography classifications have been used to extrapolate site data into a regional
inventory map (1:2.5M scale). Total NPP of wetlands is estimated as 530.5 TgDM
(teragram/megaton dry matter)yr-1, or 624.4 TgDM/yr when woody parts are
included. Lowest NPP has been assigned to wetlands at the northern part of
Taiga zone (4.5-6.2 tonDM)/ha/yr-1). Wetlands in Tundra, Forested
tundra and southern parts of Taiga zone show considerably higher NPP values.
Minimum of living biomass storage was found in middle and southern taiga
subzones. It is also increased to the north and south within West Siberian
territory.
Author's Names: A. Peregon, S. Maksyutov, N. Kosykh, et al
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DETERMINING SOIL CO2 EFFLUX FROM SOIL AIR CO2 CONCENTRATION PROFILES
Description:
In this study,
soil CO2 effluxes determined from CO2 concentration
gradients were compared to effluxes obtained with automated chamber
measurements. The CO2 concentrations showed a diurnal pattern following
the soil temperature the concentrations increasing with increasing soil depth.
Both methods gave comparable CO2 effluxes indicating that the
gradient method provides an alternative method for monitoring soil CO2
effluxes.
Author's Names: J. Pumpanen, L. Kulmala, E. Siivola C. Helenelund, et al
Filesize: 70.71 Kb
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LAND-USE COVER CHANGE AND CARBON FLUX IN A HIMALAYAN WATERSHED
Description: Based
on satellite imagery for the 1988s and 2001s, land-use/cover change and
associated carbon stock and flux as a result of changes were estimated in
Mamlay watershed of Sikkim Himalaya, India. The total area of forest was
decreased by 28%, whereas open cropped area increased by more than 100%. The
conversion of forests into other land-uses resulted in a remarkable decline in
the C densities. Across the land-use/cover, total mean C densities ranged from
46 t ha-1 in open cropped area temperate to a high of 669 t ha-1
in temperate natural dense forest. The heavily converted areas lost an
estimated 55% of their total 1988 C pools, whereas the low impacted area lost
only 0.12%. Changes in land-use released 7.78 tC ha-1 yr-1,
demonstrating that land-use changes significantly affected C flux. Therefore,
the conversion of forest to agriculture land should be reversed.
Author's Names: Purnima Sharma, and S.C. Rai
Filesize: 28.59 Kb
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RADIATIVE FORCING FROM A BOREAL FOREST FIRE
Description: We report measurements of energy and carbon fluxes
from a boreal forest fire chronosequence. Taking into account greenhouse gas
emissions and post-fire changes in the surface radiation budget, a boreal forest
fire in interior Alaska
caused the climate to cool. This result suggests that management of forests in
northern countries to preserve carbon sinks may have the opposite effect on
climate as that intended.
Author's Names: J.T. Randerson, S.D. Chambers, M. Flanner, et al
Filesize: 31.78 Kb
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INTENSIVE TILLAGE AS A MECHANISM FOR CO2 EMISSION FROM AGRICULTURAL SOILS
Description: Agricultural ecosystems can play a significant
role in production and consumption of greenhouse gases, specifically, carbon
dioxide (CO2). Information is
needed on the mechanism and magnitude of gas generation and emission from
agricultural soils with specific emphasis on tillage mechanisms. This work
reviews effect of different tillage methods on the short-term CO2
and H2O vapor flux from clay loam soils high in soil organic carbon
(C) in the northern corn belt of the U.S. [Reicosky
and Lindstrom, 1993, 1995; Reicosky,
1997, 1998]. The soil CO2 flux was measured one minute after the
tillage using a large, portable chamber as described by Reicosky and Lindstrom [1993]. The four tillage methods were
moldboard plow (MP) only, moldboard plow plus disk harrow twice, disk harrow
and chisel plow using standard tillage equipment following a wheat (T. Aestivum
L) crop compared with no tillage (NT).
Author's Names: D.C. Reicosky
Filesize: 26.51 Kb
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SOIL CARBON IN ABANDONED LANDS OF RUSSIA
Description:
Annual
changes in soil carbon stock are considered of the abandoned managed
agricultural lands that were under natural regrowth over the territory of Russia
within the period 1990-2002. Total area of abandoned agricultural land is 21,6
millions ha. The projections of changes in the carbon stock have been made for
the period from present to 2010. The ROTHC model was employed in the
investigation of carbon dynamics in soils. The territory of Russia
was subdivided into 40 regions. The average basic soil and climatic parameters,
as well as the annual input of organic matter into soils due to natural
succession were estimated for each region. Average annual net-emission over the
territory of abandoned lands was 2,1 ± 1,8 Tg C/yr in 1990-1999. CO2
removal from the atmosphere by soils was 5,2 ± 2,8 Tg C/yr on average in
2000-2002. A total increase in carbon stock of the abandoned lands over the
country can be as high as 153 Tg C (that corresponds to the removal of 561 Tg
of CO2 from the atmosphere) in 2010. Central regions of the European
part of Russia, south of
East Siberia and the Far East will have the
highest intensity of carbon sequestration.
Author's Names: A.A. Romanovskaya
Filesize: 36.11 Kb
Added on: 04-Aug-2005 Downloads: 22
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ANNUAL CARBON DIOXIDE DRAWDOWN AND THE NORTHERN ANNULAR MODE
Description:
Year-to-year variations in summer drawdown of northern
hemisphere atmospheric carbon dioxide (CO2) are compared with
corresponding year-to-year variations in sea- level pressure (SLP), surface air
temperature and the productivity of land vegetation as inferred from the
satellite-derived normalized difference vegetation index (NDVI). Annual values
of CO2 drawdown for the years 1980-2000 are estimated from smoothed
time series derived directly from individual flask samples at the 9 northern
hemisphere monitoring stations with the most continuous records. The leading
principal component of the 9 standardized drawdown time series, in which all
stations exhibit positive loadings, is used to represent the hemispheric signal
in the CO2 drawdown. Linear regression analysis is used to infer the
spatial patterns of anomalies in sea level pressure, surface air temperature
and the NDVI observed during various seasons of years in which the drawdown is
anomalously strong.
Author's Names: J.L. Russell, E. Shevliakova, S. Malyshev, and J.M. Wallace
Filesize: 13.09 Kb
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SEASONAL CHANGE OF CO2 FLUX ABOVE A JAPANESE BEECH FOREST
Description:
Forestry
and Forest Products Research Institute erected a CO2 flux observation
tower at a Japanese beech forest, and have measured CO2 flux with
closed-pass eddy covariance method for 5 years. During the observation period, 2003
was the most CO2 absorbed year, and the amount was 1.9 times larger
than 2004, which was the least CO2 absorbed year. To investigate the
cause of the smaller CO2 absorption in 2004, we referred some
meteorological factors in 2003 and 2004.
Solar radiation (during green-leaved season) was larger in 2004 than
2003, in contradiction to CO2 absorption. On the other, air temperature was higher in 2004
than 2003 (both in green-leaved and defoliated season). We assumed that larger
respiration in 2004 effected the depression of annual CO2
absorption. At our research site, annual
mean air temperature in 2004 was 0.95 degree centigrade warmer than 2003. The result of this study suggests the
tendency that warmer climate may cause less CO2 absorption in this
Japanese beech forest.
Author's Names: T. Saito, Y. Ohtani, Y. Mizoguchi, T. Morisawa
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FEASIBILITY OF EDDY COVARIANCE MEASUREMENTS OF THE ISOTOPIC COMPOSITION OF CO2 FLUXES ABOVE A ...
Description:
Better
quantification of atmosphere-ecosystem exchange of the isotopologues of CO2
could substantially improve our ability to probe underlying physiological and
ecological mechanisms controlling ecosystem carbon exchange, but the ability to
make long-term continuous measurements of the isotopic composition of exchange
fluxes has been limited by measurement difficulties. Quantum cascade (QC)
lasers are a new generation of infrared light sources that offer increased
stability and power for absorption spectroscopy applications (including the
measurement of isotope ratios in atmospheric CO2) and promise
substantial improvements over existing instruments: smaller size, increased
robustness, and most significantly for remote or long-term field deployments,
no need for cryogenic cooling of laser or detectors.
Author's Names: S.R. Saleska, J.H. Shorter, S. Herndon, et al
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THE EFFECTS OF LAND USE CHANGE AND OF SEASONAL VARIATIONS IN CLIMATE ON GPP ACROSS THE ...
Description:
Amazonian
forests play an important and complex role in the global carbon cycle,
contributing substantially to increases (via land use change emissions) and
possibly to net sequestration (in intact forests) of atmospheric CO2.
Predicting these processes of net carbon uptake and release depends crucially
on understanding ecosystem response to both seasonal and interannual
variations. However, prominent ecosystem modeling studies of the Amazonian
carbon cycle [Tian et al., 1998; Botta 2002] appear to make seasonal
predictions (wet-season carbon uptake and dry-season loss) at odds with both
some site-specific observations (which show the opposite pattern, Saleska et al., [2003]) and basin-wide
satellite observations (which imply large-scale increases in the activity of
photosynthetic vegetation during the dry season, Huete et al., [2005]).
Author's Names: S. R. Saleska, M. Pathmadevan, A. Huete, F. Cardoso, et al
Filesize: 19.68 Kb
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