ROOT AND MICROBIAL CONTRIBUTION TO THE TOTAL CO2 EFFLUX FROM SOIL AS DEPENDENT ON LAND USE
Description: The
contribution of roots to the annual CO2 emission from gray forest
and soddy podzolic soils measured in the
field experiments under crops and native vegetation varied in the wide range
from 10 to 58% of CO2 emission from the soil by mean value of 33%.
The contribution of roots to the CO2 emission from soil surface
calculated for growth season for all the ecosystems studied was equal to 44%.
In agroecosystems the contribution of roots was strongly related to the length
of crops growth. CO2 emission during dormant periods of the year was
greatly controlled by the decomposition of surface litter and detritus in the
soil than by respiration of roots and soil microorganisms.
Author's Names: A. Larionova, V. Lopes de Gerenju, D.Sapronov, I. Yevdokimov
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Added on: 01-Aug-2005 Downloads: 19
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ESTIMATING AND EVALUATING TERRESTRIAL CARBON FLUXES USING A BIOSPHERE MODEL IN TOKAI REGION
Description: Terrestrial carbon
fluxes are an important factor for the studies of global warming. This study
focuses on estimating a fluctuation
of the terrestrial carbon fluxes in the
Tokai region, Japan.
The local biosphere model used calculates carbon, water, and heat fluxes, and
required some climate and vegetation parameters as inputs. The model was
operated in 2000-2004 using meteorological data and MODIS data products.
We estimated spatial distributions in heat
and carbon fluxes at spatial resolution of 1*1 km, and validated an
adaptability of the model using measured data at the Takayama flux-site. As a
result, estimated GPP and heat fluxes had a good relationship to measured data.
We can precisely check on the accuracy of the model to estimate the
spatial and temporal patterns of the terrestrial carbon fluxes.
Author's Names: T. Sasai, K. Okamoto, K. Murakami, and Y. Yamaguchi
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Added on: 04-Aug-2005 Downloads: 24
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CARBON BALANCE OF LARCH FOREST ECOSYSTEMS
Description:
We partitioned the components of
CO2 flux by the chamber
approaches for a 45-year-old larch forest in northern Japan.
In 2003, annual soil-CO2 efflux was averaged to 9.59 tC ha-1, heterotrophic respiration was about 5.47 tC ha-1 that accounted about 57% of the soil-CO2 efflux, net annual CO2 exchange of understory
vegetation was about -0.39 tC ha-1, annual aboveground
woody
tissue respiration
was bout 0.75 tC ha-1, and annual photosynthesis and respiration
of the canopy was about
-12.75 and 1.15 tC ha-1, respectively. Annual GPP, NPP, NEP and ecosystem
respiration for this forest was estimated
to be about 13.49, 7.16, 2.04 and 11.45 tC
ha-1, respectively. The contribution of canopy respiration,
aboveground
woody
respiration, root
respiration and heterotrophic respiration to GPP was about
8.1%, 5.6%, 30.6% and 40.5%, respectively.
Author's Names: N. Liang, Y. Fujinuma, and G. Inoue
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TEMPORAL AND SPATIAL VARIABILITY OF CO2-CH4 SOURCE-SINK STRENGTH IN NORDIC ECOSYSTEMS
Description: In 2003 a Nordic Centre of Excellence on Ecosystem
Carbon Exchange and Its Interactions with the Climate System, NECC, was
initiated. The center comprises practically all eddy covariance flux sites (ca.
25) in the Nordic countries which, represents wetlands, coniferous and deciduous
forests, ‘Kyoto’
forests, lakes, agricultural sites and one urban site. The forest sites cover a
range of age classes and management practices, and long-term sites with more
than 8-10 years of continuous flux data. The center has also access to a flux
aircraft for regional assessments and involves high precision CO2
and CH4 measurements in high towers. A synthesis of the current
sink/source strength of CO2 and CH4 of the different
ecosystems is in preparation and will be presented. Analysis of long-term data
from a few sites and how it relates to annual parameters is also presented.
Author's Names: A. Lindroth
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INTERANNUAL VARIABILITY IN SOIL RESPIRATION OF FOREST, ...
Description:
Annual and seasonal dynamics of
total soil respiration (TSR) of sandy Albeluvisols and clay Phaeozems under
forest, grassland, and arable were studied in situ (Russia, Moscow Region). Measurements
of soil CO2 emission were carried out by closed chamber method from
November 1997 through October 2003 weekly. The highest mean TSR (806+86
g C·m-2·yr-1) was observed for sandy Albeluvisols under
grassland. It significantly exceeded the annual CO2 fluxes from
soils of other ecosystems (P< 0.1). The lowest value of mean annual TSR was
observed for arable clay Phaeozems (361+55 g C·m-2·yr-1).
It was reliably lower than in soils of the other cenoses (P<0.5). No significant
differences were found between annual amounts of CO2 emitted from
Albeluvisols under forest and Phaeozems under forest and grassland. The interannual
variability of TSR caused by the difference of weather conditions was 30% on average and ranged
from 25-26% (forest and grassland ecosystems on Albeluvisols) to 37% (agroecosystem
on Phaeozems). We found that TSR in natural ecosystems positively correlated
with the total annual precipitation and sum of precipitation for the spring season
(R=0.73-0.90, P<0.1). The share of the cold period (November-April) to the annual
CO2 flux was substantial and averaged 22-25% and 17% for natural and
agricultural ecosystems, respectively. Therefore, emission of CO2 during the cold
period was an essential part of the annual CO2 fluxes from soils of
sub-boreal zone, which should be taken into account while calculating the
carbon budget for the whole year.
Author's Names: V.O. Lopes de Gerenyu, I.N. Kurganova, L.N. Rozanova, et al
Filesize: 93.13 Kb
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ON-LINE SIMULATION STUDY OF THE CARBON CYCLE BETWEEN LAND SURFACE AND THE ATMOSPHERE USING ...
Description:
A
land surface model (Biosphere-Atmosphere Interaction Model Ver.2: BAIM2) can
estimate not only the energy fluxes, but also the carbon dioxide flux between
terrestrial ecosystems and the atmosphere. The photosynthesis processes for C3
and C4 plants are adopted in the model. The carbon storage of
vegetation is divided into five components (leaves, trunk, root, litter, and
soil), and the carbon exchanges among the components of vegetation and the
atmosphere are estimated in each time step of the on-line model integration.
The values of morphological parameters using in the model are derived from the
carbon storage values of the components, and the phenological changes of
vegetation are reproduced by the model. The BAIM2 was incorporated into a
spectral general circulation model, and was connected on-line to the atmospheric
model. Using this climate model, an experimental control time integration was
performed under the actual global vegetation condition. After the control time
integration, the vegetation types of Southeast Asia
were changed to the C4 grass, and the vegetation change impact
integration was performed. The results of the impact experiment were compared
with the results of the control. In the Indochina Peninsula
area, by the vegetation change from the tropical seasonal forest to the C4
grass, year mean values of the NPP generally increased, and those of the NEP also increased. On the other hand, in the
maritime continent area, by the change from the tropical rain forest to the C4
grass, the NPP values generally decreased, and the NEP
values also decreased. It was considered that the differences of phenological
changes of vegetation in these areas and the differences of climatic impact of
vegetation changes induced the different change phenomena of the carbon cycles.
There is a possibility that the influences of the vegetation changes
(deforestation) on the carbon cycles are different in the area where the
original vegetation types are different.
Author's Names: K. Mabuchi and H. Kida
Filesize: 30.75 Kb
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CO2 LOSSES FROM AGRICULTURAL SOILS IN NORTHERN KAZAKHSTAN AS AFFECTED BY PHYSIOLOGICAL STATE ...
Description:
Dynamics of organic matter in agricultural soils
attract significant interest because of strong impact on global climate. Steppe
ecosystems are considered as having high potential to preserve global carbon
and are located mainly in arid and semiarid areas with annual precipitation
smaller than 400 mm. Steppe ecosystems of the wheat belt in Kazakhstan have annual
precipitation 250 to 350 mm. Here is our attempt to evaluate whether microbial
quotients could be applied to evaluate the potential of soil to act as sink for
CO2.
Author's Names: A. Mamilov, O. Dilly
Filesize: 13.42 Kb
Added on: 01-Aug-2005 Downloads: 21
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ADVECTIVE TRANSPORT OF CO2 IN PERMEABLE MEDIA INDUCED BY ATMOSPHERIC PRESSURE FLUCTUATIONS
Description:
Pressure fluctuations at the earth’s
surface are caused by a variety of atmospheric phenomena. Examples include low
frequency barometric pressure variations, high frequency atmospheric
turbulence, atmospheric gravity waves, and quasi-static pressure fields created
as wind blows over or around topographic features, like buildings, hills, wind
breaks, etc. These naturally occurring pressure fields cause air to move in and
out of soils, snowpacks, and other permeable media. Consequently, the uptake or
release of trace gases from soils and snowpacks is a combination of molecular
diffusion and advective flows caused by surface pressure fluctuations. Such
pressure forcing has been found to influence the exchange rate of many trace
gases from the underlying substrate to the atmosphere. Given the importance of
these trace gases to understanding biogeochemical cycling and global change, it
is crucial to quantify (as much as possible) any impact these advective flows
can have on gas transport within soils and snowpacks.
Author's Names: W. J. Massman
Filesize: 17.83 Kb
Added on: 02-Aug-2005 Downloads: 59
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LONG TERM TEMPORAL AND SPATIAL VARIABILITY OF CARBON IN PERMAFROST–DOMINATED FOREST ECOSYSTEMS
Description:
The forests of Siberia
represent one of the last natural frontiers in the world. Nearly 65% of
Siberia's forests grow in areas with permafrost and Larch
forests are dominated here. According to our estimates, carbon stocks
in the
soils of permafrost forest and tundra ecosystems of Yakutia amount to
17 Gt
(altogether 126 Mha of forest area and 37 Mha of tundra). It is
about 25% of total carbon stock in
forest soils of the Russian Federation. This carbon has been
accumulated
during centuries, and rapid climate change may release its huge amount
for
relatively short period, thus enhancing rather source than sink role of
Russia.
The total stock of terrestrial phytomass carbon of forests, tundra and
meadows
of Yakutia is 2.2-4.5 Gt C, including 0.053 Gt C of tundra and meadows.
Author's Names: T.C. Maximov, A.J.Dolman, M.K.van der Molen, et al
Filesize: 84.13 Kb
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INFLUENCES OF CANOPY PHOTOSYNTHESIS AND SUMMER RAIN PULSES ON ROOT DYNAMICS AND SOIL ...
Description:
The first objective of this paper is to make the link between the
seasonality of fine root dynamics and soil respiration in a ponderosa pine (Pinus ponderosa P. & C. Lawson)
plantation located in the Sierra Nevada of California. The second objective is
to better understand how canopy photosynthesis influences fine root initiation,
growth and mortality in this ecosystem. We compared CO2 flux
measurements (NEE, soil CO2 efflux) with aboveground and belowground
root dynamics. Soil respiration was measured in a control and a trenched plot
to separate heterotrophic and autotrophic soil respiration.
Author's Names: L. Misson, A. Gershenson, J. Tang, R. Boniello, et al
Filesize: 112.58 Kb
Added on: 02-Aug-2005 Downloads: 20
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