SIMULATING EFFECTS OF LAND USE CHANGE ON CARBON FLUXES WITH A PROCESS MODEL IN SUBTROPICAL ...
Description:
A process model was used to simulate changes in the carbon fluxes and
stocks at a site that was transformed a grassland to a plantation at Qian
Yanzhou. The total carbon storage of the zonal vegetation (evergreen broadleaf
forest) was simulated and taken as the saturated carbon storage value of that site. The simulated vegetation density and soil organic
carbon (SOC) were compared with the observed. The simulates indicate
that after 20 years planting of the needle leaf forests (Pinus Massoniana, Cunninghamia lanceolata and Pinus elliottii ect) on ex-grassland, the net carbon storage increase in the plantation
was 8.03 kg
C/m2,in which the
vegetation carbon storage increased 8.5334
kg C/m2 and the soil carbon storage decreased 0.518 kg C/m2. The total
carbon storage of 20 years plantation is 58.6%
of the saturated value. The study also shows that between 0 and 7 years of land
use change the soil carbon was decreased and between 7 and 20 years it was
predicted to increase slowly.
Author's Names: M. Huang, J. Ji, M. Cao, and K. Li
Filesize: 51.59 Kb
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EVALUATION OF INTER-ANNUAL CARBON BUDGET FOR A SUB-ARCTIC BLACK SPRUCE FOREST BASED ON ...
Description: Measurements
of CO2 flux were made by the eddy correlation method over a sub-arctic
black spruce forest in interior Alaska.
Observed CO2 budget were sinks of -531~-247 and -219~0 g CO2
m-2 year-1 during 2003 and 2004, respectively. The broad
range is caused by uncertainty regarding assessment of the nocturnal fluxes. The
sequestration of CO2 during 2004 was limited by high temperature,
drought or low light intensity conditions. The net CO2 flux is in a
delicate balance between two large terms, which would shift from sink to source
due to global warming.
Author's Names: M.Ueyama, Y.Harazono, R.Okada, and A.Miyata
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Added on: 08-Aug-2005 Downloads: 18
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EFFECTS OF DISTURBANCE AND CLIMATE CHANGE ON CARBON BALANCE IN CANADA’S FORESTS AND WETLANDS
Description:
Model
simulations indicated that Canada’s
forests and wetlands acted as a carbon (C) sink of 112 Tg C
yr-1 averaged during 1901-1998. Wetlands was a crucial contributor
to this sink (50 Tg C yr-1). Disturbance history determined the decadal temporal pattern of C
balance. Nondisturbance factors enhanced C accumulations in Canada’s forests and
wetlands in the last century. The enhancement of each nondisturbance factor on
C uptake changed temporally.
Author's Names: W. Ju, and J. M. Chen
Filesize: 84.65 Kb
Added on: 29-Jul-2005 Downloads: 18
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DIRECT COMPARISON OF EDDY COVARIANCE AND BOWEN RATIO ENERGY BALANCE MEASUREMENTS OF CO2 FLUXES ...
Description: The objectives of this study were to (1) compare
annual mass and energy fluxes of sensible carbon dioxide (CO2), heat
flux density (H), and latent heat flux density (LE) from Campbell Scientific,
Inc. (CSI) manufactured eddy
covariance (EC) and Bowen Ratio/energy balance (BREB) instrumentation in a
tallgrass prairie site and (2) make similar short term (5-14 d) comparison in
other grazing ecosystems throughout the western United States. The long-term
tallgrass prairie site was located in central Oklahoma
with measurements being made from August 2001- October 2004, while the
short-term sites were located in Oregon, Colorado, Idaho, North Dakota, and Arizona
during the summers of 2003 and 2005. Results from the long-term (< 36-month)
co-located EC and BREB units indicated that both systems demonstrated similar
seasonal patterns, yet the EC consistently failed to close the energy balance
by 25-35% when compared to the BREB.
Author's Names: G.L. Doyle, W.A. Dugas, and H. Mayeux
Filesize: 13.37 Kb
Added on: 05-Aug-2005 Downloads: 18
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CARBON STORAGE BY ASPEN-DOMINATED FORESTS OF THE UPPER GREAT LAKES REGION: PAST, PRESENT AND FUTURE
Description: Aspen-dominated forests occupy >4 million ha in the
upper Great Lakes region of the United
States and are an important reservoir for carbon
(C). Although harvesting and agriculture over the past century depleted C
stored in these forests, independent estimates suggest that forests in the
upper Great Lakes now are C sinks [Lee et al., 1999; Barford et al.,
2001; Birdsey et al, 2000]. However, C storage
by forests within the region varies considerably due to site disturbance
history, forest age, and interannual climate variability.
Author's Names: C.M. Gough, C.S. Vogel, H.P. Schmid, H-B. Su, P.S. Curtis
Filesize: 41.24 Kb
Added on: 29-Jul-2005 Downloads: 19
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HISTORICAL CHANGES IN CARBON STORAGE OF THE EASTERN UNITED STATES: UNCERTAINTIES ASSOCIATED ...
Description: Process-based
models are important tools in assessments because they are able to integrate
mechanisms responsible for changes in carbon storage. Retrospective model
analyses are important for clarifying land use impacts on carbon storage
estimates. The objectives of our study were to: 1) develop a land use model
that allows annual conversion of native ecosystems to agriculture and creation
of age cohorts following harvest and cropland abandonment from 1600 to 2002; 2)
compare modeled age class distribution with independent inventory data on stand
age distributions, and 3) use these data sets to drive the Terrestrial
Ecosystem Model (TEM) and evaluate how assumptions about soil degradation and
CO2 fertilization influence estimates of changes in carbon storage
of the eastern US.
Author's Names: L.A. Joyce, A.D. McGuire, D.P. Coulson, J. Clein, T. Bumside
Filesize: 15.12 Kb
Added on: 29-Jul-2005 Downloads: 19
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FLUXES OF CO2, N2O, AND CH4 IN A COLD-TEMPERATE GRASSLAND SOIL OF NORTHERN JAPAN ESTIMATED ...
Description: Concentrations of 222Rn, CO2,
N2O and CH4 were measured in a cold-temperate northern
Japanese grassland soil during 1996 to compare the fluxes of CO2, N2O
and CH4 calculated by the 222Rn method and the static
chamber method and to estimate the source strengths of CO2 and N2O
in the soil using the 222Rn method. The 222Rn fluxes
ranged from 890 to 3400 dpm/m2/h
and the average was 1570±310 dpm/m2/h on sandy soil (50% sand). The
results of CO2, N2O and CH4
flux-measurements by the 222Rn method were in agreement with those
by the static chamber method within the observed range of error. The vertical
profiles of soil source
strengths of CO2
and N2O were also calculated from the concentration
gradients of 222Rn, CO2 and N2O to investigate
seasonal changes in the soil production rates of CO2
and N2O. The production rates of CO2 and N2O
varied significantly by season, averaging 1650±450 mgC/m3/h and
19±3.2 µgN/m3/h, respectively. These seasonal changes in the source
strengths of CO2 and N2O in the surface soil corresponded
with changes in fluxes of CO2 and N2O from the soil.
Author's Names: Yongwon Kim and Noriyuki Tanaka
Filesize: 62.26 Kb
Added on: 01-Aug-2005 Downloads: 19
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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
Filesize: 35.02 Kb
Added on: 01-Aug-2005 Downloads: 19
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TOWARDS A BETTER QUANTIFICATION OF CROPLANDS EXTENT AND MANAGEMENT CONTRIBUTION TO CARBON CYCLING
Description: The
development of agriculture responding to increasing demand for food raises the
question of the role of cultivated land in relation to carbon sources and
sinks, their spatial patterns and temporal variability.
Author's Names: P.C. Smith, N. Viovy, Y. Meurdesoif, S. Gervois, et al
Filesize: 71.66 Kb
Added on: 04-Aug-2005 Downloads: 19
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CARBON SEQUESTRATION IN AGRICULTURAL SOILS OF DIFFERENT NATURAL FERTILITY UNDER NITROGEN USAGE
Description:
The
influence of nitrogen fertilizing on carbon accumulation and decomposition in
arable soils of different fertility – gray forest soil and chernozem was
investigated in greenhouse experiment with corn. Growing of plants without N application on rich chernozem favored
the considerable (about 1% of Сorg) C
growth, and on poor gray forest soil contributed to C decrease. Soil organic
matter (SOM) decomposition in both soils under unfertilized plants was the
same. N usage on gray forest soil resulted in increase of C accumulation due to
the substantial increase of C input with roots of fertilized plants and as organic matter active phase of this soil was stable
against decomposition under N. N application on chernozem in reverse
significantly increased SOM decomposition and affected plant productivity to a
lesser degree. Thus, N fertilizing favors C sink in arable soils of low
fertility and can reduce soil C
accumulation in arable soils of high fertility.
Author's Names: A.S. Tulina, T.V. Kuznetsova, and V.M. Semenov
Filesize: 89.25 Kb
Added on: 08-Aug-2005 Downloads: 19
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