scholarly journals Large-Scale Analysis of the Spatiotemporal Changes of Net Ecosystem Production in Hindu Kush Himalayan Region

2021 ◽  
Vol 13 (6) ◽  
pp. 1180
Author(s):  
Da Guo ◽  
Xiaoning Song ◽  
Ronghai Hu ◽  
Xinming Zhu ◽  
Yazhen Jiang ◽  
...  
Keyword(s):  
Large Scale ◽  
Net Primary Production ◽  
Carbon Sink ◽  
Carbon Sources ◽  
Spatial Dynamics ◽  
Tibet Plateau ◽  
Geostatistical Model ◽  
Hindu Kush ◽  
Temporal And Spatial ◽  
The Difference

The Hindu Kush Himalayan (HKH) region is one of the most ecologically vulnerable regions in the world. Several studies have been conducted on the dynamic changes of grassland in the HKH region, but few have considered grassland net ecosystem productivity (NEP). In this study, we quantitatively analyzed the temporal and spatial changes of NEP magnitude and the influence of climate factors on the HKH region from 2001 to 2018. The NEP magnitude was obtained by calculating the difference between the net primary production (NPP) estimated by the Carnegie–Ames Stanford Approach (CASA) model and the heterotrophic respiration (Rh) estimated by the geostatistical model. The results showed that the grassland ecosystem in the HKH region exhibited weak net carbon uptake with NEP values of 42.03 gC∙m−2∙yr−1, and the total net carbon sequestration was 0.077 Pg C. The distribution of NEP gradually increased from west to east, and in the Qinghai–Tibet Plateau, it gradually increased from northwest to southeast. The grassland carbon sources and sinks differed at different altitudes. The grassland was a carbon sink at 3000–5000 m, while grasslands below 3000 m and above 5000 m were carbon sources. Grassland NEP exhibited the strongest correlation with precipitation, and it had a lagging effect on precipitation. The correlation between NEP and the precipitation of the previous year was stronger than that of the current year. NEP was negatively correlated with temperature but not with solar radiation. The study of the temporal and spatial dynamics of NEP in the HKH region can provide a theoretical basis to help herders balance grazing and forage.

scholarly journals Trends and regional distributions of land and ocean carbon sinks

2010 ◽  
Vol 7 (8) ◽  
pp. 2351-2367 ◽  
Author(s):  
J. L. Sarmiento ◽  
M. Gloor ◽  
N. Gruber ◽  
C. Beaulieu ◽  
A. R. Jacobson ◽  
...  
Keyword(s):  
Carbon Sink ◽  
Carbon Sources ◽  
Mean Value ◽  
Ocean Model ◽  
Time Interval ◽  
Sources And Sinks ◽  
Sign Convention ◽  
Net Flux ◽  
The Difference ◽  
Ocean Carbon

Abstract. We show here an updated estimate of the net land carbon sink (NLS) as a function of time from 1960 to 2007 calculated from the difference between fossil fuel emissions, the observed atmospheric growth rate, and the ocean uptake obtained by recent ocean model simulations forced with reanalysis wind stress and heat and water fluxes. Except for interannual variability, the net land carbon sink appears to have been relatively constant at a mean value of −0.27 Pg C yr−1 between 1960 and 1988, at which time it increased abruptly by −0.88 (−0.77 to −1.04) Pg C yr−1 to a new relatively constant mean of −1.15 Pg C yr−1 between 1989 and 2003/7 (the sign convention is negative out of the atmosphere). This result is detectable at the 99% level using a t-test. The land use source (LU) is relatively constant over this entire time interval. While the LU estimate is highly uncertain, this does imply that most of the change in the net land carbon sink must be due to an abrupt increase in the land sink, LS = NLS – LU, in response to some as yet unknown combination of biogeochemical and climate forcing. A regional synthesis and assessment of the land carbon sources and sinks over the post 1988/1989 period reveals broad agreement that the Northern Hemisphere land is a major sink of atmospheric CO2, but there remain major discrepancies with regard to the sign and magnitude of the net flux to and from tropical land.

scholarly journals Transport of Goods Powered by Cereal Straw: Temporal and Spatial Biomass Availability for Future Bio-LNG Production in Germany

2020 ◽  
Author(s):  
André Brosowski ◽  
Ralf Bill ◽  
Daniela Thrän
Keyword(s):  
Large Scale ◽  
Transport Sector ◽  
Data Sets ◽  
Climate Target ◽  
Cereal Straw ◽  
Arable Fields ◽  
Biomethane Production ◽  
Temporal And Spatial ◽  
The Difference ◽  
Biomass Availability

Abstract Background: Half of the UN climate target for 2030 has been achieved and further progress requires swiftly implementable solutions. In this context, the fermentation of cereal straw is a promising option. Returning the digestate to the farmland can close agricultural cycles while simultaneously producing biomethane for the transport sector. The world's first large-scale, mono-digestion plant for straw is operational since 2014. The temporal and spatial biomass availability is a key issue when replicating this concept. No detailed calculations on this subject are available, and the strategic relevance of biomethane from straw in the transport sector cannot be sufficiently evaluated.Methods: To assess the balance of straw supply and use, a total of 30 data sets are combined, taking into account the cultivation of the five most important cereal types and the straw required for ten animal species, two special crops and twelve industrial uses. The data are managed at district level and presented for the years 2010 to 2018. In combination with high-resolution geodata, the results are linked to actual arable fields, and the availability of straw throughout the country is evaluated using a GIS.Results: During the analysis period, the mobilisable potential for future biomethane production is between 13.9–21.5 Tg fm a-1; this is up to 62 % higher than the previously known level. The annual potential fluctuates considerably due to weather anomalies. The all-time maximum in 2014 and the minimum for the last 26 years in 2018 are separated by just four years and a difference of 7.6 Tg fm. However, large parts of the potential are concentrated only in a few regions and liquefied biomethane could fully cover the fuel required for vessels, and up to a quarter of that for heavy goods vehicles. Up to 11.3 Tg CO2-eq. could be saved, reducing the difference to achieve the UN climate target by 3.7 %.Conclusion: Despite the strong fluctuations, the potential is sufficient to supply numerous plants and to produce relevant quantities of liquefied biomethane even in weak years. To unlock the potential, the outcomes should be discussed further with stakeholders in the identified priority regions.

scholarly journals Climate-driven shifts in continental net primary production implicated as a driver of a recent abrupt increase in the land carbon sink

2016 ◽  
Vol 13 (5) ◽  
pp. 1597-1607 ◽  
Author(s):  
Wolfgang Buermann ◽  
Claudie Beaulieu ◽  
Bikash Parida ◽  
David Medvigy ◽  
George J. Collatz ◽  
...  
Keyword(s):  
Climate Variability ◽  
Primary Production ◽  
North Atlantic ◽  
Large Scale ◽  
Net Primary Production ◽  
Carbon Sink ◽  
Northern Eurasia ◽  
Sink Strength ◽  
Independent Evidence ◽  
The North

Abstract. The world's ocean and land ecosystems act as sinks for anthropogenic CO2, and over the last half century their combined sink strength grew steadily with increasing CO2 emissions. Recent analyses of the global carbon budget, however, have uncovered an abrupt, substantial ( ∼  1 PgC yr−1) and sustained increase in the land sink in the late 1980s whose origin remains unclear. In the absence of this prominent shift in the land sink, increases in atmospheric CO2 concentrations since the late 1980s would have been  ∼  30 % larger than observed (or  ∼  12 ppm above current levels). Global data analyses are limited in regards to attributing causes to changes in the land sink because different regions are likely responding to different drivers. Here, we address this challenge by using terrestrial biosphere models constrained by observations to determine if there is independent evidence for the abrupt strengthening of the land sink. We find that net primary production significantly increased in the late 1980s (more so than heterotrophic respiration), consistent with the inferred increase in the global land sink, and that large-scale climate anomalies are responsible for this shift. We identify two key regions in which climatic constraints on plant growth have eased: northern Eurasia experienced warming, and northern Africa received increased precipitation. Whether these changes in continental climates are connected is uncertain, but North Atlantic climate variability is important. Our findings suggest that improved understanding of climate variability in the North Atlantic may be essential for more credible projections of the land sink under climate change.

scholarly journals Satellite-inferred European carbon sink larger than expected

2014 ◽  
Vol 14 (24) ◽  
pp. 13739-13753 ◽  
Author(s):  
M. Reuter ◽  
M. Buchwitz ◽  
M. Hilker ◽  
J. Heymann ◽  
O. Schneising ◽  
...  
Keyword(s):  
Large Scale ◽  
Current Knowledge ◽  
Carbon Sink ◽  
A Priori ◽  
Surface Flux ◽  
Satellite Observation ◽  
Particle Dispersion ◽  
The Difference ◽  
Using Data

Abstract. Current knowledge about the European terrestrial biospheric carbon sink, from the Atlantic to the Urals, relies upon bottom-up inventory and surface flux inverse model estimates (e.g. 0.27±0.16 GtC a−1 for 2000–2005 (Schulze et al., 2009), 0.17±0.44 GtC a−1 for 2001–2007 (Peters et al., 2010), 0.45±0.40 GtC a−1 for 2010 (Chevallier et al., 2014), 0.40±0.42 GtC a−1 for 2001–2004 (Peylin et al., 2013)). Inverse models assimilate in situ CO2 atmospheric concentrations measured by surface-based air sampling networks. The intrinsic sparseness of these networks is one reason for the relatively large flux uncertainties (Peters et al., 2010; Bruhwiler et al., 2011). Satellite-based CO2 measurements have the potential to reduce these uncertainties (Miller et al., 2007; Chevallier et al., 2007). Global inversion experiments using independent models and independent GOSAT satellite data products consistently derived a considerably larger European sink (1.0–1.3 GtC a−1 for 09/2009–08/2010 (Basu et al., 2013), 1.2–1.8 GtC a−1 in 2010 (Chevallier et al., 2014)). However, these results have been considered unrealistic due to potential retrieval biases and/or transport errors (Chevallier et al., 2014) or have not been discussed at all (Basu et al., 2013; Takagi et al., 2014). Our analysis comprises a regional inversion approach using STILT (Gerbig et al., 2003; Lin et al., 2003) short-range (days) particle dispersion modelling, rendering it insensitive to large-scale retrieval biases and less sensitive to long-range transport errors. We show that the satellite-derived European terrestrial carbon sink is indeed much larger (1.02±0.30 GtC a−1 in 2010) than previously expected. This is qualitatively consistent among an ensemble of five different inversion set-ups and five independent satellite retrievals (BESD (Reuter et al., 2011) 2003–2010, ACOS (O’Dell et al., 2012) 2010, UoL-FP (Cogan et al., 2012) 2010, RemoTeC (Butz et al., 2011) 2010, and NIES (Yoshida et al., 2013) 2010) using data from two different instruments (SCIAMACHY (Bovensmann et al., 1999) and GOSAT (Kuze et al., 2009)). The difference to in situ based inversions (Peylin et al., 2013), whilst large with respect to the mean reported European carbon sink (0.4 GtC a−1 for 2001–2004), is similar in magnitude to the reported uncertainty (0.42 GtC a−1). The highest gain in information is obtained during the growing season when satellite observation conditions are advantageous, a priori uncertainties are largest, and the surface sink maximises; during the dormant season, the results are dominated by the a priori. Our results provide evidence that the current understanding of the European carbon sink has to be revisited.

scholarly journals Analysis of Carbon Flux in Terrestrial Ecosystems from GOSAT Data in China

2018 ◽  
Vol 53 ◽  
pp. 03012
Author(s):  
Lanlan Zhang ◽  
Jinye Zhang ◽  
Hui Lv ◽  
Bangwu Sun
Keyword(s):  
Carbon Storage ◽  
Carbon Flux ◽  
Storage Capacity ◽  
Carbon Sink ◽  
Carbon Sources ◽  
Net Ecosystem Exchange ◽  
Terrestrial Ecosystems ◽  
Vegetation Coverage ◽  
Temporal And Spatial Distribution ◽  
Temporal And Spatial

In recent years, the evaluation of carbon sources and carbon sinks has become one of the major research topics. The temporal and spatial distribution of carbon flux and some factors that affect carbon flux were analyzed in this paper based on the Net Ecosystem Exchange (NEE) data, which were provided by Greenhouse Gases Observing Satellite (GOSAT) project and FLUXNET project. Then, we found that carbon flux had obvious seasonal variation. It was carbon sink in summer and carbon source in winter. The total amount of carbon flux in July or August was about -1.377 ~ -1.882 gcm-2day-1, and 0.64 gcm-2day-1 in November. The fluctuation of carbon flux in coastal area was stronger than that in inland. Forest areas had stronger carbon storage capacity than that in other vegetation areas, and the flux in forest areas had the largest change. The vegetation coverage was larger, and the carbon storage capacity was stronger.

scholarly journals Climate-driven shifts in continental net primary production implicated as a driver of a recent abrupt increase in the land carbon sink

2015 ◽  
Vol 12 (16) ◽  
pp. 13767-13791
Author(s):  
W. Buermann ◽  
C. Beaulieu ◽  
B. Parida ◽  
D. Medvigy ◽  
G. J. Collatz ◽  
...  
Keyword(s):  
Climate Variability ◽  
Primary Production ◽  
North Atlantic ◽  
Large Scale ◽  
Net Primary Production ◽  
Carbon Sink ◽  
Northern Eurasia ◽  
Sink Strength ◽  
Independent Evidence ◽  
The North

Abstract. The World's ocean and land ecosystems act as sinks for anthropogenic CO2, and over the last half century their combined sink strength grew steadily with increasing CO2 emissions. Recent analyses of the global carbon budget, however, uncovered an abrupt, substantial (~ 1 PgC yr−1) and sustained increase in the land sink in the late 1980s whose origin remains unclear. In the absence of this prominent shift in the land sink, increases in atmospheric CO2 concentrations since the late 1980s would have been ~ 30 % larger than observed (or ~ 12 ppm above current levels). Global data analyses are limited in regards to attributing causes to changes in the land sink because different regions are likely responding to different drivers. Here, we address this challenge by using terrestrial biosphere models constrained by observations to determine if there is independent evidence for the abrupt strengthening of the land sink. We find that net primary production has significantly increased in the late 1980s (more so than heterotrophic respiration) consistent with the inferred increase in the global land sink, and that large-scale climate anomalies are responsible for this shift. We identify two key regions in which climatic constraints on plant growth have eased: northern Eurasia experienced warming, and northern Africa received increased precipitation. Whether these changes in continental climates are connected is uncertain, but North Atlantic climate variability is important. Our findings suggest that improved understanding of climate variability in the North Atlantic may be essential for more credible projections of the land sink under climate change.

Die Kohlenstoff-Senkenkapazität des Schweizer Waldes | Carbon sink capacity of Swiss forests

2008 ◽  
Vol 159 (9) ◽  
pp. 273-280
Author(s):  
Annett Wolf
Keyword(s):  
Large Scale ◽  
Carbon Sink ◽  
Carbon Sources ◽  
Growth Potential ◽  
Carbon Uptake ◽  
Sink Strength ◽  
Sink Capacity ◽  
Climate Influences ◽  
Management Changes

To assess the carbon sink capacity of Swiss forests, we summarize what is known about the carbon content of Swiss forests today, considering carbon stored in the trees as well as in soils. We explain briefly how climate influences carbon uptake and carbon emissions from forest ecosystems. Finally, we analyze simulation studies, which investigate the future development of carbon pools and fluxes in Swiss forests. We found that carbon stocks in Swiss forests are already high today, hence the growth potential that would lead to further carbon uptake is comparatively small. Still, within the next decades Swiss forests are likely to act as carbon sinks as long as management does not change dramatically. The afforestation of abandoned land and the change in treeline will be mainly responsible for the additional uptake of carbon. In the next decades, management decisions will influence the sink strength of Swiss forests more than climatic changes. In the long term, the sink capacity of forests is likely to decrease and in case of drastic climatic or management changes, the forests can even become large-scale carbon sources.

scholarly journals Trends and regional distributions of land and ocean carbon sinks

2009 ◽  
Vol 6 (6) ◽  
pp. 10583-10624 ◽  
Author(s):  
J. L. Sarmiento ◽  
M. Gloor ◽  
N. Gruber ◽  
C. Beaulieu ◽  
A. R. Jacobson ◽  
...  
Keyword(s):  
Growth Rate ◽  
Climate Model ◽  
Carbon Sink ◽  
Carbon Sources ◽  
Ocean Model ◽  
Model Simulations ◽  
Sources And Sinks ◽  
Sign Convention ◽  
The Difference ◽  
Ocean Carbon

Abstract. We show here a new estimate of the variability and long-term trends in the net land carbon sink from 1960 onwards calculated from the difference between fossil fuel emissions, the observed atmospheric growth rate, and the ocean uptake obtained by recent ocean model simulations forced with reanalysis wind stress and heat and water fluxes. The net land carbon sink appears to have increased by −0.88 (−0.77 to −1.04) Pg C yr−1 after ~1988/1989 from a relatively constant mean of −0.27 Pg C yr−1 before then to −1.15 Pg C yr−1 thereafter (the sign convention is negative out of the atmosphere). This result is significant at the 1% critical level. The increase in net land uptake is partially compensated by a reduction in the expected oceanic uptake, which we estimate from model simulations as about 0.35 (0.26 to 0.49) Pg C yr−1. This implies that the atmospheric growth rate must have decreased by about −0.53 (−0.51 to −0.55) Pg C yr−1 (equivalent to −0.25 ppm yr−1) below what would have been projected if the ocean uptake had continued to grow at the rate expected from a constant climate model and if the net land uptake had continued at its pre-1988/1989 level. A regional synthesis and assessment of the land carbon sources and sinks over the post 1988/1989 period reveals broad agreement that the northern hemisphere land is a major sink of atmospheric CO2, but there remain major discrepancies with regard to the sign and magnitude of the net flux to and from tropical land.

Relationship between total plasma homocysteine and the risk of aneurysms – a meta-analysis

VASA ◽  
2020 ◽  
pp. 1-6
Author(s):  
Hanji Zhang ◽  
Dexin Yin ◽  
Yue Zhao ◽  
Yezhou Li ◽  
Dejiang Yao ◽  
...  
Keyword(s):  
Large Scale ◽  
Meta Analysis ◽  
Single Species ◽  
Total Plasma ◽  
Control Groups ◽  
Randomized Controlled ◽  
Randomized Controlled Studies ◽  
The Difference ◽  
The Relationship ◽  
Healthy Participants

Summary: Our meta-analysis focused on the relationship between homocysteine (Hcy) level and the incidence of aneurysms and looked at the relationship between smoking, hypertension and aneurysms. A systematic literature search of Pubmed, Web of Science, and Embase databases (up to March 31, 2020) resulted in the identification of 19 studies, including 2,629 aneurysm patients and 6,497 healthy participants. Combined analysis of the included studies showed that number of smoking, hypertension and hyperhomocysteinemia (HHcy) in aneurysm patients was higher than that in the control groups, and the total plasma Hcy level in aneurysm patients was also higher. These findings suggest that smoking, hypertension and HHcy may be risk factors for the development and progression of aneurysms. Although the heterogeneity of meta-analysis was significant, it was found that the heterogeneity might come from the difference between race and disease species through subgroup analysis. Large-scale randomized controlled studies of single species and single disease species are needed in the future to supplement the accuracy of the results.

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