Contribution of natural and drained wetland systems to carbon stocks, CO2, N2O, and CH4 fluxes: an Australian perspective

Soil Research ◽  
2011 ◽  
Vol 49 (5) ◽  
pp. 377 ◽  
Author(s):  
K. L. Page ◽  
R. C. Dalal
Keyword(s):  
Greenhouse Gas ◽  
Carbon Sources ◽  
Ghg Emissions ◽  
Co2 Flux ◽  
Carbon Stocks ◽  
Carbon Accounting ◽  
Natural State ◽  
Climatic Zones ◽  
Forest Wetlands ◽  
Ch4 And N2o

Greenhouse gas (GHG) flux from wetland systems, both in their natural state and following drainage, has not been well accounted for in the carbon accounting process. We review GHG production from both natural and drained wetlands, and estimate the likely GHG emissions from these systems in Australia. Only a small number of studies have quantified GHG emissions from undisturbed Australian wetland environments. Consequently, in order to estimate GHG flux for Australia, it was necessary to collate data collected overseas from similar climatic zones. Using this approach, it appears that undisturbed, vegetated wetlands in Australia are likely to be net GHG sinks, with the greatest rates of sequestration occurring in mangrove ecosystems (–2669 g CO2-e/m2.year) where biomass production is high but CH4 emissions are limited by salinity. The uncertainty surrounding these values is high, however, due to (a) the low number of measurements from Australia, (b) the low number of measurements for CO2 flux, and (c) the low number of studies where all GHGs have been measured concurrently. It was estimated that the drainage of melaleuca and mangrove forest wetlands in Australia would turn them from carbon sinks into carbon sources, and that in the first 50 years since drainage, this has increased global warming potential by 1149 Tg CO2-e or 23 Tg CO2-e/year. This is significant given that GHG emissions due to land-use change in 2007 totalled 77.1 Tg CO2-e. However, data surrounding the area of wetlands drained, carbon stocks in drained wetlands, and the effect of drainage on CH4 and N2O flux are limited, making the uncertainty surrounding these estimates high. Further study is clearly required if Australia wishes to accurately incorporate wetland systems into national carbon and greenhouse gas accounting budgets.

scholarly journals Effects of Forage Rice Cultivation on Carbon and Greenhouse Gas Balances in a Rice Paddy Field

Atmosphere ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 504 ◽  
Author(s):  
Fumiaki Takakai ◽  
Masahiro Kobayashi ◽  
Takashi Sato ◽  
Kentaro Yasuda ◽  
Yoshihiro Kaneta
Keyword(s):  
Greenhouse Gas ◽  
Paddy Field ◽  
Net Primary Production ◽  
Ghg Emissions ◽  
Co2 Flux ◽  
Rice Paddy ◽  
Bare Soil ◽  
Rice Cultivation ◽  
Forage Rice ◽  
Ch4 And N2o

The effects of conversion from staple rice to forage rice on carbon and greenhouse gas (GHG) balances in a paddy field were evaluated. A staple rice plot without the application of livestock manure compost (LMC, S − M plot) and forage rice plots with and without the application of LMC, derived mainly from cattle (2 kg−FW m−2, F + M and F − M plots, respectively), were established. CH4 and N2O fluxes and CO2 flux from a bare soil plot for organic matter decomposition (OMD) were measured. The carbon budget was calculated by subtracting the OMD, CH4 emission, and harvested grain and straw (forage rice only) from the net primary production and LMC. The net GHG balance was calculated by integrating them as CO2 equivalents. There were no significant differences in GHG flux among the plots. Compared to the carbon loss in the S − M plot, the loss increased by harvesting straw and was mitigated by LMC application. The net GHG emission in the F + M plot was significantly lower than that in other plots (1.78 and 2.63−2.77 kg CO2-eq m−2 year−1, respectively). There is a possibility that GHG emissions could be suppressed by forage rice cultivation with the application of LMC.

scholarly journals Greenhouse gas balance of cropland conversion to bioenergy poplar short-rotation coppice

2016 ◽  
Vol 13 (1) ◽  
pp. 95-113 ◽  
Author(s):  
S. Sabbatini ◽  
N. Arriga ◽  
T. Bertolini ◽  
S. Castaldi ◽  
T. Chiti ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Arable Land ◽  
Hybrid Poplar ◽  
Ghg Emissions ◽  
Net Ecosystem Exchange ◽  
Short Rotation Coppice ◽  
Co2 Uptake ◽  
Greenhouse Gas Balance ◽  
Short Rotation ◽  
Ch4 And N2o

Abstract. The production of bioenergy in Europe is one of the strategies conceived to reduce greenhouse gas (GHG) emissions. The suitability of the land use change from a cropland (REF site) to a short-rotation coppice plantation of hybrid poplar (SRC site) was investigated by comparing the GHG budgets of these two systems over 24 months in Viterbo, Italy. This period corresponded to a single rotation of the SRC site. The REF site was a crop rotation between grassland and winter wheat, i.e. the same management of the SRC site before the conversion to short-rotation coppice. Eddy covariance measurements were carried out to quantify the net ecosystem exchange of CO2 (FCO2), whereas chambers were used to measure N2O and CH4 emissions from soil. The measurements began 2 years after the conversion of arable land to SRC so that an older poplar plantation was used to estimate the soil organic carbon (SOC) loss due to SRC establishment and to estimate SOC recovery over time. Emissions from tractors and from production and transport of agricultural inputs (FMAN) were modelled. A GHG emission offset, due to the substitution of natural gas with SRC biomass, was credited to the GHG budget of the SRC site. Emissions generated by the use of biomass (FEXP) were also considered. Suitability was finally assessed by comparing the GHG budgets of the two sites. CO2 uptake was 3512 ± 224 g CO2 m−2 at the SRC site in 2 years, and 1838 ± 107 g CO2 m−2 at the REF site. FEXP was equal to 1858 ± 240 g CO2 m−2 at the REF site, thus basically compensating for FCO2, while it was 1118 ± 521 g CO2 m−2 at the SRC site. The SRC site could offset 379.7 ± 175.1 g CO2eq m−2 from fossil fuel displacement. Soil CH4 and N2O fluxes were negligible. FMAN made up 2 and 4 % in the GHG budgets of SRC and REF sites respectively, while the SOC loss was 455 ± 524 g CO2 m−2 in 2 years. Overall, the REF site was close to neutrality from a GHG perspective (156 ± 264 g CO2eq m−2), while the SRC site was a net sink of 2202 ± 792 g CO2eq m−2. In conclusion the experiment led to a positive evaluation from a GHG viewpoint of the conversion of cropland to bioenergy SRC.

Processes and magnitude of CO2, CH4, and N2O fluxes from liming of Australian acidic soils: a review

Soil Research ◽  
2009 ◽  
Vol 47 (8) ◽  
pp. 747 ◽  
Author(s):  
K. L. Page ◽  
D. E. Allen ◽  
R. C. Dalal ◽  
W. Slattery
Keyword(s):  
Agricultural Soils ◽  
Ghg Emissions ◽  
Primary Objective ◽  
Carbon Accounting ◽  
Accounting System ◽  
Biological Processes ◽  
Recent Approach ◽  
Tier 1 ◽  
Ch4 And N2o ◽  
Induced Changes

Increases in soil acidification have led to large increases in the application of aglime to Australian agricultural soils. The addition of aglime has the potential to increase greenhouse gas (GHG) emissions due to the release of CO2 during the chemical dissolution of aglime and due to pH-induced changes to soil biological processes. Currently, Australia’s GHG accounting system assumes that all the carbon contained in aglime is released to the atmosphere during dissolution in accordance with the Tier 1 methodology of the IPCC. However, a recent approach by TO West and AC McBride has questioned this assumption, hypothesising that a proportion of the carbon from riverine-transported aglime may be sequestered in seawater. In addition, there is presently no capacity within Australia’s carbon accounting system to quantify changes to GHG emissions from lime-induced changes to soil biological processes. Therefore, the primary objective of this review was to examine the chemical and biological processes occurring during the application of aglime and the subsequent fluxes in CO2, N2O, and CH4 from soil, with particular reference to the Australian environment. Estimates for CO2 emissions from aglime application in Australia using the contrasting methodologies of the IPCC and West and McBride were compared. Using the methodology of the IPCC it was determined that from the aglime applied in Australia in 2002, 0.995 Tg of CO2 would have been emitted, whereas this figure was reduced to 0.659–0.860 Tg of CO2 using the methodology of West and McBride. However, the accuracy of these estimates is currently limited by poor understanding of the manner in which aglime moves within the Australian landscapes. In addition, there are only a very small number of Australian studies that have examined the effect of aglime on GHG emissions due to changes in soil biological processes, limiting the ability of Australian modellers to accurately incorporate these processes within the carbon accounting system.

scholarly journals A closed-chamber method to measure greenhouse gas fluxes from dry aquatic sediments

2017 ◽  
Vol 10 (6) ◽  
pp. 2377-2382 ◽  
Author(s):  
Lukas Lesmeister ◽  
Matthias Koschorreck
Keyword(s):  
Greenhouse Gas ◽  
Field Experiments ◽  
Ghg Emissions ◽  
Co2 Flux ◽  
No Production ◽  
Co2 Fluxes ◽  
Aquatic Sediments ◽  
Closed Chamber ◽  
Sealing Material ◽  
Gas Fluxes

Abstract. Recent research indicates that greenhouse gas (GHG) emissions from dry aquatic sediments are a relevant process in the freshwater carbon cycle. However, fluxes are difficult to measure because of the often rocky substrate and the dynamic nature of the habitat. Here we tested the performance of different materials to seal a closed chamber to stony ground both in laboratory and field experiments. Using on-site material consistently resulted in elevated fluxes. The artefact was caused both by outgassing of the material and production of gas. The magnitude of the artefact was site dependent – the measured CO2 flux increased between 10 and 208 %. Errors due to incomplete sealing proved to be more severe than errors due to non-inert sealing material.Pottery clay as sealing material provided a tight seal between the chamber and the ground and no production of gases was detected. With this approach it is possible to get reliable gas fluxes from hard-substrate sites without using a permanent collar. Our test experiments confirmed that CO2 fluxes from dry aquatic sediments are similar to CO2 fluxes from terrestrial soils.

Voluntary Emissions Reduction

2011 ◽  
pp. 241-273
Author(s):  
Robert Bailis ◽  
Neda Arabshahi
Keyword(s):  
United Nations ◽  
Greenhouse Gas ◽  
Ghg Emissions ◽  
Carbon Accounting ◽  
Emissions Reduction ◽  
Comparable Data ◽  
Firm Level ◽  
Global Compact ◽  
Emission Reductions ◽  
Set Up

While binding regulations on greenhouse gas (GHG) emissions have yet to be introduced outside of a limited number of high-emitting sectors in the EU, several organizations have set up voluntary GHG programs that promote firm-level inventories and/or emission reductions. Many argue that these programs are not forceful or rigorous enough to result in real emissions reductions and may simply encourage “greenwashing.” In 2007, the United Nations Global Compact initiated the voluntary Caring for Climate (C4C) platform for businesses wishing to demonstrate climate leadership. To assess how voluntary emissions reduction programs have performed, this study examines the progress that C4C signatories have made. The results show widely dispersed GHG quantities and a range of reduction plans. Due to the lack of uniform, comparable data, the authors call for standardized, clearly defined carbon accounting guidelines as the first step towards effective corporate GHG management.

scholarly journals Assessing the carbon capture potential of a reforestation project

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
David Lefebvre ◽  
Adrian G. Williams ◽  
Guy J. D. Kirk ◽  
Paul ◽  
J. Burgess ◽  
...  
Keyword(s):  
Carbon Capture ◽  
Ghg Emissions ◽  
Anthropogenic Disturbances ◽  
Carbon Stocks ◽  
Carbon Accounting ◽  
Environmental Costs ◽  
Peruvian Amazon ◽  
Ecosystem Level ◽  
Below Ground ◽  
Climatic Disturbances

AbstractThe number of reforestation projects worldwide is increasing. In many cases funding is obtained through the claimed carbon capture of the trees, presented as immediate and durable, whereas reforested plots need time and maintenance to realise their carbon capture potential. Further, claims usually overlook the environmental costs of natural or anthropogenic disturbances during the forest’s lifetime, and greenhouse gas (GHG) emissions associated with the reforestation are not allowed for. This study uses life cycle assessment to quantify the carbon footprint of setting up a reforestation plot in the Peruvian Amazon. In parallel, we combine a soil carbon model with an above- and below-ground plant carbon model to predict the increase in carbon stocks after planting. We compare our results with the carbon capture claims made by a reforestation platform. Our results show major errors in carbon accounting in reforestation projects if they (1) ignore the time needed for trees to reach their carbon capture potential; (2) ignore the GHG emissions involved in setting up a plot; (3) report the carbon capture potential per tree planted, thereby ignoring limitations at the forest ecosystem level; or (4) under-estimate tree losses due to inevitable human and climatic disturbances. Further, we show that applications of biochar during reforestation can partially compensate for project emissions.

scholarly journals Animal nutrition strategies to reduce greenhouse gas emissions in dairy cattle

2018 ◽  
Vol 28 (5) ◽  
pp. 34-41
Author(s):  
Juan Antonio Rendon-Huerta ◽  
Juan Manuel Pinos-Rodríguez ◽  
Ermias Kebreab
Keyword(s):  
Dairy Cattle ◽  
Greenhouse Gas ◽  
Dietary Protein ◽  
Ghg Emissions ◽  
N2o Emission ◽  
Nitrogen Excretion ◽  
Animal Nutrition ◽  
Intergovernmental Panel ◽  
Ch4 And N2o ◽  
Forage:Concentrate Ratio

The objective of this study was to analyze different animal nutrition strategies from published papers to reduce greenhouse gas (GHG) emissions, particularly methane (CH4) and nitrous oxide (N2O) in dairy cattle. Ration data used (n = 32 diets) was obtained from 15 published papers selected according to differences between forage:concentrate ratio and crude protein (CP) content. An empirical model was used to estimate enteric methane emissions based on fiber and CP content in the diets. The N2O emission was calculated according to Intergovernmental Panel of Climate Change (IPCC) recommendations. Differences between CH4 and N2O affected by FC or CP content were analyzed through a variance analysis. Furthermore, a correlation analysis was carried out to compare CP content and nitrogen excretion in feces, urine and milk. Estimations of enteric CH4 were not significantly different between diets with various forage content levels. Diets with high concentrate content had lower GHG intensity. Nitrogen excretion in feces and urine increased linearly as dietary protein level was increased from the lowest to the highest concentrations, but conversion of nitrogen intake to nitrogen excreted in milk was not affected by increasing dietary protein. In conclusion, dietary manipulation could decrease GHG emissions by unit of produced milk. 

scholarly journals Estimating greenhouse gas fluxes from an agriculture-dominated landscape using multiple planetary boundary layer methods

2014 ◽  
Vol 14 (3) ◽  
pp. 3231-3267 ◽  
Author(s):  
X. Zhang ◽  
X. Lee ◽  
T. J. Griffis ◽  
J. M. Baker ◽  
W. Xiao
Keyword(s):  
Greenhouse Gas ◽  
Eddy Covariance ◽  
Co2 Flux ◽  
N2o Emissions ◽  
Top Down ◽  
Equilibrium Method ◽  
Flux Aggregation ◽  
Ch4 And N2o ◽  
Ghg Fluxes ◽  
Tall Tower

Abstract. Quantification of regional greenhouse gas (GHG) fluxes is essential for establishing mitigation strategies and evaluating their effectiveness. Here, we used multiple top-down approaches and multiple trace gas observations at a tall tower to estimate GHG regional fluxes and evaluate the GHG fluxes derived from bottom-up approaches. We first applied the eddy covariance, equilibrium, inverse modeling (CarbonTracker), and flux aggregation methods using three years of carbon dioxide (CO2) measurements on a 244 m tall tower in the Upper Midwest, USA. We then applied the equilibrium method for estimating methane (CH4) and nitrous oxide (N2O) fluxes with one-month high-frequency CH4 and N2O gradient measurements on the tall tower and one-year concentration measurements on a nearby tall tower, and evaluated the uncertainties of this application. The results indicate that: (1) the flux aggregation, eddy covariance, the equilibrium method, and the CarbonTracker product all gave similar seasonal patterns of the regional CO2 flux (105–106 km2), but that the equilibrium method underestimated the July CO2 flux by 52–69%. (2) The annual budget varied among these methods from 74 to −131 g C-CO2 m−2 yr−1, indicating a large uncertainty in the annual CO2 flux estimation. (3) The regional CH4 and N2O emissions according to a top-down method were at least six and two times higher than the emissions from a bottom-up inventory (Emission Database for Global Atmospheric Research), respectively. (4) The global warming potentials of the CH4 and N2O emissions were equal in magnitude to the cooling benefit of the regional CO2 uptake. The regional GHG budget, including both biological and anthropogenic origins, is estimated at 7 ± 160 g CO2 eq m−2 yr−1.

Modelled greenhouse gas emissions from beef cattle grazing irrigated leucaena in northern Australia

2016 ◽  
Vol 56 (3) ◽  
pp. 594 ◽  
Author(s):  
Chris A. Taylor ◽  
Matthew T. Harrison ◽  
Marnie Telfer ◽  
Richard Eckard
Keyword(s):  
Beef Cattle ◽  
Greenhouse Gas ◽  
Effective Means ◽  
Ghg Emissions ◽  
Cattle Grazing ◽  
Carbon Stocks ◽  
Total Carbon ◽  
Native Vegetation ◽  
Ghg Emission ◽  
Livestock Emissions

Agriculture produces an estimated 14.5% of global anthropogenic greenhouse gases, with livestock emissions being the largest source of enteric methane. Reducing greenhouse gas (GHG) emissions from production and processing of beef cattle will become increasingly important with time, particularly in line with global efforts to mitigate rising GHG emissions. The present study compared several GHG emission scenarios from beef cattle grazing on irrigated Leucaena leucocephala (Lam.) de Wit cv. Cunningham (leucaena) in Queensland, Australia. Animals began grazing the leucaena paddocks when they were 16 months old and continued until ~240 days, before being sold to market. Three scenarios were modelled with cattle grazing leucaena and the resulting GHG emissions calculated, representing (1) the current leucaena paddock (current leucaena scenario), (2) clearing native vegetation and extending the leucaena paddock (extended leucaena scenario) and (3) extending the leucaena paddock onto previously cleared paddocks (alternative leucaena scenario). These were compared with a pre-scenario baseline, where the steers grazed on native vegetation until the time of sale. Herd GHG emission intensities (EI) were reduced in comparison with the baseline (EI of 8.4 tCO2-e/t liveweight sold) for all the leucaena scenarios, where reductions were modelled for the current, extended and alternative leucaena scenarios, which had an EI of 3.9, 3.7 and 3.6 tCO2-e/ t liveweight sold, respectively. Reductions were attributed to the higher growth rates of the steers on leucaena and the anti-methanogenic potential of leucaena. Where leucaena was planted on previously cleared paddocks, carbon stocks (t C/ha) nearly doubled a decade following planting, with most carbon sequestered in the soil. However, total carbon stocks on the property reduced over the modelled period (112 years), where native vegetation, e.g. eucalyptus woodland, was cleared for leucaena planting, but soil carbon yield increased. The combined sequestration of leucaena and the reduction of GHG emission intensities resulted in overall net reductions of GHG emissions for the three leucaena scenarios compared with the baseline. These results demonstrated that the use of leucaena for grazing can be an effective means for farmers to reduce the GHG emissions and increase productivity of their herds. The study also demonstrated that it would take 9 years of reduced emissions to compensate for the carbon lost as emissions from clearing the eucalyptus woodland, suggesting that farmers should use other methods of intensifying production from existing leucaena paddocks if their sole purpose is short-term emissions abatement.

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