Interactive comment on "Growing season CH4 and N2O fluxes from a sub-arctic landscape in northern Finland"

2016 ◽  
Author(s):  
Anonymous
Keyword(s):  
Growing Season ◽  
N2o Fluxes ◽  
Ch4 And N2o

scholarly journals Different responses of CO<sub>2</sub>, CH<sub>4</sub>, and N<sub>2</sub>O fluxes to seasonally asymmetric warming in an alpine grassland of Tianshan Mountains

2020 ◽  
Author(s):  
Yanming Gong ◽  
Ping Yue ◽  
Kaihui Li ◽  
Anwar Mohammat ◽  
Yanyan Liu
Keyword(s):  
Temperature Increase ◽  
Response Rate ◽  
Co2 Flux ◽  
Growing Season ◽  
Tianshan Mountains ◽  
Alpine Grassland ◽  
Ch4 Flux ◽  
Greenhouse Gas Flux ◽  
N2o Fluxes ◽  
Ch4 And N2o

Abstract. An experiment was conducted to investigate the effect of seasonally asymmetric warming on CO2, CH4, and N2O fluxes in alpine grassland of Tianshan Mountains of Central Asia, from October 2016 to September 2019. Our results indicated that the CO2, CH4 and N2O fluxes varied in the range 0.56–98.03 mg C m−2 h−1, −94.30–0.23 μg C m−2 h−1, and −1.28–10.09 μg N m−2 h−1, respectively. The CO2 and N2O fluxes were negatively correlated with soil temperature, but the CH4 fluxes decreased with the increase in temperature. Furthermore, the variation in greenhouse gas flux under seasonally asymmetric warming was different between the growing season (June to September) and the non-growing season (October to May). In addition, the response rates of CO2 and N2O fluxes to temperature increases was significantly reduced due to warming throughout the year. Warming during the growing season led to a significant decrease in the response rate of CO2 flux to temperature increases. However, warming during the non-growing season caused a significant increase in the response rate of CO2 flux to temperature increases. The response rate of CH4 flux was insensitive to temperature increase under seasonally asymmetric warming. Thus, the main finding of our results was that seasonally asymmetric warming resulted in different responses in the fluxes of individual greenhouse gases to rising temperatures in the alpine grassland.

scholarly journals Carbon Sequestration and Contribution of CO2, CH4 and N2O Fluxes to Global Warming Potential from Paddy-Fallow Fields on Mineral Soil Beneath Peat in Central Hokkaido, Japan

Agriculture ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 6 ◽  
Author(s):  
Habib Mohammad Naser ◽  
Osamu Nagata ◽  
Sarmin Sultana ◽  
Ryusuke Hatano
Keyword(s):  
Global Warming ◽  
Carbon Sequestration ◽  
Growing Season ◽  
Rice Paddy ◽  
Paddy Fields ◽  
N2o Emissions ◽  
Growing Period ◽  
N2o Fluxes ◽  
Ch4 And N2o ◽  
Winter Fallow

Since each greenhouse gas (GHG) has its own radiative capacity, all three gasses (CO2, CH4 and N2O) must be accounted for by calculating the net global warming potential (GWP) in a crop production system. To compare the impact of GHG fluxes from the rice growing and the fallow season on the annual gas fluxes, and their contribution to the GWP and carbon sequestration (CS) were evaluated. From May to April in Bibai (43°18′ N, 141°44′ E), in central Hokkaido, Japan, three rice paddy fields under actual management conditions were investigated to determine CS and the contribution of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes to GWP. Methane and N2O fluxes were measured by placing the chamber over the rice plants covering four hills and CO2 fluxes from rice plants root free space in paddy fields were taken as an indicator of soil microbial respiration (Rm) using the closed chamber method. Soil CS was calculated as the difference between net primary production (NPP) and loss of carbon (C) through Rm, emission of CH4 and harvest of crop C. Annual cumulative Rm ranged from 422 to 519 g C m−2 yr−1; which accounted for 54.7 to 55.5% of the rice growing season in particular. Annual cumulative CH4 emissions ranged from 75.5 to 116 g C m−2 yr−1 and this contribution occurred entirely during the rice growing period. Total cumulative N2O emissions ranged from 0.091 to 0.154 g N m−2 yr−1 and from 73.5 to 81.3% of the total N2O emissions recorded during the winter-fallow season. The CS ranged from −305 to −365 g C m−2 yr−1, suggesting that C input by NPP may not be compensate for the loss of soil C. The loss of C in the winter-fallow season was much higher (62 to 66%) than in the growing season. The annual net GWP from the investigated paddy fields ranged from 3823 to 5016 g CO2 equivalent m−2 yr−1. Annual GWPCH4 accounted for 71.9 to 86.1% of the annual net GWP predominantly from the rice growing period. These results indicate that CH4 dominated the net GWP of the rice paddy.

scholarly journals Comparison of Soil Greenhouse Gas Fluxes during the Spring Freeze–Thaw Period and the Growing Season in a Temperate Broadleaved Korean Pine Forest, Changbai Mountains, China

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1135
Author(s):  
Chuying Guo ◽  
Leiming Zhang ◽  
Shenggong Li ◽  
Qingkang Li ◽  
Guanhua Dai
Keyword(s):  
Global Warming ◽  
Greenhouse Gas ◽  
Global Warming Potential ◽  
Growing Season ◽  
Korean Pine ◽  
Soil Co2 ◽  
Freeze Thaw ◽  
N2o Fluxes ◽  
Ch4 And N2o ◽  
Ghg Fluxes

Soils in mid-high latitudes are under the great impact of freeze–thaw cycling. However, insufficient research on soil CO2, CH4, and N2O fluxes during the spring freeze–thaw (SFT) period has led to great uncertainties in estimating soil greenhouse gas (GHG) fluxes. The present study was conducted in a temperate broad-leaved Korean pine mixed forest in Northeastern China, where soils experience an apparent freeze–thaw effect in spring. The temporal variations and impact factors of soil GHG fluxes were measured during the SFT period and growing season (GS) using the static-chamber method. The results show that the soil acted as a source of atmospheric CO2 and N2O and a sink of atmospheric CH4 during the whole observation period. Soil CO2 emission and CH4 uptake were lower during the SFT period than those during the GS, whereas N2O emissions were more than six times higher during the SFT period than that during the GS. The responses of soil GHG fluxes to soil temperature (Ts) and soil moisture during the SFT and GS periods differed. During the SFT period, soil CO2 and CH4 fluxes were mainly affected by the volumetric water content (VWC) and Ts, respectively, whereas soil N2O flux was influenced jointly by Ts and VWC. The dominant controlling factor for CO2 was Ts during the GS, whereas CH4 and N2O were mainly regulated by VWC. Soil CO2 and N2O fluxes accounted for 97.3% and 3.1% of the total 100-year global warming potential (GWP100) respectively, with CH4 flux offsetting 0.4% of the total GWP100. The results highlight the importance of environmental variations to soil N2O pulse during the SFT period and the difference of soil GHG fluxes between the SFT and GS periods, which contribute to predicting the forest soil GHG fluxes and their global warming potential under global climate change.

Effects of water table changes on soil CO2, CH4 and N2O fluxes during the growing season in freshwater marsh of Northeast China

2012 ◽  
Vol 69 (6) ◽  
pp. 1963-1971 ◽  
Author(s):  
Cuicui Hou ◽  
Changchun Song ◽  
Yingchen Li ◽  
Jiaoyue Wang ◽  
Yanyu Song ◽  
...  
Keyword(s):  
Water Table ◽  
Northeast China ◽  
Growing Season ◽  
Freshwater Marsh ◽  
Soil Co2 ◽  
N2o Fluxes ◽  
Ch4 And N2o

scholarly journals The Effect of Land-Use Change on Soil CH4 and N2O Fluxes: A Global Meta-Analysis

Ecosystems ◽  
2019 ◽  
Vol 22 (6) ◽  
pp. 1424-1443 ◽  
Author(s):  
M. D. McDaniel ◽  
D. Saha ◽  
M. G. Dumont ◽  
M. Hernández ◽  
M. A. Adams
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Meta Analysis ◽  
N2o Fluxes ◽  
Ch4 And N2o

Stem CH4 and N2O fluxes of Fraxinus excelsior and Populus alba trees along a flooding gradient

2021 ◽  
Author(s):  
Erwin Moldaschl ◽  
Barbara Kitzler ◽  
Katerina Machacova ◽  
Thomas Schindler ◽  
Andreas Schindlbacher
Keyword(s):  
Fraxinus Excelsior ◽  
Populus Alba ◽  
N2o Fluxes ◽  
Ch4 And N2o

scholarly journals Automatic high-frequency measurements of full soil greenhouse gas fluxes in a tropical forest

2018 ◽  
Author(s):  
Elodie Alice Courtois ◽  
Clément Stahl ◽  
Benoit Burban ◽  
Joke Van den Berge ◽  
Daniel Berveiller ◽  
...  
Keyword(s):  
High Frequency ◽  
Co2 Flux ◽  
Appropriate Technology ◽  
Flux Chamber ◽  
Soil Co2 Flux ◽  
Reliable Estimation ◽  
Closure Time ◽  
N2o Fluxes ◽  
Ch4 And N2o ◽  
Carbon Dioxide Co2

Abstract. Measuring in situ soil fluxes of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) continuously at high frequency requires appropriate technology. We tested the combination of a commercial automated soil CO2 flux chamber system (LI-8100A) with a CH4 and N2O analyzer (Picarro G2308) in a tropical rainforest for 4 months. A chamber closure time of 2 minutes was sufficient for a reliable estimation of CO2 and CH4 fluxes (100 % and 98.5 % of fluxes were above Minimum Detectable Flux – MDF, respectively). This closure time was generally not suitable for a reliable estimation of the low N2O fluxes in this ecosystem but was sufficient for detecting rare major peak events. A closure time of 25 minutes was more appropriate for reliable estimation of most N2O fluxes (85.6 % of measured fluxes are above MDF ± 0.002 nmol m−2 s−1). Our study highlights the importance of adjusted closure time for each gas.

Effects of afforestation on soil CH4 and N2O fluxes in a nsubtropical karst landscape

2020 ◽  
Vol 705 ◽  
pp. 135974 ◽  
Author(s):  
Ping Chen ◽  
Minghua Zhou ◽  
Shijie Wang ◽  
Weijun Luo ◽  
Tao Peng ◽  
...  
Keyword(s):  
Karst Landscape ◽  
N2o Fluxes ◽  
Ch4 And N2o

scholarly journals Methane and nitrous oxide sources and emissions in a subtropical freshwater reservoir, South East Queensland, Australia

2014 ◽  
Vol 11 (18) ◽  
pp. 5245-5258 ◽  
Author(s):  
K. Sturm ◽  
Z. Yuan ◽  
B. Gibbes ◽  
U. Werner ◽  
A. Grinham
Keyword(s):  
Nitrous Oxide ◽  
Water Column ◽  
Water Flux ◽  
No Production ◽  
Pore Waters ◽  
Ch4 Production ◽  
N2o Fluxes ◽  
Ch4 And N2o ◽  
Diffusive Fluxes ◽  
Carbon Dioxide Co2

Abstract. Reservoirs have been identified as an important source of non-carbon dioxide (CO2) greenhouse gases with wide ranging fluxes for reported methane (CH4); however, fluxes for nitrous oxide (N2O) are rarely quantified. This study investigates CH4 and N2O sources and emissions in a subtropical freshwater Gold Creek Reservoir, Australia, using a combination of water–air and sediment–water flux measurements and water column and pore water analyses. The reservoir was clearly a source of these gases as surface waters were supersaturated with CH4 and N2O. Atmospheric CH4 fluxes were dominated by ebullition (60 to 99%) relative to diffusive fluxes and ranged from 4.14 × 102 to 3.06 × 105 μmol CH4 m−2 day−1 across the sampling sites. Dissolved CH4 concentrations were highest in the anoxic water column and sediment pore waters (approximately 5 000 000% supersaturated). CH4 production rates of up to 3616 ± 395 μmol CH4 m−2 day−1 were found during sediment incubations in anoxic conditions. These findings are in contrast to N2O where no production was detected during sediment incubations and the highest dissolved N2O concentrations were found in the oxic water column which was 110 to 220% supersaturated with N2O. N2O fluxes to the atmosphere were primarily through the diffusive pathway, mainly driven by diffusive fluxes from the water column and by a minor contribution from sediment diffusion and ebullition. Results suggest that future studies of subtropical reservoirs should monitor CH4 fluxes with an appropriate spatial resolution to ensure capture of ebullition zones, whereas assessment of N2O fluxes should focus on the diffusive pathway.

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