Net exchange of greenhouse gases from soils in an unimproved pasture and regenerating indigenous Kunzea ericoides shrubland in New Zealand

Monthly measurements of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) fluxes were made at 3 sites along a sequence of naturally regenerating Kunzea ericoides shrubland in New Zealand, consisting of unimproved pasture (UP), young (8–12 years) Kunzea trees (YK), and old (80 years) Kunzea trees (OK). The CO2 flux at a base temperature of 10°C was highest at the OK site (0.51 g CO2/m2.h) and lowest at the UP site (0.26 g CO2/m2.h). Values of CO2 flux were regulated by soil temperature (Ts) throughout the year, and water availability modified the response to Ts when root-zone water content, (θ), fell below 0.27–0.29 m3/m3 in spring and summer. The soils were mostly CH4 sinks, although there were net CH4 emissions during wet periods at the YK site. The maximum CH4 flux at the YK site was –49.7 μg CH4/m2.h compared with –33.4 μg CH4/m2.h for the UP (and –90.4 μg CH4/m2.h for OK), indicating the potential for rapid recovery of methanotrophic populations in the YK shrubland over 8–12 years. However, on an annual basis our data suggest that CH4 oxidation rates decrease as land reverts from unimproved pasture to shrubland. Methane oxidation rates were strongly dependent on θ and only weakly dependent on Ts. Measurements of N2O fluxes were below the minimum detectable limit throughout the year at the UP and YK sites, and low but dependent on both Ts and θ at the OK site. Annual estimates of soil CO2 flux were 39.9, 23.3, and 21.9 × 103 kg CO2/ha.year at the OK, YK, and UP sites, respectively. All 3 sites were a net sink for CH4, with the highest oxidation rate of –5.1 kg CH4/ha.year at the OK site compared with –1.52 kg CH4/ha.year at the UP site. On a CO2-equivalent basis, the OK site was a greater CH4 sink (–127.3 kg CO2-e/ha.year) than a N2O source (77.5 kg CO2-e/ha.year), demonstrating the potential for soils to oxidise CH4 with forest succession as a possible mitigation strategy for land managers to reduce net emissions.

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

10.5194/bg-2018-341 ◽

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.

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

Biogeosciences ◽

10.5194/bg-16-785-2019 ◽

2019 ◽

Vol 16 (3) ◽

pp. 785-796 ◽

Cited By ~ 8

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 min 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 min 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.

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Differential Responses and Controls of Soil CO2 and N2O Fluxes to Experimental Warming and Nitrogen Fertilization in a Subalpine Coniferous Spruce (Picea asperata Mast.) Plantation Forest

Forests ◽

10.3390/f10090808 ◽

2019 ◽

Vol 10 (9) ◽

pp. 808 ◽

Cited By ~ 1

Author(s):

Dandan Li ◽

Qing Liu ◽

Huajun Yin ◽

Yiqi Luo ◽

Dafeng Hui

Keyword(s):

Co2 Flux ◽

N Fertilization ◽

Response Patterns ◽

Soil Co2 ◽

Plantation Forest ◽

Soil Co2 Flux ◽

Soil Microbial ◽

Picea Asperata ◽

Negative Effect ◽

N2o Fluxes

Emissions of greenhouse gases (GHG) such as CO2 and N2O from soils are affected by many factors such as climate change, soil carbon content, and soil nutrient conditions. However, the response patterns and controls of soil CO2 and N2O fluxes to global warming and nitrogen (N) fertilization are still not clear in subalpine forests. To address this issue, we conducted an eight-year field experiment with warming and N fertilization treatments in a subalpine coniferous spruce (Picea asperata Mast.) plantation forest in China. Soil CO2 and N2O fluxes were measured using a static chamber method, and soils were sampled to analyze soil carbon and N contents, soil microbial substrate utilization (MSU) patterns, and microbial functional diversity. Results showed that the mean annual CO2 and N2O fluxes were 36.04 ± 3.77 mg C m−2 h−1 and 0.51 ± 0.11 µg N m−2 h−1, respectively. Soil CO2 flux was only affected by warming while soil N2O flux was significantly enhanced by N fertilization and its interaction with warming. Warming enhanced dissolve organic carbon (DOC) and MSU, reduced soil organic carbon (SOC) and microbial biomass carbon (MBC), and constrained the microbial metabolic activity and microbial functional diversity, resulting in a decrease in soil CO2 emission. The analysis of structural equation model indicated that MSU had dominant direct negative effect on soil CO2 flux but had direct positive effect on soil N2O flux. DOC and MBC had indirect positive effects on soil CO2 flux while soil NH4+-N had direct negative effect on soil CO2 and N2O fluxes. This study revealed different response patterns and controlling factors of soil CO2 and N2O fluxes in the subalpine plantation forest, and highlighted the importance of soil microbial contributions to GHG fluxes under climate warming and N deposition.

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Soil CO2 flux affected by Aporrectodea caliginosa earthworms

Open Life Sciences ◽

10.2478/s11535-010-0017-1 ◽

2010 ◽

Vol 5 (3) ◽

pp. 364-370 ◽

Cited By ~ 4

Author(s):

Miloslav Šimek ◽

Václav Pižl

Keyword(s):

Co2 Emissions ◽

Co2 Flux ◽

Co2 Concentration ◽

Experimental Period ◽

Aporrectodea Caliginosa ◽

Soil Co2 Flux ◽

Soil Air ◽

Soil Microbial ◽

Carbon Dioxide Co2 ◽

Soil Accumulation

AbstractThe effects of Aporrectodea caliginosa earthworms on both carbon dioxide (CO2) accumulation in and emissions from soil, as well as the simultaneous impact of earthworms on soil microbiological properties were investigated in a microcosm experiment carried out over 5.5 months. Concentration of CO2 in soil air was greater at a depth of 15 cm when compared with a depth of 5 cm, but varied during the season both in control and earthworm-inhabited chambers. Peaks of CO2 concentrations at both depths occurred in both treatments during August, approximately 80 days after the experiment started. Generally, the presence of earthworms increased the CO2 concentration at 15-cm depth. Larger CO2 emissions were consistently recorded in conjunction with higher amounts of CO2 in soil air when chambers were inhabited by earthworms. The total CO2 emissions during the experimental period covering 161 days were estimated at 118 g CO2-C m−2 and 99 g CO2-C m−2 from chambers with and without earthworms respectively. Moreover, the presence of earthworms increased microbial biomass in the centre and at the bottom of chambers, and enhanced both dehydrogenase activity and nitrifying enzyme activity in the soils. We suggest that the effect of earthworms on both the enhanced soil accumulation of CO2 as well as emissions of CO2 was mostly indirect, due to the impacts of earthworms on soil microbial community.

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Soil CO2 flux baseline in an urban monogenetic volcanic field: the Auckland Volcanic Field, New Zealand

Bulletin of Volcanology ◽

10.1007/s00445-013-0757-7 ◽

2013 ◽

Vol 75 (11) ◽

Cited By ~ 10

Author(s):

Agnès Mazot ◽

Elaine R. Smid ◽

Luitgard Schwendenmann ◽

Hugo Delgado-Granados ◽

Jan Lindsay

Keyword(s):

New Zealand ◽

Co2 Flux ◽

Volcanic Field ◽

Soil Co2 ◽

Auckland Volcanic Field ◽

Soil Co2 Flux ◽

Monogenetic Volcanic Field

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Non-growing season soil CO2 flux and its contribution to annual soil CO2 emissions in two typical grasslands in the permafrost region of the Qinghai-Tibet Plateau

European Journal of Soil Biology ◽

10.1016/j.ejsobi.2015.10.004 ◽

2015 ◽

Vol 71 ◽

pp. 45-52 ◽

Cited By ~ 17

Author(s):

Tao Zhang ◽

Genxu Wang ◽

Yan Yang ◽

Tianxu Mao ◽

Xiaopeng Chen

Keyword(s):

Co2 Emissions ◽

Co2 Flux ◽

Growing Season ◽

Tibet Plateau ◽

Permafrost Region ◽

Soil Co2 ◽

Soil Co2 Flux ◽

Soil Co2 Emissions ◽

Qinghai Tibet Plateau

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Trace gas fluxes of CO2, CH4 and N2O in a permanent grassland soil exposed to elevated CO2 in the Giessen FACE study

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-9333-2011 ◽

2011 ◽

Vol 11 (17) ◽

pp. 9333-9342 ◽

Cited By ~ 5

Author(s):

M. Kaleem Abbasi ◽

C. Müller

Keyword(s):

Elevated Co2 ◽

15N Tracer ◽

Organic N ◽

N2o Emissions ◽

Ch4 Oxidation ◽

N2o Production ◽

N Application ◽

Oxidation Rates ◽

Controlled Conditions ◽

N2o Fluxes

Abstract. Long-term field observations showed that N2O fluxes observed shortly after N application were not significantly affected by elevated CO2 in the Giessen Free Air Carbon dioxide Enrichment (FACE) study. To further investigate this unexpected result a 15N tracer study was carried out under controlled conditions where in parallel treatments either the NH4+ pool (15NH4NO3) or the NO3− pool (NH415NO3) was enriched with 15N. Fluxes of CO2, CH4, and N2O as well as the 15N enrichment of the N2O were measured. Denitrifying Enzyme Activity (DEA), total denitrification (N2 + N2O) and N2-to-N2O ratios were quantified in separate experiments. Over the 57 day incubation, N2O fluxes averaged 0.090 ng N2O-N g−1 h−1 under ambient and 0.083 ng N2O-N g−1 h−1 under elevated CO2 (not significantly different). The N2O production processes were identified by a two-source model. Results showed that N2O must have also been produced by a third source – possibly related to organic N transformation – which was stimulated by elevated CO2. Soil CO2 fluxes were approximately 20 % higher under elevated CO2 than soil from ambient but the differences were not significant. CH4 oxidation rates were on average −1.75 ng CH4-C g−1 h−1 in the elevated and −1.17 ng CH4-C g−1 h−1 in the ambient indicating that elevated CO2 increased the CH4 oxidation by 49 % compared to ambient CO2 under controlled conditions. N fertilization increased CH4 oxidation by 3-fold in both CO2 treatments. CO2 did not have any significant effect on DEA while total denitrification and N2-to-N2O ratios increased by 36 and 33 %, respectively. The results indicate that shortly after N application elevated CO2 must have stimulated both the N2O production and reduction to N2 to explain the increased N2-to-N2O ratio and at the same time explain the non-responsiveness of the N2O emissions. Thus, the observed variation of the CO2 effect on N2O emissions throughout the year is possibly governed by the dynamics of the N2O reductase activity.

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