Spatial Variation of Soil CO2, CH4 and N2O Fluxes Across Topographical Positions in Tropical Forests of the Guiana Shield

Abstract. Soil macronutrient availability is one of the abiotic controls that alters the exchange of greenhouse gases (GHGs) between the soil and the atmosphere in tropical forests. However, evidence on the macronutrient regulation of soil GHG fluxes from central African tropical forests is still lacking, limiting our understanding of how these biomes could respond to potential future increases in nitrogen (N) and phosphorus (P) deposition. The aim of this study was to disentangle the regulation effect of soil nutrients on soil GHG fluxes from a Ugandan tropical forest reserve in the context of increasing N and P deposition. Therefore, a large-scale nutrient manipulation experiment (NME), based on 40 m×40 m plots with different nutrient addition treatments (N, P, N + P, and control), was established in the Budongo Central Forest Reserve. Soil carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) fluxes were measured monthly, using permanently installed static chambers, for 14 months. Total soil CO2 fluxes were partitioned into autotrophic and heterotrophic components through a root trenching treatment. In addition, soil temperature, soil water content, and nitrates were measured in parallel to GHG fluxes. N addition (N and N + P) resulted in significantly higher N2O fluxes in the transitory phase (0–28 d after fertilization; p<0.01) because N fertilization likely increased soil N beyond the microbial immobilization and plant nutritional demands, leaving the excess to be nitrified or denitrified. Prolonged N fertilization, however, did not elicit a significant response in background (measured more than 28 d after fertilization) N2O fluxes. P fertilization marginally and significantly increased transitory (p=0.05) and background (p=0.01) CH4 consumption, probably because it enhanced methanotrophic activity. The addition of N and P (N + P) resulted in larger CO2 fluxes in the transitory phase (p=0.01), suggesting a possible co-limitation of both N and P on soil respiration. Heterotrophic (microbial) CO2 effluxes were significantly higher than the autotrophic (root) CO2 effluxes (p<0.01) across all treatment plots, with microbes contributing about two-thirds of the total soil CO2 effluxes. However, neither heterotrophic nor autotrophic respiration significantly differed between treatments. The results from this study suggest that the feedback of tropical forests to the global soil GHG budget could be disproportionately altered by increases in N and P availability over these biomes.

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Simple models for soil CO2, CH4, and N2O fluxes calibrated using a Bayesian approach and multi-site data

Ecological Modelling ◽

10.1016/j.ecolmodel.2011.01.013 ◽

2011 ◽

Vol 222 (7) ◽

pp. 1283-1292 ◽

Cited By ~ 29

Author(s):

Shoji Hashimoto ◽

Tomoaki Morishita ◽

Tadashi Sakata ◽

Shigehiro Ishizuka ◽

Shinji Kaneko ◽

...

Keyword(s):

Bayesian Approach ◽

Soil Co2 ◽

N2o Fluxes ◽

Ch4 And N2o ◽

Simple Models

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Short-term effects of clearfelling on soil CO2, CH4, and N2O fluxes in a Sitka spruce plantation

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2005.03.004 ◽

2005 ◽

Vol 37 (11) ◽

pp. 2025-2036 ◽

Cited By ~ 60

Author(s):

Argyro Zerva ◽

Maurizio Mencuccini

Keyword(s):

Sitka Spruce ◽

Soil Co2 ◽

Short Term ◽

N2o Fluxes ◽

Ch4 And N2o ◽

Short Term Effects

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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 ◽

10.3390/f11111135 ◽

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.

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

Environmental Earth Sciences ◽

10.1007/s12665-012-2031-2 ◽

2012 ◽

Vol 69 (6) ◽

pp. 1963-1971 ◽

Cited By ~ 13

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

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Nutrient limitations regulate soil greenhouse gas fluxes from tropical forests: evidence from an ecosystem-scale nutrient manipulation experiment in Uganda

10.5194/soil-2020-94 ◽

2021 ◽

Author(s):

Joseph Tamale ◽

Roman Hüppi ◽

Marco Griepentrog ◽

Laban Frank Turyagyenda ◽

Matti Barthel ◽

...

Keyword(s):

Tropical Forest ◽

Tropical Forests ◽

Large Scale ◽

Soil Co2 ◽

Mineral N ◽

Environmental Controls ◽

Nutrient Manipulation ◽

N2o Fluxes ◽

Ghg Fluxes ◽

Manipulation Experiment

Abstract. Tropical forests contribute significantly to the emission and uptake of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). However, studies on the soil environmental controls of greenhouse gases (GHGs) from African tropical forest ecosystems are still rare. The aim of this study was to disentangle the regulation effect of soil nutrients on soil GHG fluxes in a tropical forest in northwestern Uganda. Therefore, a large-scale nutrient manipulation experiment (NME) based on 40 m × 40 m plots with different nutrient addition treatments (nitrogen (N), phosphorus (P), N + P, and control) was established. Soil CO2, CH4, and N2O fluxes were measured monthly using permanently installed static chambers for 14 months. Total soil CO2 fluxes were partitioned into autotrophic and heterotrophic components through a root trenching treatment. In addition, soil temperature, soil water content, and mineral N were measured in parallel to GHG fluxes. N addition (N, N + P) resulted in significantly higher N2O fluxes in the transitory phase (0–28 days after fertilization, p

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