Impacts of soil accumulation from erosion on greenhouse gas production and emission from soil within a complex and cultivated landscape
Bibliographic record
Abstract
In cultivated, topographically complex landscapes, soil erosion results in the redistribution of large amounts of soil.This soil redistribution changes the source materials and related soil properties within landscapes and within soil profile.These changes are expected to affect production and emission of greenhouse gases (GHG).To evaluate the effect of soil accumulation on CO2 and, N2O production and emission, two laboratory experiments and one fierd experiment were carried out.The column study was f,trst conducted in a growth chamber to study the relatio¡ship between soil depth and GHG emission.Results showed soil depth had a great effect on CO2 flux.Co2 flux increased drarnatically with soil depth.Regression analysis of data collected over 70 days showed the relationship between cumulative flux and soil depth can be described using a linear regression.However, as soil depth increased, emissions are not expected to increase proportionally.The effect of soil depth on N2O flux was observed as well.Generally, N2o flux increased with soil depth.Regressio¡ analysis of data collected over 70 days showed the cumulative flux also increased lìnearly.This experiment was lirnited in ability to determine the exact effect of soil depth due to lirnited numbers of depth treatments and the single replicate.Based on the preliminary results of the column study, a detailed field experiment was conducted to study the effect of soil accumulation from soil erosion on GHG profile concentrations and surface emissions.This study was carried out in three depressions within a complex, cultivated landscape, 17 krn north of Brandon, Manitoba.Results showed COz flux and profrle concentrations had obvious seasonal patterns.Co2 flux and concentration changed dramatically as air and soil temperature varied, indicati¡g that temperature is the key factor controlling greenhouse gas production and ernission.The highest variation in COz concentration occurred during the growing season.Higher CO2 concentration occurred at the greater depth in these depressions, probably resulting frorn high production and low diffusion rates.A thicker A horizon due to soil accumulation, root respiration, and microbial respiration resulted in higher CO2 production.The high water table level and poor drainage in the depressions limited gas diffusion to the aboveground atmosphere as well.Significant soil accumulation was observed in each of the three depressions.The soil accumulation favored CO2 production in that it increased quantities of soil organic carbon and nitrogen in the soil surface.However, the effect of soil accumulation on CO2 flux was different in the three depressions due to soil moisture conditions.Results also showed N2O profile concentrations and surface flux had significant seasonal patterns as well.High N2O flux and profile concentrations only occurred during spring thaw periods.High soil moisture and available carbon and nitrogen during spring thaw periods rnight have contributed to the high production rates.Although soil accumulation enriched organic carbon and nitrogen in the soil prof,rles, the effect of soil accurnulation on N2O production and emission only occurred during the spring thaw events.The thickened A horizon increased N2O production in soil profiles.However, this accurnulation may have decreased N2O emission due to the limited diffusion in the soil resulting in the conversion of NzO to N2.Thus, the effect of soil depositio' from erosion on N2O emission was cornplicated by hydrologic and pedologic co¡ditions.The potential production of CO2 and N2O at different soil depths from the field site was further studied with a microcosm experiment.This study revealed the potential gas production decreased with increased soil depth for both CO2 and N2O.The surface 25 cm of soil appeared to be the major potential source in COz and N2O production, in that this lIt layer was found to be rich in organic carbon and nitrogen, favoring microbial activity and mìcrobial biomass.Therefore, the accumulation of soil on the surface rich in organic carbon should increase COz and N2O production within the soil profile, at least in the short-tenn.In summary, the effect of the soil accumulation on GHG production and emission was complex.Its effect on CO2 and N2O flux was soil environment-specific. Soil accunulation increased GHG production in that it thickens the surface soil with high available carbon and nitrogen.However, this accumulation may have decreased COz and N2O emission due to the limited diffusion in the soil resulting in the further conversion of N2O to Nz.The effect of soil deposition also could affect GHG flux through its effect on soil moisture, temperature and substrate availability.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".