High soil solution carbon und nitrogen concentrations in a drained Atlantic bog are reduced to natural levels by 10 yr of rewetting

Abstract. Artificial drainage of peatlands causes dramatic changes in the release of greenhouse gases and in the export of dissolved carbon (C) and nutrients to downstream ecosystems. Rewetting anthropogenically altered peatlands offers a possibility to reduce nitrogen (N) and C losses. In this study, we investigate the impact of drainage and rewetting on the cycling of dissolved C and N as well as on dissolved gases over a period of 1 yr and 4 month, respectively. The peeper technique was used to receive a high vertical sampling resolution. Within one Atlantic bog complex a near natural site, two drained grasslands sites with different mean water table positions, and a former peat cutting area rewetted 10 yr ago were chosen. Our results clearly indicate that drainage increased the concentration of dissolved organic carbon (DOC), ammonia, nitrate and dissolved organic nitrogen (DON) compared to the near natural site. Drainage depth further determined the release and therefore the concentration level of DOC and N species, but the biochemical cycling and therefore dissolved organic matter (DOM) quality and N species composition were unaffected. Thus, especially deep drainage can cause high DOC losses. In general, DOM at drained sites was enriched in aromatic moieties as indicated by SUVA280 and showed a higher degradation status (lower DOC to DON ratio) compared to the near natural site. At the drained sites, equal C to N ratios of uppermost peat layer and DOC to DON ratio of DOM in soil solution suggest that the uppermost degraded peat layer is the main source of DOM. Nearly constant DOC to DON ratios and SUVA280 values with depth furthermore indicated that DOM moving downwards through the drained sites remained largely unchanged. DON and ammonia contributed most to the total dissolved nitrogen (TN). The subsoil concentrations of nitrate were negligible due to strong decline in nitrate around mean water table depth. Methane production during the winter months at the drained sites moved downwards to areas which were mostly water saturated over the whole year (>40 cm). Above these depths, the recovery of the water table in winter months led to the production of nitrous oxide around mean water table depth at drained sites. 10 yr after rewetting, the DOM quality (DOC to DON ratio and SUVA280) and quantity were comparable to the near natural site, indicating the re-establishment of mostly pristine biochemical processes under continuously water logged conditions. The only differences occur in elevated dissolved methane and ammonia concentrations reflecting the former disturbance by drainage and peat extraction. Rewetting via polder technique seems to be an appropriate way to revitalize peatlands on longer timescales and to improve the water quality of downstream water bodies.

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High soil solution carbon and nitrogen concentrations in a drained Atlantic bog are reduced to natural levels by 10 years of rewetting

Biogeosciences ◽

10.5194/bg-11-2309-2014 ◽

2014 ◽

Vol 11 (8) ◽

pp. 2309-2324 ◽

Cited By ~ 31

Author(s):

S. Frank ◽

B. Tiemeyer ◽

J. Gelbrecht ◽

A. Freibauer

Keyword(s):

Water Table ◽

Peat Layer ◽

Groundwater Levels ◽

Dissolved Carbon ◽

Total Dissolved Nitrogen ◽

Natural Site ◽

Nitrogen Concentrations ◽

Annual Water ◽

Water Saturated ◽

The Impact

Abstract. Anthropogenic drainage of peatlands releases additional greenhouse gases to the atmosphere, and dissolved carbon (C) and nutrients to downstream ecosystems. Rewetting drained peatlands offers a possibility to reduce nitrogen (N) and C losses. In this study, we investigate the impact of drainage and rewetting on the cycling of dissolved C and N as well as on dissolved gases, over a period of 1 year and a period of 4 months. We chose four sites within one Atlantic bog complex: a near-natural site, two drained grasslands with different mean groundwater levels and a former peat cutting area rewetted 10 years ago. Our results clearly indicate that long-term drainage has increased the concentrations of dissolved organic carbon (DOC), ammonium, nitrate and dissolved organic nitrogen (DON) compared to the near-natural site. DON and ammonium contributed the most to the total dissolved nitrogen. Nitrate concentrations below the mean groundwater table were negligible. The concentrations of DOC and N species increased with drainage depth. In the deeply-drained grassland, with a mean annual water table of 45 cm below surface, DOC concentrations were twice as high as in the partially rewetted grassland with a mean annual water table of 28 cm below surface. The deeply drained grassland had some of the highest-ever observed DOC concentrations of 195.8 ± 77.3 mg L−1 with maximum values of >400 mg L−1. In general, dissolved organic matter (DOM) at the drained sites was enriched in aromatic moieties and showed a higher degradation status (lower DOC to DON ratio) compared to the near-natural site. At the drained sites, the C to N ratios of the uppermost peat layer were the same as of DOM in the peat profile. This suggests that the uppermost degraded peat layer is the main source of DOM. Nearly constant DOM quality through the profile furthermore indicated that DOM moving downwards through the drained sites remained largely biogeochemically unchanged. Unlike DOM concentration, DOM quality and dissolved N species distribution were similar in the two grasslands and thus unaffected by the drainage depth. Methane production during the winter months at the drained sites was limited to the subsoil, which was quasi-permanently water saturated. The recovery of the water table in the winter months led to the production of nitrous oxide around mean water table depth at the drained sites. The rewetted and the near-natural site had comparable DOM quantity and quality (DOC to DON ratio and aromaticity). 10 years after rewetting quasi-pristine biogeochemical conditions have been re-established under continuously water logged conditions in the former peat cut area. Only the elevated dissolved methane and ammonium concentrations reflected the former disturbance by drainage and peat extraction. Rewetting via polder technique seems to be an appropriate way to revitalize peatlands on longer timescales and to improve the water quality of downstream water bodies.

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Hydrological control of dissolved organic carbon dynamics in a rehabilitated <i>Sphagnum</i>-dominated peatland: a water-table based modelling approach

Hydrology and Earth System Sciences ◽

10.5194/hess-22-4907-2018 ◽

2018 ◽

Vol 22 (9) ◽

pp. 4907-4920 ◽

Cited By ~ 4

Author(s):

Léonard Bernard-Jannin ◽

Stéphane Binet ◽

Sébastien Gogo ◽

Fabien Leroy ◽

Christian Défarge ◽

...

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Dissolved Organic Carbon ◽

Water Table ◽

Control Area ◽

Hydrological Processes ◽

Deep Drainage ◽

Suitable Alternative ◽

Doc Concentration ◽

The Impact

Abstract. Hydrological disturbances could increase dissolved organic carbon (DOC) exports through changes in runoff and leaching, which reduces the potential carbon sink function of peatlands. The objective of this study was to assess the impact of hydrological restoration on hydrological processes and DOC dynamics in a rehabilitated Sphagnum-dominated peatland. A conceptual hydrological model calibrated on the water table and coupled with a biogeochemical module was applied to La Guette peatland (France), which experienced a rewetting initiative on February 2014. The model (eight calibrated parameters) reproduced water-table (0.1<NS<0.61) and pore-water DOC concentrations (2<RMSE<11 mg L−1) in a time series (1 April 2014 to 15 December 2017) in two contrasting locations (rewetted and control) in the peatland. Hydrological restoration was found to impact the water balance through a decrease in slow deep drainage and an increase in fast superficial runoff. Observed DOC concentrations were higher in summer in the rewetted location compared to the control area and were linked to a difference in dissolved organic matter composition analyzed by fluorescence. Hydrological conditions, especially the severity of the water-table drawdown in summer, were identified as the major factor controlling DOC-concentration dynamics. The results of the simulation suggest that the hydrological restoration did not affect DOC loads, at least in a short-term period (3 years). However, it impacted the temporal dynamics of DOC exports, which were the most episodic and were mainly transported through fast surface runoff in the area affected by the restoration, while slow deep drainage dominated DOC exports in the control area. In relation to dominant hydrological processes, exported DOC is expected to be derived from more recent organic matter in the top peat layer in the rewetted area, compared to the control area. Since it is calibrated on water-table and DOC concentration, the model presented in this study proved to be a relevant tool in identifying the main hydrological processes and factors controlling DOC dynamics in different areas of the same peatland. It is also a suitable alternative to a discharge-calibrated catchment model when the outlet is not easy to identify or to monitor.

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Temporal water table changes in soil toposequence of the Poznań Lakeland (western Poland)

Soil Science Annual ◽

10.1515/ssa-2017-0021 ◽

2017 ◽

Vol 68 (4) ◽

pp. 167-173

Author(s):

Michał Kozłowski ◽

Jolanta Komisarek

Keyword(s):

Regression Analysis ◽

Linear Regression ◽

Water Table ◽

Root Zone ◽

Linear Regression Analysis ◽

Temporal Trends ◽

Water Table Depth ◽

The Mean ◽

The Impact

Abstract The paper presents results of determination of temporal changes in water table depths in the toposequence of Retisols/Luvisols and Phaeozems/Gleysols. Assessment of temporal trends in the water table depth was made with the use of the linear regression analysis. The results obtained indicate that the mean water table depth and mean high and low water table depths were deeper in the soil at the upper part of the slope in comparison with soil located at the footslope. A higher amplitude of water table was observed in Retisols than in Gleysols but the highest variability of water table level was noted in the soils at the footslope compared to those at the slope summit. In Retisols, with each month of observation from 1993 to 2012, the water table showed a tendency to increase. These trends were the highest from January to April, which may be related to the tendency of increasing monthly sums of precipitation in December, January and February. In the Gleysol at the footslope, in the period 1993–2012 and in the vegetation season, the water table depth showed a tendency to decrease. This trend may be due to the impact of water table on the soil water content at the root zone, which is used in the process of evapotranspiration.

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Hydrological control of dissolved organic carbon dynamics in a rehabilitated <i>Sphagnum</i>–dominated peatland: a water-table based modelling approach

10.5194/hess-2017-578 ◽

2017 ◽

Author(s):

Léonard Bernard-Jannin ◽

Stéphane Binet ◽

Sébastien Gogo ◽

Fabien Leroy ◽

Christian Défarge ◽

...

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Dissolved Organic Carbon ◽

Water Table ◽

Control Area ◽

Hydrological Processes ◽

Deep Drainage ◽

Suitable Alternative ◽

Doc Concentration ◽

The Impact

Abstract. Hydrological disturbances could increase dissolved organic carbon (DOC) exports through runoff and leaching, reducing the potential carbon sink function of peatlands. The objective of this study was to assess the impact of hydrological restoration on hydrological processes and DOC dynamics in a rehabilitated Sphagnum–dominated peatland. A conceptual hydrological model calibrated on the water table and coupled with a biogeochemical module was applied to La Guette peatland (France), which experienced a rewetting action on February 2014. The model (ten calibrated parameters) reproduced water table and pore water DOC concentration time series (01/04/2014 to 15/07/2017) in two contrasted locations (rewetted and control) of the peatland. Hydrological restoration was found to impact the water balance through a decrease in slow deep drainage and an increase in fast superficial runoff. Observed DOC concentrations were higher in summer in the rewetted location compared to the control and were linked with a difference in dissolved organic matter composition analyzed by fluorescence. Hydrological conditions, especially the severity of the water table drawdown, were identified as the major factors controlling DOC concentration dynamics. The results of the simulation suggest that the hydrological restoration did not affect DOC loads, at least on a short-term period (3 years). However, it impacted the temporal dynamics of DOC exports, which were the most episodic and mainly transported through fast surface runoff in the area affected by the restoration while slow deep drainage dominated DOC exports in the control area. In relation with dominant hydrological processes, exported DOC is expected to be derived from more recent organic matter of the top peat layer in the rewetted area than in the control area. Since it is calibrated on water table and DOC concentration, the model presented in this study proved to be a relevant tool to identify the main hydrological processes and factors controlling DOC dynamics in different areas of the same peatland. It is also a suitable alternative to a discharge calibrated catchment model when the outlet is not easily identifiable.

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The role of Controlled and Mole Drainage in Relation to Water Saving, Salt Accumulation on Sugar Beet Yield and Quality in North Nile Delta, Egypt

International Journal of Plant & Soil Science ◽

10.9734/ijpss/2021/v33i130407 ◽

2021 ◽

pp. 47-58

Author(s):

Kh. M. El-Ghannam ◽

Amira El-sherief ◽

I. A. Nageeb

Keyword(s):

Sugar Beet ◽

Water Table ◽

Soil Salinity ◽

Field Experiments ◽

Nile Delta ◽

Water Saving ◽

Water Table Depth ◽

Controlled Drainage ◽

Average Water ◽

The Impact

Two field experiments were conducted at Sidi Salem region, Kafr El-Sheikh Governorate, Egypt, during two winter seasons 2018/2019 and 2019/2020 to study the impact of controlled drainage at 0.5, 0.75, 1.25 m and mole drain spacing 2 m on soil salinity, water-saving and sugar beet productivity. Results obtained that using controlled drainage saved irrigation water 24.56 and 11.35% in 1st season and 23.73 and 15.08% in 2nd season for 50, 75 cm depth of water table respectively, compared to 125 cm depth of water table. Application of mole drains seems to be more effective in decreasing soil salinity and sodicity especially, in the topsoil (0-60 cm) and narrow spacing between the plowed lines (2 m).Data showed that the water table level at 0.5 and 0.75 m treatments rose more rapidly and remained higher for longer time than the uncontrolled drainage treatment, the average water table depth was above specified depths between irrigation intervals from 3-7 days depending on the depth. There was a marked variation between the treatments that controlled drainage increased the yield at 0.50 m water table depth by 39 and 30% for both seasons, respectively. It can be concluded that the treatment of controlled drainage may give more profit than the uncontrolled one. At the same time, the contents of K+, Na+, alpha- amino N and alkalinity in root beet were insignificantly affected by controlled subsurface drainage in both seasons.

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Geographic Setting and Groundwater Table Control Carbon Emission from Indonesian Peatland: A Meta-Analysis

Forests ◽

10.3390/f12070832 ◽

2021 ◽

Vol 12 (7) ◽

pp. 832

Author(s):

Nisa Novita ◽

Nurul Silva Lestari ◽

Mega Lugina ◽

Tatang Tiryana ◽

Imam Basuki ◽

...

Keyword(s):

Land Cover ◽

Co2 Emissions ◽

Water Table ◽

Emission Reduction ◽

Meta Analysis ◽

Water Table Depth ◽

Climate Mitigation ◽

Soil Emissions ◽

Emission Reduction Target ◽

The Impact

Peat restoration is a key climate mitigation action for achieving Indonesia’s Nationally Determined Contribution (NDC) emission reduction target. The level of carbon reduction resulting from peat restoration is uncertain, owing in part to diverse methodologies and land covers. In this study, a meta-analysis was conducted to assess the impact of rewetting on reduction of total CO2 in soil and heterotrophic emissions at the country level. The tier 2 emission factor associated with the land cover category in Indonesia was also calculated. The analysis included a total of 32 studies with 112 observations (data points) for total CO2 emissions and 31 observations for heterotrophic emissions in Indonesia. The results show that the land cover category is not a significant predictor of heterotrophic and total soil emissions, but the highest observed soil emissions were found in the plantation forest. Using the random-effects model, our results suggest that an increase in the water table depth of 10 cm would result in an increase in total CO2 emissions of 2.7 Mg CO2 ha−1 year−1 and an increase in heterotrophic emissions of 2.3 Mg CO2 ha−1 year−1. Our findings show that managing water table depth in degraded peatlands in various land cover types is important to achieve Indonesia’s emission reduction target by 2030.

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Temporal and Local Heterogeneities of Water Table Depth under Different Agricultural Water Management Conditions

Water ◽

10.3390/w13162148 ◽

2021 ◽

Vol 13 (16) ◽

pp. 2148

Author(s):

Jonathan A. Lafond ◽

Silvio J. Gumiere ◽

Virginie Vanlandeghem ◽

Jacques Gallichand ◽

Alain N. Rousseau ◽

...

Keyword(s):

Water Management ◽

Water Table ◽

Cropping Systems ◽

Irrigation Management ◽

Sprinkler Irrigation ◽

Water Table Depth ◽

Management Systems ◽

Integrated Water Management ◽

Growing Seasons ◽

Good Drainage

Integrated water management has become a priority for cropping systems where subirrigation is possible. Compared to conventional sprinkler irrigation, the controlling water table can lead to a substantial increase in yield and water use efficiency with less pumping energy requirements. Knowing the spatiotemporal distribution of water table depth (WTD) and soil properties should help perform intelligent, integrated water management. Observation wells were installed in cranberry fields with different water management systems: Bottom, with good drainage and controlled WTD management; Surface, with good drainage and sprinkler irrigation management; Natural, without drainage, or with imperfectly drained and conventional sprinkler irrigation. During the 2017–2020 growing seasons, WTD was monitored on an hourly basis, while precipitation was measured at each site. Multi-frequential periodogram analysis revealed a dominant periodic component of 40 days each year in WTD fluctuations for the Bottom and Surface systems; for the Natural system, periodicity was heterogeneous and ranged from 2 to 6 weeks. Temporal cross correlations with precipitation show that for almost all the sites, there is a 3 to 9 h lag before WTD rises; one exception is a subirrigation site. These results indicate that automatic water table management based on continuously updated knowledge could contribute to integrated water management systems, by using precipitation-based models to predict WTD.

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Modelling response of infiltration loss toward water table depth using RBFN, RNN, ANFIS techniques

International Journal of Knowledge-based and Intelligent Engineering Systems ◽

10.3233/kes-210066 ◽

2021 ◽

Vol 25 (2) ◽

pp. 227-234

Author(s):

Sandeep Samantaray ◽

Abinash Sahoo

Keyword(s):

Neural Network ◽

Mean Square Error ◽

Water Table ◽

Environmental Sustainability ◽

Model Development ◽

Water Table Depth ◽

Water Levels ◽

Coefficient Of Determination ◽

Mean Square ◽

Inference System

Accurate prediction of water table depth over long-term in arid agricultural areas are very much important for maintaining environmental sustainability. Because of intricate and diverse hydrogeological features, boundary conditions, and human activities researchers face enormous difficulties for predicting water table depth. A virtual study on forecast of water table depth using various neural networks is employed in this paper. Hybrid neural network approach like Adaptive Neuro Fuzzy Inference System (ANFIS), Recurrent Neural Network (RNN), Radial Basis Function Neural Network (RBFN) is employed here to appraisal water levels as a function of average temperature, precipitation, humidity, evapotranspiration and infiltration loss data. Coefficient of determination (R2), Root mean square error (RMSE), and Mean square error (MSE) are used to evaluate performance of model development. While ANFIS algorithm is used, Gbell function gives best value of performance for model development. Whole outcomes establish that, ANFIS accomplishes finest as related to RNN and RBFN for predicting water table depth in watershed.

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The distinct roles of water table depth and soil properties in controlling alternative woodland-grassland states in the Cerrado

Oecologia ◽

10.1007/s00442-021-04869-z ◽

2021 ◽

Author(s):

Jonathan W. F. Ribeiro ◽

Natashi A. L. Pilon ◽

Davi R. Rossatto ◽

Giselda Durigan ◽

Rosana M. Kolb

Keyword(s):

Soil Properties ◽

Water Table ◽

Water Table Depth

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Role of tree stand evapotranspiration in maintaining satisfactory drainage conditions in drained peatlands

Canadian Journal of Forest Research ◽

10.1139/x10-084 ◽

2010 ◽

Vol 40 (8) ◽

pp. 1485-1496 ◽

Cited By ~ 48

Author(s):

Sakari Sarkkola ◽

Hannu Hökkä ◽

Harri Koivusalo ◽

Mika Nieminen ◽

Erkki Ahti ◽

...

Keyword(s):

Bulk Density ◽

Water Table ◽

Interactive Effect ◽

Late Summer ◽

Water Table Depth ◽

Separate Analysis ◽

Tree Stand ◽

Stand Volume ◽

Linear Effect ◽

Subsequent Decrease

Ditch networks in drained peatland forests are maintained regularly to prevent water table rise and subsequent decrease in tree growth. The growing tree stand itself affects the level of water table through evapotranspiration, the magnitude of which is closely related to the living stand volume. In this study, regression analysis was applied to quantify the relationship between the late summer water table depth (DWT) and tree stand volume, mean monthly summertime precipitation (Ps), drainage network condition, and latitude. The analysis was based on several large data sets from southern to northern Finland, including concurrent measurements of stand volume and summer water table depth. The identified model demonstrated a nonlinear effect of stand volume on DWT, a linear effect of Ps on DWT, and an interactive effect of both stand volume and Ps. Latitude and ditch depth showed only marginal influence on DWT. A separate analysis indicated that an increase of 10 m3·ha–1 in stand volume corresponded with a drop of 1 cm in water table level during the growing season. In a subsample of the data, high bulk density peat showed deeper DWT than peat with low bulk density at the same stand volume.

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