The effect of forestry drainage practices on the emission of methane from northern peatlands

1995 ◽  
Vol 25 (3) ◽  
pp. 491-499 ◽  
Author(s):  
Nigel T. Roulet ◽  
T. R. Moore
Keyword(s):  
Water Table ◽  
Drainage Ditches ◽  
Flux Data ◽  
Northern Peatlands ◽  
Forested Bog ◽  
The Impact ◽  
Forest Drainage

Methane (CH4) flux was measured from undrained, drained, and ditched portions of treed fen, forested bog, and treed bog sites in the Wally Creek experimental drainage site (near Cochrane, Ontario), from May to October 1991. Drainage for 7 years lowered the water table from between −21 and −49 cm to −41 and −93 cm at the three respective sites. Drainage resulted in a conversion of the peatlands from a CH4 source (0 to 15 mg CH4 •m−2 •d−1) to a small CH4 sink (0 to −0.4 mg CH4 •m−2 •d−1). In contrast, CH4 efflux from the ditches ranged from <5 to >400 mg CH4 m−2 •d−1. The flux data were used to estimate the impact of forest drainage practices on net CH4 emissions from a forest drainage complex. For the treed and forested bogs, there was a net increase in CH4 emissions where ditch spacing was closer than 38 m. Even with very close ditch spacing (>12 m), there was a net decrease in CH4 flux from the treed fen. The results of this study indicate that the combination of low antecedent CH4 fluxes from an undrained peatland, and moderate fluxes from the drainage ditches, will produce a net increase in CH4 emissions from forest drainage.

scholarly journals Methane flux from drained northern peatlands: Effect of a persistent water table lowering on flux

1993 ◽  
Vol 7 (4) ◽  
pp. 749-769 ◽  
Author(s):  
Nigel T. Roulet ◽  
R. Ash ◽  
W. Quinton ◽  
Tim Moore
Keyword(s):  
Water Table ◽  
Methane Flux ◽  
Northern Peatlands

Assessing the impact of exceptional inter-annual climatic variability on rates of net ecosystem carbon dioxide exchange at Clara bog.

2021 ◽  
Author(s):  
Matthew Saunders ◽  
Ruchita Ingle ◽  
Shane Regan
Keyword(s):  
Water Table ◽  
Elevated Temperatures ◽  
Ecosystem Respiration ◽  
Anthropogenic Activities ◽  
Climatic Variability ◽  
Growing Season ◽  
Carbon Dioxide Exchange ◽  
Mean Annual Temperature ◽  
Monitoring Networks ◽  
The Impact

&lt;p&gt;Peatland ecosystems are integral to the mitigation of climate change as they represent significant terrestrial carbon sinks. In Ireland, peatlands cover ~20% of the land area but hold up to 75% of the soil organic carbon stock however many of these ecosystems (~85% of the total area) have been degraded due to anthropogenic activities such as agriculture, forestry and extraction for horticulture or energy. Furthermore, the carbon stocks that remain in these systems are vulnerable to inter-annual variation in climate, such as changes in precipitation and temperature, which can alter the hydrological status of these systems leading to changes in key biogeochemical processes and carbon and greenhouse gas exchange.&amp;#160; During 2018 exceptional drought and heatwave conditions were reported across Northwestern Europe, where reductions in precipitation coupled with elevated temperatures were observed. Exceptional inter-annual climatic variability was also observed at Clara bog, a near natural raised bog in the Irish midlands when data from 2018 and 2019 were compared. Precipitation in 2018 was ~300 mm lower than 2019 while the average mean annual temperature was 0.5&amp;#176;C higher. The reduction in precipitation, particularly during the growing season in 2018, consistently lowered the water table where ~150 consecutive days where the water table was &gt;5cm below the surface of the bog were observed at the central ecotope location. The differing hydrological conditions between years resulted in the study area, as determined by the flux footprint of the eddy covariance tower, acting as a net source of carbon of 53.5 g C m&lt;sup&gt;-2&lt;/sup&gt; in 2018 and a net sink of 125.2 g C m&lt;sup&gt;-2&lt;/sup&gt; in 2019. The differences in the carbon dynamics between years were primarily driven by enhanced ecosystem respiration (R&lt;sub&gt;eco&lt;/sub&gt;) and lower rates of Gross Primary Productivity (GPP) in the drier year, where the maximum monthly ratio of GPP:R&lt;sub&gt;eco&lt;/sub&gt; during the growing season was 0.96 g C m&lt;sup&gt;-2&lt;/sup&gt; month in 2018 and 1.14 g C m&lt;sup&gt;-2&lt;/sup&gt; month in 2019. This study highlights both the vulnerability and resilience of these ecosystems to exceptional inter-annual climatic variability and emphasises the need for long-term monitoring networks to enhance our understanding of the impacts of these events when they occur.&lt;/p&gt;

Monitoring of water table dynamics in peatlands with OPTRAM: Towards globally applicable algorithms in Google Earth Engine using Landsat and Sentinel-2

2021 ◽  
Author(s):  
Iuliia Burdun ◽  
Michel Bechtold ◽  
Viacheslav Komisarenko ◽  
Annalea Lohila ◽  
Elyn Humphreys ◽  
...  
Keyword(s):  
Time Series ◽  
Water Table ◽  
Input Data ◽  
Short Wave ◽  
Google Earth ◽  
Google Earth Engine ◽  
Short Wave Infrared ◽  
Northern Peatlands ◽  
Sentinel 2

&lt;p&gt;Fluctuations of water table depth (WTD) affect many processes in peatlands, such as vegetation development and emissions of greenhouse gases. Here, we present the OPtical TRApezoid Model (OPTRAM) as a new method for satellite-based monitoring of the temporal variation of WTD in peatlands. OPTRAM is based on the response of short-wave infrared reflectance to the vegetation water status. For five northern peatlands with long-term in-situ WTD records, and with diverse vegetation cover and hydrological regimes, we generate a suite of OPTRAM index time series using (a) different procedures to parametrise OPTRAM (peatland-specific manual vs. globally applicable automatic parametrisation in Google Earth Engine), and (b) different satellite input data (Landsat vs. Sentinel-2). The results based on the manual parametrisation of OPTRAM indicate a high correlation with in-situ WTD time-series for pixels with most suitable vegetation for OPTRAM application (mean Pearson correlation of 0.7 across sites), and we will present the performance differences when moving from a manual to an automatic procedure. Furthermore, for the overlap period of Landsat and Sentinel-2, which have different ranges and widths of short-wave infrared bands used for OPTRAM calculation, the impact of the satellite input data to OPTRAM will be analysed. Eventually, the challenge of merging different satellite missions in the derivation of OPTRAM time series will be explored as an important step towards a global application of OPTRAM for the monitoring of WTD dynamics in northern peatlands.&lt;/p&gt;

scholarly journals Assessment of the Quality of Soil and Groundwater of the Agricultural Area of Sidi Yahya Region, Morocco

2020 ◽  
Vol 150 ◽  
pp. 01001
Author(s):  
M. Lahmar ◽  
N. El Khodrani ◽  
S. Omrania ◽  
H. Dakak ◽  
R. Moussadek ◽  
...  
Keyword(s):  
Water Table ◽  
Land Management ◽  
Research Work ◽  
Sustainable Use ◽  
Soil Samples ◽  
Agricultural Area ◽  
Soil Parameters ◽  
The Impact ◽  
Soil And Water

The Gharb plain is the largest agricultural area in Morocco. It is characterized by fertile soils and the availability of water either from surface or groundwater which allowed intensive agriculture. The aim of this research work is to study the impact of this land management on the quality of water and soil. The study was done for the irrigated perimeter of Sidi Yahya belonging to the province of Sidi Slimane, Gharb (Morocco). Depth of water table and water pH were measured in situ while water and soil samples were collected and brought to the laboratory for their physico-chemical analyses. Sampling of 33water wells and soil samples, from six different zones, was done between May and October 2018. Analysis of variance (ANOVA) was used to check if mean water and soil parameters differed between zones. The results showed that the minimal and maximal water table depth were 6 and 96 m, respectively. Also, slightly more than half of the wells (51.5%) were inadequate for irrigation since they were either highly or extremely saline. Furthermore, soils were poor to moderately poor in organic matter but very rich in potassium and the phosphorus content was highly variable. Based on the statistical analysis, it is clear that the six zones had significantly different means for CaCO3, pH, OM, and exchangeable sodium percentage. Soil degradation like pollution and salinization may occur in this region if poor quality water is used for irrigation and if land is mismanaged. This research work can be considered as a first step towards a program for monitoring the quality of soil and water for adapting the land management with the final objective of securing high productivity and sustainable use of soil and water resources.

Spatial patterns of aerobic limit depth and oxygen diffusion rate at two peatlands drained for forestry in Alberta

1999 ◽  
Vol 29 (1) ◽  
pp. 53-61 ◽  
Author(s):  
U Silins ◽  
R L Rothwell
Keyword(s):  
Spatial Variability ◽  
Water Table ◽  
Spatial Patterns ◽  
Oxygen Diffusion ◽  
Diffusion Rate ◽  
Drainage Ditches ◽  
Soil Aeration ◽  
Rooting Zone ◽  
Capillary Zone ◽  
Oxygen Diffusion Rate

The spatial variability of soil aeration (aerobic limit depth and oxygen diffusion rate (ODR)) among different drainage ditch spacings and at various distances from drainage ditches was examined at two peatlands drained for forestry in north-central Alberta. Drainage lowered mean water table levels (p < 0.001) at both peatlands. Lower water table levels within drained areas were associated with greater aerobic limit depths (p < 0.001) and greater ODR (p < 0.001 at Saulteaux River; p < 0.027 at Wolf Creek) compared with undrained areas of both peatlands. Spatial patterns of aerobic limit depth and ODR indicated strong spatial variability of soil aeration in the immediate vicinity of drainage ditches. However, little sensitivity of soil aeration to different ditch spacings was evident. Potential effects of post-drainage subsidence on soil aeration was evident as increased distance of both the aerobic limit, and near-zero oxygen diffusion rates above the water table surface at both peatlands. One effect of post-drainage peatland subsidence may be to increase the thickness of the capillary zone above the water table. However, reduction of aeration within the rooting zone of peatland trees due to subsidence was not observed because of low water tables within the drained areas of both peatlands.

scholarly journals Impact of water table level on annual carbon and greenhouse gas balances of a restored peat extraction area

2016 ◽  
Vol 13 (9) ◽  
pp. 2637-2651 ◽  
Author(s):  
Järvi Järveoja ◽  
Matthias Peichl ◽  
Martin Maddison ◽  
Kaido Soosaar ◽  
Kai Vellak ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Water Table ◽  
Gross Primary Production ◽  
Vascular Plant ◽  
Plant Cover ◽  
Climate Impacts ◽  
N2o Emissions ◽  
Extraction Area ◽  
Peat Extraction ◽  
The Impact

Abstract. Peatland restoration may provide a potential after-use option to mitigate the negative climate impact of abandoned peat extraction areas; currently, however, knowledge about restoration effects on the annual balances of carbon (C) and greenhouse gas (GHG) exchanges is still limited. The aim of this study was to investigate the impact of contrasting mean water table levels (WTLs) on the annual C and GHG balances of restoration treatments with high (ResH) and low (ResL) WTL relative to an unrestored bare peat (BP) site. Measurements of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes were conducted over a full year using the closed chamber method and complemented by measurements of abiotic controls and vegetation cover. Three years following restoration, the difference in the mean WTL resulted in higher bryophyte and lower vascular plant cover in ResH relative to ResL. Consequently, greater gross primary production and autotrophic respiration associated with greater vascular plant cover were observed in ResL compared to ResH. However, the means of the measured net ecosystem CO2 exchanges (NEE) were not significantly different between ResH and ResL. Similarly, no significant differences were observed in the respective means of CH4 and N2O exchanges. In comparison to the two restored sites, greater net CO2, similar CH4 and greater N2O emissions occurred in BP. On the annual scale, ResH, ResL and BP were C sources of 111, 103 and 268 g C m−2 yr−1 and had positive GHG balances of 4.1, 3.8 and 10.2 t CO2 eq ha−1 yr−1, respectively. Thus, the different WTLs had a limited impact on the C and GHG balances in the two restored treatments 3 years following restoration. However, the C and GHG balances in ResH and ResL were considerably lower than in BP due to the large reduction in CO2 emissions. This study therefore suggests that restoration may serve as an effective method to mitigate the negative climate impacts of abandoned peat extraction areas.

scholarly journals A robust data cleaning procedure for eddy covariance flux measurements

2020 ◽  
Vol 17 (6) ◽  
pp. 1367-1391
Author(s):  
Domenico Vitale ◽  
Gerardo Fratini ◽  
Massimo Bilancia ◽  
Giacomo Nicolini ◽  
Simone Sabbatini ◽  
...  
Keyword(s):  
Systematic Error ◽  
Eddy Covariance ◽  
Outlier Detection ◽  
Stochastic Dynamics ◽  
Data Cleaning ◽  
Observation System ◽  
Correct Identification ◽  
Cleaning Procedure ◽  
Flux Data ◽  
The Impact

Abstract. The sources of systematic error responsible for introducing significant biases in the eddy covariance (EC) flux computation are manifold, and their correct identification is made difficult by the lack of reference values, by the complex stochastic dynamics, and by the high level of noise characterizing raw data. This work contributes to overcoming such challenges by introducing an innovative strategy for EC data cleaning. The proposed strategy includes a set of tests aimed at detecting the presence of specific sources of systematic error, as well as an outlier detection procedure aimed at identifying aberrant flux values. Results from tests and outlier detection are integrated in such a way as to leave a large degree of flexibility in the choice of tests and of test threshold values, ensuring scalability of the whole process. The selection of best performing tests was carried out by means of Monte Carlo experiments, whereas the impact on real data was evaluated on data distributed by the Integrated Carbon Observation System (ICOS) research infrastructure. Results evidenced that the proposed procedure leads to an effective cleaning of EC flux data, avoiding the use of subjective criteria in the decision rule that specifies whether to retain or reject flux data of dubious quality. We expect that the proposed data cleaning procedure can serve as a basis towards a unified quality control strategy for EC datasets, in particular in centralized data processing pipelines where the use of robust and automated routines ensuring results reproducibility constitutes an essential prerequisite.

Evaluating the Impact of Nonisothermal Flow on Vadose Zone Processes in Presence of a Water Table

Soil Science ◽  
2014 ◽  
Vol 179 (2) ◽  
pp. 57-67 ◽  
Author(s):  
Jiangbo Han ◽  
Zhifang Zhou ◽  
Zhimin Fu ◽  
Jinguo Wang
Keyword(s):  
Water Table ◽  
Vadose Zone ◽  
Nonisothermal Flow ◽  
The Impact

Groundwater assessment for a proper management and sustainable use of the resources in the middle-high venetian plain

2020 ◽  
Author(s):  
Tommaso Trentin ◽  
Giulia Mazzarotto ◽  
Paolo Salandin
Keyword(s):  
Water Table ◽  
Sustainable Use ◽  
Layered System ◽  
Guidance Document ◽  
Water Service ◽  
Service Companies ◽  
Positive Effects ◽  
Finite Element Software ◽  
Groundwater Assessment ◽  
The Impact

&lt;p&gt;This work describes a project that aims to assess and forecast the groundwater balance and the spatiotemporal behavior of fluxes in a regional aquifer located in the middle-high venetian plain between rivers Brenta and Piave (Italy) to analyze the impact of future irrigation policies and to define at regional scale the risk of contamination.&lt;/p&gt;&lt;p&gt;The area is widely exploited for agricultural purposes and over time many wells (owned by Water Service Companies and private bodies) have been drilled for the supply of drinking water. A dense network of ditches, that still guarantee most agricultural requirements by border irrigation, is replaced year by year with pressurized systems (sprinkler and drip). This change shows positive effects, reducing the amount of diverted water from rivers helping the Ecological Flows (Eflows) requirements (EU Guidance Document No. 31 2015). On the other hand, it actually reduces the infiltrated volumes (acting as artificial recharge) that sustain the groundwater reserve since centuries ago. Together with the growing number of active and potential sources of pollution, all this jeopardizes the water supply from wells intended for human consumption.&lt;/p&gt;&lt;p&gt;This situation requires proper knowledge and tools to anticipate consequences of a changing environment and to suggest policies for an appropriate management and sustainable use of groundwater.&lt;/p&gt;&lt;p&gt;The study area develops north to south from the Prealps to the middle of the plain, between Brenta River (west) and Piave River (east). Evidences from geological surveys show a sand and gravel aquifer extending from uplands in the north piedmont region to the southern one where a layered system of nine aquifers can be recognized. The hypothetical separation takes place along alluvial springs that origin the river Sile, that acts as a drain for the upper aquifer of the whole area.&lt;/p&gt;&lt;p&gt;A numerical model of the aquifer is under development using Feflow&amp;#174; by DHI, a finite element software able to reproduce the subsurface flow field and transport phenomena. Geological description and vertical stratigraphy of boreholes were used to build the geo-structural model, whose spatial extent was also chosen on the availability of data &amp;#8211; water table, piezometric levels and/or fluxes &amp;#8211; to be imposed on the boundaries. Rainfall, irrigation, evapotranspiration and water withdrawal artificially from wells or naturally from springs, as well as the flow interchange across the section of rivers, are the external forcing varying in time and controlling the water table and piezometric levels behaviors.&lt;/p&gt;&lt;p&gt;Water table and piezometric level information are fundamental in the calibration of the subsurface hydraulic parameters. The actual monitoring network, that considers sensors in wells property of Regional Environmental Agency and different Water Service Companies, has been improved to mitigate its non-uniform spatial distribution instrumenting 25 new positions to reach in the whole area (about 900 km&lt;sup&gt;2&lt;/sup&gt;) a total number of 84 monitored wells (density of about 1 sensor every 10 km&amp;#178;).&lt;/p&gt;&lt;p&gt;Information about historical evolution of different irrigation techniques have been gathered from the three Land Reclamation Authorities managing the investigated area to reproduce the present situation and forecast future different scenarios.&lt;/p&gt;

Ecological effects of peatland drainage for forestry

1995 ◽  
Vol 3 (3-4) ◽  
pp. 286-303 ◽  
Author(s):  
Jukka Laine ◽  
Harri Vasander ◽  
Tapani Sallantaus
Keyword(s):  
Ecological Effects ◽  
Ground Vegetation ◽  
Climatic Warming ◽  
Tree Stand ◽  
Faunal Change ◽  
Peatland Hydrology ◽  
Northern Peatlands ◽  
Surface Peat ◽  
Forest Drainage

Production forestry in peatlands, associated with drainage, is a controversial but widely applied forestry practice, especially in northern Europe. This paper aims to provide a synthesis of the ecological effects of forest drainage. Effects of the hydrological change, brought about by drainage on the chemical and physical properties of the surface peat, microbial activity, tree stand and ground vegetation, biodiversity, and faunal change, are reviewed. Finally, the role of forestry use of northern peatlands in the global climatic warming is synthesized.Key words: biodiversity, environmental impacts, forest drainage, global change, peatland hydrology.

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