scholarly journals Spontaneous revegetation of a peatland in Manitoba after peat extraction: diversity of plant assemblages and restoration perspectives

Botany ◽  
2018 ◽  
Vol 96 (11) ◽  
pp. 779-791 ◽  
Author(s):  
Félix Gagnon ◽  
Line Rochefort ◽  
Claude Lavoie
Keyword(s):  
Water Table ◽  
Plant Cover ◽  
High Water ◽  
Point Of View ◽  
Water Table Level ◽  
Peat Extraction ◽  
Peatland Restoration ◽  
Water Ph ◽  
Plant Assemblages ◽  
A Site

There are very few studies on the spontaneous revegetation of cutover fens or bogs from which peat has been extracted to the minerotrophic layers. Most peatlands with fen-type residual peat have problems regenerating a plant cover satisfactorily from a restoration point of view. We nevertheless found a site (Moss Spur, Manitoba, Canada) presenting a substantial and diversified spontaneous plant cover. We estimated that the site would provide insights about natural revegetation processes operating in peatlands. Vegetation assemblages and environmental conditions were surveyed 19 years after extraction activities ceased. Moss Spur has densely revegetated (163 plant species, vegetation cover of 94%) with minimal human assistance. However, the composition of plant assemblages varies considerably across the site, depending on certain abiotic variables, particularly water pH, water table level, and the thickness of the residual peat layer. Moss Spur was remarkably wet considering the past peat extraction activities and the absence of active rewetting procedures. The high water table level may in part explain the successful revegetation. However, plant assemblages were not of equal quality from a restoration perspective. Some assemblages were highly diversified, and especially those dominated by Scirpus cyperinus, a species that should be further considered in peatland restoration projects to direct the recovery of the peatland towards a natural fen species composition.

Design of a hydrodynamic leachate containment system

1989 ◽  
Vol 16 (5) ◽  
pp. 615-626 ◽  
Author(s):  
M. D. Haug ◽  
D. J. L. Forgie ◽  
S. L. Barbour
Keyword(s):  
Contaminant Transport ◽  
Water Table ◽  
High Water ◽  
Groundwater Table ◽  
Cutoff Wall ◽  
Transport Modelling ◽  
High Water Table ◽  
Cutoff Walls ◽  
A Site

This paper presents the design concept for a case study sanitary landfill on a site that would not normally have been approved owing to the presence of a high water table. In this design, the base of the landfill was intentionally placed below the water table. A massive 2.5 m wide, 2.5 m high cutoff wall and a 0.3 m thick liner with hydraulic conductivities of approximately 5 × 10−10 m/s were constructed of recompacted glacial till to limit both groundwater intrusion into the landfill and leachate migration out of the landfill. In this case study, the landfill base was placed below the water table to (i) provide a relatively inexpensive source of cover material and (ii) use the hydrodynamic gradient from the high water table to help contain the leachate. Finite element modelling of the seepage and contaminant transport, for alternate designs for lined and unlined landfills placed above and below the groundwater table, is shown to confirm a previous, less-sophisticated, estimation that placing a lined landfill below the groundwater table has definite advantages in reducing both leachate seepage and contaminant transport. Key words: landfill, leachate, hydrodynamic containment, liners, compacted earth cutoff walls, seepage and contaminant transport modelling.

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 Subirrigated Bell Pepper Production with Reduced Water Table Levels and Fertilizer Rates

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 884C-884
Author(s):  
C.D. Stanley ◽  
G.A. Clark
Keyword(s):  
Water Table ◽  
Soil Surface ◽  
High Water ◽  
Bell Pepper ◽  
Soil Water Storage ◽  
Lateral Field ◽  
Water Storage Capacity ◽  
Water Table Level ◽  
Growing Seasons ◽  
Fertilizer Rates

The effect of water table level and fertilizer rates on bell pepper production grown with the fully enclosed subirrigation (FES) system was studied over three fall growing seasons (1992–94). The FES system uses buried microirrigation tubing in the field to convey water for maintaining a water table level and has shown to achieve application savings of 30% to 40% compared to the conventional subirrigation method that maintains a high water table using lateral field ditches. Controlled water table levels of 45, 60, and 75 cm below soil surface and fertilizer rates of 1194, 1716, and 2239 kg·ha–1 (18–0–21 expressed as N–P–K) were used as treatments replicated in time over 3 growing seasons. The 45-cm water table level and 2239 kg·ha–1 fertilizer rate are considered the conventional commercial practices. Results showed that comparable seasonal production levels were achieved among fertilizer rates and water table levels with no significant interactions between treatments. These data indicate that using a lower target water table level allows lower rates of fertilizer to be used because the susceptibility of the fertilizer to leaching caused by excessive rainfall is lessened due to increased soil water storage capacity.

SOIL PROPERTIES IN RELATION TO WATER REGIME AT A SITE NEAR QUEBEC CITY

1974 ◽  
Vol 54 (4) ◽  
pp. 427-446 ◽  
Author(s):  
C. R. DE KIMPE ◽  
J. A. McKEAGUE ◽  
G. C. TOPP
Keyword(s):  
Water Table ◽  
Seasonal Changes ◽  
Soil Structure ◽  
Sedimentary Rock ◽  
High Water ◽  
Soil Variability ◽  
Quebec City ◽  
Redox Potentials ◽  
Water Tables ◽  
A Site

Properties of soils along the 3% slope were affected both by water table levels and by the nature of the parent sedimentary rock. All of the soils had upper sola of medium to fine texture, due largely to the disintegration of the underlying shaly gravel. Relatively impermeable shaly bedrock at depths of 1–2 m from the surface maintained generally high water tables. Redox potentials, gley colors and mottling were closely associated with proximity to the surface of the water table. Evidence of podzolisation and of clay weathering and translocation were obscured by the release of bases and clay from the disintegrating gravel. Hydraulic conductivities of the surficial layers were generally much lower than those of the gravelly subsoil layers, but the data were highly variable due to soil variability, seasonal changes in soil structure and problems with methodology. The data suggest that surface ridging might be more effective than tiles for draining soils such as these.

scholarly journals Étude Lithostratigraphique Des Formations Superficielles Urbaines Du Secteur Nord De La Ville De Fès, Maroc

2017 ◽  
Vol 13 (33) ◽  
pp. 129
Author(s):  
Boukhir Mohammed ◽  
Jamal Mohamed ◽  
Azzouzi Kamal
Keyword(s):  
Water Table ◽  
Laboratory Tests ◽  
Flood Plain ◽  
Point Of View ◽  
Solid Base ◽  
The West ◽  
Water Table Level ◽  
The City ◽  
Northern Sector

The superficial formations of the northern sector of the city of Fez majorly show clay lithostratigraphy in the west of this sector. They are conglomeratic at the center and are composed of limestone deposits in the East. As for the land embankments, they met at two banks of Oued Fès. From a geotechnical point of view, the formations which are exposed to the phenomena of compressing or liquefaction are the argillaceous and anthropic formations. These phenomena of the instability of the grounds can worsen when the water table level increases significantly, especially during the rainy seasons where it can reach the surface at the Oued Fez flood plain. As for the conglomeratic formations, the geotechnical analysis shows that the conglomerates forming a very hard rocky slab constitute a rather solid base and is indeformable. Their thickness, therefore, exceeds 2m of power. This is the case of conglomerates located at the center of this sector. Laboratory tests have classified these soils to be relatively stable.

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

2015 ◽  
Vol 12 (20) ◽  
pp. 17177-17218 ◽  
Author(s):  
J. Järveoja ◽  
M. Peichl ◽  
M. Maddison ◽  
K. Soosaar ◽  
K. 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 water table levels (WTL) on the annual C and GHG balances of restoration treatments with high (Res-H) and low (Res-L) 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 Res-H relative to Res-L. Consequently, greater gross primary production and autotrophic respiration associated with greater vascular plant cover were observed in Res-L compared to Res-H. However, the means of the measured net ecosystem CO2 exchanges (NEE) were not significantly different between Res-H and Res-L. Similarly, no significant differences were observed in the respective means of CH4 and N2O exchanges in Res-H and Res-L, respectively. In comparison to the two restored sites, greater net CO2, similar CH4 and greater N2O emissions occurred in BP. On the annual scale, Res-H, Res-L 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 three years following restoration. However, the C and GHG balances in Res-H and Res-L were considerably lower than in BP owing 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.

Evaluation of nutrient runoff from the kako river by continuous daily sampling

1996 ◽  
Vol 34 (12) ◽  
pp. 67-72
Author(s):  
Yukio Komai
Keyword(s):  
Suspended Solids ◽  
Water Discharge ◽  
Electronic Conductivity ◽  
High Water ◽  
Nutrient Loads ◽  
Discharge Condition ◽  
Nutrient Runoff ◽  
Average Value ◽  
Daily Sampling ◽  
A Site

A water sample was taken once a day for 15 months at a site near an estuary of the Kako River, Japan, to estimate nutrient loads from rivers to the sea. Total phosphorus (T-P), total nitrogen (T-N), suspended solids (SS) and electronic conductivity (EC) were measured. T-P and SS concentrations varied in proportion to the discharge, and T-P concentrations increased with those of SS, too. EC varied inversely with the discharge, but the fluctuations of T-N concentrations were less than those of T-P and SS concentrations. Water quality remained, for the most part, constant throughout the day. T-P, T-N and SS load were 181t/year, 2320t/year and 51000t/year in 1992, respectively, 54% of T-P load, 47% of T-N load and 80% of SS loads outflowed in those cases where the discharge was more than 100 m3/s, which were 36 days in 1992. 79% of T-P load, 69% of T-N load and 92% of SS load outflowed in periods of high water discharge, which were 88 in 1992. T-P and T-N loads calculated by using one day's data in every month were 151t/year and 2450t/year. But nutrient loads calculated by using the average value of data from an ordinary discharge were two or three times lower than calculated yearly loads. These results showed the importance of estimating the yearly load considering the discharge condition and sampling at a time of high water discharge.

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