scholarly journals Greenhouse Gas Emissions Dynamics in Restored Fens After In-Situ Oil Sands Well Pad Disturbances of Canadian Boreal Peatlands

2020 ◽  
Vol 8 ◽  
Author(s):  
Meike Lemmer ◽  
Line Rochefort ◽  
Maria Strack
Keyword(s):  
Global Warming ◽  
Plant Species ◽  
Global Warming Potential ◽  
Oil Sands ◽  
Construction Materials ◽  
Complete Removal ◽  
Partial Removal ◽  
Moss Species ◽  
Rich Fen

In-situ oil extraction activities impact the vast mosaic of boreal wetlands and uplands. Peatland restoration in these regions aims at reestablishing crucial peatland functions, such as peat accumulation and carbon (C) sequestration. In order to assess the success of fen restoration, we evaluated the biogeochemical conditions, the seasonal carbon balances via carbon dioxide (CO2) fluxes and methane (CH4) emissions, and addressed the global warming potential following different restoration techniques at two restored in-situ oil sands well pads, during two consecutive growing seasons. Restoration work involved: 1) the partial or complete removal of introduced well pad construction materials, and spontaneous revegetation, or 2) the partial removal of foreign clay, in addition to reintroduction of typical fen plant species such as Larix laricina, Salix lutea and Carex aquatilis. Comparisons were done with regional reference ecosystems (REF) consisting of three peatlands: a wooded bog, a wooded rich fen and a wooded extreme-rich fen. While the average electric conductivity of restored sectors (946 μS cm−1) was higher compared to REF (360 μS cm−1), the pH was quite similar (pH 5.8 REF, pH 6 restored). Dissolved organic carbon concentration was lower in all restored sectors (5–11 mg L-1 restored sectors, 15–35 mg L-1 REF), presumably due to the still incomplete recovery of vegetation and lower organic matter content associated with remnant well pad material. Re-establishment of shrub and brown moss species improved significantly the C uptake. However, the active introduction of plant species was no crucial restoration step, in order to return species beneficial for C uptake. Restoration treatments that were leveled closest to the surrounding REF showed the most similar seasonal C balance to REF. In shallow open water areas resulting from the complete removal of all construction materials, we measured the highest methane emissions making these flooded sites net C sources to the atmosphere with elevated global warming potential. The partial removal of the well pad’s mineral soil to near the water table level and the surface elevation of the surrounding ecosystem seems to be the most effective site management method to sequester carbon efficiently. However, further research is needed to evaluate the suitability of this restoration method for the recovery of biodiversity and possible impacts of residual foreign materials on fen ecosystems.

scholarly journals Green-house gas mitigation capacity of a small scale rural biogas plant calculations for Bangladesh through a general life cycle assessment

2017 ◽  
Vol 35 (10) ◽  
pp. 1023-1033 ◽  
Author(s):  
Khondokar M Rahman ◽  
Lynsey Melville ◽  
David Fulford ◽  
SM Imamul Huq
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Global Warming Potential ◽  
Construction Materials ◽  
Biogas Plant ◽  
Small Scale ◽  
Potential Saving ◽  
Carbon Dioxide Equivalent

Calculations towards determining the greenhouse gas mitigation capacity of a small-scale biogas plant (3.2 m3 plant) using cow dung in Bangladesh are presented. A general life cycle assessment was used, evaluating key parameters (biogas, methane, construction materials and feedstock demands) to determine the net environmental impact. The global warming potential saving through the use of biogas as a cooking fuel is reduced from 0.40 kg CO2 equivalent to 0.064 kg CO2 equivalent per kilogram of dung. Biomethane used for cooking can contribute towards mitigation of global warming. Prior to utilisation of the global warming potential of methane (from 3.2 m3 biogas plant), the global warming potential is 13 t of carbon dioxide equivalent. This reduced to 2 t as a result of complete combustion of methane. The global warming potential saving of a bioenergy plant across a 20-year life cycle is 217 t of carbon dioxide equivalent, which is 11 t per year. The global warming potential of the resultant digestate is zero and from construction materials is less than 1% of total global warming potential. When the biogas is used as a fuel for cooking, the global warming potential will reduce by 83% compare with the traditional wood biomass cooking system. The total 80 MJ of energy that can be produced from a 3.2 m3 anaerobic digestion plant would replace 1.9 t of fuel wood or 632 kg of kerosene currently used annually in Bangladesh. The digestate can also be used as a nutrient rich fertiliser substituting more costly inorganic fertilisers, with no global warming potential impact.

In situ dry cleaning of Si wafer using OF2/NH3 remote plasma with low global warming potential

2018 ◽  
Vol 51 (44) ◽  
pp. 445201 ◽  
Author(s):  
Jin Woo Park ◽  
Myeong Gyoon Chae ◽  
Doo San Kim ◽  
Won Oh Lee ◽  
Han Dock Song ◽  
...  
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Remote Plasma ◽  
Dry Cleaning ◽  
Low Global Warming Potential ◽  
Si Wafer

Habitat heterogeneity stimulates regeneration of bryophytes and vascular plants on disturbed minerotrophic peatlands

2019 ◽  
Vol 49 (3) ◽  
pp. 281-295
Author(s):  
Richard T. Caners ◽  
Varina Crisfield ◽  
Victor J. Lieffers
Keyword(s):  
Plant Species ◽  
Oil Sands ◽  
Woody Plants ◽  
Vascular Plants ◽  
Western Canada ◽  
Vegetation Development ◽  
Northeastern Alberta ◽  
Trees And Shrubs ◽  
Surface Vegetation

Wooded rich fens (WRF), characterized by high variation in surface topography and numerous plant species organized along microtopographic gradients, are abundant in continental western Canada. In regions where in situ oil sands exploration (OSE) prevails, however, winter operations eliminate the surface vegetation and mechanically flatten the exposed peat. This results in saturated or flooded soils during the growing season and eliminates plant species dependent on naturally elevated microhabitats, with implications for peatland recovery. In northeastern Alberta, we redeveloped hummock topography on replicate WRF after OSE by extracting blocks of frozen peat from peatland surfaces in the winter. Peat mounds and adjacent unmounded flattened areas were left to regenerate naturally and were sampled four to five summers later. Mounds facilitated the colonization of many peatland plants not adapted to waterlogged soils. For bryophytes, mean richness and diversity of liverworts, Sphagnum, and true mosses were higher in mounded plots than in unmounded plots. For vascular plants, woody plants (trees and shrubs) had higher richness, cover, and diversity (trees only) in mounded plots. Peat mounding may be effective for stimulating vegetation development on OSE-degraded WRF. All mounds, however, will require lateral expansion by hummock-forming mosses to provide the habitat volume required for development of large woody plants.

Notes from the Polar Night

2020 ◽  
Vol 9 (4) ◽  
pp. 35-43
Author(s):  
Chris Ingraham
Keyword(s):  
Global Warming ◽  
The Sun ◽  
Polar Night ◽  
Academic Scholarship

Drawing from in situ fieldwork in Longyearbyen, Svalbard, the northernmost settlement on Earth, these notes bring out the affective, ambient, and atmospheric power of extended darkness during the polar night, when the sun does not appear above the horizon for several months at a time. Each entry is composed of 113 words to reflect the number of days without light in Longyearbyen during the winter of my visit. Through a mixture of ethnographic observations, researched academic scholarship, and some endeavors of poetic worldmaking, these notes attempt to evoke the ineffable force of global warming by performing the sort of acutely observed and felt attentiveness to planetary being that is needed for our time.

scholarly journals Variation in Soil Properties Regulate Greenhouse Gas Fluxes and Global Warming Potential in Three Land Use Types on Tropical Peat

Atmosphere ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 465 ◽  
Author(s):  
Kiwamu Ishikura ◽  
Untung Darung ◽  
Takashi Inoue ◽  
Ryusuke Hatano
Keyword(s):  
Global Warming ◽  
Soil Moisture ◽  
Groundwater Level ◽  
Global Warming Potential ◽  
C:N Ratio ◽  
Co2 Flux ◽  
Nitrate Content ◽  
N2o Flux ◽  
Ch4 Flux ◽  
In The Beginning

This study investigated spatial factors controlling CO2, CH4, and N2O fluxes and compared global warming potential (GWP) among undrained forest (UDF), drained forest (DF), and drained burned land (DBL) on tropical peatland in Central Kalimantan, Indonesia. Sampling was performed once within two weeks in the beginning of dry season. CO2 flux was significantly promoted by lowering soil moisture and pH. The result suggests that oxidative peat decomposition was enhanced in drier position, and the decomposition acidify the peat soils. CH4 flux was significantly promoted by a rise in groundwater level, suggesting that methanogenesis was enhanced under anaerobic condition. N2O flux was promoted by increasing soil nitrate content in DF, suggesting that denitrification was promoted by substrate availability. On the other hand, N2O flux was promoted by lower soil C:N ratio and higher soil pH in DBL and UDF. CO2 flux was the highest in DF (241 mg C m−2 h−1) and was the lowest in DBL (94 mg C m−2 h−1), whereas CH4 flux was the highest in DBL (0.91 mg C m−2 h−1) and was the lowest in DF (0.01 mg C m−2 h−1), respectively. N2O flux was not significantly different among land uses. CO2 flux relatively contributed to 91–100% of GWP. In conclusion, it is necessary to decrease CO2 flux to mitigate GWP through a rise in groundwater level and soil moisture in the region.

scholarly journals Photosynthetic parameters of a sedge-grass marsh as a big-leaf: effect of plant species composition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Markéta Mejdová ◽  
Jiří Dušek ◽  
Lenka Foltýnová ◽  
Lenka Macálková ◽  
Hana Čížková
Keyword(s):  
Species Composition ◽  
Plant Species ◽  
Photosynthetic Parameters ◽  
Acorus Calamus ◽  
Dominant Plant Species ◽  
Local Plant ◽  
Rate Of Photosynthesis ◽  
Carex Acuta ◽  
Leaf P

AbstractThe study estimates the parameters of the photosynthesis–irradiance relationship (PN/I) of a sedge-grass marsh (Czech Republic, Europe), represented as an active “green” surface—a hypothetical “big-leaf”. Photosynthetic parameters of the “big-leaf” are based on in situ measurements of the leaf PN/I curves of the dominant plant species. The non-rectangular hyperbola was selected as the best model for fitting the PN/I relationships. The plant species had different parameters of this relationship. The highest light-saturated rate of photosynthesis (Asat) was recorded for Glyceria maxima and Acorus calamus followed by Carex acuta and Phalaris arundinacea. The lowest Asat was recorded for Calamagrostis canescens. The parameters of the PN/I relationship were calculated also for different growth periods. The highest Asat was calculated for the spring period followed by the summer and autumn periods. The effect of the species composition of the local plant community on the photosynthetic parameters of the “big-leaf” was addressed by introducing both real (recorded) and hypothetical species compositions corresponding to “wet” and “dry” hydrological conditions. We can conclude that the species composition (or diversity) is essential for reaching a high Asat of the “big-leaf ”representing the sedge-grass marsh in different growth periods.

scholarly journals PATH-23. ADULT SPINAL CORD ASTROBLASTOMA WITH EWSR1-BEND2 FUSION

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii429-iii429
Author(s):  
Takeyoshi Tsutsui ◽  
Yoshiki Arakawa ◽  
Yasuhide Makino ◽  
Hiroharu Kataoka ◽  
Sachiko Minamiguti ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Residual Tumor ◽  
Intramedullary Tumor ◽  
Partial Removal ◽  
Weighted Image ◽  
Eosinophilic Cytoplasm ◽  
S 100 ◽  
High Cellularity ◽  
Adult Spinal Cord

Abstract The most recurrent fusion of CNS high-grade neuroepithelial tumor with MN1alteration(HGNET-MN1) is MN1- BEN Domain Containing 2(BEND2) fusion. Recently, there was a report of a 3-month-old boy with spinal astroblastoma, classified as CNS HGNET-MN1 by DKFZ methylation classification but positive for EWSR1-BEND2 fusion(Yamasaki, 2019). Here, we report a 36-year old man with a spinal cord astroblastoma with EWSR1 alternation. The patient presented with back pain, gait disorder and dysesthesia in lower extremities and trunk was referred to our hospital. MRI showed intramedullary tumor in Th3-5 level, displaying low-intensity on T1 weighted image, high-intensity on T2 weighted image, and homogeneous gadolinium enhancement. Partial removal was performed with the laminectomy. The tumor extended to extramedullary and its boundary was unclear. Histological examinations showed the epithelium-like tumor cells with eosinophilic cytoplasm with high cellularity palisade, intracellar fibrosis, and mitosis. Immunohistochemical staining showed positive for Olig2, GFAP, EMA, SSTR2, S-100, but negative for p53, PgRAE1/AE3. The tumor was diagnosed as astroblastoma, and was classified as HGNET-MN1 by the DKFZ methylation classifier. However, the MN1 alternation was not detected by fluorescence in situ hybridization, instead EWSR1 and BEND2 alternations which suggested EWSR1-BEND2 fusion were detected. After radiation therapy of 54Gy/30fr with bevacizumab and temozolomide, the residual tumor reduced the size and his symptoms improved. This case provides evidence that EWSR1-BEND2 fusion is recurrent in HGNET-MN1 and, as previously reported, suggests the importance of BEND2 in this entity. These two cases suggested that it may be the BEND2 alteration that biologically defines the HGNET-MN1 subclass rather than MN1.

scholarly journals Influence of technical and electrical equipment in life cycle assessments of buildings: case of a laboratory and research building

2021 ◽  
Author(s):  
E. Hoxha ◽  
D. Maierhofer ◽  
M.R.M Saade ◽  
A. Passer
Keyword(s):  
Global Warming ◽  
Environmental Impacts ◽  
Global Warming Potential ◽  
Electrical Equipment ◽  
Primary Energy ◽  
Electronic Equipment ◽  
Detailed Result ◽  
Detailed Calculation ◽  
System Boundary ◽  
Operational Energy

Abstract Purpose A detailed assessment of the environmental impacts of the building requires a substantial amount of data that is time- and effort-consuming. However, limitation of the system boundary to certain materials and components can provide misleading impact calculation. In order to calculate the error gap between detailed and simplified assessments, the purpose of this article is to present a detailed calculation of the environmental impacts of the building by including in the system boundary, the technical, and electrical equipment. Method To that end, the environmental impacts of a laboratory and research building situated in Graz-Austria are assessed following the EN-15978 norm. Within the system boundaries of the study, the material and components of building fabric, technical, and electronic equipment for the building lifecycle stages of production, construction, replacement, operational energy and water, and end-of-life are considered. The input data regarding the quantity of materials is collected from the design and tendering documents, invoices, and from discussion with the head of the building’s construction site. Primary energy and global warming potential indicators are calculated on the basis of a functional unit of 1 m2 of energy reference area (ERA) per year, considering a reference building service life of 50 years. Results and discussion The primary energy indicator of the building is equal to 1698 MJ/m2ERA/year. The embodied impacts are found to be responsible for 28% of which 6.4% is due to technical and electronic equipment. Furthermore, the embodied impacts for the global warming potential, equal to 28.3 kg CO2e/m2ERA/year, are responsible for 73%. Together, technical and electrical equipment are the largest responsible aspects, accounting for 38% of the total impacts. Simplified and detailed result comparisons show a gap of 29% and 7.7% for global warming and primary energy indicators. These differences were from the embodied impacts and largely from the exclusion of electrical equipment from the study’s system boundary. Conclusions Technical and electrical equipment present a significant contribution to the overall environmental impacts of the building. Worthy of inclusion in the system boundary of the study, the environmental impacts of technical and electrical equipment must be calculated in detail or considered with a reliable ratio in the early design phase of the project. Further research is necessary to address the detailed impact calculation of the equipment and notably the minimization of their impacts.

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