Numerous recent studies have documented dynamic changes in the behaviors of large marine-terminating outlet glaciers and ice streams in Greenland, the Antarctic Peninsula, and West Antarctica. However, fewer observations of outlet glaciers and ice shelves exist for the East Antarctic Ice Sheet. In addition, most recent surface velocity mappings of the Lambert Glacier-Amery Ice Shelf system (LAS) are derived for the time period of 1997-2000. From this research, surface velocity measurements provide a more extended view of the behavior and stability of the LAS over the past two decades than can be gleaned from a single observational period. This study uses remote sensing to investigate whether significant changes in velocities have occurred from the late 1980’s through the late 2010’s and assesses the magnitude of mass balance changes observed at the grounding line. To accomplish this goal, surface velocities of the LAS from late 1980’s to late 2010’s for three separate time periods are measured. The observed surface velocities of the LAS ranged from 0 to 1300 m yr^-1 during 1988-1990. A slight slowing down is detected in the central Amery Ice Shelf front by analyzing the surface velocity measurements made along the centerlines. The mass balance is the difference between snow accumulation and the outflux of the grounded LAS and is calculated for individual sub-basin during the three time intervals of 1988-1990, 1999-2004, and 2007-2011 to illustrate the mass balance variation under sub-basin level. The flux gates of the Lambert Glacial sub-basin combined with the Mellor Glacial and the Fisher Glacial sub-basin appear to be the largest outlet of the grounded ice of the LAS. The ice mass transported from the interior region through the three flux gates in total is 43.58 Gt yr^-1, 36.72 Gt yr^-1, and 38.61 Gt yr^-1 respectively for the three time intervals above. The sub-basins in the eastern side appear differently than the western side. The outfluxes of the eastern sub-basins vary from 15.85 to 18.64 Gt yr^-1, while the western outfluxes vary from 15.85 to 18.64 Gt yr^-1. The grounded LAS has discharged ice from 84.55 to 81.60 Gt yr^-1 and to 79.20 Gt yr^-1 during 1980s-1990s and 1990s-2000s. Assuming the snow accumulation distribution is stable, the grounded LAS mass lose has increased 2.95 Gt yr^-1 from 1980s to 1990s and 2.40 Gt yr^-1 from 1990s to 2000s. These results indicate insight into the stability of the Amery Ice Shelf over the last few decades.

Soil salinity affects an estimated one billion hectares worldwide. Excess salinity inhibits plant growth, limiting crop production. This is caused by osmotic stress in saline soil, nutrient imbalance and specific ion toxicity. There have been many methods of remediation investigated, including excavation, soil washing and phytoremediation. Phytoremediation involves the growth of plants on impacted soils to degrade or sequester contaminants. The remediation of salts relies on the uptake of ions into plant biomass where the salt is sequestered and the biomass can then be harvested. This method removes the salt from the site and leaves the top soil in place, which aids in revegetation after site remediation is completed. Plant-growth promoting rhizobacteria (PGPR) improves plant growth by lowering the levels of stress ethylene within the plant, thereby increasing the biomass available to sequester ions. The objectives of this research were to investigate the efficiency of phytoremediation of salt impacted soils in field remediation sites. Previously isolated strains of PGPR (UW3, Pseudomonas putida; UW4, Pseudomonas putida; and CMH3, Pseudomonas corrugata) were used in field trials involving the planting of oats (Avena sativa), annual ryegrass (Lolium multiflorum), tall wheatgrass (Agropyron elongatum) and tall fescue (Festuca arundinacea C.V. Inferno). The salt tolerance of various switchgrass (Panicum virgatum L.) cultivars (Cave-In-Rock, Southlow, Forestburg, and common) was compared to tall wheatgrass and Inferno tall fescue to investigate the potential of switchgrass for phytoremediation. Improvement of seed germination under salt stress by H2O2 pre-treatment was investigated both as an individual treatment and in combination with CMH3 treatment. The ion uptake into plant biomass was iii compared to the change in salinity, to determine how much of the decrease in site salinity is accounted for by uptake of salt by plants. H2O2 pretreatment resulted in a 50% increase in root and shoot emergence of tall wheatgrass under 75 mM NaCl stress compared to control treatments, which matched the germination improvement observed with PGPR treatment. The combination of H2O2 and CMH3 showed a similar improvement to root emergence under stress, but had no observable effect on shoot emergence when compared to the no-H2O2-no-PGPR control. Switchgrass cultivars showed a lower germination rate than tall wheatgrass at salt levels from 0 mM to 150 mM NaCl. The measured uptake of Na+, K+, Ca2+, Mg2+ and Cl- into plant biomass during a phytoremediation field trial was able to account for approximately 70% of the observed change in salinity in 2008. In 2009 the uptake of Na+ and Cl- into Kochia scoparia, a weed species that invaded the field site after a hard frost, was able to account for 36% of the observed change in salinity.

No description available.

The environmental impacts of broiler production have recently gained considerable public attention due to concerns regarding the amount of ammonia (NH3) released into the atmosphere from poultry facilities. Sound scientific data are needed to accurately estimate the production of manure waste products and gaseous emissions. This research project was undertaken to quantify nitrogen (N) loss through air emissions from a broiler grow-out facility over 18 consecutive flocks using the mass balance method. Measurement of litter and caked litter (cake) mass at the end of each flock allowed for the calculation of litter and cake production rates for broilers reared on recycled rice hull litter. Nutrient (nitrogen, phosphorus, and potassium) content of all litter materials was also measured. Broilers were reared in a research facility under simulated commercial conditions. All input materials (birds, feed, and litter) used in this study were obtained directly from a commercial broiler integrator to assure applicability to the broiler industry. The litter management technique of ??top-dressing?? was also investigated to determine its effects on N emissions and litter and cake production rates. Nitrogen emissions, litter and cake production rates, and nutrient density of litter materials were found to vary significantly between flocks reared at different times of the year. Nitrogen emissions were significantly greater for summer flocks than winter flocks. Average N loss over all 18 flocks was 11.07 g N/kg of marketed broiler (g N/kg). Nitrogen partitioning as a percentage of inputs averaged 15.29, 6.84, 55.52, 1.27, and 21.08% for litter, caked litter, broiler carcasses, mortalities and nitrogen loss, respectively, over all 18 flocks. Litter and cake production was lower in the summer compared to winter. Average litter, cake, and all litter (litter + cake) production was 153.3, 74.8, and 228.2 g of dry litter material/kg of marketed broiler. Litter and cake phosphorus and potassium content was elevated during summer flocks, while litter material N content decreased in summer flocks. Therefore, season of the year is an important factor that scientists and broiler producers must take into account when performing measurements and calculations, sampling litter materials and air emissions, and developing nutrient management plans.

A mass-balance modeling approach has been applied to gain an improved understanding of the relative contributions of phosphorus loading from various sources into a freshwater lake with cage-aquaculture in Ontario. All cage-aquaculture in Ontario is located within Lake Huron and Georgian Bay of the Great Lakes where concerns about potential environmental issues are constraining growth of the industry. Phosphorus is of particular concern for cage-aquaculture operations in Ontario since this nutrient may accelerate eutrophication of freshwater. Sound scientific information is needed for the Ministry of Environment lake managers to make defensible decisions to move the industry forward in a sustainable manner. Lake Wolsey is located on Manitoulin Island in Lake Huron, Ontario. The lake is connected to the North Channel by a small inlet where water exchanges periodically. A cage-aquaculture operation was established in 1986 and has an average annual production of approximately 250 metric tonnes of rainbow trout. We have estimated total phosphorus loadings from eight sources of inputs and three sinks from the lake. We then applied a sensitivity analysis to establish parameters that require empirical measurement and field validation. Results show non-point sources as the leading contributor of total phosphorus to Lake Wolsey (40%, 1120 kg) followed by the farm (32%, 915 kg), groundwater (11%, 305 kg), and dwellings (8%, 219 kg), internal phosphorus load from the hypoxic hypolimnion mid-lake (7%, 186 kg), precipitation (3%, 79 kg) and leaf litter (0.3%, 8 kg). Results of the sensitivity analysis show non point sources to be the most significant parameter in terms of total phosphorus loading, followed by the lake sedimentation, then the contribution by the aquaculture operation. This is followed by the exchange via the inlet, groundwater, dwellings, the internal phosphorus, sportfishing, precipitation and leaf litter. Information from this project will provide water quality managers with scientific information to aid in decisions pertaining to policy and regulatory approaches for water quality risk assessment and management of cage-aquaculture in Ontario. / Great Lakes Sustainablility Fund, Great Lakes Action Plan V, Ontario Sustainable Aquaculture Working Group

No description available.

Soil salinity affects an estimated one billion hectares worldwide. Excess salinity inhibits plant growth, limiting crop production. This is caused by osmotic stress in saline soil, nutrient imbalance and specific ion toxicity. There have been many methods of remediation investigated, including excavation, soil washing and phytoremediation. Phytoremediation involves the growth of plants on impacted soils to degrade or sequester contaminants. The remediation of salts relies on the uptake of ions into plant biomass where the salt is sequestered and the biomass can then be harvested. This method removes the salt from the site and leaves the top soil in place, which aids in revegetation after site remediation is completed. Plant-growth promoting rhizobacteria (PGPR) improves plant growth by lowering the levels of stress ethylene within the plant, thereby increasing the biomass available to sequester ions. The objectives of this research were to investigate the efficiency of phytoremediation of salt impacted soils in field remediation sites. Previously isolated strains of PGPR (UW3, Pseudomonas putida; UW4, Pseudomonas putida; and CMH3, Pseudomonas corrugata) were used in field trials involving the planting of oats (Avena sativa), annual ryegrass (Lolium multiflorum), tall wheatgrass (Agropyron elongatum) and tall fescue (Festuca arundinacea C.V. Inferno). The salt tolerance of various switchgrass (Panicum virgatum L.) cultivars (Cave-In-Rock, Southlow, Forestburg, and common) was compared to tall wheatgrass and Inferno tall fescue to investigate the potential of switchgrass for phytoremediation. Improvement of seed germination under salt stress by H2O2 pre-treatment was investigated both as an individual treatment and in combination with CMH3 treatment. The ion uptake into plant biomass was iii compared to the change in salinity, to determine how much of the decrease in site salinity is accounted for by uptake of salt by plants. H2O2 pretreatment resulted in a 50% increase in root and shoot emergence of tall wheatgrass under 75 mM NaCl stress compared to control treatments, which matched the germination improvement observed with PGPR treatment. The combination of H2O2 and CMH3 showed a similar improvement to root emergence under stress, but had no observable effect on shoot emergence when compared to the no-H2O2-no-PGPR control. Switchgrass cultivars showed a lower germination rate than tall wheatgrass at salt levels from 0 mM to 150 mM NaCl. The measured uptake of Na+, K+, Ca2+, Mg2+ and Cl- into plant biomass during a phytoremediation field trial was able to account for approximately 70% of the observed change in salinity in 2008. In 2009 the uptake of Na+ and Cl- into Kochia scoparia, a weed species that invaded the field site after a hard frost, was able to account for 36% of the observed change in salinity.

Differential GPS data from 2007-2014 are used to assess horizontal and vertical velocity variations of the Kaskawulsh Glacier at interannual and intra-annual timescales. These indicate that an upglacier propagating high velocity event occurs every spring at the onset of melt, and that a downglacier propagating high velocity event occurs every fall or winter after melt has finished. These events suggest that the subglacial drainage system alternates between a distributed system in the winter and channelized system in the summer and fall. In addition, there is a strong negative correlation between summer melt and velocity the following fall and winter, with strong melt years resulting in low velocities. For each additional metre of summer melt, an 8.6% average decrease in velocity is observed on the glacier the following fall-winter. These results suggest that changes in the subglacial drainage system limit the sensitivity of glacier motion to increased meltwater inputs. Glacier motion will likely show a net decrease under a warming climate due to the negative correlation between surface melt rates and ice motion and a decrease in driving stresses as a result of reduced ice thicknesses. In addition, future fall-winter velocity patterns could be accurately predicted from only a month or two of summer melt data, with May-June melt providing the best indication of fall-winter motion. This study also suggests that the common assumption that glaciers are ‘stable’ in the late fall and winter is incorrect.

This thesis presents a detailed study of recent changes in the mass balance and dynamics of Penny Ice Cap (PIC), and projects its evolution under a warming climate. Mass losses from 2005-2014 were quantified from airborne altimetry elevation change measurements, and adjusted for vertical ice motion caused by firn compaction and/or ice dynamics. Mass loss from PIC increased four-fold between the mid-1990s (-1.3 ± 0.7 Gt a-1) and 2005-2013 (-5.4 ± 1.9 Gt a-1). The adjustment calculations indicate that mass loss may be overestimated by 19% if vertical motion is not properly accounted for. The velocity response to increased surface melt was quantified using satellite imagery and historical ground measurements from Highway Glacier, on the southern part of PIC. Over the period 1985-2011, the six largest outlet glaciers on the ice cap decelerated at an average rate of 21 m a-1 over the 26 year period (0.81 m a-1), or 12% decade-1. Highway Glacier decelerated by 71% between 1953 and 2009/11. The recent slowdown of outlet glaciers has coincided with increases in mass loss and an inferred reduction in basal sliding. The ice-cap-wide mass balance was modeled from 1958 to 2099 with an enhanced temperature index model. Since the mid-1990s mass balance rates over PIC have become increasingly negative. Peak mass loss is projected to occur in the late 2070s and PIC is expected to lose 16-20% of its 2014 ice volume by 2099 assuming a moderate climate warming scenario (RCP4.5). If a +2°C offset is applied to this scenario, the ice cap is expected to lose 30-40% of its initial ice volume by 2099. These results provide the first comprehensive evaluation of the impact of vertical ice motion on mass loss derived from geodetic measurements over a large Arctic ice cap. The ice velocity record provides insights into the relationship between surface melt rates and glacier motion over the past 30-60 years. This study projects the mass change of the largest ice cap in the southern Canadian Arctic to 2099, calibrated and validated with a wealth of spatially distributed data for the first time.

Mass balance records of glaciers help to understand long term climate change, yet there are very few in-situ measurements of mass balance in Himalayan glaciers. Mass balance of major glaciers in the Sagarmatha National Park was assessed using Digital Elevation Model prepared from ASTER images for period 2002 & 2005 and 2002 & 2008, employing geodetic model. Overall glacial mass balance during 2002-2005 was -2.978 plus/minus 0.89 and during 2002-2008 was -0.94 plus/minus 0.34 m.w.e per annum. Glacier melt could form glacial lakes in high Himalayas. One of the glacial lakes, Imja Lake in the study area increased its surface area by 268% from 1975 to 2010. Temperature analysis from MODIS data between 2000 and 2011 indicated increase in temperature in the study area. General loss of glacial mass in the Himalayan region indicated, and these loses if continue in the future will lead to catastrophic environmental and economic impacts.