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Seasonal variation of water source and geochemistry in a northwest Iceland watershed
Get PDFSource water and flow paths of stream water draining a subarctic catchment in northwestern Iceland were investigated using a multi-tiered, high time-resolution, monitoring program during the spring and summer of 2011. Stream water isotopic and geochemical tracers identified snowmelt as a major control on source water and flow paths for streams in the 102 km2Vatnsdalsvatn catchment. A two end-member mixing model showed an increasing percent contribution of snowmelt-like water corresponding to water originating from the more northerly high-elevation regions. This shift co-occurred with increased subsurface connectivity of highland soils, as the highland snow cover receded. A conceptual model of flow generation was established from these results.
Significant temporal chemical flux variations were observed in the stream water, reflective of differing environmental controls. Runoff was the dominant control for solute stream water fluxes of Na, Si, and K, whereas V and Rb were controlled primarily by snowmelt, the release of the soil matrix from snow cover, and the hydrologic connection of the highlands to the river. In contrast, dissolved Al, Ti, Pb, Zn, Mo, and Mn --all weathering products of basalt --remained immobile until a rain event on July 2, 2011 and only then were connected to the fluvial system. Dissolved Ca:Sr molar ratios in stream water further support this analysis, suggesting that reduced snow cover co-occurs with an increased flux of dissolved basalt weathering products. This research shows the conditions under which different hydro geologic sections of the watershed might be contributing materials to Lake Vatnsdalsvatn. Furthermore, the research suggests that during warmer and wetter conditions, the subsurface highland soil water flow paths are more hydrologically connected, whereas cooler, drier years may lead to more persistent snowpack and/or a persistent frost layer in the highlands, acting as a barrier to soil porewater.Electronic Thesis or Dissertatio
Bioinformatic and gene expression analysis of an SLC6 homolog in the toxin-producing marine diatom pseudo-nitzschia multiseries
Get PDFPseudo-nitzschia multiseries (Ps-n) is a marine pennate diatom that produces the neurotoxin, domoic acid (DA). The molecular processes involved in toxin synthesis have yet to be elucidated. Previous work generated a suite of candidate genes that were found to be up-regulated under toxin-producing conditions. One such gene showed high sequence homology to the SLC6 family of amino acid transporters, which have been found to transport an array of amino acid substrates. This thesis focused on further characterizing the gene structure and expression patterns of this gene which we have designated PSN0072. Sequence analysis of the predicted protein revealed a conserved domain found in the SLC6 transporter family. Alignment of this amino acid sequence with a functional alignment of SLC6 homologs revealed the conservation of functionally relevant residues, strengthening the putative identification of PSN0072 as a member of the SLC6 family. Gene expression analyses revealed a link between the regulation of this gene and DA levels. Interestingly, PSN0072 was also up-regulated under nitrogen limited conditions, a finding consistent with other characterized amino acid importers. The results presented in this thesis suggest that PSN0072 may be involved in the export of DA or the import of another amino acid substrate, either as a nitrogen source or as a precursor to DA synthesis. A possible hypothesis to explain the results presented is that PSN0072 may be able to perform both of these important functions to Ps-n physiology.Electronic Thesis or Dissertatio
Winter climate change and the hydraulic properties of the northern hardwood forest
Get PDFCurrently sugar maple (Acer saccharum) and yellow birch (Betula alleghaniensis) are in decline in the northeast U.S. This decline disease is caused by multiple stressors which weakens the tree, making it more vulnerable to acute stress events or disturbances. Stressors affecting the northern hardwood forest include atmospheric deposition, insect pests and pathogens, invasive species, fragmentation, and climate change. Of these stressors, much is uncertain about the effects of climate change on tree species physiology, health and future distributions in New England. Winter climate change is especially important because many trees species in the northern hardwood forest are not very cold hardy and rely on snowpack over winter as insulation which protects roots from soil frost damage. Furthermore, recent temperature increases have been greater over the winter season compared to summer, providing a greater emphasis on the winter season. A better understanding of the impacts of winter climate change will allow for improved land management practices for forest industries, like timber and maple sugaring, which can provide economic longevity for New England. Sap velocity can be directly linked to productivity in tree individuals as the flow of sap is closely correlated to the rate of transpiration, a by-product of photosynthesis. We present the heat dissipation method for calculating tree sap velocity in two experiments under the general theme of winter climate change and the hydraulic properties of the northern hardwood forest. The experiments in this document include 1) comparing root percent embolism and sap velocity in yellow birch stands over natural gradients and 2) the pre-bud break sap velocities of sugar maple trees in response to winter variability, air temperature fluxes and sapwood aspect and depth.
Chapter 1 Results: Snowpack variation over natural gradients of aspect and elevation was greatest over winter 2010/2011 compared to 2009/2010 at the HBEF and differences in root percent embolism using a repeated measured ANOVA with elevation and aspect as factors were significant in 2011 (p=0.05488); however no significant differences were found in 2010. Overall snowpack depth (80-130cm) and duration (18 weeks) was greatest over winter 2010/2011 compared to 2009/2010 (40-70cm and 16 weeks) and root percent embolism was greatest at all plots in 2010, with the exception of the Kineo Mid plot. These results suggest that annual snowpack variation in depth and duration influences root embolism patterns in yellow birch trees. In comparing average root percent embolism to average sap velocity we found that within class of aspect all plots with the greatest average root percent embolism had the lowest average sap velocity and vice-versa for both years, with the exception of Kineo Low and WS 3 High in 2010, likely due to drought during 1 of the 2 days when sap velocities were compared. This trend suggests that root embolism may be limiting sap flow in yellow birch trees.
Chapter 2 Results: Sap velocities of sugar maple trees during the early spring sugaring season in 2011 and 2012 were influenced by thaw-freeze cycling and temperature fluctuations, where these conditions were important in producing the greatest sap velocities. After two days of above freezing night temperatures in 2011 xylem pressure was greatly reduced. Sap velocity was greatest at 2cm sapwood depth and south aspect (up to 3,000 g/m²/s), where stem temperature fluctuation was likely the greatest due to sun exposure. Sapwood depth had a greater influence on flow rates than sapwood aspect. Sugar maple trees had later and greater pre-bud break sap velocities in 2011 (Julian day 96, 3000 g/m²/s)compared to 2012 (Julian day 80, 120 g/m²/s) where the winter prior to the sugaring season in 2012 was very mild with little snowpack compared to winter conditions prior to the sugaring season in 2011.Electronic Thesis or Dissertatio
A climate of change: the need for water resource education in Pakistan to meet the current and upcoming challenges
Get PDFPakistan is faced with growing issues concerning water availability and water quality. Participants in the U.S. State Department grant funded Pakistani Educational Leadership (PEL) Project held during the summer at Plymouth State University, 2011 are trying to improve water literacy in Pakistan to prepare for how climate change and other management factors affect water resources in the country. This research evaluated a component of the PEL Project that helps promote environmental sustainability education in Pakistan through a summer professional development institute where participants have to develop master action plans to be implemented upon their return in their home communities. The project focused on the development of knowledge and skills related to watershed education including specifically fieldtrips and activities related to water quality and quantity, biomonitoring, riparian buffer assessment, and more. The Pemigewasset River in New Hampshire was used as a model and participants were encouraged to adapt and transfer meaningful lessons from the Pemigewasset River to the Indus River Watershed in Pakistan. Social networking played a role in supporting grass roots efforts to empower the Pakistani educators to effect positive change.Electronic Thesis or Dissertatio
Through our eyes: What effect does participation in an inclusive primary grade classroom community have on a typical student? a qualitative study
Get PDFThe purpose of this qualitative research study was to determine what effect my inclusive primary grade classroom has had on my typical students. This study was designed using a qualitative phenomenological method of inquiry that drew on the analysis methods of Moustakas (1994), Creswell (1998; 2007), and Van Manen (1994). I used these phenomenological methods to look for the phenomenon of the everyday lived experience in an inclusive primary grade classroom and its impact on typical students (Van Manen, 1990).The research question that guided this study was: What impact does participation in an inclusive primary grade classroom setting have on typical students?
���Phenomenology is the description of lived experience� which is also described as the essence of the experience (Van Manen, 1990, p. 25). The lived experience of being in an inclusive classroom was described by twenty of my present and former typical students. Research focused on the collection of the students��� responses to interview and survey questions, anecdotes collected from entries in my reflective journals which included stories from my colleagues and parents of students.
Analysis of data revealed three themes: inclusion means learning together; it is okay to be different; and a classroom community means everyone learning together. These three themes described the lived experience of being in an inclusive classroom through the eyes of my students.
The data analysis revealed students had been impacted by the inclusive primary classroom community and it also revealed that the essence of my inclusive classroom is the community my students and I build together.Electronic Thesis or Dissertatio
Relationships, relevancy, and value: assessing community partners' perceptions of engagement with higher education
Get PDFExternal stakeholders affect higher education's academic, civic, and operational functions. Understanding community needs and expectations has become more important as colleges and universities have faced increasing demands for accountability, innovation, and evidence of economic and social value. Community engagement has emerged as one response to address these challenges and opportunities and created a unique class of external stakeholders.
The purpose of this mixed method study was to explore the nature of relationships between higher education and a discrete population of community stakeholders who had been involved in engagement activities with Campus Compact for New Hampshire members. Three conceptual models guided the data analysis: stakeholder identification, profiles, and salience; higher education's level of commitment to engagement; and partnership satisfaction.
Stakeholders perceived their campus-to-community collaborations as positive experiences, notwithstanding the challenges of communication, partnership development, relationship building, and resources. They perceived that they did have some influence on higher education and that collaboration was beneficial to the individual community partners and to their organizations. The findings also identified differences among community partners' levels of satisfaction with different types of college and university partners.
Four conclusions emerged from this study. First, community partners were predisposed to meaningful collaboration. Second, the underlying structural and operational differences between higher education and community partners are potential threats to future engagement. Third, community partners expect higher education to fulfill its social responsibility and to lead the search for solutions to social problems. Forth, sustainable collaboration requires institutional commitment, leadership, and integration across the organization.Electronic Thesis or Dissertatio
Assessing the effectiveness of federal acid rain policy using remote and high elevation lakes in northern New England
Get PDFThe 1990 U.S. Clean Air Act Amendments (CAAA) set target reductions for both sulfur and nitrogen emissions to reduce acidic deposition and improve the biologically-relevant chemistry of low ANC surface waters in the United States. The Maine High Elevation Lake Monitoring (HELM) project was designed to complement other acid rain status and trend assessments in the northeast that were known to have underestimated the number of acidic lakes. HELM lakes are more susceptible to the effects of acid deposition than lowland lakes typically included in other surveys because they receive higher amounts of precipitation, and the watersheds are less able to neutralize acidic inputs because of steep slopes, shallow soils, and resistant bedrock. Furthermore, development impacts that affect water quality and cloud our interpretation of recovery from deposition in many lowland lakes are absent in the HELM lakes.
Since 1986, HELM surface water SO4-2 concentration has decreased at a rate of 1.6�eq/L/yr.. HELM lake ANC has increased at a rate of 0.58 �eq/L/yr. and hydrogen ion has decreased at a rate of 0.05 �eq/L/yr. since 1986, highlighting the positive effect the CAAA is having on HELM acidity. Over the same time period, HELM DOC has increased at rate of 0.03 mg/L/yr., raising the median DOC in HELM lakes by 21%. Furthermore, we calculate that organic anions (OA-) now contribute 10% to 15% more to total anionic charge while at the same time, the lakes have become 23% more dilute. The increase in DOC has led to a shift in the source of acidity from anthropogenic inorganic (acid rain), to natural organic DOC sources. While this shift appears to complicate the interpretation of acid-base data coming from acid-sensitive lakes, in reality it highlights recovery to a more natural state for these surface waters.
A comparison of HELM recovery data to recent data from the New Hampshire Remote Pond (NHRP) project serves to put the NHRP in regional perspective as well as enabling us to make inferences about the recovery status of NH's most sensitive aquatic ecosystems. We estimate that the number of acidic NHRP lakes has been cut in half since the CAAA took effect, from 26% to 13%.Electronic Thesis or Dissertatio
Comparing variable updraft melting layer heights to convective speeds using polarimetric radar data
Get PDFThe melting layer (ML) appears on vertical radar cross sections as a bright band of higher reflectivity values. Single polarization radars only detect this feature in stratiform precipitation events, whereas dual polarization radars offer the advantage of detecting the ML in both stratiform and convective precipitation events. The ML is known to be lifted higher locally within a convective updraft, so the goal of the present study was to determine if there is a correlation between the vertical displacement of the ML in an updraft (above the ambient ML) and the speed of the storm's reported wind gusts. Fourteen storms were investigated. Wind reports from the Storm Prediction Center (SPC) website were used and radar data were obtained from the National Climatic Data Center (NCDC) website for two dual polarization radar sites: Vance Air Force Base (KVNX) in Enid, OK, and Wichita, KS (KICT). Each storm was studied in detail using a combination of plan views of the cross correlation coefficient (pHV, which drops to anomalously low values within the ML) and vertical cross sections of reflectivity. Ultimately, no correlation was found between the height of the updraft ML and the speed of the convective wind gusts. This suggests that the height to which a parcel is lifted by an updraft does not affect the speed at which it descends in the ensuing downdraft. This is likely due to the fact that the mechanisms determining updraft strength are almost entirely separate from those that determine downdraft strength. For example, instability and lift govern updraft strength, whereas downdraft strength is predominantly governed by evaporational cooling and negative buoyancy.Electronic Thesis or Dissertatio
Establishing baseline phenology trends for northern hardwood trees along an elevation gradient
Get PDFThere is ample evidence that climate change has notable effects on the phenology of vegetation, effects that are variable at different elevations and across species. Two years of climate and phenology records were collected and analyzed to establish baseline phenology trends and temperature thresholds for four northern hardwood tree species. Seventeen deciduous trees were observed along an elevation transect spanning ~4 km on 1,220 m Mount Tecumseh in New Hampshire. Spring and autumn phenology observations (e.g. budburst, first leaf color) were conducted weekly to twice weekly throughout the growing (budburst through leaf elongation) and senescence (first leaf color and drop through last leaf color and drop) seasons. Microclimate measurements were obtained via dataloggers measuring ambient air temperature placed at regular intervals along the elevation transect. Phenology and microclimate data were analyzed in combination with a larger meteorological dataset obtained from the Lorenz Weather Station atop the summit ridge of Mount Tecumseh. Spring comes later and autumn sooner at higher elevations on Mount Tecumseh. This trend in phenology is in accord with the noted delay in spring and the advance in autumn calculated along the elevation gradient (1.03 days for every 30 m increase in elevation in spring and 1.46 days in autumn.) Mid8elevation trees did not always follow this trend. Threshold temperatures for specific phenological stages were not established as the spring phenophases and the autumn leaf fall phenophases showed wide variation in accumulated degree8days from one year to the next. Only leaf color in autumn indicated a possible threshold in accumulated chilling degree8days for triggering that particular phenology. A comparison among the Mount Tecumseh study and two other regional studies of northern hardwood trees and their phenology was conducted. Results on Mount Tecumseh confirmed the order of progression of spring and autumn phenology for several northern hardwood tree species as evidenced at Hubbard Brook Experimental Forest in Thornton, NH. There is a marked advance in spring phenology and a delay in autumn, evidenced by comparison between Mount Tecumseh and Mount Mansfield in Underhill, VT. Overall, phenology progression patterns among species between the two most recent studies were similar. Continued efforts are necessary to ensure the ongoing support of phenology monitoring sites. Long8term data records will be necessary to clarify seasonal trends in phenology and assess the ongoing and future impacts of climate change on the northeastern forest.Electronic Thesis or Dissertatio
Citizen participation, transportation corridor planning and the intersection with land use planning in New Hampshire communities: what are best practices?
Get PDFThis research tested thirteen Context Sensitive Solutions (CSS) principles, as outlined in Stamatiadis et al (2009). Principles were tested with two New Hampshire corridor planning processes: Route 16 and I-93/CTAP. Through content analysis, web surveys and interviews, a determination was made regarding whether the two projects utilized the principles, and to what extent in the data sources. Both projects demonstrated evidence in at least two data sources for eleven of thirteen principles. However, participants had very different perceptions of how these principles were implemented. This study provides groundwork for the development of a checklist that can be used in corridor planning processes, to ensure these processes are collaborative and incorporate the needs and values of stakeholders and the broader public.Electronic Thesis or Dissertatio