<p> In recent years a surge in research focused on the influences of water on humans. However, few have studied the effects of water on our relationship with nature, particularly to explore enduring impressions from a longitudinal perspective. Addressing these gaps, this qualitative exploratory research enlisted a case study methodology that employed multiple methods to investigate how a multi-day wilderness trip on the Tatshenshini River might affect participants&rsquo; connection to nature and position toward a sustainable lifestyle. The 12 participants were administered the Kellert Shorb Biophilic Indicator (KSBVI) questionnaire prior to the trip and reflected in journals during the experience. Six months after the trip ended a survey was administered. After 16 months, in-depth interviews were conducted. The results suggest that immersion into <i> river time</i>, an experience conceptualization that connected participants to nature&rsquo;s rhythm, generally equated with a <i>flow</i> state and a condition of <i>blue mind</i>, positively influenced their connection to nature. It appears that living water in concert with awe-inspiring encounters in the natural world enhanced and affirmed participants&rsquo; position toward a sustainable lifestyle. Furthermore, this multi-day wilderness experience seemed to inform their orientation toward sustainability. The findings suggest that further research into the lasting effects of river time and awe within these types of contexts is warranted.</p><p>

<p> Green roofs are living rooftops that have been around for centuries. Green roofs serve many purposes including food production, insulation of buildings, and reducing the urban heat island effect. More and more research is being done to utilize unused space on top of buildings for a better community. Food shortage is one of the biggest problems in the United States and across the world. Due to increased population and a decrease of resources, fresh food is becoming more difficult to obtain. Fresh produce intake increases in communities as the amount of available produce within 100 meters of their residence increases (Bodor et al., 2007). Urban agriculture could help mitigate the shortage of healthy food by getting the community involved to produce their own food. Local food production results in less cost and less spoilage of food due to decreased transportation and increased quality of produce. My study was designed to demonstrate that vegetables can be produced successfully on a green roof in three different growth media. The growth media blends evaluated were 100% compost, 50% green roof media and 50% compost, and 100% green roof media. Vegetables were grown in Filtrexx^&reg; GardenSoxx^&reg;. Vegetables were planted over two growing seasons from 2015 to 2016. The results from my study demonstrated that carrots and lettuce are viable crops on a rooftop garden using the studied system. In the one harvest of Buttercrunch lettuce, there was no significant difference in lettuce biomass produced between the three different growth media blends used. The first growing season with Short &lsquo;n Sweet carrots, showed no significant difference in carrot biomass produced between the three growth media blends. In the second growing season, started July 2016, the results of the carrot biomass harvest varied between the growth media blends. Carrots grown in the 50% compost and 50% green roof media blend had the most biomass when compared with carrot biomass from the 100% compost blend. I have demonstrated that Short &lsquo;n Sweet carrots and Buttercrunch lettuce can be grown in GardenSoxx^&reg; on a rooftop garden in three different growth media blends.</p><p>

<p> Wood dynamics that store, transport, break down, and ultimately export wood pieces through watershed networks are key elements of stream complexity and ecosystem health. Efforts to quantify wood processes are advancing rapidly as technological innovations in field data collection, remotely sensed data acquisition, and data analyses become increasingly sophisticated. The ability to extend the temporal and spatial scales of wood data acquisition has been particularly useful to the investigations presented herein. The primary contributions of this dissertation are focused on two aspects of wood dynamics: watershed-scale wood export processes as identified using the depositional environment of a mountain reservoir, and wood deposition mechanisms in a bedrock-dominated mountain river. Three chapters present this work: </p><p> In Chapter 1, continuous video monitoring of wood in transport revealed seasonal and diurnal hydrologic cycle influences on the variable rates at which wood transports. This effort supports the efficacy of utilizing continuous data collection methods for wood transport studies. Annual wood export data were collected via field efforts and aerial image analyses from New Bullards Bar Reservoir on the North Yuba River, Sierra Nevada, California. Examination of data revealed linkages between decadal-scale climatic patterns, large flood events, and episodic wood export quantities. A watershed-specific relation between wood export quantities and annual peak discharge contributes to the notion that peak discharge is a primary control on wood export, and yielded prediction of annual wood export quantities where no data were available. Linkages between seasonality, climatic components, and hydrologic events that exert variable control on watershed scale wood responses are presented as a functional framework. An accompanying conceptual model supports the framework presumption that wood responses are influenced by seasonal variations in Mediterranean-montane climate conditions and accompanying hydrologic responses. </p><p> Chapter 2 contains development of new theory in support of the introduction of multiplicative coefficients, categorized by water year type, that were used to predict wood export quantities via utilization of an existing discharge-based theoretical equation. This new theory was the product of continued investigations into watershed-scale factors in search of explanation of observed variation of wood export rates into New Bullards Bar Reservoir. The gap between known variability and the attribution of wood export to one hydrologic relation continues to be a persistent issue, as the hierarchical and stochastic temporal and spatial nature of wood budget components remain difficult to quantify. The development of &ldquo;watershed processes&rdquo; coefficients was specifically focused on a generalized, parsimonious approach using water year type categories, with validation exercises supporting the approach. In dry years, predictions more closely represented observed wood export quantities, whereas the previously derived annual peak discharge relation yielded large over-predictions. Additional data are needed to continue development of these watershed-specific coefficients. This new approach to wood export prediction may be beneficial in regulated river systems for planning purposes, and its efficacy could be tested in other watersheds. </p><p> Chapter 3 presents the results of an investigation into wood deposition mechanisms in a 12.2 km segment of the confined, bedrock-dominated South Yuba River watershed. Inclusion of coarse wood particles in the analyses was essential in recognizing depositional patterns, thus supporting the value of utilizing a wider wood-size range. A near-census data collection effort yielded myriad data, of which topographic wetted width and bed elevation data, developed for an observed 4.5-year flood event, were standardized in 10-m intervals and then univariate and linked values were ordered into landform classifications using decision tree analyses. Digital imagery collected via kite-blimp was mosaicked into a geographic information system and all resolvable wood pieces greater then 2.5 cm in one dimension were delineated and categorized into piece count density classes. Visual imagery was also key in identifying two river corridor terrains: bedrock outcrops and cobble-boulder-vegetation patches. A conceptual model framed an investigation into how topographic variability and structural elements might influence observed wood deposition dynamics. Forage ratio test results that quantified wood piece utilization versus interval availability revealed that high-density wood deposition patterns were most significantly co-located with five discrete bedrock outcrops that dominated small portions of the river corridor in high flow conditions. Topographic variations and cobble-boulder-vegetation patches were found to be subordinate factors in wood deposition patterns. Bedrock outcrops with specific structural components were the primary depositional environments that acted as floodplain extents for coarse wood deposition, with mechanisms such as topographic steering, eddying, trapping, stranding, backwater effects, and lateral roughness features inferred to be responsible for observed wood deposition patterns.</p><p>

<p> During and following the Deepwater Horizon (DWH) accident in 2010, concerns about air and seafood quality were paramount. Though individual perceptions varied, many people in coastal communities in southeast Louisiana felt they had been exposed to oil- and dispersant-related compounds. We hypothesized that implementation of a Community-based Participatory Research (CBPR) project would promote a more transparent and mutually beneficial relationship between researchers and the community. We conducted both in-home and community-based assessments (n=198) in culturally diverse populations most impacted by the DWH event, including the Vietnamese in New Orleans East and the residents of the Bayou communities. Levels of volatile organic compounds (VOCs) in paired indoor/outdoor air samples and polycyclic aromatic hydrocarbons (PAHs) in seafood samples were determined with chemical analysis. Data were collected from multiple self-administered surveys regarding environmental awareness and impact of the DWH event, access to, and trusted sources of, information, perceptions about safety, and selected behavioral and socio-demographic variables. In an effort to enhance public understanding of the interconnectedness of their health with the Gulf ecosystem, we disseminated the information directly to the participants as well as the larger communities at risk. Through post-dissemination follow-up surveys, we explored the effectiveness of our environmental CBPR research strategy with our primary goals being to improve risk communication and promote informed decision-making among our coastal populations.</p><p>

<p> Environmental sustainability is an extension of the concept of sustainability that focuses on the importance of understanding the interconnectivity between natural and socio-economic systems without compromising resource capacity. In this study, it is incorporated into a framework that applies to the sustainable development of small counties in the South Texas region of the Eagle Ford Shale. </p><p> The research involved a qualitative approach through the distribution of a questionnaire to a surveyed sample of Texas residents from Gonzales and Karnes counties. The purpose of the questionnaire was to obtain the expressed perspectives of residents regarding the impacts of shale development on their quality of life. These locations of interest were selected because of the different levels of shale development they experienced. Aspects of quality of life were analyzed as indicators of the survey responses to open and closed-ended questions. Participants described and scaled variables regarding impacts, benefits, and notable changes they experienced from the development of shale resources in their counties. Content analysis was used to obtain results relevant to developing the conceptual model for environmental sustainability proposed in this study. Findings showed that the sample of participating residents highly identified with socio-economic interests compared to environmental interests, considering that when the study was conducted shale oil and gas production was in decline as a result of fallen global energy prices. </p><p> In this study the terms sustainability and sustainable development were used interchangeably, while development was addressed in a broad sense, referring to the overall improvement of quality of life.</p><p>

<p> The predominant method to quantify reef fish populations is the Open Circuit SCUBA (OC) <i>in-situ</i> fish survey. However, there are many biases associated with these surveys including the expelled OC exhaust which can cause visual and audible disturbances. This study aims to evaluate the bias created by OC exhaust utilizing closed-circuit rebreather (CCR) surveys, along surveys were conducted in protected areas and fished areas. The three sites in the main Hawaiian Islands were Kealakekua Bay (KK), Old Kona Airport (OA), and P&umacr;p&umacr;kea (PK) marine life conservation district. This study found that the total fish biomass and species richness from all sites pooled showed no significant differences between gear types. However, there was a significant interaction between the gear type and the protection status (Pr(>|t|) = 0.025), indicating that there are greater differences between OC and CCR in the fished areas than the protected areas. The difference between the gear types showed a greater magnitude of OC having a higher biomass in the fished areas opposed to the protected areas where that difference was smaller. When fished species (Table 4 &ndash; a, b) were examined, significant differences between gear types were shown (Pr(>|t|) = 0.010). The OC surveys showed more fished biomass than the CCR surveys which could mean that the attraction to the exhaust within the protected areas were greater than the repulsion of the exhaust in the fished areas. Differences in the fished species biomass while having no difference in the all fish biomass supports the previous studies findings that fishing pressure is very influential on the magnitude of difference between the gear types. For researchers, estimating fishing pressure is of high importance in order to assess the level of bias associated with OC exhaust on surveys. These biases need to be accounted for in population estimations for protected areas and non-protected areas in order to get more accurate biological fish data.</p><p>

<p> Russian olive is an exotic actinorhizal tree intentionally introduced to the U.S. in the early 1900&rsquo;s. It has become a dominant component of riparian ecosystems throughout the western U.S. Unlike most other riparian trees in the semi-arid west, Russian olive germinates and grows both in the open and in the understory of mature cottonwood stands. As an actinorhizal species, it forms an endosymbiosis with soil actinobacteria in the genus <i>Frankia</i> that allows for atmospheric N₂-fixation. This leads to higher soil N concentrations and mineralization rates underneath the tree&rsquo;s canopy than outside. Russian olive&rsquo;s high abundance and impact on soil N suggest it may alter plant communities, but these impacts have not been previously demonstrated. I investigated the impacts of Russian olive on shading, soil N availability, and plant communities and documented how those impacts varied across a semi-arid riparian ecosystem along the South Fork of the Republican River in eastern Colorado. Of the suite of environmental variables I measured, presence or absence of cottonwood canopy had the largest effect on Russian olive impacts. Russian olive increased shading, soil N availability, and proportion exotic plant and forb cover more in the open than underneath a cottonwood overstory.</p><p> Actinorhizal endosymbioses provides an important N source in terrestrial ecosystems, but N₂-fixation rates decrease due to high exogenous N and low photosynthetically active radiation (PAR). The amount that these environmental variables reduce N₂-fixation in host-<i>Frankia </i> symbiosis types dictates the strength and duration of those symbioses&rsquo; impacts on ecosystems. To understand how the two main types of endosymbioses (<i>Alnus-</i> and <i>Elaeagnus-Frankia</i>) differ in their response to environmental variability, I conducted a greenhouse experiment comparing growth and nodulation between two genera of actinorhizal species, <i> Elaeagnus</i> and <i>Alnus,</i> across exogenous N and PAR levels. Overall, <i>Elaeagnus</i> species had higher nodulation rates and tissue % N than <i>Alnus</i> species. Nodulation rate and growth response to nodulation were both lower at low PAR than high PAR for both genera. The reduction in the growth response to nodulation at high exogenous N was lower in <i>Elaeagnus-Frankia</i> symbiosis than <i> Alnus-Frankia</i> symbiosis. These results suggest that <i>Elaeagnus </i> species are more likely to cause a greater and longer-lasting increase in soil N than <i>Alnus</i> species.</p><p> A main objective of exotic species management is to increase native plant cover. However, few studies monitor plant community response to exotic species management, and the few that have suggest secondary invasion is likely, particularly when effects of the target invasive persists and management efforts cause disturbance. To measure the role of these two factors in plant community response to Russian olive removal, I monitored soil N availability and plant communities along the South Fork of the Republican River two years before and three years after the tree&rsquo;s removal. Russian olive&rsquo;s impact on soil N availability persisted, with levels staying high around removed Russian olive stems three years after removal. The plant community around removed Russian olive also had no increase in native plant cover but a dramatic increase in kochia (<i> Bassia scoparia</i>) cover following removal. My research demonstrates that Russian olive increases exotic plant cover in areas it invades and simply removing the tree does not promote native species recovery.</p><p>

<p> The primary goal for remediation of sediments contaminated with polychlorinated biphenyls (PCBs) is the reduction of bioaccumulation in the aquatic food web, particularly in fish that is the source of exposure to top level predators and humans. While empirical results are available in the literature on bioavailability reductions after amendment of PCB-contaminated sediment with a strong sorbent like activated carbon (AC) or biochar, there is a lack of quantitative understanding on how reductions in sediment porewater and food concentrations impact accumulation in fish. Although passive sampling can measure freely dissolved concentrations accurately, there is a major gap in the utilization of fate and biouptake models that can use such measurements. In addition, well-calibrated partitioning models based on accurate freely dissolved concentrations that can predict uptake by pelagic organisms are lacking. The primary objective of this research was to test the ability of frequently used bioaccumulation models to predict changes in fish uptake upon amendment of AC sediment and use passive sampling inputs and additional studies to refine the predictions made by these bioaccumulation models. </p><p> Results from laboratory exposure studies with pelagic and benthic feeding fish indicate that by incorporating changes in porewater and overlying freely dissolved PCB concentrations in kinetic bioaccumulation models and by taking into account changes in food concentration it is possible to predict effectiveness of sediment remediation in reducing PCB uptake in fish. Assimilation efficiency of PCBs in the sediment were independently measured in a separate study and incorporated into the model. The modified model led to reasonable estimations of PCB uptake in the benthic feeding fish and was capable of predicting the dominant exposure pathways in the benthic and pelagic feeding fish as a result of their different feeding behaviour. Additionally, passive sampling measurements were linked to PCB accumulation in algae and zooplankton and resulted in refined models. Lastly, several scenarios were simulated to show the potential of a linked fate and biouptake model to capture the effect of different inputs. </p><p> This research presents a robust modeling framework that is able to predict uptake in fish after <i>in situ</i> remediation that alters bioavailability of PCBs in sediments with implications for risk assessment and management.</p><p>

<p> This study gained novel insights into mechanistic interactions of dust and smoke particles with large-scale climate dynamics. This study revealed that the variability Saharan dust radiative properties is significantly linked to high-frequency atmospheric wave activity across the tropical Atlantic storm tracks, while the variability of smoke particles from the South African biomass burning is attributed by low-frequency oscillations of baroclinic instability of the region. </p><p> We proposed that the impacts of Saharan Air Layer (SAL) on large-scale climate dynamics mainly occur through coupling of dust radiative forcing with eddy energetics of the African easterly jet-African easterly waves (AEJ-AEWs) systems. This study quantified the thermal/mechanical impacts of oceanic SAL on activity of the AEWs and the regional feedback of eddies onto the mean-circulations from a climatological point of view. We found that both upstream and downstream developments of eddy energy are affected by oceanic SAL radiative forcing. It is suggested that dust radiative forcing has the capability to affect the transient changes in baroclinic instability of the jet-wave system through eddy available potential energy, and contribute in exchange of kinetic energy between the AEWs and AEJ through baroclinic and barotropic conversions.</p><p> This study discussed that Saharan dust radiative properties have both constructive and destructive effects on behaviors of the AEWs, which depend on structure of the waves at different time-scale: the eddy kinetic energy (EKE) of the 2&mdash;6-day ultrahigh-frequency waves are amplified in average 1-day after enhancing of dust radiative forcing, while the EKE of the 6&mdash;11-day intermediate-frequency waves weakens during dust storm events. In addition, over the western African monsoon (WAM) region and the entrance of the tropical Atlantic storm track, the 2&mdash;6-day filtered AEWs become more barotropic during oceanic SAL outbreaks. The anomalous changes in meridional and quadruple momentum fluxes of 2&mdash;6-day filtered AEWs, associated with enhanced dust in the oceanic SAL, tend to an easterly feedback onto the southern edge of the mean-AEJ. However, at the middle- to exit region of the southern storm track, the anomalous convergent momentum fluxes of 2&mdash;6-day AEWs, associated with dust outbreak, tends to increase the regional baroclinic instability through the 3 main local energy packets, which may initiate a higher chance of hurricane activity.</p><p> Applying ensemble of large NASA satellite observations data sets, such as MODIS, SeaWiFS and TRMM as well as GOCART aerosol model and MERRA reanalysis indicates that the suggested results are consistent regardless of the selected data sets. Overall, we proposed that the regional radiative properties of aerosols and thermal/mechanical activity of wave-jet systems are dynamically coupled and it is not suggested to consider either as a response to one another. </p><p>

The Monument Valley UMTRA Site is a former uranium mining site that is located in Cane Valley, Arizona. The mining that occurred there from 1943 to 1968 created a groundwater contaminant plume that consists of nitrate, sulfate, and uranium. There are only a few viable methods for remediation of these types of contaminants occurring in large, deep plumes. Monitored natural attenuation is a popular approach because it is a green and low-cost alternative. However, it is often ineffective without some form of supplemental enhancement. In-situ biosequestration is one method of enhanced attenuation, which involves injecting an electron- donating substrate that will promote microbial activity and sequester contaminants by bioprecipitation, biomineralization, and enhanced adsorption. Prior tests conducted at the Monument Valley site in the center of the plume using ethanol as the electron donor proved effective in the treatment of nitrate, sulfate, and uranium. Subsequent pilot scale tests are being conducted in the source zone of the Monument Valley Site to further investigate the feasibility and effectiveness of using in-situ biosequestration for treatment of uranium contaminated groundwater. The preliminary results of these tests are discussed.