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Description
Mycorrhizal fungi form symbiotic relationships with plant roots, increasing nutrient and water availability to plants and improving soil stability. Mechanical disturbance of soil has been found to reduce mycorrhizal inoculum in soils, but findings have been inconsistent. To examine the impact of restoration practices on riparian mycorrhizal inoculum potential, soil

Mycorrhizal fungi form symbiotic relationships with plant roots, increasing nutrient and water availability to plants and improving soil stability. Mechanical disturbance of soil has been found to reduce mycorrhizal inoculum in soils, but findings have been inconsistent. To examine the impact of restoration practices on riparian mycorrhizal inoculum potential, soil samples were collected at the Tres Rios Ecosystem Restoration and Flood Control Project located at the confluence of the Salt, Gila, and Agua Fria rivers in central Arizona. The project involved the mechanical removal of invasive Tamarix spp.( tamarisk, salt cedar) and grading prior to revegetation. Soil samples were collected from three stages of restoration: pre-restoration, soil banks with chipped vegetation, and in areas that had been graded in preparation for revegetation. Bioassay plants were grown in the soil samples and roots analyzed for arbuscular mycorrhizal (AM) and ectomycorrhizal (EM) infection percentages. Vegetations measurements were also taken for woody vegetation at the site. The mean number of AM and EM fungal propagules did not differ between the three treatment area, but inoculum levels did differ between AM and EM fungi with AM fungal propagules detected at moderate levels and EM fungi at very low levels. These differences may have been related to availability of host plants since AM fungi form associations with a variety of desert riparian forbs and grasses and EM fungi only form associations with Populus spp. and Salix spp. which were present at the site but at low density and canopy cover. Prior studies have also found that EM fungi may be more affected by tamarisk invasions than AM fungi. Our results were similar to other restoration projects for AM fungi suggesting that it may not be necessary to add AM fungi to soil prior to planting native vegetation because of the moderate presence of AM fungi even in soils dominated by tamarisk and exposed to soil disturbance during the restoration process. In contrast when planting trees that form EM associations, it may be beneficial to augment soil with EM fungi collected from riparian areas or to pre-inoculate plants prior to planting.
ContributorsArnold, Susanne (Author) / Stutz, Jean (Thesis advisor) / Alford, Eddie (Committee member) / Green, Douglas (Committee member) / Arizona State University (Publisher)
Created2012
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Description
The explicit role of soil organisms in shaping soil health, rates of pedogenesis, and resistance to erosion has only just recently begun to be explored in the last century. However, much of the research regarding soil biota and soil processes is centered on maintaining soil fertility (e.g., plant nutrient availability)

The explicit role of soil organisms in shaping soil health, rates of pedogenesis, and resistance to erosion has only just recently begun to be explored in the last century. However, much of the research regarding soil biota and soil processes is centered on maintaining soil fertility (e.g., plant nutrient availability) and soil structure in mesic- and agro- ecosystems. Despite the empirical and theoretical strides made in soil ecology over the last few decades, questions regarding ecosystem function and soil processes remain, especially for arid areas. Arid areas have unique ecosystem biogeochemistry, decomposition processes, and soil microbial responses to moisture inputs that deviate from predictions derived using data generated in more mesic systems. For example, current paradigm predicts that soil microbes will respond positively to increasing moisture inputs in a water-limited environment, yet data collected in arid regions are not congruent with this hypothesis. The influence of abiotic factors on litter decomposition rates (e.g., photodegradation), litter quality and availability, soil moisture pulse size, and resulting feedbacks on detrital food web structure must be explicitly considered for advancing our understanding of arid land ecology. However, empirical data coupling arid belowground food webs and ecosystem processes are lacking. My dissertation explores the resource controls (soil organic matter and soil moisture) on food web network structure, size, and presence/absence of expected belowground trophic groups across a variety of sites in Arizona.
ContributorsWyant, Karl Arthur (Author) / Sabo, John L (Thesis advisor) / Elser, James J (Committee member) / Childers, Daniel L. (Committee member) / Hall, Sharon J (Committee member) / Stromberg, Juliet C. (Committee member) / Arizona State University (Publisher)
Created2014
Description
Despite the wealth of folk music traditions in Portugal and the importance of the clarinet in the music of bandas filarmonicas, it is uncommon to find works featuring the clarinet using Portuguese folk music elements. In the interest of expanding this type of repertoire, three new works were commissioned from

Despite the wealth of folk music traditions in Portugal and the importance of the clarinet in the music of bandas filarmonicas, it is uncommon to find works featuring the clarinet using Portuguese folk music elements. In the interest of expanding this type of repertoire, three new works were commissioned from three different composers. The resulting works are Seres Imaginarios 3 by Luis Cardoso; Delirio Barroco by Tiago Derrica; and Memória by Pedro Faria Gomes. In an effort to submit these new works for inclusion into mainstream performance literature, the author has recorded these works on compact disc. This document includes interview transcripts with each composer, providing first-person discussion of each composition, as well as detailed biographical information on each composer. To provide context, the author has included a brief discussion on Portuguese folk music, and in particular, the role that the clarinet plays in Portuguese folk music culture.
ContributorsFerreira, Wesley (Contributor) / Spring, Robert S (Thesis advisor) / Bailey, Wayne (Committee member) / Gardner, Joshua (Committee member) / Hill, Gary (Committee member) / Schuring, Martin (Committee member) / Solis, Theodore (Committee member) / Arizona State University (Publisher)
Created2013
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Description
Despite the breadth of studies investigating ecosystem development, an underlying theory guiding this process remains elusive. Several principles have been proposed to explain ecosystem development, though few have garnered broad support in the literature. I used boreal wetland soils as a study system to test a notable goal oriented principle:

Despite the breadth of studies investigating ecosystem development, an underlying theory guiding this process remains elusive. Several principles have been proposed to explain ecosystem development, though few have garnered broad support in the literature. I used boreal wetland soils as a study system to test a notable goal oriented principle: The Maximum Power Principle (MPP). The MPP posits that ecosystems, and in fact all energy systems, develop to maximize power production or the rate of energy production. I conducted theoretical and empirical investigations to test the MPP in northern wetlands.

Permafrost degradation is leading to rapid wetland formation in northern peatland ecosystems, altering the role of these ecosystems in the global carbon cycle. I reviewed the literature on the history of the MPP theory, including tracing its origins to The Second Law of Thermodynamics. To empirically test the MPP, I collected soils along a gradient of ecosystem development and: 1) quantified the rate of adenosine triphosphate (ATP) production--literally cellular energy--to test the MPP; 2) quantified greenhouse gas production (CO2, CH4, and N2O) and microbial genes that produce enzymes catalyzing greenhouse gas production, and; 3) sequenced the 16s rRNA gene from soil microbes to investigate microbial community composition across the chronosequence of wetland development. My results suggested that the MPP and other related theoretical constructs have strong potential to further inform our understanding of ecosystem development. Soil system power (ATP) decreased temporarily as the ecosystem reorganized after disturbance to rates of power production that approached pre-disturbance levels. Rates of CH4 and N2O production were higher at the newly formed bog and microbial genes involved with greenhouse gas production were strongly related to the amount of greenhouse gas produced. DNA sequencing results showed that across the chronosequence of development, the two relatively mature ecosystems--the peatland forest ecosystem prior to permafrost degradation and the oldest bog--were more similar to one another than to the intermediate, less mature bog. Collectively, my results suggest that ecosystem age, rather than ecosystem state, was a more important driver for ecosystem structure and function.
ContributorsChapman, Eric (Author) / Childers, Daniel L. (Thesis advisor) / Cadillo-Quiroz, Hinsby (Committee member) / Hall, Sharon J (Committee member) / Turetsky, Merritt (Committee member) / Arizona State University (Publisher)
Created2015
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Description

This study presents the results of one of the first attempts to characterize the pore water pressure response of soils subjected to traffic loading under saturated and unsaturated conditions. It is widely known that pore water pressure develops within the soil pores as a response to external stimulus. Also, it

This study presents the results of one of the first attempts to characterize the pore water pressure response of soils subjected to traffic loading under saturated and unsaturated conditions. It is widely known that pore water pressure develops within the soil pores as a response to external stimulus. Also, it has been recognized that the development of pores water pressure contributes to the degradation of the resilient modulus of unbound materials. In the last decades several efforts have been directed to model the effect of air and water pore pressures upon resilient modulus. However, none of them consider dynamic variations in pressures but rather are based on equilibrium values corresponding to initial conditions. The measurement of this response is challenging especially in soils under unsaturated conditions. Models are needed not only to overcome testing limitations but also to understand the dynamic behavior of internal pore pressures that under critical conditions may even lead to failure. A testing program was conducted to characterize the pore water pressure response of a low plasticity fine clayey sand subjected to dynamic loading. The bulk stress, initial matric suction and dwelling time parameters were controlled and their effects were analyzed. The results were used to attempt models capable of predicting the accumulated excess pore pressure at any given time during the traffic loading and unloading phases. Important findings regarding the influence of the controlled variables challenge common beliefs. The accumulated excess pore water pressure was found to be higher for unsaturated soil specimens than for saturated soil specimens. The maximum pore water pressure always increased when the high bulk stress level was applied. Higher dwelling time was found to decelerate the accumulation of pore water pressure. In addition, it was found that the higher the dwelling time, the lower the maximum pore water pressure. It was concluded that upon further research, the proposed models may become a powerful tool not only to overcome testing limitations but also to enhance current design practices and to prevent soil failure due to excessive development of pore water pressure.

ContributorsCary, Carlos (Author) / Zapata, Claudia E (Thesis advisor) / Wiczak, Matthew W (Thesis advisor) / Kaloush, Kamil (Committee member) / Sandra, Houston (Committee member) / Arizona State University (Publisher)
Created2011
ContributorsBurton, Charlotte (Performer) / ASU Library. Music Library (Publisher)
Created2018-04-08
ContributorsDruesedow, Elizabeth (Performer) / ASU Library. Music Library (Publisher)
Created2018-04-07
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Description
Aboveground net primary production (ANPP) is an important ecosystem process that, in drylands, is most frequently limited by water availability. Water availability for plants is in part controlled by the water holding capacity of soils. Available water holding capacity (AWHC) of soils is strongly influenced by soil texture and depth.

Aboveground net primary production (ANPP) is an important ecosystem process that, in drylands, is most frequently limited by water availability. Water availability for plants is in part controlled by the water holding capacity of soils. Available water holding capacity (AWHC) of soils is strongly influenced by soil texture and depth. This study drew upon localized rain gauge data and four data-sets of cover-line and biomass data to estimate ANPP and to determine annual precipitation (PPT). I measured soil depth to caliche and texture by layer of 112 plots across the four landscape units for which estimation of ANPP were available. A pedotransfer function was used to estimate AWHC from soil depth increments to depth of caliche measurements and texture analysis. These data were analyzed using simple and multivariate regression to test the effect of annual precipitation and available water holding capacity on aboveground net primary production. Soil texture remained constant among all plots (sandy loam) and depth to caliche varied from 15.16 cm to 189 cm. AWHC and the interaction term (PPT*AWHC) were insignificant (p=0.142, p=0.838) and annual PPT accounted for 18.4% of the variation in ANPP. The y-intercept was significantly different for ANPP ~ annual PPT when considering AWHC values either above or below 3 cm. Shrub ANPP was insensitive to precipitation regardless of AWHC (R2=-0.012, R2=0.014). Results from this study indicate that a model incorporating annual PPT and AWHC may not serve as a good predictor for ANPP at a site level where there is little variation in soil texture.
ContributorsWagner, Svenja K (Author) / Sala, Osvaldo E. (Thesis advisor) / Cease, Arianne (Committee member) / Hall, Sharon (Committee member) / Peters, Debra (Committee member) / Arizona State University (Publisher)
Created2019
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Description
As a result of growing populations and uncertain resource availability, urban areas are facing pressure from federal and state agencies, as well as residents, to promote conservation programs that provide services for people and mitigate environmental harm. Current strategies in US cities aim to reduce the impact of municipal and

As a result of growing populations and uncertain resource availability, urban areas are facing pressure from federal and state agencies, as well as residents, to promote conservation programs that provide services for people and mitigate environmental harm. Current strategies in US cities aim to reduce the impact of municipal and household resource use, including programs to promote water conservation. One common conservation program incentivizes the replacement of water-intensive turfgrass lawns with landscapes that use less water consisting of interspersed drought-tolerant shrubs and trees with rock or mulch groundcover (e.g. xeriscapes, rain gardens, water-wise landscapes). A handful of previous studies in experimental landscapes have shown that converting a turfgrass yard to a shrub-dominated landscape has the potential to increase rates of nitrate (NO3-) leaching. However, no studies have examined the drivers or patterns across diverse management practices. In this research, I compared soil nutrient retention and cycling in turfgrass and lawn-alternative xeriscaped yards along a chronosequence of time since land cover change in Tempe, Arizona, in the semi-arid US Southwest. Soil inorganic extractable nitrogen (N) pools were greater in xeriscapes compared to turfgrass lawns. On average xeriscapes contained 2.5±0.4 g NO3--N/m2 in the first 45 cm of soil, compared to 0.6±0.7 g NO3--N/m2 in lawns. Soil NO3--N pools in xeriscaped yards also varied significantly with time: pools were largest 9-13 years after cover change and declined to levels comparable to turfgrass at 18-21 years. Variation in soil extractable NO3--N with landscape age was strongly influenced by management practices that control soil water availability, including shrub cover, the presence of sub-surface plastic sheeting, and the frequency of irrigation. This research is the first to explore the ecological outcomes and temporal dynamics of an increasingly common, ‘sustainable’ land use practice that is universally promoted in US cities. Our findings show that transitioning from turfgrass to water-efficient residential landscaping can lead to an accumulation of NO3--N that may be lost from the soil rooting zone over time, through leaching following irrigation or rainfall. These results have implications for best management practices to optimize the benefits of water-conserving residential yards.
ContributorsHeavenrich, Hannah (Author) / Hall, Sharon J (Thesis advisor) / Larson, Kelli L (Committee member) / Potaki, Diane E (Committee member) / Arizona State University (Publisher)
Created2015
Description
This project includes a recording and performance guide for three newly commissioned pieces for the clarinet. The first piece, shimmer, was written by Grant Jahn and is for B-flat clarinet and electronics. The second piece, Paragon, is for B-flat clarinet and piano and was composed by Dr. Theresa Martin. The

This project includes a recording and performance guide for three newly commissioned pieces for the clarinet. The first piece, shimmer, was written by Grant Jahn and is for B-flat clarinet and electronics. The second piece, Paragon, is for B-flat clarinet and piano and was composed by Dr. Theresa Martin. The third and final piece, Duality in the Eye of a Bovine, was written by Kurt Mehlenbacher and is for B-flat clarinet, bass clarinet, and piano. In addition to the performance guide, this document also includes background information and program notes for the compositions, as well as composer biographical information, a list of other works featuring the clarinet by each composer, and transcripts of composer and performer interviews. This document is accompanied by a recording of the three pieces.
ContributorsPoupard, Caitlin Marie (Author) / Spring, Robert (Thesis advisor) / Gardner, Joshua (Thesis advisor) / Hill, Gary (Committee member) / Oldani, Robert (Committee member) / Schuring, Martin (Committee member) / Arizona State University (Publisher)
Created2016