Soils provide many essential functions that support the world. With a decline in soil health, these functions also decrease in efficiency, and can threaten the health of billions of people around the world. Typically, soil health tests do not use biological indicators, however microbes drive and perform vital functions to increase soil health. One way to increase soil health is through the use of cover crops to reduce soil erosion during fallow periods, increasing soil organic matter, as well as collecting nutrients from soil into their biomass. These cover crops are then terminated through various methods such as herbicides, disk tillage, or no tillage. The termination method can have an impact on soil health, by chemically affecting soil microbes with herbicides, disturbing soil, microbial communities, and fungi with tillage, or creating residue barriers on the surface of soil such as with using roller crimping (no tillage). Fertilization can also affect soil health, controlling rates of nutrient turnover and decomposition through the needs of microbes for carbon and nitrogen. This study quantifies the effects of four termination methods and four fertilization treatments on soil biological indicators during one growing season of sweet corn. Plots that were not tilled and terminated using roller crimping showed highest rates of decomposition, as well as increased labile carbon pools to feed microbes slowly throughout the growing season. Microbial activity was also observed to respond to fertilization, as patterns in activity spiked directly after fertilization. This study informs agricultural land management by the usage of biological indicators to further support the use of cover crops to increase soil health along with using no-till termination methods. Root biomass contributions toward soil health was also investigated, and how they may be affected by tillage.

The effect of trampling on vegetation and soil, as a result of recreational pressure, was studied in the Buffalo campground of the Targhee National Forest, Idaho. Site deterioration was most evident in the forty-two year old site. The tree stand had matured, but there were few young trees and tree reproduction had been reduced to ten seedlings per acre for Pinus contorta. Only two shrub species were sampled with a combined population of eight individuals per acre. Most of the grass species had been seeded; forbs provided 20% of the ground cover, 13% was bare ground and 71% litter. The soil had become compacted, and a hard-pan had formed. Similar deterioration was found in the six-year old site, but to a lesser degree. The year-old site was most similar to the control area, but site deterioration had occurred. It is difficult to reverse or halt site deterioration and still maintain the area as a public facility. Seeding and rest-rotation could improve the oldest site; younger sites could be maintained by restrotation, to allow existing vegetation to re-stock the depleted areas.

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The emergence of smart cities as a field of study focuses on integrating hardware and data-driven solutions to enhance the efficiency, sustainability, and quality of life in urban areas. A smart city looks to integrate various Internet of Things (IoT) technologies such as sensor hardware, wireless communication networks, and data analysis methods into urban infrastructure and services optimization. Smart city initiatives typically aim to address challenges related to environmental monitoring, energy generation, waste management, and healthcare, among others. At its core, the field of smart cities fuses various elements of wireless IoT sensor technologies in ways that aim to create more livable and resilient urban environments for residents. The work outlined in this thesis looks to investigate and overcome some of the challenges involved with wide-scale implementation of IoT devices in an urban environment. The thesis begins by defining a "smart city" and discussing the current status of IoT devices development and their applications for smart cities. Included in this analysis is an outline of common wireless communication protocols, sensor integration methodologies, and motivations for biomedical and environmental applications of wireless sensor networks. Next, this thesis presents advancements in the integration of implantable biomedical devices with wireless sensor tags. These devices were realized with Bluetooth low energy (BLE) and long range radio wide area network (LoRaWAN) wireless communication protocols in form factors appropriate for rodent models. To enable these implantable devices, a novel design methodology for biocompatible antennas was developed and implemented in a LoRaWAN data link. In addition, the behavioral effects of various commercial printed circuit board technologies were studied in rodents in an effort to study the least invasive methods to design implantable devices. Next this thesis discusses IoT applications in urban soils health monitoring. In this work, low cost soil sensors were developed with BLE and LoRaWAN varieties. These sensors are capable of measuring light, humidity, temperature, and nutrient concentration (Nitrogen, Phosphorus, and Potassium) to determine changes in soil health. Additionally, these sensors were integrated with a dendrometer to record weather patterns remotely over the course of a few months. Finally, this thesis concludes with a study on the network characteristics of a LoRaWAN communication link on the physical (PHY) and medium access control (MAC) layers. In this study, the entirety of New York City's Upper West Side was used as an urban test bed to fully measure the performance of long-range LoRaWAN communication links in a dense urban environment. This characterization compared devices from different application spaces and measured their power consumption, signal to noise ratio (SNR), received signal strength indicator (RSSI), and approximate distance from a receiver to analyze device performance over a majority of northern Manhattan.

Mangrove stands and oyster reefs are two common coastal habitats in the Indian River Lagoon. Each habitat provides diverse ecosystem services, including carbon sequestration and carbon storage. A decrease in freeze events and an increase in sea levels are leading to mangrove habitat expansion, including encroachment onto live oyster reefs in the IRL’s northernmost portion, Mosquito Lagoon. This study investigates how the encroachment of black mangroves (Avicennia germinans) and red mangroves (Rhizophora mangle) on eastern oyster reefs (Crassostrea virginica) impacts the abundance and stability of soil carbon relative to each habitat alone. Soil and sediment samples (0-10cm) were collected from three locations in Mosquito Lagoon, each containing a mangrove-only, oyster-only, and mangrove-encroached oyster reef habitat. Total and active carbon were quantified, and stable carbon was determined through physical and density fractionation that isolates persistent mineral-associated organic matter (MAOM). Results showed total, active, and MAOM-carbon averaged 2-3 times greater in mangroves than oyster reefs, while mangrove-encroached oyster reefs were intermediate in concentration. However, mangrove-oyster soils have the highest proportion of the total carbon pool protected as MAOM (54.9%), compared to each habitat alone (mangrove-only, 35.3%, oyster-only, 30.3%). This research is the first to provide data on blue carbon storage in areas where mangroves encroach on oyster reefs, including differentiating total carbon based on its stability in the soil.

Der Bodenschutz in städtischen Ballungsräumen wie Berlin hat die Ziele, den Flächenverbrauch zu minimieren und noch vorhandene Bodenfunktionen zu sichern. Vor diesem Hintergrund ist eine Neufassung eines überregional und allgemein anwendbaren großmaßstäbigen Bewertungssystems erforderlich, das die Wiederherstellung von Bodenfunktionen und die Aspekte des vorsorgenden Bodenschutzes in Planungs- und Zulassungsverfahren in Großstädten verstärkt berücksichtigen muss. Um dieses Bewertungssystem für Stadtböden zu entwickeln, werden hier die Bewertungsmethoden von Verfahren in Berlin, Hamburg und München auf ausgewählten Testflächen in der Stadt Berlin angewendet, durch Erstellung der Bodenfunktionskarten bei großmaßstäbigen Bewertung verglichen und unter fachlichen Gesichtspunkten in einer strukturierten Weise im Rahmen des Vergleichs überprüft. Die fachlichen Merkmale von untersuchten Bewertungsmethoden auf der Basis der gewonnenen Erkenntnisse und Bewertungsergebnisse werden hergeleitet und das Bewertungsverfahren für Stadtböden mit seinem Inhalt entwickelt. Für die Anpassung dieses vorgeschlagenen Verfahrens an Berliner Böden zu einem räumlichen Planungsfall wird hier eine Methode zur aggregierten Gesamtbewertung dieser Böden hinsichtlich ihrer bewerteten Boden(teil)funktionen erarbeitet. Abschließend lässt sich sagen, dass das vorgeschlagene großmaßstäbige Bewertungsverfahren, das für die Anwendung im großen Maßstabsbereich (>_ 1: 10.000) konzipiert, hinsichtlich der Ergebnisse, die für den Einsatz im Bodenschutz und in der Planungspraxis für Großstädte abgeleitet werden, dem Planungsträger Empfehlungen als „Entscheidungsgrundlage“, insbesondere für planerische Fragestellungen - ob ein Standort mit seinen Böden mehr oder weniger schützenswert ist, liefern kann. / The soil conservation in urban agglomerations such as Berlin aims to minimize the consumption of land and to preserve existing services and functions. It is against this background that a revision of nationwide and commonly applicable large scale evaluation systems is required, which will take greater account of the restoration of soil functions and aspects of preventing soil conservation within planning and approval procedures. In order to develop an evaluation system for soil functioning in urban areas, the valuation methods of different procedures in Berlin, Hamburg and Munich have been practically applied, through the preparation of soil maps for large scale evaluation compared and reviewed with regard to technical aspects in a structured manner in the context of the comparison. The technical characteristics of the assessed evaluation methods are derived based on the knowledge gained from this study and the evaluation system for urban soils is developed in a content oriented manner. A method of overall aggregate assessment of soils relating to their (sub) functions was developed for the adaptation of the proposed procedure to soils of Berlin to a spatial planning purpose. In conclusion, the proposed assessment procedures, which are designed for use on the scale of 1:10,000 or larger, based on the results, which are derived for the application in soil conservation and planning in big cities, serve the purpose of supporting cities and their development bodies as “planning recommendations”, especially for planning issues such as, making a decision, if the soils found at one specific location are of higher conservational value than the soils found at another location.

Thesis (MScAgric (Soil Science))--University of Stellenbosch, 2005. / The purpose of this study was to investigate and identify the occurrence of specific soil properties that may be important for vegetation functioning and the possible effect of the loss of or changes in these properties on rehabilitation success on the sandy coastal plains of the West Coast, South Africa. The study area covered approximately 9 400 ha on the Namaqualand coast in the vicinity of Brand-se-Baai (31º18'S 17º54'E), approximately 350 km north of Cape Town and 70 km north-west of the nearest town, Lutzville. A soil survey was done to reveal the presence of important pedological features. The 20 soil profiles surveyed are situated within six vegetation communities. Pedological features such as surface water repellency, permeable apedal subsurface horizons, subsurface impediments such as cemented (calcrete or dorbank) hardpans and significantly more clayey (cutanic, luvic) horizons were identified. A comparative study between rehabilitated and natural soils indicates that mining operations result in the formation of saline sand tailings, stripped of a large portion of the clay and organic matter fraction. The natural leaching of solutes, over a period of 25 months, is sufficient to lower salinity of the tailings to levels comparable to natural soils. This leaching can also results in lowering of soil fertility. Removal of the dorbank and the dense neocutanic horizon in the western side of the mine, loss of topographical features such as small dune systems and heuweltjies, destruction of natural soil profile morphology and the lowering of organic carbon and clay plus silt fraction can have detrimental effects on attempts at rehabilitation of this area to a natural condition similar to that which preceded the mining operation. Infiltration fingering and deep percolation results in the development of an aquifer below the reach of shallow-rooted desert shrubs. A method of water acquisition by vegetation through water distillation is investigated as a possible solution to the apparent discontinuum between the shallow root systems and deeper-lying aquifer. Volumetric water content measurements indicated that precipitation of 29.5 mm, over a period of 10 days, did not result in any variation at 235 mm, 360 mm and 900 mm depths. An average volumetric water content increase of 0.4 mm per night was measured in the first 23.5 cm of soil surface. This amount is a significant source of water that can explain the shallow root distribution. Water vapour movement due to temperature gradients can explain the diurnal volumetric water content fluctuations observed. Further studies are necessary to determine to what extent the depth of water infiltration influences the capacity of subsurface dew to provide plants with a nocturnal water source. Findings of this study can be summarised into two concepts namely: • Heuweltjies, small dune systems, and variation in depth of cemented hardpans are the main features that contribute to pedosphere variation and possibly to biodiversity. • Pedogenic features such as topsoil hydrophobicity, and cemented dorbank and dense more clayey (cutanic, luvic) subsurface horizons are important components of a soil water distillation process that could be a driving force behind vegetation functioning in this region. Mine activities result in the loss of certain pedogenic features and soil properties that that could be key ingredients to ecosystem functioning. The inability to recognise their significance and ignorance thereof when planning rehabilitation methods might prevent sustainable restoration of the environment.

The effects of managing soil with organic amendments were examined with respect to soil microbial community dynamics, macroaggregate formation, and plant physio-genetic responses. The objective was to examine the possibility of managing soil microbial communities via soil management, such that the microbial community would provide agronomic benefits. In part one of this research, effects of three amendments (hairy vetch residue, manure, compost) on soil chemical and microbial properties were examined relative to formation of large macroaggregates in three different soils. Vetch and manure promoted fungal proliferation (measured via two biomarkers: fatty acid methyl ester 18:2ω6c and ergosterol) and also stimulated the greatest macroaggregate formation. In part two of this research, effects of soil management (same amendments as above, inorganic N fertilization, organic production) on soil chemical and microbial properties were examined relative to the expression of nitrogen assimilation and defense response genes in tomato (Solanum lycopersicum L.). Soil management affected expression of a nitrogen assimilation gene (GS1, glutamine synthetase) and several defense-related genes. The GS1 gene was downregulated with inorganic N fertilization, expression of the pathogenesis-related PR1b gene (which codes for the pathogenesis-related PR1b protein) was increased in plants grown in soil amended with compost, vetch, and N fertilizer, and expression of three other defense-related genes coding for chitinase (ChiB), osmotin (Osm), and β-1,3-glucanase (GluA) were decreased in plants from soil amended with manure and in plants from the organically managed soil. Differential expression of defense-related genes was inversely related to the relative abundance of Gram-negative bacteria. The relative abundance of the 18:1ω7c Gram‑negative bacterial biomarker was greatest in manure treated soil and in organically managed soil (which recieves seasonal manure applications). These treatments also had the lowest expression of ChiB, Osm, and GluA, leading to speculation that manure, through increases in Gram-negative bacteria, may have suppressed populations of soil organisms that induce a defense response in plants, possibly allowing for less-stressed plants. Outcomes of this research may be useful for those interested in developing management strategies for maintaining or improving soil structure as well as those interested in understanding management effects plant physio-genetic responses.

Increased nutrient availability globally has the potential to affect community functional composition of plants in nutrient limited environments, such as coastal grassland systems. Stability of these systems are threatened worldwide by urbanization, as well as effects of sea level rise and increased frequency and intensity of storms, and atmospheric N deposition, associated with climate change. Annual net primary productivity (ANPP), species composition, and functional traits (community weighted specific leaf area (CWSLA), leaf area index (LAI), growth form and photosynthetic pathway) were measured across four treatments to assess multiple resource limitation of nitrogen (N) and phosphorus (P) and functional community response in a coastal grassland on Hog Island, VA within the Virginia Coast Reserve, Long Term Ecological Research Network (LTER) applied at a rate of 10 g m-2 yr-1 Nutrient enrichment did not alter species diversity or richness. ANPP was highest in plots receiving any type of nitrogen enrichment, and was higher than expected of low nutrient systems. CWSLA was significantly higher in NP plots, and was lower than other grasslands. P treatments were not significantly different from controls. Graminoid species, specifically C4 species responded with higher ANPP than C3 forbs or graminoids within treatments. Evidence of synergistic NP effects were seen on community level resource allocation and leaf construction, but no significant species changes occurred over a 1-year time span. These results have expanded the knowledge of functional response to increased nutrient availability in an understudied, coastal grassland, which are at high risk to being lost to sea level rise and anthropogenic development and inform community assembly processes in stressful environments.