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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Overseeding Winter Grasses into Bermudagrass Turf

Kopec, David, Umeda, Kai 10 1900 (has links)
2 pp. / Describes the proper timing of overseeding, selecting winter grasses, and procedures to prepare for overseeding with the amount of seed to use followed by irrigating, fertilizing, and mowing.
2

Use of uprooted invasive buffelgrass (Pennisetum ciliare) parent plants as thatch to reduce progeny seedling emergence

Jernigan, Marcus Brendon January 2013 (has links)
Buffelgrass (Pennisetum ciliare) is a perennial bunchgrass native to Africa that has invaded ecologically intact areas of the Sonoran Desert in southern Arizona. It threatens many native plant species by means of competitive exclusion as well as increased fire frequency and intensity. Since the 1990s, efforts have been underway in southern Arizona to control buffelgrass using manual removal. A problem with this method is that the resulting bare, disturbed soil provides a favorable environment for buffelgrass seed germination. This study examined whether thatch composed of uprooted buffelgrass parent plants spread over disturbed areas reduces the density of progeny seedlings. A secondary goal was to determine whether light attenuation and/or autoallelopathy were major factors involved in the effect of thatch on buffelgrass seedling density. The effect of light attenuation on seedling density was tested in containers in the field and in the greenhouse. The propensity of thatch to produce autoallelopathic chemicals was tested in the greenhouse. Field plots with thatch had 1.9 buffelgrass seedlings/m² which was significantly fewer (p= 0.03) than the 2.9 seedlings/ m² in plots without thatch. These results suggest that the placement of thatch over areas disturbed during manual treatment of dense stands of buffelgrass will increase the efficiency of follow-up control of buffelgrass progeny seedlings in these areas. Results of the field container study suggest that light attenuation does not play a significant role (p= 0.39) in the reduction of seedling density by thatch, whereas those of the greenhouse shade treatment study indicated that light attenuation is a significant factor (p= 0.004). However, because percent germination was very low in the field container study, those results may be of little value compared to the greenhouse shade treatment study results which indicate that light attenuation is a mechanism by which thatch reduces buffelgrass seedling emergence. Chemicals leached from decomposed buffelgrass thatch did not have a significant effect (p= 0.09) on buffelgrass seedling density. Only the combination of thatch and leached chemicals significantly reduced (p= 0.014) seedling density. Thatch may also increase the activity of other factors that could reduce seedling density such as pathogens, and predators of seeds and seedlings.
3

Building Community with Bamboo: ”Six volcanoes” multifunctional public space in Los Baños, Laguna, Philippines

Ranara, Jeff January 2021 (has links)
Inspired by regional Austronesian vernacular architecture, volcanic forms in the northern island of Luzon in the Philippines, and the natural geometry of the Fibonacci spiral, “Six volcanoes” is a multifunctional public space in the municipality of Los Baños, Laguna, Philippines, located a stone’s throw southeast of the University of the Philippines, Los Baños campus, in the peri-urban community of Barangay (village) Tuntungin Putho.   The 3500 sqm. site rises one meter from the original street level to a 14 m. high 1100 sqm. main space. A slightly lower 6 m. high 150 sqm. auxiliary space is southwest of the main space.  Bamboo poles, which could be grown and harvested on an adjacent mini-mountain, “Pulong Malake”, serve as building material, with steel connector joinery where appropriate.  Laid-stone foundations and the thatched-roof cogon grass material are sourced from a local quarry and local fields.  Possible uses of the spaces include a wifi-lounge, learning and workshop activities, sporting events, festivities and concerts, church services, meetings and conferences.  Open to all in the area, from impoverished squatters to residents of adjacent gated communities and walled homes, “Six volcanoes” would facilitate social networking and cohesion, combating informal social segregation and bridging socio-economic class divides.
4

Understanding Rare Species in California: An Assessment of Camatta Canyon Amole (Hooveria Purpurea Var. Reducta) and a Meta-Analysis of California Rare Plants in Literature

Althaus, Kieran N, , 01 June 2022 (has links) (PDF)
California is currently in the midst of a biodiversity crisis. There are approximately 5,000 native species of plants in California, a quarter of which are considered rare. Determining threats to these rare plants is often times difficult. Despite California's botanical resources, we still know very little about much of California’s rare plants. San Luis Obispo County is home to 2,000 of California’s native plant taxa, one- third of which are rare or endemic to the county. These species are of great local and environmental concern. In Chapter 1, we attempted to assess the impact of non native species on a threatened species in eastern San Luis Obispo County. We conducted an invasive thatch removal experiment on 10 vegetation plots of Camatta Canyon Amole, Hooveria purpurea var. reducta. The Camatta Canyon Amole (CCA) is a federally listed “threatened” plant that is only known to occur on 21.15 ha of land on Los Padres National Forest (LPNF). In the 1980s, U.S. Fish and Wildlife Service established 10 plots to monitor the population of CCA. These biologists recorded a decrease in the CCA since the establishment of those plots in the 1980s. One hypothesis for the decline is the absence of cattle grazing from LPNF, which has resulted in the accumulation of a dense thatch layer. We experimentally removed this thatch layer in five of the 1980s vegetation plots to test this hypothesis. While our the experiment was designed to be a long term treatment, from the first 1.5 years, we found no relationship between thatch removal and the amount of CCA in each plot. The effect of our treatment may take many years to materialize. In Chapter 2, we conducted extensive botanical surveys of the Camatta Ranch, a 32,000 acre cattle ranch in eastern San Luis Obispo County. The goal of these surveys was to estimate the distribution and population size of CCA on private property, which has never before been accessed or surveyed. We did this in two ways: 1) We created a density ratio estimate based off of plot sampling done on the ranch and 2) we created a species distribution model (SDM) to predict the likelihood of presence throughout the ranch. Our surveys of Camatta Ranch, coupled with our SDM suggest that a majority of CCA’s preferred habitat is on Camatta Ranch, making the ranch of paramount concern for CCA’s protection. Our estimates suggest that 90% of the total population of CCA occurs on Camatta Ranch. In Chapter 3, we attempted to quantify biases in the literature about California’s flora. The California Floristic Province is one of the most biologically diverse floras in the world. Considerable legal and conservation attention is given to rare plants in California. However, there is no information as to the research effort given to rare species in California. Here we ask the question: Is there more research done on rare plants in California than on non-rare species? To answer this question, we quantified the amount of literature available on Google Scholar for California’s rare plants, weeds, and non-rare natives. To account for the differences in species geographic extent, we aggregated occurrence data for each species from GBIF to determine their ranges. We found that rare species were severely under-represented in the literature, even after accounting for the differences in species extent.
5

Exposure to organochlorine compounds at the aerly stages of DDT use for indoor residual spraying in domestic environments in Manhiça, Mozambique.

Manaca, Maria Nélia Joquim 27 September 2011 (has links)
Past and present uses of DDT and pyrethroids have led to their incorporation into humans, mainly through the food chain and sometimes by direct exposure. The present work focuses on establishing the levels of DDT, its analogous compounds (DDE and DDD), and pyrethroids in humans and the human environment in Manhiça, a rural area where they have been used as insecticides for indoor residual spraying (IRS) and insecticide treated nets (ITN) in malaria control programs. Thatch samples from human dwellings, breast milk from pregnant women and cord blood from newborns were analyzed for assessment of the concentration levels of these compounds. The results showed that DDT and its analogues were already present in humans and dwellings before reintroduction of this insecticide for IRS. As consequence of these applications DDT concentrations increased significantly. The higher proportion of 4,4’-DDT than 4,4’-DDE evidenced that the observed amounts were due to recent applications of this insecticide. Concerning pyrethroids, their presence has been identified in both breast milk and human dwellings showing that both agricultural applications and use for ITN may be responsible for their occurrence in humans and human environments of Manhiça. / L’ús en el passat i en temps actuals del DDT i piretroides ha donat lloc a la seva incorporació en els humans, principalment mitjançant la cadena tròfica i a vegades per exposició directa. Aquest treball té com objectiu establir els nivells de DDT i els seus compostos anàlegs (DDE i DDD), i piretroides en humans i l’ambient humà a Manhiça, una àrea rural on aquests s’han utilitzat com insecticides per aplicació interna (indoor residual spraying, IRS) i tractament de xarxes de protección (insecticide treated nets, ITN) en programes de control de la malària. Per a esbrinar els nivells de concentració d’aquests compostos s’analitzaren mostres de palla de cabanes, de llet materna i de sang de cordó de nou nats. Els resultats mostraren que el DDT i els seus compostos anàlegs ja eren presents en humans i cabanes abans de la reintroducció d’aquest insecticida per IRS. L’ús del DDT en aquest programa féu augmentar considerablement les concentracions d’aquest insecticida. La major proporció de 4,4’-DDT que 4,4’-DDE posà de manifest que les quantitats observades corresponien a aplicacions recents d’aquest insecticida. Respecte als piretroides, s’han trobat en mostres de llet materna i cabanes tot mostrant que tant les aplicacions agrícoles com el seu ús en ITN poder esser la causa de la seva presència en els humans i els ambients humans de Manhiça.
6

Hanácký statek - stavebně technologický projekt / Hanacky estate - construction and technological project

Troubilová, Hana January 2012 (has links)
In this diploma thesis is designed replica Hanacky estate from the 19th century. The whole structure includes not only a replica of the estate but also including the reconstruction of a barn or shelter. Hanacky estate will be part of Zoopark Vyškov and will serve as an environmental education center. Thesis I deal with a construction technological project. I focus here on the transport links, building-site cell site equipment, calculation of water and electricity, design tools and machinery, calculation, budget and schedule, the use of machines and workers, limitky. I deal with the technological regulations innovative technology. Furthermore, it is the control and test plans, security, ecology, design contract for work. In the last part of my thesis I deal with natural building materials.

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