<p> Scientists widely accept that modern agriculture is unsustainable, but the best methods for addressing unsustainability are still contested (Constance, Konefal, and Hatanaka 2018). Grassroots sustainable agriculture communities have long participated in the exploration of solutions for agriculture unsustainability, and their momentum continues to grow in the technical age. Practitioners of grassroots sustainable agriculture use many information systems that were not originally built to support the design of agricultural systems. Based on ethnographic research with two grassroots sustainable agriculture communities, I show that participants&rsquo; personal and community values frequently clashed with those embedded in information systems, including ones used to look for and manage plant information. Furthermore, I demonstrate a range of information challenges that participants faced in the absence of tools designed to support their specific work. I argue that practitioners of grassroots sustainable agriculture need information systems tailored to their goals and values in order to productively address barriers to designing and building agroecosystems for their communities. </p><p> This dissertation provides an example of how to involve communities in the development of information technology artifacts and strengthen efforts to support sustainability via technological interventions. First, I engaged in two grassroots sustainable agriculture communities as a participant, experiencing their practices, values, and information challenges first hand. Then, I worked with the communities to create a plant database web application (SAGE Plant Database) that supports agroecosystem design in local contexts. Members of the communities participated in the design, development, and data population stages so that the SAGE Plant Database supports their design context and upholds their technological and holistic sustainability values. At the foundation of the database is a plant ontology grounded in the participants&rsquo; practice of designing agroecosystems. My comparative analysis of the design of the SAGE Plant Database to other databases demonstrates its relevance due to its emphasis on agroecological relationships among plants and between plants and the environment, the inclusion of ethnobotanical data, and the embedded community values. By engaging in this research, I seek to make progress towards transforming the technology-supported food system into one that furthers food security, food sovereignty, and holistic sustainability.</p><p>

<p> Although savanna ecosystems cover approximately 20 % of the terrestrial land surface and can have productivity equal to some closed forests, their role in the global carbon cycle is poorly understood. This study explored the applicability of a past spaceborne Lidar mission and the potential of future missions to estimate canopy height and carbon storage in these biomes. </p><p> The research used data from two Oak savannas in California, USA: the Tejon Ranch Conservancy in Kern County and the Tonzi Ranch in Santa Clara County. In the first paper we used non-parametric regression techniques to estimate canopy height from waveform parameters derived from the Ice Cloud and land Elevation Satellite&rsquo;s Geoscience Laser Altimeter System (ICESat-GLAS) data. Merely adopting the methods derived for forests did not produce adequate results but the modeling was significantly improved by incorporating canopy cover information and interaction terms to address the high structural heterogeneity inherent to savannas. Paper 2 explored the relationship between canopy height and aboveground biomass. To accomplish this we developed generalized models using the classical least squares regression modeling approach to relate canopy height to above ground woody biomass and then employed Hierarchical Bayesian Analysis (HBA) to explore the implications of using generalized instead of species composition-specific models. Models that incorporated canopy cover proxies performed better than those that did not. Although the model parameters indicated interspecific variability, the distribution of the posterior densities of the differences between composition level and global level parameter values showed a high support for the use of global parameters, suggesting that these canopy height-biomass models are universally (large scale) applicable. </p><p> As the spatial coverage of spaceborne lidar will remain limited for the immediate future, our objective in paper 3 was to explore the best means of extrapolating plot level biomass into wall-to-wall maps that provide more ecological information. We evaluated the utility of three spatial modeling approaches to address this problem: deterministic methods, geostatistical methods and an image segmentation approach. Overall, the mean pixel biomass estimated by the 3 approaches did not differ significantly but the output maps showed marked differences in the estimation precision and ability of each model to mimic the primary variable&rsquo;s trend across the landscape. The results emphasized the need for future satellite lidar missions to consider increasing the sampling intensity across track so that biomass observations are made and characterized at the scale at which they vary. </p><p> We used data from the Multiple Altimeter Beam Experimental Lidar (MABEL), an airborne photon counting lidar sensor developed by NASA Goddard to simulate ICESat-2 data. We segmented each transect into different block sizes and calculated canopy top and mean ground elevation based on the structure of the histogram of the block&rsquo;s aggregated photons. Our algorithm was able to compute canopy height and generate visually meaningful vegetation profiles at MABEL&rsquo;s signal and noise levels but a simulation of the expected performance of ICESat-2 by adjusting MABEL data's detected number of signal and noise photons to that predicted using ATLAS instrument model design cases indicated that signal photons will be substantially lower. The lower data resolution reduces canopy height estimation precision especially in areas of low density vegetation cover. </p><p> Given the clear difficulties in processing simulated ATLAS data, it appears unlikely that it will provide the kind of data required for mapping of the biophysical properties of savanna vegetation. Rather, resources are better concentrated on preparing for the Global Ecosystem Dynamics Investigation (GEDI) mission, a waveform lidar mission scheduled to launch by the end of this decade. In addition to the full waveform technique, GEDI will collect data from 25 m diameter contiguous footprints with a high across track density, a requirement that we identified as critically necessary in paper 3. (Abstract shortened by UMI.)</p>

Thesis (Ph. D.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains xii, 174 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Also available in print.

Thesis (M.S. in landscape architecture)--Washington State University. / Includes bibliographical references.

<p>Wetland monitoring and preservation efforts have the potential to be enhanced with advanced remote sensing acquisition and digital image analysis approaches. Progress in the development and utilization of Unmanned Aerial Systems (UAS) and Unmanned Aerial Vehicles (UAV) as remote sensing platforms has offered significant spatial and temporal advantages over traditional aerial and orbital remote sensing platforms. Photogrammetric approaches to generate high spatial resolution orthophotos of UAV acquired imagery along with the UAV?s low-cost and temporally flexible characteristics are explored. A comparative analysis of different spectral based land cover maps derived from imagery captured using UAV, satellite, and airplane platforms provide an assessment of the Huntington Beach Wetlands. This research presents a UAS remote sensing methodology encompassing data collection, image processing, and analysis in constructing spectral based land cover maps to augment the efforts of the Huntington Beach Wetlands Conservancy by assessing ecological and temporal changes at the Huntington Beach Wetlands.

Thesis (M.S.)--University of North Texas, Aug., 2007. / Title from title page display. Includes bibliographical references.

Dissertation (Ph.D.)--The University of North Carolina at Greensboro, 2009. / Directed by Susan Walcott; submitted to the Dept. of Geography. Title from PDF t.p. (viewed Jun. 7, 2010). Includes bibliographical references (p. 195-206).

Thesis (Ph. D.)--University of Oklahoma. / Bibliography: leaves 93-110.

Orientador: Tadeu Siqueira / Resumo: A natureza é ruidosa. Passarinhos gorjeiam enquanto o vento silva ao pentear os campos com abelhas e seus zunzuns rondando flores. Desatentos, deixamos de notar uma incrível quantidade de elementos retumbando em nosso entorno. No entanto, cada som parte de uma fonte, deixando uma pista sobre a situação na qual foi produzido. Podemos identificar a espécie de passarinho pelo seu canto, e, quem sabe, revelar a passagem de uma espécie migratória. A imagem de um campo nos é desperta ao escutar o vento soprando por gramíneas, que ressoaria diferente se soprasse por uma floresta. Por conseguinte, podemos registrar a atividade acústica dos organismos e descrever as dinâmicas de ecossistemas através de um conjunto de técnicas oferecidas pelo monitoramento acústico passivo. Além disto, os diversos sons emitidos por animais são produzidos sobretudo para fins reprodutivos e territoriais. Sua produção possui elevado custo energético e influencia se a performance de um organismo resultará em saldo positivo para a perpetuação de seus descendentes. Diante disso, alguns percalços no caminho entre a emissão e a recepção desses sons podem adulterar suas características e inviabilizar seu reconhecimento. Por serem ondas mecânicas, a vegetação pode refratar e absorver elementos dos sons emitidos por animais. Ou ainda, em grandes agregações, como os coros por aves no amanhecer e por anuros e invertebrados ao ocaso, os diversos sons podem gerar interferências. Em ambos os casos, a degradação sonora... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Nature is noisy. Birds chirps while the wind whistle when brushing the fields, with bees buzzing around flowers. Meanwhile, our absence of mind prevents us to notice many elements rumbling on our surroundings. However, each sound has a source that leaves clues about the situation in which it was produced. The songbird can be identified by its song and eventually reveal the passage of a migratory species. The wind blowing through the grass quickly resemble the image of a field that would otherwise sound different if it blew through a forest. Therefore, such acoustic activity of the organisms can be recorded and used to describe ecosystems dynamics through a set of techniques included in passive acoustic monitoring. In addition, sounds emitted by animals are produced mainly for reproductive and territorial purpose. Its production is costly and influences whether the performance of an organisms will lead a positive balance for the perpetuation of its descendants. As such, obstacles on the path between sound emission and reception may distort its characteristics and impair sound recognition. As sound are mechanical waves, vegetation can refract and absorb elements on the acoustic signal, or in large aggregations, such as dawn bird chorus and dusk anuran and invertebrate choruses, an abundance of animal sounds can generate interferences. In both cases, sound degradation may compromise species’ reproductive success. On the contrary, another perspective predicts that such obstacles ... (Complete abstract click electronic access below) / Doutor