• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4830
  • 1863
  • 600
  • 431
  • 218
  • 163
  • 93
  • 88
  • 56
  • 56
  • 56
  • 56
  • 56
  • 56
  • 44
  • Tagged with
  • 10625
  • 1666
  • 1654
  • 1558
  • 1533
  • 1207
  • 1201
  • 1014
  • 951
  • 926
  • 808
  • 803
  • 669
  • 632
  • 626
  • 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.
441

ECOLOGICAL IMPLICATIONS OF INTERNATIONAL PATENT REGIMES: A COMPARATIVE ANALYSIS OF LAWS AND CASES FROM THE UNITED STATES, INDIA, AND BRAZIL

Leary, Alyssa 26 June 2014 (has links)
Patents spur technological innovation; often, patented technologies have helped diminish the impact of some of the worlds most pressing concerns: from population growth, to world hunger, to global warming. A more contentious side of patents has emerged within the last several decades as more information is gathered on the sources and origins of biotechnological patents, evidencing misappropriation of traditional knowledge and resources, biopiracy. Biopiracy has been studied in detail for the social justice implications of wrongfully acquiring property of indigenous and traditional groups, but the literature is nearly void of the ecological implications of different patent regimes. International treaties and discussions have addressed the need to combat biopiracy and enable appropriate mechanisms of benefit sharing, but the implementation and success of laws and regulations guided by the treaties on a national level have been varied and inadequately quantified. This comment explores the international agreements governing intellectual property and access to natural resources, and examines how such agreements have been enacted in three countries: the United States, India, and Brazil. This comment then draws connections between the laws and policies of each country and their ecological environment. The goal of this comment is to draw attention to the direct ecological impact of patent laws in each country and the different national approaches to combat biopiracy. This comment will highlight the strengths and weaknesses of the variety of approaches and suggest ways to move forward with patent law and alternative mechanisms that are more conducive to balancing private property rights and technological innovation with biodiversity conservation and social justice.
442

Analyzing the error structure and simultaneous nature of multi-dimensional, density dependent growth models for ponderosa pine

Furlaud, James 26 June 2014 (has links)
A precommercial thinning study for ponderosa pine (Pinus ponderosa) was initiated by the U.S. Forest Service, the Nez Perce Tribe, and the Spokane Tribe of Indians in 1997/98. The agencies ran plot inventories and measured tagged trees before thinning and then at 1, 3, and 5 years post-thinning. In 2011, at 13/14 years after the original thinning, the Inland Northwest Growth and Yield Cooperative returned to the site to re-measure the tagged trees. This dataset presented an opportunity to quantify the effect of precommercial thinning on ponderosa pine growth in the Inland Northwest, where the effects of this treatment have yet to be rigorously documented. I used this dataset to build density dependent growth models in an attempt to quantify the precise effects of density management on three dimensions of individual tree growth. I first estimated these models using nonlinear least-squares. These models confirmed the results of previous precommercial thinning studies in other regions, that changing densities significantly impact diameter growth and crown dimensions at the individual tree level, and that density management does not significantly affect height. These models captured the mean trends in growth variation quite well, yet because the data exhibited heteroskedasticity and autocorrelation, nonlinear least-squares coeffi- cient estimates were inefficient, and coefficient standard error estimates were biased. I therefore attempted to model the heteroskedasticity and autocorrelation of the data, and reestimated the coefficients, using generalized nonlinear least-squares. These models confirmed the existence of heteroskedasticity and autocorrelation in the data by parameterizing statistically significant parameters for these two conditions. Parame- terizing the covariance structure also resulted in a clarification of residual trends, which led to the addition of another explanatory variable to the basal area increment models. In the height increment and height to crown base models, parameterizing the variance did not appreciably alter the models descriptions of mean growth trends, within the context of my analyses. Lastly, I performed parametric bootstrapping simulations to investigate the poten- tial for coefficient biases due to the simultaneous nature of the basal area growth, height growth, and height to crown base models. Simulated data were generated using six different error structures to investigate the consequences of ignoring contemporaneous cross-correlation. I found that ignoring a level of contemporaneous cross-correlation consistent with the empirical levels in this dataset did not result in substantial simul- taneity bias in the model coefficient estimates. However, if the level of contemporaneous cross-correlation between the height and basal area increment residuals was increased, the potential simultaneity bias grew substantial enough to result in meaningful changes in expected predictions.
443

SECURING FOOD AND LIVELIHOODS: OPPORTUNITIES AND CONSTRAINTS TO SUSTAINABLY ENHANCING HOUSEHOLD FOOD PRODUCTION IN SANTA FAMILIA VILLAGE, BELIZE

Lozada, Siobhan B. 03 June 2014 (has links)
Rural households play an active role in reorganizing their livelihood strategies to respond to external stresses and shocks. What is unclear is the extent to which rural households can remain resilient in the face of continued external stresses and how policy actions at larger scales can more effectively encourage rural food and livelihood sustainability. Economic and ecological stresses and shocks have negatively impacted livelihood security and wider economic stability in Belize. This has increased the number of people below the poverty line to 41.3 percent, who remain disproportionately located in rural areas. With a high degree of import dependency, global food price surges have resulted in direct pass through effects on domestic prices, creating food price inflation of up to 22.8 percent between 2006 and 2009. Within this context, this study assesses the state of livelihood security in a village of the Cayo district by assessing the quality of household capital assets, including human, financial, natural and social capital. Semi-structured face-to-face interviews were conducted in 2012 using a random sample of 64 households. Participant observation, key-informant interviews, the use of secondary sources and extra-local interviews with government officials were also employed to gain deeper insight into the complexity of the rural environment and institutional policies related to food security and sustainable agricultural development. Results show high levels of livelihood diversification among both grain farmers and non-farming households. No significant difference existed between total household median incomes. However, the median income of non-grain male household heads is significantly greater than that of grain farmer male householders (U = 1393, n1 = 43, n2 = 16, p < .05). Part-time farming households maintained the highest number of livelihood strategies compared to non-grain households, with a median of 4 to 3 respectively (U = 506, n1 = 11, n2 = 48, p < .0005). Compared to non-farmers, part-time farmers are disproportionately engaged in day labor as a primary income strategy, where pay is lower and work is less reliable (Chi = 57, df = 1, p < .01). Human capital is low among both household types, with 65 percent of non-farming male householders receiving no education above the primary school level, while all grain farmers received no education above the primary school level (Chi = 59, df = 1, p < .01). Domestic and foreign remittances did not impact the majority of participants, as only 28 percent reported they received, or would receive, some amount of extra-household monetary support. Yet, the median value of out-country remittances were significantly greater for non-farmers compared to grain farmers (U = 21.00, n1 = 4, n2 = 3, p < .05). Despite these strategies, financial capital remains constrained, as over 75% of households are unable to save money, and the large majority of working females worked out of necessity. In addition, nearly two thirds of households have reduced meal size in recent years, with no significant difference between household types. Nearly three quarters of all householders valued home gardens as a mode to adding diversity to the diet and improving health or reducing purchasing costs. Among grain farmers, 94 percent stated that grain farms provided their family with food, where 62.5 percent indicated risk management, specifically, as their reason for farming. This proportion rises to 83.3 percent when looking at white corn producers exclusively. When asked if farming has become more difficult, less difficult, or the same compared to the past, 62.5 percent of grain farmers stated that agriculture in Belize has become more difficult (Chi = 6.5, df = 2, p < .05). Biophysical constraints among both household types include vulnerability to waterlogging and drought, soil fertility and pest problems. Input costs are also of concern, while grain farmers faced additional transaction risk. Furthermore, land tenure insecurity is widespread. To compound the problem, social capital is also weak given disillusionment with formal organizing, where exclusionary policies by the local cooperative further restrict access to relevant low-cost and low-input technologies. Expanding access to sustainable technologies through participatory research and extension is recommended. However, greater access to technology alone is insufficient for sustaining intensification that can ensure resilient food and livelihood strategies. Reducing costs and risk through secure access to productive resources, markets, and financial services in a manner that accounts for heterogeneity in farming systems and local food security priorities are also essential. To this end, and with attention to national-level social and economic conditions, a pro-poor agricultural growth strategy is considered within a dynamic food sovereignty framework.
444

Escape probability: an alternative risk metric to support and evaluate wilderness fire management decisions

Barnett, Kevin Matthew 03 June 2014 (has links)
Inside many U.S. federally designated wilderness areas, fire suppression is the dominant management strategy largely due to the risk that fires pose to resources adjacent to the wilderness boundary. Opportunities to exploit the fuel treatment and risk-mitigation benefits of allowing wilderness fires to burn are foregone when ignitions are suppressed. Existing risk-based metrics (e.g. burn probability) produced from wildfire simulation models were not designed to inform management of wilderness fires. They focus on the management of fuels, or on suppression resource allocation, not managing ignitions through monitoring strategies for resource benefits. The purpose of this research was to develop a risk-based decision support metric to support wilderness fire management. The metric, escape probability, was developed using the Bob Marshall Wilderness Complex, Montana, USA, (BMWC) as the case study landscape, and applied to evaluate previous management decisions to suppress ignitions within the BMWC. The outputs from two wildfire simulation models, FARSITE (Finney, 1998) and FSim (Finney et al., 2011), were used to map escape probability for two different landscape scenarios in 2007: (1) an observed landscape reflecting fuel conditions as a result of actual wildfire management strategies; and (2) a treated landscape that reflects hypothetical fuels and vegetation assuming suppressed ignitions in 2007 had been allowed to burn. First, wildfire spread and behavior for suppressed ignitions in 2007 were retrospectively simulated using FARSITE. Hypothetical fuels layers were created for each retrospectively simulated fire by modifying the observed pre-fire fuels conditions within the simulated perimeter based on modeled burn severity. The observed and hypothetical fuels layers were then used as inputs in FSim, a large wildfire modeling system commonly used in quantitative wildfire risk analyses. Differences in the likelihood of future wilderness fire escape between the observed and treated landscape scenarios were examined for both inside the simulated area burned by the suppressed ignitions (i.e. the treated area) and the area within several kilometers of the simulated wildfire perimeters (i.e. the off-site effects). Results suggest that larger treated areas arising from ignitions closer to the wilderness boundary had the greatest effect on reducing the likelihood of wilderness fire escape within the treated area. The relationship between ignition location, fire size, and reduction in escape probability outside the treated area was variable. Fire and fuels managers can use escape probability information during strategic decision-making and pre-season planning to allow natural fires to burn absent of suppression, as well as to evaluate the effectiveness of different risk-mitigation strategies based on how the strategies affect future opportunities to allow natural ignitions to burn.
445

Effects of Disturbance on Tree Community Dynamics in Whitebark Pine Ecosystems

Amberson, Jeremy Travis 03 June 2014 (has links)
Whitebark pine (Pinus albicaulis), a keystone species of high-elevation ecosystems of western North America, is warranted for listing under the Endangered Species Act due to the combined threats of fire exclusion, white pine blister rust (Cronartium ribicola), and increased pressure from insects due to climate warming. Despite widespread knowledge of the potential causes of the trees decline, there is limited understanding of its ecology, including successional dynamics in forests disturbed by white pine blister rust and mountain pine beetle. Specifically, there is a need for more information on successional replacement by subalpine fir and whitebark seedling regeneration dynamics. I assessed changes in forest composition and structure and seedling regeneration dynamics over a 22-year period (1990-2012) at 19 sites in the Cascade Mountains of Washington State (USA). Over the two decades analyzed, 26% of sites experienced wildfire, 58% were disturbed by mountain pine beetle, and 68% were infected by white pine blister rust. Only one of 19 sites showed no evidence of disturbance by these agents. Tree community composition changed significantly during the study period, primarily due to a significant decline in mature (≥20-cm DBH) whitebark pine . Despite loss of mature whitebark pine, I found little evidence of successional replacement by other tree species. I also found insignificant correlation between whitebark seedling density and basal area of mature whitebark pine. Seedling density was positively correlated with herb and shrub cover. These observed regeneration dynamics appear to contradict the conventional view that seedling establishment is contingent on local seed production and microsites free of competing vegetation. Additional, long-term studies are needed to comprehensively quantify the effects of novel disturbances on successional trajectories in whitebark pine ecosystems.
446

AN EMPRIRICAL TEST OF THE EFFECTIVENESS OF AN INDIRECT MANAGEMENT TOOL IN INCREASING OPTIONAL SHUTTLE USE AT GLACIER NATIONAL PARK

Weinberg, Alex Benjamin 03 June 2014 (has links)
Glacier National Park instituted an optional, free shuttle system on the Going-to-the-Sun Road in 2007.It was recently discovered that the shuttle system was having an adverse impact on parking congestion at the Logan Pass parking lot. This was occurring because visitors were able to park at Logan Pass all day while they performed a looped hike from the Highline trailhead to the Loop trailhead. Upon completion of their hike, visitors would take the shuttle back to their vehicles. A variety of data suggests that the shuttle system may be inadvertently adding 40-60 day-long passenger vehicles to the Logan Pass parking area as a result of this phenomenon. In order to alleviate management issues in protected areas, managers typically employ two types of management techniques: indirect or direct management. Direct management typically calls for placing direct constraints on visitor behavior while indirect management employs a more subtle approach which typically consists of persuasive messaging. Visitors typically prefer indirect management because it preserves a sense of freedom. This study tested the effectiveness of indirect management in increasing optional shuttle use among St. Mary Campground and Rising Sun Campground occupants. It was surmised that if the technique was shown to be effective at increasing shuttle use among a target population it could be useful at alleviating the problem described above. The present study constructed a persuasive message that was guided by the theory of planned behavior, elaboration likelihood model of persuasion, research pertaining to alternative transportation in National Parks, and research pertaining to the effectiveness of indirect management in recreation settings. Results suggested that the brochure was ineffective at increasing shuttle use and the researcher concludes by recommending that the park use a direct form of management to alleviate the problem described in this paper. Furthermore, contrary to suggestions provided in prior research, this study suggests that providing messages to increase shuttle use will not be effective at increasing optional shuttle ridership. The researcher suggests that if managers want to increase use on park shuttles they should first examine constraints, incentives and disincentives pertaining to shuttle use in order to understand the barriers concerning shuttle ridership.
447

UNDERSTANDING THE NATURE OF INTERACTIONS BETWEEN VISITORS AND MOUNTAIN GOATS (OREAMNOS AMERICANUS) ON THE HIDDEN LAKE TRAIL, GLACIER NATIONAL PARK

Markegard, Sarah Ilene 03 June 2014 (has links)
This study examined interactions between visitors and mountain goats on the most heavily used trail in Glacier National Park. The primary objective was to give park managers a baseline of unbiased, reliable data with which to make informed decisions and improve the quality of interactions between visitors and mountain goats. Secondarily, this research was intended to achieve a thorough understanding of both human and wildlife responses during interactions on publically protected lands. The study was conducted over a two month period during the summer of 2013, and it was purely observational. Observations were recorded five days a week for approximately six hours each day, between the hours of 8 AM and 8 PM. Focal sampling and scan sampling methods were used to collect data on goat and visitor behaviors as well as emotional responses. Information was also collected on setting attributes (e.g. weather, time), the duration of interactions, the distance between mountain goats and visitors and the elevation of mountain goats relative to visitors. Results show that mountain goats along Hidden Lake Trail exhibited significantly different behaviors during interactions compared to when no interaction was occurring. In addition, the behaviors that mountain goats exhibited more frequently during interactions were more energy costly. Negative interactions occurred 42% of the time, but typically only one negative behavior was observed in these interactions, and the behavior was low in intensity. The likelihood of an interaction occurring was largely influenced by environmental variables such as weather, time of day and the location of mountain goats relative to visitors, while the duration of interactions was affected by the number of mountain goats present and the elevation of mountain goats relative to visitors. Ninety percent of all interactions were emotional experiences for visitors, and 95% of the emotions exhibited were positive in nature. Emotional responses varied based on the distance between mountain goats and visitors, time of day, weather, visitor group composition and the number of mountain goat kids present. Twelve emotional responses (both positive and negative) were also significantly correlated with duration. These findings illustrate the importance of understanding both wildlife and human responses, including emotional responses during interactions. Without the awareness of both, our knowledge is incomplete and effective management decisions cannot be made.
448

Linking Conservation with Sustainable Mountain Livelihoods: A Case Study of Northern Pakistan

KHAN, SHAH RAEES 20 September 2012 (has links)
This study investigated the livelihood strategies of mountain communities and their relationships with natural resources in northern Pakistan. Interventions by the State to conserve biodiversity have led to the “decommonisation” of the commons and with strict sanctions on the local communities restricting their access to the resources. This has resulted in severe conflicts between the State and the local communities. In light of the adverse effects of “decommonisation,” prevailing institutions, international conservation organizations, have initiated the “re-coupling” of the local communities with resource management. However, this process of “new-commonisation” appears to be failing because it has not provided “a sense of ownership” among the local communities. To investigate the pertinent issues, this research encompassed five areas for analysis: 1) the dynamics of mountain livelihoods; 2) the vulnerability and coping strategies of mountain communities; 3) the “decommonisation” of mountain commons; 4) international NGO-led “new commonisation” of natural resource endowments, with efforts to involve local communities; and 5) the formulation of a framework towards sustainable mountain livelihoods. The study collected evidence from two communities in northern Pakistan, namely, Shimshal and Naltar Valley, during July 2006-September 2008. A four-tier field method was used that included introductory workshops, household surveys, focus group discussions, and data validation. This investigation identified the following findings: 1) there has been a significant reduction in the livelihood options of local communities due to State-induced “Protected Areas,” 2) traditional pasture management systems have been facing serious threats from State institutional measures; 3) some communities have proactively attempted to diversify their economy by expanding household portfolios into non-agricultural sectors; 4) external drivers of local socio-economic conditions have augmented local vulnerability; 5) in the face of external threats, some traditional institutions have transformed themselves into formalized institutions with the capability to establish cross-scale linkages. There is a potential to manage the commons through revitalized local institutions that would promote “self-governance” in managing the commons. It stresses the need to understand the local livelihoods from the perspective of the local people, so as to advance effectively the conservation of natural resources in the context of mountain areas.
449

The Political ecology and ecosystem services in Yerba Maté (Ilex paraguariensis) agroforestry of the South America Atlantic forest

Beatty, Branden John 11 April 2012 (has links)
Agroforestry offers a land-use management methodology that may provide solutions to environmental degradation in the tropics. However, practitioners of agroforestry are faced with the dilemma of clearing more forest cover in order to increase crop size and sustain their income. The aim of this study is to understand the agroforester’s dilemma and to measure the value of the agroforestry ecosystem stewardship in yerba maté (Ilex paraguariensis A. St. Hil.) agroforestry parcels of the South American Atlantic forest eco-region. Biodiversity, carbon sequestration and vegetation cover were measured to be considerably higher in yerba maté (Ilex paraguariensis A. St. Hil.) agroforestry plantations than in neighboring monoculture crops. Agroforestry vegetation cover values were measured to have between 65-89% cover while monocultures had roughly 25% cover. Agroforestry stored carbon values ranged between 154.7-172.7 Mg C ha-1, compared to monoculture plantation values of 81.3 Mg C ha-1. Finally, as measured using the Shannon index, values of species richness ranged from 2.7-3.5 in agroforestry parcels and between 0.9-1.3 in monocultures, and values of evenness ranged between 0.6 and 0.8 in agroforestry parcels, and 0.2 in monocultures. These findings illustrate that yerba maté agroforestry can potentially contribute as a regional climate change mitigation strategy. Valuating and monetizing ecosystem services and engaging smaller farmers with worldwide ecosystem marketplaces offer the potential to expand the dialogue around payments for the valuable ecosystem services that agroforesters are providing. An analysis of market prices available within the ecosystem marketplace for total ecosystem services being conserved on agroforestry parcels amounted to a range in value between $16 – $160 ha-1 yr-1. To address environmental degradation in the Atlantic Forest region, in South America, governments should motivate environmental conservation to support a shift towards sustainable yerba maté production which supports livelihoods of small-scale farmers, economic justice and environmental sustainability. / Graduate
450

Byo by and fusuma : developing an approach to the conservation of Japanese screens through historical and technical study and an investigation of current practices

Grantham, Sandra January 1999 (has links)
No description available.

Page generated in 0.0435 seconds