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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.
81

Biophysical and Economic Analysis of Black Spruce Regeneration in Eastern Canada using Global Climate Model Productivity Outputs

Lee, Jung Kuk January 2016 (has links)
This study explores the biophysical potential and economic attractiveness of black spruce (Picea mariana) regeneration in eastern Canada under future climate changes. It integrates process-based ecosystem model simulated forest productivities from three major global climate models (GCMs), growth and yield formulations specific to black spruce and economic analyses to determine the overall investment value of black spruce, both including and excluding carbon sequestration benefits. Net present value (NPV) was estimated to represent the financial attractiveness of long-rotation forest plantations through time. It was assumed that stands would not be harvested at volumes less than 80 m3 ha-1. The price of stumpage was set to $20 m-3, stand establishment cost was set to $500 ha-1, and the discount rate was considered at 4%, with sensitivity analyses conducted around these assumptions. The growth and yield of black spruce was simulated for an extreme future climate scenario – IPCC-RCP 8.5. The results suggested a general North-South gradient in forest productivity where gross merchantable wood volumes increased with decreasing latitudes. This pattern was also observed in NPVs, with higher values projected for the southern portion of the study area. Based on the base economic assumptions and sensitivity analyses, study results suggested that black spruce plantations are not economically attractive, unless carbon sequestration benefits of at least $5 ton-1 CO2 are realized. Further sensitivity analyses showed that discount rate plays a significant role in determining the optimal harvest age and value. Furthermore, the optimal harvest rotation age increases with increasing carbon price by approximately 9 to 18 years. / Thesis / Master of Science (MSc)
82

Diffusion of innovations : reforestation in Haiti

Bellanca, Raffaella January 2007 (has links)
Development discourse emerged from the implicit assumption that the technological achievements and societal organizations of western civilization represent successes of humankind in inhabiting the planet, and should therefore be promoted among other cultures. The ecological threats of this time suggest the contrary, forcing us to reconsider the positiveness of over exploitations of natural resources and to recognize the paradox of the economical growth model. A new urgent meaning for development is that of rediscussing what characterizes an ideal society and enabling the transformation toward sustainability and justice. Among the many challenges that the planet is facing deforestation well represents the reach of the problems since it affects humans at several levels: from the smallest scale of family economy with the products they can directly offer; to the national size through the effect they have on the environmental conditions of countries; and to the global level for the influence over the planet’s climate. In this era of tremendous transformations, demanding the reduction of consumptions for developed countries and appropriate planning of future consumption for developing ones, communication plays a central role. Exchange of information without preferential directions and between different levels (global-local, local-local) is at the base of this process. This study analyses the communication dynamics of a reforestation campaign in Haiti operated by the NGO AMURT. Assuming that the idea of planting trees rather then cutting them can be seen as an innovation, I adopted as a theoretical framework the findings of “Diffusion of Innovation” research. In particular I used the field work to critically assess some of the diffusion model’s findings, especially concerning the characterization of early adopters which I perceived as pro-innovation biased.An analysis of the NGO communication strategy according to diffusion of innovation parameters revealed several positive points, such as the use of homophile change agents, the adaptation of messages to the audience and the characterization of the meaning of the innovation from a receiver’s perspective. Nevertheless, the most important reasons for the success of the program rather seemed to sit in the NGO approach: the relationship of trust, the stability of its presence in the area and the intimate contact and cooperation with the local social structures.
83

Potential effects of technical assistance foresters on pine planting on non-industrial private forestland in the South

Skinner, Michael D. January 1989 (has links)
Over the next few decades, timber harvest levels on the South's non-industrial private forestlands (NIPFs) are projected to increase by 40 percent. These ownerships include 75 percent of the commercial timberland in the South, and account for 64 percent of the timber volume harvested in the region annually. Long-term sustained yield of softwood timber volumes from NIPFs depends on successful reforestation of harvested pine stands and afforestation of marginal agricultural lands. Available technical assistance is regarded as a significant factor in NIPP tree planting accomplishment. This study compares technical assistance available to NIPFs from various sources and attempts to measure response to technical assistance in terms of acres planted. Four sources of technical assistance are considered: state forestry agencies, consulting foresters, industry landowner assistance departments, and industry procurement staffs. Extensive south-wide surveys of technical assistance available from these four sources were conducted to determine the types and degrees of assistance available. Cross-sectional comparisons were made between 29 sub-state zones in 12 southern states to explore variation in NIPF acres planted attributable to variation in technical assistance. The surveys located just under 2,000 foresters having some professional involvement with southern landowners in 1985. The number of consulting foresters operating in the South seems to be growing, while the number of landowners enrolled in industry landowner assistance programs (LAPs) is also increasing. Assistance available to NIPF owners from all sources ranges from advice and recommendations to actual performance of site preparation and tree planting. The types and intensities of technical assistance are variable both within and across forester types. A cross-sectional statistical analysis using multiple linear regression was unable to demonstrate a significant south-wide effect of technical assistance on NIPF tree planting. Within the range of technical assistance presently available, variation in technical assistance did not prove to be a significant predictor of tree planting accomplishment. The results of this study indicate that diversity in the NIPF population, combined with diversity in silvicultural and market potential pine production, prevents quantification of a regional effect of technical assistance. A positive correlation between forester numbers and NIPF tree planting accomplishments was found. But only timber harvest levels and cost share expenditures were significant predictors of acres planted in multiple variable models. / Master of Science
84

Five-year fertilizer and ground cover effects on surface-mine soils and pine growth

Klemp, Mary Therese 01 August 2012 (has links)
During the last three years, 80% of mining permits in Virginia listed forestland as the post-mining land use. Adequate stocking and growth of tree stands at time of bond-release eligibility and beyond is an important beginning for returning mined lands to a productive state. In order to ensure reforestation success, biological constraints, including low mine soil fertility and competition from herbaceous ground cover, must be overcome. The effect of cultural treatments on the growth of three commercial pine species on reclaimed surface-mined land in southwestern Virginia was studied. In June, 1981, containerized seedlings of loblolly (Pinus taeda L.), Virginina (P. virginiana Mill.), and eastern white (P. strobus L.) pines were planted on a flat bench site (Site I) and a site returned to approximate original contour (Site I1). Seedlings were artificially inoculated with Pisolithus tinctorius ((Pers.) Coker and Couch), fertilized with slow-release fertilizer pellets at time of planting and broadcast with N fertilizer prior to the fourth growing season, and the ground cover around them was controlled with herbicides through the third growing season. Survival and growth of these seedlings after the first and second growing seasons were reported by Schoenholtz and Burger (1984). The response of these pines to treatments at the end of the third and fifth growing seasons were evaluated in this study. Treatment effects on foliar nutrient levels and soil properties were also examined. At the end of five years, loblolly and Virginia pines have been successfully established and are performing as well as trees in stands growing don natural soils in the southeastern U.S. Eastern white pine grows slowly the first three years and was just beginning to exhibit a response to treatment. Ground-cover control had the greatest effect on loblolly pine volume-index and elicited as much as an 86% increase in volume-index at the end of five growing seasons. Volume-index of Virginia pine was improved with ground-cover control on Site I and with fertilization on Site II. All species show an additive growth response to the combined treatments. At age five, white pine responded synergistically to combined fertilizer and ground-cover control treatments. The peak response to treatments occurred generally at age two for both loblolly and Virginia pines, while white pine response never peaked. The status of foliar and soil nutrients corroborated the importance of these cultural treatments in improving growth. Negative relationships between volume-index and foliar N and mineralizable N showed that N was not limiting pine growth at this time. Mature stands of serecia lespedeza may have supplied adequate N. A positive relationship between white pine volume-index and foliar P levels suggested that insufficient P may have limited growth of this species. As mine soils in this region age, soil P tends to be fixed by Fe-oxides present in the spoil, making competition for low levels of available-P even greater. Fertilization and ground-cover control will improve tree growth on reforested surface mines by alleviating complex interacting water and nutrient deficiencies. These treatments, implemented during establishment, were still evident at age five, a time that coincides with bond-release eligibility, and response curves suggested that response to treatments will continue as the stands develop. / Master of Science
85

Hydroseeding pine-grass-legume mixtures for erosion control and reforestation of mine spoils

Preve, Ricardo E. January 1983 (has links)
Growth and mycorhizal colonization of surface-seeded pine (Pinus spp.) as affected by two mine-spoil types (siltstone and sandstone), two fertilizer levels (control and 100 kg/ha each of N, P, and K), and three mycorrhizal inoculation treatments (control, 56 kg/ha pine litter, and 250g/ha Pisolithus tinctorius spores) were evaluated in a greenhouse experiment. The effects of four nurse crops and three fertilizer levels on ground cover, spoil erosion, and establishment of hydroseeded pines on a recontoured strip-mine in southwestern Virginia were also studied. In the greenhouse experiment, germination was highest (12, 55, and 34% for P. strobus, P. virginiana, and P. taeda, respectively) in non-fertilized siltstone, but survival was highest (85, 100, and 95% for the same species) in non-fertilized sandstone. Seedlings grown in fertilized sandstone had significantly higher stern and root biomass than those Mycorrhizal in any other inoculation spoil and treatments sandstone but not in siltstone spoil. In the field experiment, use fertilizer combination. were effective in of a nurse crop significantly increased ground cover over the controls, but the addition of a nurse crop or fertilizer resulted in a decrease in pine establishment of at least 46%. The only nurse crop to obtain the minimum 75% ground cover required by law was a Lolium perenne, Festuca rubra, and Lotus corniculatus mixture which, at 60 kg N/ha, reduced spoil erosion by about 70% over the controls while still allowing the establishment of 6,000 trees/ha. / M.S.
86

Vegetational change resulting from forest conversion in the central Piedmont of Virginia and their implications for wildlife

Felix, Antone Costa 24 September 2008 (has links)
Conversion of natural forest to loblolly pine plantations has become a common practice on commercial forest land in the central Piedmont of Virginia. To gain insight as to bow habitat conditions for wildlife vary over time, vegetation composition and structure were quantified in 21 converted stands at two state forests. The stands represented three replications of seven developmental stages ranging in age from 1 to 22 years. Six natural forest stands Which typify sites presently being converted were selected for comparison. The seral process can be exemplified by comparing vegetative changes in species richness, evenness, and vegetative coverage in the ground stratum (<1m). Richness and vegetative coverage showed the same trends: high values in stands 1 to 5 years of age followed by a decline from 5 to 15 years, at Which point canopy closure was complete and these variables were relatively stable for the next seven years. Evenness over time was fairly constant, except for three-rear-old stands where a decline occurred due to predominance by <u>Andropogon virginicus</u>. Trends in richness and evenness differed from the old-field successional model due to a diverse reservoir of propagative units at the initiation of succession and the rapid closure of the canopy by co-developing pines and sprout hardwoods. From an analysis of habitat variables, it appeared that one-year-old stands satisfied requirements of bobwhite quail and wild turkey; stands aged three years were deficient in food plants and probably too densely vegetated. Nine-year-old stands still provided browse for white-tailed deer. Post-canopy closure stands (15 to 22 yrs) were of little value to wildlife. In native forest stands (72 yrs), understory forage production was comparable to the post-canopy closure stands, while mast production, as estimated by Oak basal area and density, was more than adequate for good deer and turkey habitat. The present value of converted stands to wildlife depends on their size and interspersion with native forest and other cover types. Their future value could vary significantly depending on the silvicultural treatments applied. / Master of Science
87

Reforestation Management to Prevent Ecosystem Collapse in Stochastic Deforestation

Chong, Fayu 24 May 2024 (has links)
The increasing rate of deforestation, which began decades ago, has significantly impacted on ecosystem services. In this context, secondary forests have emerged as crucial elements in mitigating environmental degradation and restoration. This study is motivated by the need to understand the reforestation management in secondary forests to prevent irreversible ecosystem damage. We begin by setting the drift and volatility in stochastic primary forests. However, it is more manageable to take control of replantation. We employ a dynamic programing approach, integrating ecological and economic perspectives to assess ecosystem services. To simulate a real-world case, we investigate the model in the Brazil Amazon Basin. Special attention is given to the outcome at the turning point, tipping point, and transition point, considering a critical threshold beyond which recovery becomes implausible. Our findings suggest that reducing tenure costs has advantages, while substitution between primary and secondary forests is not necessarily effective in postponing ecosystem collapse. This research contributes to a broader goal of sustainable forest management and offers strategic guidance for future reforestation initiatives in the Amazon Basin and similar ecosystems worldwide. / Master of Science / Deforestation has been drawing attention from institutions since the 1940s, and this global issue has been discussed for its negative impacts and the ways to restore what has been lost. Reforestation initiatives introduced by global environmental organizations consider forest plantations essential in re-establishing trees and the natural ecosystem. This study aims to investigate how different techniques target the growth of secondary forests to mitigate the irreversible damage of ecosystem services. Our research begins by defining the uncertain primary forests. Primary forests and deforestation face long-term climate changes and immediate shocks like fires, droughts, and human activities, meanwhile, policymakers have difficulties predicting and fully controlling them. We integrate considerations of ecology and economy to the ecosystem functioning, introducing stochasticity in deforestation into our dynamic optimization problem. We apply our models to the Brazil Amazon Basin, a region known for its diverse tropical forests and vast cases of deforestation. We pay close attention to the timing of tipping point that leads to ecosystem collapse, the turning point where reforestation rate catches up with deforestation rate, and the moment of forest type transition. Through simulation and sensitivity analysis, we gain a better grasp on guiding the management of secondary forests under uncertain conditions. Our results indicate that reforestation approaches that lower tenure costs can be beneficial, but merely substituting primary forests cannot necessarily delay an ecosystem collapse. This paper provides practical insights for policymakers, local communities, and international organizations.
88

Two-year Performance of Hybrid and Pure American Chestnut <i>Castanea Dentata</i> (Fagaceae) Seedlings and Benefit of <i>Pisolithus Tinctorius</i> (Sclerodermataceae) on Eastern Ohio Mine Spoil

Herendeen, Robert V. 24 August 2007 (has links)
No description available.
89

Exploring the Feasibility of Economic Incentives for Reforestation in the Fond D’Or Watershed, St. Lucia

Richardson, Amanda 08 October 2008 (has links)
This thesis examines the feasibility of economic incentives for reforestation, with improved water quality being one potential benefit, in the Fond D’or watershed of Saint Lucia. Population growth, economic development, and the onset of climate change have decreased the environmental quality in Small Island Developing State (SIDS) while increasing risk to the islands’ water security. The unique topography and geology of Caribbean island nations contribute to the challenges of managing freshwater resources. The governments of SIDS often lack the human and financial resources to provide potable water for their citizens, as well as to monitor and enforce environmental regulations limiting land use in watersheds. Therefore, a new approach to watershed management in Saint Lucia is imperative for the provision of valuable ecosystem services at the local, regional, and global scales. Payments for ecosystem services (PES) are a promising approach to the protection and maintenance of public ecosystem services where there is little incentive for private landowners to provide them. The first article explores household willingness-to-pay (WTP) for reforestation in Fond D’or watershed. The contingent valuation method was used to obtain residents’ WTP for a hypothetical scenario in which an increase in water users’ fees are used to fund a program where farmers in the upper watershed are compensated for taking land near water sources out of agricultural production for reforestation. The findings from 294 household surveys provide a description of the state of water quality and quantity in the Fond D’or, domestic water uses and sources, as well as attitudes and opinions about current water service. Bivariate analyses were performed to identify underlying factors that influence WTP, revealing that increased WTP is not a result of higher education and income. Rather, residence in a particular community group likely influences opinions about water, ultimately shaping WTP. Lastly, I discuss WTP in terms of its potential contribution to a PES scheme in Saint Lucia; WTP by local beneficiaries represents one potential funding source for PES mechanisms as well as public support for environmental improvement programs. The second article describes a methodological approach to constructing a PES scheme in the Fond D’or watershed. Of the five environmental policy approaches— prescription, penalties, property rights, persuasion, and payments—payment is likely to be the most feasible method to influence private land management decisions for the provision of ecosystem services for the public good. This article draws upon existing PES schemes for hydrological services around the globe to provide key lessons for expanding the use of the instrument to Saint Lucia. I apply these lessons to the social, political, and institutional context of Saint Lucia, identifying opportunities for and challenges to developing local or regional payment schemes for ecosystem services in the Fond D'or watershed. I outline the steps to constructing a PES and recommend further research to Saint Lucian policymakers.
90

Zatravňování, zalesňování a opouštění zemědělské půdy Česka po roce 1990 / Grassing, reforestation and abandonment of agricultural land of Czechia after 1990

Kříž, Jaroslav January 2015 (has links)
Jaroslav KŘÍŽ: Grassing, reforestation and abandonment of agriculture land of Czechia after 1990 The thesis deals with land use changes on the Czech territory, which run from 1990 to the present, focusing on extensification processes, primarily for grassing, reforestation and abandonment of agricultural land. Research will focus on revealing the factors that these processes at the level of individual agricultural parcels influence. Examined are both natural factors (slope, productive capacity of the soil) and socioeconomic factors (distance from settlements and roads, the number of owners of the area, the distance from the area of residence of the owner). Research is carried out in two model areas, which also correspond to the cadastral area. Current data are collected by field survey and then compared to the situation before 1990, which is shown in map sheets of the State Map derived 1: 5000. The natural factors have extensification processes influence both slope and the productive capacity of the soil. For socio- economic factors, especially the number of owners of the area, and the distance between their place of residence. The grassing, reforestation and abandonment of agricultural land also occurs on average smaller areas than those on which there are, for example, arable land, and also in...

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