Thesis (M.S. in horticulture)--Washington State University, December 2008. / Title from PDF title page (viewed on Apr. 17, 2009). "Department of Horticulture and Landscape Architecture." Includes bibliographical references.

Thesis (M. A.), Memorial University of Newfoundland, 1999. / Bibliography: p. 337-354.

Thesis (M.A.)--Ohio University, June, 2010. / Title from PDF t.p. Includes bibliographical references.

Efficient and environmentally responsible tree planting is crucial to sustainable land management. Tree planting processes involve significant machinery and labor, impacting efficiency and ecosystem health. In response, Södra Skogsägarna introduced the BraSatt initiative to develop an autonomous planting vehicle called E-Beaver. This vehicle aims to simultaneously address efficiency and ecological concerns by autonomously planting saplings in clear-felled areas. BIT ADDICT, partnering with Södra Skogsägarna, is re- sponsible for developing the control system for E-Beaver’s autonomous navigation and perception.  In this thesis work, we examine the possibility of using the computer vision models YOLO and U-Net for detecting and segmenting newly planted saplings in a clear felled area. We also compare the models’ performances with and without augmenting the dataset to see if that would yield better-performing models. RGB and RGB-D images were gath- ered with the ZED 2i stereo camera. Two different models are presented, one for detecting saplings in RGB images taken with a top-down perspective and the other for segmenting saplings trunks from RGB-D images taken with a side perspective. The purpose of this the- sis work is to be able to use the models for evaluating the plating of newly planted saplings so that autonomous tree planting can be done.  The outcomes of this research showcase that YOLOv8s has great potential in detecting tree saplings from a top-down perspective and the YOLOv8s-seg models in segmenting sapling trunks. The YOLOv8s-seg models performed significantly better on segmenting the trunks compared to U-Net models.  The research contributes insights into using computer vision for efficient and ecologi- cally sound tree planting practices, poised to reshape the future of sustainable land man- agement. / BraSatt

The objective of this study was to develop diameter/basal area increment equations for loblolly pine trees in thinned and unthinned plantations on cutover, site-prepared areas. Results indicated that one set of coefficients was sufficient to estimate individual tree growth (for the three year period following thinning) on lightly thinned and heavily thinned plots. However, unthinned plots required a separate set of coefficients and therefore a separate equation to estimate growth. Diameter growth was adequately explained by some form of the following regressor variables: pine basal area, hardwood basal area, initial age, initial diameter, average height of the dominant and codominant trees, and crown ratio ( optional). Transforming the dependent variable from a function of diameter to a similar function of basal area had no apparent effect on the precision of the predicted results. Two alternative methods of predicting diameter growth were evaluated: (1) direct fitting of diameter growth, and (2) fitting a potential diameter growth equation and a modifier function. Even though the potential times modifier approach performed slightly better in terms of fitting the data, it provided unrealistic results at ages beyond the upper range of the data. After additional data are obtained at older ages, the potential times modifier approach may surpass the direct approach. However, at present, the direct diameter growth model was chosen as the final model form. / M.S.

Kong Hoi-Yeung. / Thesis submitted in: November 2003. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 132-146). / Abstracts in English and Chinese. / Abstract --- p.i / Abstract (in Chinese) --- p.iv / Acknowledgement --- p.v / Table of contents --- p.vii / List of tables --- p.x / List of figures --- p.xi / List of plates --- p.xii / List of appendices --- p.xii / Chapter Chapter one --- Introduction / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Afforestation in Hong Kong --- p.2 / Chapter 1.3 --- Conceptual framework of the study --- p.6 / Chapter 1.4 --- Objectives of the study --- p.13 / Chapter 1.5 --- Scope and significance of the study --- p.14 / Chapter 1.6 --- Organization of the thesis --- p.15 / Chapter Chapter Two --- The Study Area / Chapter 2.1 --- Geographical setting of Hong Kong --- p.17 / Chapter 2.1.1 --- Climate --- p.17 / Chapter 2.1.2 --- Geology --- p.19 / Chapter 2.1.3 --- Soils --- p.20 / Chapter 2.1.4 --- Vegetation --- p.21 / Chapter 2.1.5 --- Characteristics of Lophostemon confertus --- p.23 / Chapter 2.2 --- Site selection --- p.24 / Chapter Chapter Three --- Stand Characteristics of Lophostemon confertus Plantations / Chapter 3.1 --- Introduction --- p.31 / Chapter 3.2 --- Methodology --- p.35 / Chapter 3.2.1 --- Sample plots design --- p.35 / Chapter 3.2.2 --- Tree density --- p.35 / Chapter 3.2.3 --- Tree growth parameters --- p.35 / Chapter 3.2.4 --- Data processing and statistical analysis --- p.36 / Chapter 3.3 --- Results and discussion --- p.37 / Chapter 3.3.1 --- Tree density and mortality rate --- p.37 / Chapter 3.3.2 --- Growth performance of Lophostemon confertus --- p.39 / Chapter 3.3.3 --- Growth rate of Lophostemon confertus in the plantations --- p.41 / Chapter 3.4 --- Conclusion --- p.44 / Chapter Chapter Four --- Soil Characteristics of Lophostemon confertus Plantations / Chapter 4.1 --- Introduction --- p.47 / Chapter 4.2 --- Methodology --- p.51 / Chapter 4.2.1 --- Soil sampling --- p.51 / Chapter 4.2.2 --- Laboratory analysis --- p.52 / Chapter 4.2.3 --- Texture --- p.52 / Chapter 4.2.4 --- Soil pH --- p.53 / Chapter 4.2.5 --- Organic carbon --- p.53 / Chapter 4.2.6 --- Total Kjeldahl Nitrogen (TKN) --- p.53 / Chapter 4.2.7 --- Carbon: Nitrogen ratio --- p.54 / Chapter 4.2.8 --- Mineral nitrogen (NH4-H and N03-N) --- p.54 / Chapter 4.2.9 --- Available phosphorus --- p.55 / Chapter 4.2.10 --- Exchangeable cations --- p.55 / Chapter 4.3 --- Data processing and statistical analysis --- p.55 / Chapter 4.4 --- Results and discussion --- p.56 / Chapter 4.4.1 --- Soil texture --- p.56 / Chapter 4.4.2 --- Effects of Lophostemon confertus plantations on reaction pH --- p.58 / Chapter 4.4.3 --- "Effects of Lophostemon confertus plantations on SOM, TKN and mineral nitrogen" --- p.59 / Chapter 4.4.4 --- Effects of Lophostemon confertus plantations on available P and exchangeable cations --- p.69 / Chapter 4.4.5 --- Effects of Lophostemon confertus plantations on nutrient status of the soils --- p.73 / Chapter 4.5 --- Conclusion --- p.79 / Chapter Chapter Five --- Understorey Vegetation of Lophostemon confertus Plantations / Chapter 5.1 --- Introduction --- p.81 / Chapter 5.2 --- Methodology --- p.85 / Chapter 5.2.1 --- Understorey plant sampling --- p.85 / Chapter 5.2.2 --- Species identification and nomenclature --- p.86 / Chapter 5.2.3 --- Plant growth parameters --- p.87 / Chapter 5.2.4 --- Data processing and statistical analysis --- p.87 / Chapter 5.3 --- Results and discussion --- p.89 / Chapter 5.3.1 --- Floristic composition of the Lophostemon confertus plantations --- p.89 / Chapter 5.3.2 --- "Species richness, diversity and woody abundance of the understorey" --- p.93 / Chapter 5.3.3 --- Species composition and structure of understories --- p.99 / Chapter 5.3.4 --- Dynamics of species establishment in the understorey --- p.109 / Chapter 5.4 --- Conclusion --- p.112 / Chapter Chapter Six --- Conclusion / Chapter 6.1 --- Summary of findings --- p.114 / Chapter 6.2 --- Implications of the study --- p.118 / Chapter 6.2.1 --- Ecological value of Lophostemon confertus plantations in Hong Kong --- p.118 / Chapter 6.2.2 --- Rehabilitation of badland derived from granite --- p.124 / Chapter 6.2.3 --- Management of the existing plantations --- p.126 / Chapter 6.3 --- Limitations of the study --- p.129 / Chapter 6.4 --- Suggestions for future study --- p.130 / References --- p.132 / Appendices --- p.147

Orientador: Jean-Paul Laclau / Coorientador: Iraê Amaral Guerrini / Banca: Christophe Jourdan / Banca: José Leonardo de Moraes Gonçalves / Banca: Ciro Antonio Rosolem / Banca: Jean-Christophe Domec / Resumo: Melhorar nossa compreensão sobre a dinâmica espaço-temporal de raízes finas e dos gases de efeito estufa em camadas profundas do solo é um componente chave para identificar práticas silviculturais mais sustentáveis para florestas plantadas num contexto de mudança climática e para melhorar os atuais modelos biogeoquímicos. Nosso estudo teve como objetivo avaliar o efeito do corte raso e da seca na produção de raízes finas, nos efluxos de CO2, CH4 e N2O do solo e da produção ao longo dos perfis profundos do solo até o lençol freático nas plantações de eucalipto manejadas em talhadia. A raízes finas foram amostradas até 17 m de profundidade num experimento de exclusão de chuva comparando parcelas com 37% de precipitação excluída (-W) e sem exclusão de chuva (+ W). A dinâmica das raízes foi estudada usando minirhizotron em duas trincheiras permanentes até 17 m de profundidade nos tratamentos -W e + W, durante 1 ano antes do corte raso e 2 anos depois do corte em talhadia, e tambem até 4 m de profundidade numa parcela sem corte (NH), servindo como controle. Os efluxos de CO2, CH4 e N2O na superfície do solo foram medidos ao longo de três anos utilizando o método de câmara manual nos tratamentos -W, + W e NH. As concentrações de CO2, CH4 e N2O no solo foram medidas a partir das trincheiras até uma profundidade de 15.5 m nos tratamentos -W, + W e NH durante 3 meses antes do corte raso e 1.5 ano depois em talhadia. Após o corte, ocorreu um grande crescimento radicular das árvores con... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Tree growth is highly dependent on the absorptive function of fine roots for water and nutrients. Fine roots also play a major role in the global carbon (C) cycle, mainly through production, respiration, exudation and decomposition processes. Improving our understanding of the spatiotemporal dynamics of fine roots and greenhouse gases in deep soil layers is a key component to identify more sustainable silvicultural practices for planted forests in a context of climate change and to improve the current biogeochemical models. Our study aimed to assess the effect of clear-cutting and drought on fine-root production, soil CO2, CH4 and N2O effluxes and production throughout deep soil profiles down to the water table in Brazilian coppice-managed Eucalyptus plantations. Fine roots (i.e. diameter < 2 mm) were sampled down to a depth of 17 m in a throughfall exclusion experiment comparing stands with 37% of throughfall excluded by plastic sheets (-W) and stands without rain exclusion (+W). Root dynamics were studied using minirhizotron in two permanent pits down to a depth of 17 m in treatments -W and +W, over 1 year before clear-cutting, then over 2 years in coppice, as well as down to a depth of 4 m in a non-harvested plot (NH) serving as a control. CO2, CH4 and N2O surface effluxes were measured over three years using the closed-chamber method in treatments -W, +W and NH. CO2, CH4 and N2O concentrations in the soil were measured from the pits down to a depth of 15.5 m in treatments -W, +W and NH over 3 months before the clear-cut and 1.5 years after in coppice. After harvesting, spectacular fine root growth of trees conducted in coppice occurred in very deep soil layers (> 13 m) and, surprisingly, root mortality remained extremely low whatever the depth and the treatment. Total fine-root biomass in coppice down to a depth of 17 m was 1266 and 1017 g m-2 in treatments +W and -W, respectively, at 1.5 years a ... / Resume: Améliorer notre compréhension de la dynamique spatio-temporelle des racines fines et des gaz à effet de serre dans les couches profondes du sol est un élément clé pour identifier des pratiques sylvicoles plus durables pour les forêts plantées dans un contexte de changement climatique et pour améliorer les modèles biogéochimiques actuels. Cette étude visait à évaluer l'effet de la coupe des arbres et de la sécheresse sur la production de racines fines et la production de CO2, N2O et CH4 dans des profils de sol très profonds en plantation d'Eucalyptus conduite en taillis au Brésil. Les racines fines, d'un diamètre inférieur à 2 millimètres, ont été échantillonnées jusqu'à une profondeur de 17 m sur un dispositif d'exclusion de pluie comparant des peuplements soumis à une exclusion de 37% des pluies (-W) et des peuplements sans exclusion (+ W). La dynamique des racines a été étudiée à l'aide de minirhizotrons installés dans deux fosses permanentes d'une profondeur de 17 m dans les traitement -W et + W, pendant un an avant la coupe des arbres, puis pendant deux ans en taillis, et jusqu'à 4 m de profondeur dans un peuplement non récolté (NH) servant de témoin. Les efflux de CO2, CH4 et N2O à la surface du sol ont été mesurés durant trois ans dans les traitements -W, + W et NH. Les concentrations en CO2, CH4 et N2O dans le sol ont été mesurées à partir de fosses permanentes jusqu'à une profondeur de 15.5 m dans les traitements -W, + W et NH durant 3 mois avant la coupe des arbres et 1.5 ans après la coupe, en taillis. La croissance des racines fines était considérable à grande profondeur (> 13 m) chez les arbres menés en taillis et, étonnamment, la mortalité des racines fines était extrêmement faible quelle que soit la profondeur et le traitement. La biomasse totale de racines fines jusqu'à 17 m de profondeur était de 1266 et 1017 g ... / Doutor

Thesis (M.S.)--Mississippi State University. Department of Forestry. / Title from title screen. Includes bibliographical references.

Afforestation projects in China have substantially contributed to national CO2 sequestration and play an important role in international climate change mitigation. However, these nation-wide afforestation projects are usually funded by the national government, with very large and unsustainable investments. It is important to find alternative sources of funding to finance afforestation, and convince poor farmers to become involved in afforestation projects. Carbon-subsidized afforestation could be the solution. The current study aims to find i) whether farmers need additional subsidies to reforest their marginal farmland; if so, ii) whether the value of carbon sequestration of afforestation can offset farmers' net costs. To do this, first I determine the amount of carbon sequestration though afforestation. Second, I assess the value of carbon sequestration, the costs and benefits of afforestation projects, and the costs and benefits of crop production. Third, I investigate the optimal rotation period of the plantations considering a joint production of timber and carbon, for different species. Results show that total carbon sequestration through tree biomass and soil carbon following afforestation differs among tree species and stand age as well as across regions. Economic trees sequester less carbon than ecological trees and bamboo. Among economic trees, nut trees with an inedible hard shell sequester more carbon than fruit trees. The regional context significantly influences the carbon sequestration potential, with more carbon sequestered in southern and eastern regions than in northern regions. Bamboo also shows a remarkable carbon sequestration potential, which is even greater than Chinese fir and Poplar in northern regions. Although afforestation programs have huge potential to store carbon, the voluntary acceptance by landowners crucially depends on their economic outcome. I found that usually carbon credits can compensate for the opportunity costs of alternative land uses, except i) when highly profitable croplands are afforested, in which case carbon credits are not sufficient, and ii) when croplands that generates low incomes are afforested, in which case carbon credits are not needed. Fruit trees are the most cost-effective option for afforestation. Bamboo afforestation is economically attractive if carbon revenues is included. The minimum price of carbon credit decreases with increasing project duration because more carbon is stored when time increases. This does not hold for fast-growing trees like Eucalyptus, for which the minimum price increases with extended project duration. Given the temporal variations of joint production of timber and carbon sequestration, the carbon accounting regimes (tCER, temporary Certified Emission Reductions and lCER, long-term Certified Emission Reductions) have a significant impact on the optimal rotation as well as on the revenue. Forest managers have an incentive to use tCER accounting to finance slow-growing plantations, and lCER for fast-growing ones. I perform a sensitivity analysis detects the changes of rotation period with different carbon prices and discount rates. While the optimal decision for slow-growing species (e.g. Chinese fir) is highly sensitive to changes in both variables under tCER accounting, the results concerning fast-growing species (e.g. Eucalyptus) are most sensitive under the lCER accounting regime. In contrast, carbon revenues have a minimal impact on the optimal rotation of Poplar plantations, no matter which regime is applied. I conclude that carbon-subsidized afforestation is a feasible way to offset the opportunity costs of retired farmland and support the livelihood of farmers. The findings can contribute to the efficient and sustainable management of forestry projects using carbon sequestration, while the methodology can also be applied to other regions in the world.

Scholars and civil society organizations have over the last decade referred to large-scale carbon sequestration TPPs as "carbon colonialism" (Carmody and Taylor, 2016) as well as a "development by dispossession" dressed in new clothing behind words such as climate change mitigation and development (Kröger, 2012). Concerns have been raised that the trade-offs from the implementation of industrial tree plantations (ITPs) may result in conflicting effects on countries' overall development (The Oakland Institute, 2019; Osborne, 2015; Nel &amp; Hill, 2013). Moreover, NGO's and think tanks, such as FIAN (2012) and the Oakland Institute (2017, 2019), have released reports in which such tree planting projects are accused of displacing people and violating human rights (FIAN, 2012; The Oakland Institute, 2017, 2019; Carmody &amp; Taylor, 2016).  This thesis explores the impacts of carbon forestry projects, emphasizing the impacts of ITPs on local livelihoods and their subsequent effects on development. Three dimensions have been chosen to limit the scope of this thesis: (1) food security; (2) access to land; and (3) employment &amp; income. The thesis is conducted using a qualitative desk study and secondary analysis of two multiple case studies of Uganda and Mozambique. The findings presented suggest carbon forestry projects may negatively affect all three dimensions, ultimately affecting communities' sustainable development. The author recommends further research to evaluate the complex effects of carbon forestry projects.