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1
Holmström, Hampus. "Data acquisition for forestry planning by remote sensing based sample plot imputation /." Umeå : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2001. http://epsilon.slu.se/avh/2001/91-576-6086-7.pdf.
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Figuera, Dilcia. "FACET Simulation in the Imataca Forest Reserve, Venezuela: Permanent Plot Data and Spatial Analysis." Thesis, University of North Texas, 2006. https://digital.library.unt.edu/ark:/67531/metadc5282/.
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Tree diameter data from 29 years of observations in six permanent plots was used to calculate the growth rate parameter of the FACET gap model for 39 species in the Imataca forests in Venezuela. The compound topographic index was used as a measure of differential soil water conditions and was calculated using geographic information systems. Growth rate values and topographic conditions typical of hill and valley were input to FACET to simulate dynamics at the species level and by ecological and functional groups. Species shade-tolerance led to expected successional patterns. Drought-tolerant/saturation-intolerant species grew in the hills whereas drought-intolerant/saturation-tolerant species occurred in the valleys. The results help to understand forest composition in the future and provide guidance to forest management practices.
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Bhandari, Rajendra Man Singh Sansanee Choowaew. "Applying adaptive community forest management in Nepal : Silviculture demonstration plot perspective : a case study of Nureni Chisapani Community Forest user group, Makwanpur, Central Nepal /." Abstract, 2007. http://mulinet3.li.mahidol.ac.th/thesis/2550/cd398/4837458.pdf.
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Popescu, Sorin Cristian. "Estimating Plot-Level Forest Biophysical Parameters Using Small-Footprint Airborne Lidar Measurements." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/27109.
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The main study objective was to develop robust processing and analysis techniques to facilitate the use of small-footprint lidar data for estimating forest biophysical parameters measuring individual trees identifiable on the three-dimensional lidar surface. This study derived the digital terrain model from lidar data using an iterative slope-based algorithm and developed processing methods for directly measuring tree height, crown diameter, and stand density. The lidar system used for this study recorded up to four returns per pulse, with an average footprint of 0.65 m and an average distance between laser shots of 0.7 m. The lidar data set was acquired over deciduous, coniferous, and mixed stands of varying age classes and settings typical of the southeastern United States (37° 25' N, 78° 41' W). Lidar processing techniques for identifying and measuring individual trees included data fusion with multispectral optical data and local filtering with both square and circular windows of variable size. The window size was based on canopy height and forest type. The crown diameter was calculated as the average of two values measured along two perpendicular directions from the location of each tree top, by fitting a four-degree polynomial on both profiles. The ground-truth plot design followed the U.S. National Forest Inventory and Analysis (FIA) field data layout. The lidar-derived tree measurements were used with regression models and cross-validation to estimate plot level field inventory data, including volume, basal area, and biomass. FIA subplots of 0.017 ha each were pooled together in two categories, deciduous trees and pines. For the pine plots, lidar measurements explained 97% of the variance associated with the mean height of dominant trees. For deciduous plots, regression models explained 79% of the mean height variance for dominant trees. Results for estimating crown diameter were similar for both pines and deciduous trees, with R2 values of 0.62-0.63 for the dominant trees. R2 values for estimating biomass were 0.82 for pines (RMSE 29 Mg/ha) and 0.32 for deciduous (RMSE 44 Mg/ha). Overall, plot level tree height and crown diameter calculated from individual tree lidar measurements were particularly important in contributing to model fit and prediction of forest volume and biomass.<br>Ph. D.
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Kribel, Jacob Robert George. "Long Term Permanent Vegetation Plot Studies in the Matoaka Woods, Williamsburg, Virginia : Establishment and Initial Data Analysis of Plots Established with the North Carolina Vegetation Survey Protocol, Resampling of Single Circular Plots and a Comparison of Results from North Carolina Vegetation Survey Protocol and Single Circular Plot Methods." W&M ScholarWorks, 2003. https://scholarworks.wm.edu/etd/1539624378.
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Kho, Lip Khoon. "Carbon cycling in a Bornean tropical forest : exploring carbon allocation and cycling of tropical forest in the 52-ha Lambir Hills forest dynamics plot." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:bfa1f206-97bf-4bcd-a148-521506225c90.
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The tropical forests on the island of Borneo are among of the richest in the world in terms of tree diversity, and their capacity to store a large reservoir of carbon. The Southeast Asian forests are fundamentally different from Neotropical and African forests, with their single-family dominance by dipterocarp trees, and with inherently greater stature and biomass. The carbon productivity and allocation in Asian tropical forests is still poorly quantified, and their responses to environmental drivers are still poorly understood. Almost all recent advances in tropical forest carbon cycling research have occurred in the Neotropics, with very few studies in Asia. The principal aim of this thesis is to quantify the carbon budget of a lowland dipterocarp forest in the Lambir Hills National Park, Miri, Sarawak, Malaysian Borneo. I examined and explored the productivity and carbon cycling processes and their responses to environmental factors across two major and contrasting soil types, in particular the clay and sandy loam soils. I recorded and analysed the Net Primary Productivity (NPP) and respiration for the above- and below-ground components, and observed the responses to seasonal variation and environmental drivers. Total soil respiration was relatively high and contributed a great deal to ecosystem respiration. Variation in soil respiration rates appeared closely related to soil moisture content. I found a strong diurnal cycle in soil respiration. On the basis of the first soil carbon dioxide (CO2) efflux partitioning study undertaken in a tropical forest, the diurnal cycle in total soil respiration appeared to be entirely driven by the diurnal cycle in litter respiration, and in turn litter is strongly controlled by moisture. There was little seasonal variation in allocation of net primary productivity (NPP), but there was evidence showing potential inter-annual variability for several components of NPP. Further, the allocation of NPP showed a strong seasonal shift between the forest plots on clay and sandy loam soils. Combining all the data measured and obtained in this D.Phil. thesis, the overall carbon budget assessed in this lowland dipterocarp forest showed a high level of agreement with other studies in Asia using micrometeorological techniques and the situation appears to be comparable to tropical forests in Amazonia. The key difference is that the aboveground NPP is higher and is the largest component contributing to the overall carbon budget, with relatively higher carbon use efficiency (CUE). The lowland dipterocarp forest in Lambir shows higher allocation in the above-ground NPP, and there were also differences in NPP and its allocation between sandy and clay-rich plots.
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Romero-Saltos, Hugo G. "Community and Functional Ecology of Lianas in the Yasuní Forest Dynamics Plot, Amazonian Ecuador." Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_dissertations/529.
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I studied the community of lianas in the Yasuní Forest Dynamics Plot (YFDP), in Amazonian Ecuador. I found that species diversity of lianas in valley habitat was higher than in ridge habitat, but liana abundance was similar. I also found that community structure (species composition and their abundances) of lianas in ridge was distinct from that in valley because of the differential distribution and abundance of certain species along the topographic gradient. In an attempt to explain this phenomenon deterministically, I took two approaches: (1) to explore if trait expression of leaf-based traits, wood specific gravity and stem growth rate was different among species with ridge habitat association, species with valley habitat association, and generalist species; and (2) to explore if frequencies of different whole-plant growth strategies in the forest understory—defined by whether a liana was free-standing or already climbing, by its climbing mechanism, and by its understory appearance—were different between ridge and valley. My underlying rationale was that if certain trait expression or understory growth strategy can be associated to a given species, or group of species, and such species also drive the community structure difference between ridge and valley, then ecological insight on the biological deterministic mechanisms driving the difference can be gained. I end this one-page dissertation abstract right here and purposely leave you, the reader, perplexed—I invite you to seek answers to the liana distribution conundrum in the YFDP by perusing this dissertation.
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Sakabe, Ayaka. "Methane dynamics in a temperate forest revealed by plot-scale and ecosystem-scale flux measurements." Kyoto University, 2015. http://hdl.handle.net/2433/199353.
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Kyoto University (京都大学)<br>0048<br>新制・課程博士<br>博士(農学)<br>甲第19029号<br>農博第2107号<br>新制||農||1030(附属図書館)<br>学位論文||H27||N4911(農学部図書室)<br>31980<br>京都大学大学院農学研究科地域環境科学専攻<br>(主査)教授 谷 誠, 教授 北山 兼弘, 教授 川島 茂人<br>学位規則第4条第1項該当
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Bishop, Brian David. "Classification of Plot-Level Fire-Caused Tree Mortality in a Redwood Forest Using Digital Orthophotography and Lidar." DigitalCommons@CalPoly, 2014. https://digitalcommons.calpoly.edu/theses/1171.
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Swanton Pacific Ranch is an approximately 1,300 ha working ranch and forest in northern Santa Cruz County, California, managed by California Polytechnic State University, San Luis Obispo (Cal Poly). On August 12, 2009, the Lockheed Fire burned 300 ha of forestland, 51% of the forested area on the property, with variable fire intensity and mortality. This study used existing inventory data from 47 permanent 0.08 ha (1/5 ac) plots to compare the accuracy of classifying mortality resulting from the fire using digital multispectral imagery and LiDAR. The percent mortality of trees at least 25.4 cm (10”) DBH was aggregated to three classes (0-25, 25-50, and 50-100%). Three separate Classification Analysis and Regression Tree (CART) models were created to classify plot mortality. The first used the best imagery predictor variable of those considered, the Normalized Difference Vegetation Index (NDVI) calculated from 2010 National Agricultural Imagery Program (NAIP) aerial imagery, with shadowed pixel values adjusted, and non-canopy pixels removed. The second used the same NDVI in combination with selected variables from post-fire LiDAR data collected in 2010. The third used the same NDVI in combination with selected variables from differenced LiDAR data calculated using post-fire LiDAR and pre-fire LiDAR collected in 2008. The imagery alone was 74% accurate; the imagery and post-fire LiDAR model was 85% accurate, while the imagery and differenced LiDAR model was 83% accurate. These findings indicate that remote sensing data can accurately estimate post-fire mortality, and that the addition of LiDAR data to imagery may yield only modest improvement.
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Xia, Binyan. "How to Present Statistical Comparisons between Swedish Hospitals and Counties." Thesis, Uppsala universitet, Statistiska institutionen, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-154805.
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Background The Swedish Association of local authorities and regions in collaboration with the national board of health and welfare produces the yearly “Swedish Health Care Report” in order to provide evaluations of the hospitals and counties in Sweden for both the politicians and the general public. Method We describe several standard methods which have been used to present the performance of each hospital or county: Forest plot (FL), League Table (LT), League Plot (LP) and Funnel Plot (FP). Using simulation technique to produce the League Plot of rank is also presented in order to illustrate the unreliable of the ranking principle. Results The league plot with confidence interval is easily understood by people, but it should provide the total number of operations (sample size) as well. The resulting multiple-indicators system gives a clear overview of the whole system, but the cut-off points used in the traffic light method is not the best choice. Several possible improved methodologies are: A league plot traffic light method and a standard funnel plot traffic light method is recommended when aiming at finding the outliers; A p=0.67 funnel plot traffic light method is suggested when wishing to divide the units into approximately equally large groups; A one-side traffic light method seems to be a wonderful choice when focusing on the bad performance units.
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Furniss, Tucker J. "The Utah Forest Dynamics Plot: Long-Term Ecological Monitoring and Theoretical Ecology in a High-Elevation Subalpine Environment." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/5193.
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The Unified Neutral Theory of Biodiversity has been advanced as a universal theory for species coexistence in forests worldwide, but few studies have examined its relevance to high-elevation, stressful environments. I established the Utah Forest Dynamics Plot (UFDP) in a heterogeneous subalpine forest at 3,091 m elevation on the Colorado Plateau to examine three underlying assumptions of neutral theory (functional equivalence, ecological equivalence, and habitat generality) and one prediction (the species abundance distribution). The UFDP comprises 27,845 stems ≥1 cm diameter at breast height of 17 species, 10 genera, and 6 families over 13.6 ha. The neutral model was a poor fit to the observed species abundance distribution, but I did not find the alternative lognormal model to provide a better fit. Using spatial pattern analyses of tree data, topography, and soil type, I found some limited support for the neutral theory assumptions of functional and ecological equivalency, with notable exceptions. Populus tremuloides, Pinus flexilis, and Pinus longaeva were characterized by non-neutral recruitment processes, and Abies bifolia and Populus tremuloides exhibited asymmetric competitive and facilitative interactions. The assumption of habitat generality was strongly contradicted, with all ten abundant species in the UFDP having habitat preference. In this subalpine temperate forest, species diversity and community structure are influenced more by habitat heterogeneity, species differences, and niche selection, with neutral processes playing a lesser role.
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Hogan, James Aaron. "Revisiting the Relative Roles of Land-Use and the Environment in Subtropical Wet Forest| 21-years of Dynamics from the Luquillo Forest Dynamics Plot, Puerto Rico." Thesis, University of Puerto Rico, Rio Piedras (Puerto Rico), 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1595301.
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<p> The Luquillo Forest Dynamics Plot (LFDP) has played a critical role in the initial discovery and subsequent investigation of many processes that govern tropical island wet forest dynamics. Previous work has identified past land use as the main factor in creating forest community compositional and structural differences across the plot. The responses of different species to past land-use intensity and to hurricane disturbances have created an evolving forest mosaic ideal for studying tropical forest successional dynamics. I revisited the interaction of land-use legacies and natural disturbance in the LFDP with new data and new approaches, with the motivation to reveal new information about the relative roles of anthropogenic disturbance and environmental-niche partitioning on tropical plant communities over time. </p><p> In the context of tropical forests and their successional dynamics, I asked how succession resulting from a history of human land use and more recent hurricanes interacts with background environmental variation to effect community structure and diversity. Community dynamics, in terms of forest structure and composition, were summarized over a twenty-one year period, noticing a decreasing trend in species richness over time and structural maturation of the forest, shown by a decline in small stems (trees < 10 cm diameter) as it recovered from the compound effect of two major hurricane disturbances – Hugo, 1989 and Georges, 1998. We evaluate the magnitude of past human land use effects over time and define indicator species for areas of differing land-use pressure within the 16-Ha permanent LFDP. Using redundancy analysis, plant community-environmental relationships with respect to soils and topography are quantified. Spatial variables, computed using a principle coordinates of neighborhood matrix, explained the majority of the variability in plant community composition between areas of high and low past land-use within the LFDP, meaning environmental differences (e.g. niche differentiation among tree species) were found to be secondary to land-use legacies in determining forest community composition. </p><p> Over two decades, the effect of past land-use peaked about 15-years following the first of two hurricanes, and remained relative stable over time. Despite damaging the forest, hurricanes preserved community differences in species composition and reinforced structural asymmetries due primarily to two species; <i> Dacryodes excels</i> Vahl., a dominant primary forest tree species, and <i> Casearia arborea</i> (Rich.) Urb., an abundant secondary forest species. Abiotic environmental factors (e.g. soil resources and topographic variation) were weak at explaining differences in forest community composition. Plant community-environmental relationships were stronger in more anthropogenically-disturbed areas, suggesting long-term effects of land use on tropical forest communities on current community dynamics.</p>
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Sherlock, Mark David. "Plot-scale hydrometric and tracer characterisation of soil water flow in two tropical rain forest catchments in Southeast Asia." Thesis, Lancaster University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387444.
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This research has endeavoured to characterise soil water flow vectors across a distribution of plots within two undistributed tropical rain forest catchments in Southeast Asia. The research focused on the potentially contrasting flow pathways through two different soil types: the Ferric Acrisol of the Jungle Falls catchment (Singapore), and the Haplic Alisol of the W8S5 catchment (Sabah, Malaysia). The research also sought to determine the uncertainty associated with the flow characterisation methodologies. Flow pathways were determined using two quite separate techniques within each experimental plot. A traditional Darcy-approach (i.e. use of the Darcy-Buckingham equation) was used in combination with an artificial tracer approach, to determine if sound flow predictions can be made from local measurements of hydraulic conductivity and capillary potential. Analysis of the results indicates that the flow pathways within the two soils contrasted markedly. Tracer evidence suggests that soil water movement within the Ferric Acrisol (Jungle Falls catchment) was predominantly vertical. In the Haplic Alisol (W8S5 catchment), the dominant flow pathway of the tracer was laterally though A and B1 horizons. Often rapid tracer breakthrough velocities were observed, which exceeded the measured soil saturated hydraulic conductivity by several orders of magnitude. This infers the macropores are an important flow route within both the Ferri Acrisol and the Haplic Alisol. In general, the Darcy-based approach failed to predict the velocity and dominant pattern of the tracer flows. This resulted from problems associated with the measurement of the soil parameters needed to solve the Darcy-Buckingham equation. Uncertainty analysis of the measurement and empirical techniques used to derive the Darcy-Buckingham equation parameters indicated that there is serious potential for error, particularly in the derivation of saturated hydraulic conductivity.
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Karfakis, Theodoros. "Amazonian forest functional composition and resilience to sellective logging : an enquiry using permanent sample plot data and computer simulation models." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/31410.
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This study set out to explore the hypothesis that previously undisturbed Amazonian terra firme (non-flooded) tropical forests show a gradient in resilience to selective logging as a function of tree species functional composition and in particular a positive relation with the presence of a specific ecological guild regarded as intermediate in the process of ecological succession known as the light hardwoods (LHW's). Field data came from the Manaus and Tapajos regions in Brazil and the Puerto Maldonado region in Peru. In response to drought stress induced canopy opening which is the natural disturbance analogue to selective logging, there was a significantly better performance in terms of turnover (diameter growth, mortality and recruitment) of the LHW's relative to climax species. Inresponse to selective logging trees growing within logging gaps showed a similar growth performance gradient 3 years after logging when species ecological guild was not taken under account. In series simulation experiments where conducted to determine actual stand levelcompositional and biomass responses to logging. Forest dynamics models in the SYMFORframework were used to conduct simulations of the most common logging practices. Results indicated that functional composition deviation from undisturbed forest showed a positive relation with resilience with LHW's proportions but only up to a certain threshold. Above this their proportion was positively related with deviation from primary forest conditions and therefore negatively related to resilience. A similar pattern was observed for stand basal area with intermediate sites showing the greatest resilience. For sites with low and medium proportions the opposite pattern was observed with sites of highest proportions showing the second greatest resilience followed by sites with lowest. This study indicates that there is a positive correlation between proportions of LHW trees in a forest stand and resilience to selective logging as currently practiced in the Brazilian Amazon but only up to a certain compositional threshold in functional composition.
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Leeson, Ryan Elizabeth. "Interactions between white-tailed deer and vegetation in southern Illinois." OpenSIUC, 2018. https://opensiuc.lib.siu.edu/theses/2314.
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White-tailed deer (Odocoileus virginianus) have considerable impacts on woody and herbaceous vegetation. Many oak-hickory forests in the eastern U.S. are experiencing a lack of oak (Quercus) and hickory (Carya) regeneration, with deer being a likely culprit. Furthermore, few have studied deer use of different herbaceous food plot mixtures. I addressed these gaps in the literature by assessing deer impacts on forest and herbaceous vegetation in southern Illinois. I established 150 paired plots (enclosed and control) in June 2015 and measured 25 habitat variables to assess impacts of deer herbivory from August 2015 to August 2016. Oak seedlings were present more often and in higher numbers within enclosed plots (F1,299 = 6.25, P < 0.050 and F1,387 = 4.50, P < 0.050, respectively). There were no differences in the height of oak seedlings or the presence, number, or height of hickory seedlings in enclosed versus control plots (F1,53 = 0.010, P = 0.938; F1,299 = 0.850, P = 0.357; F1,267 = 1.16, P = 0.282; and F1,15 = 0.030, P = 0.855; respectively). During September-November 2015, I counted and marked fallen acorns within 50 random paired plots; the number of acorns discovered or lost did not differ between enclosed and control plots (F1,94 = 0.310, P = 0.578 and F1,8 = 0.120, P = 0.736, respectively). I suggest managers incorporate potential deer impacts when designing management plans to best encourage oak regeneration. During September-November 2015, I established 16 food plots (half tilled; each 0.05 ha in size), planted to 4 food plot types. I compared Big Tine Buck Brunch, Evolved Harvest Throw & Gro, Antler King No Sweat, and a food plot mixture that I created. I measured deer use via 2 methods: vegetation growth in exclosures versus control (i.e., unfenced) areas and camera traps. Deer used all 4 food plot mixtures (n = 292 – 2,522 pictures/plot over 9 weeks), having a negative impact on mean vegetation height outside of exclosures (F3,1148 = 6.71, P < 0.001). Analysis of camera data indicated that deer did not preferentially use any one food plot mixture over the others (F3,12 = 0.090, P > 0.050). There also was no difference in the proportion of deer pictured in the process of eating within each food plot mixture (F3,12 = 0.592, P > 0.050). I suggest any of these 4 food plot varieties could be planted by a hunter or wildlife manager in the Midwest and observe similar use by deer.
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Storck, Pascal. "Trees, snow, and flooding : an investigation of forest canopy effects on snow accumulation and melt at the plot and watershed scales in the Pacific Northwest /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/10103.
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Goffe, Renan Fischer. "Determinação de tamanhos de parcelas para otimização amostral em remanescentes de florestas nativas em Itatinga-SP." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-29092015-112027/.
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Devido a atual situação de degradação da vegetação remanescente do estado de São Paulo, existe com relativa urgência uma grande necessidade de estudos que apoiem práticas de monitoramento e conservação dos fragmentos florestais para melhor gerenciá-los. Parte destas demandas é referente ao campo de amostragem, um conjunto de técnicas específicas para pesquisas ecológicas, onde a unidade amostral (parcela) é um dos fatores determinantes de sua eficiência. O objetivo deste estudo foi definir e propor o tamanho ideal de parcelas para otimizar o inventário florestal de áreas remanescentes de Floresta Estacional Semidecidual (FES) e de Cerrado (CER), assim como também de Floresta Estacional Semidecidual em processo de regeneração (FESreg). O trabalho foi realizado na Estação Experimental de Ciências Florestais de Itatinga - SP (EECFI/ESALQ/USP), visando à otimização da amostragem para as variáveis diâmetro à altura do peito (DAP), altura total, densidade populacional, área basal, volume total, volume de fuste, volume de galho, biomassa e índices de Shannon, de Simpson e de Riqueza. O delineamento experimental foi realizado com o auxílio de uma grade amostral, na qual foram distribuídas aleatoriamente 15 parcelas de 1.000 m2 cada, sendo cinco repetições em cada uma das três fisionomias florestais estudadas, onde todos os indivíduos com circunferência à altura do peito (CAP) acima de 16 cm foram mensurados e identificados. Cada unidade amostral foi divida em 10 subparcelas, permitindo assim avaliar os tamanhos de 100 m2 (10X10 m), 200 m2 (10x20 m), 300 m2 (10x30 m), 400 m2 (10x40 m e 20x20 m), 500 m2 (10x50 m), 600 m2 (20x30 m), 800 m2 (20x40 m) e 1.000 m2 (20x50 m). Os tratamentos (tamanhos) foram analisados através de análise de variância, métodos da curvatura máxima e esforço amostral. Com base nos resultados, recomenda-se respectivamente para Cerrado, Floresta Estacional Semidecidual e Floresta Estacional Semidecidual em regeneração o uso de parcelas de 200 m2, 200 m2 e 600 m2 para estimar qualquer uma das variáveis dendrométricas ou parcelas de 200 m2 para estimativas apenas de diversidade. Esses resultados são bastante úteis por embasarem uma série de pesquisas ambientais, deste modo, aperfeiçoando operações de inventário florestal para que o processo de amostragem não tenha esforço amostral desnecessário sem prejuízo da precisão.<br>Because of advanced status of degradation of the natural forest of the state of São Paulo, there is a relatively urgent need for the conduction of studies to support monitoring and conservation practices of forest fragments for their better management. Of these needs refers to sampling, with the use specific techniques for ecological research, in which characteristics of the sampling unit is of outmost importance. The objective of this study was to define and propose optimal plot sizes for inventories remnant areas of Semideciduous Forest (FES) and Cerrado (CER), as well as of Semideciduous forest in regeneration process (FESreg). The study was conducted at Estação Experimental de Ciências Florestais de Itatinga - SP (EECFI/ESALQ/USP), aiming to optimize the sampling for the variables diameter at breast height (DBH), total height, density, basal area, wood volume, volume of stem, branch volume, biomass as well as Shannon, Simpson and Richness indexes. The experiment was carried out with the aid of a sampling grid, in which 15 sampling units of 1,000 m2 each were randomly determined, with five replicates in each type of forest five. In each unit, all trees with circumference (girth) at breast height (GBH) above 16 cm were measured and identified. Each unit was divided into 10 subplots, so as to allow the evaluation in areas of 100 m2 (10x10 m), 200 m2 (10x20 m), 300 m2 (10x30 m), 400 m2 (10x40 and 20x20 m), 500 m2 (10x50 m), 600 m2 (20x30 m), 800 m2 (20x40 m) and 1,000 m2 (20x50 m). Treatments (sizes) were analyzed by analysis of variance, maximum curvature methods and sampling effort. The results indicated that for areas of Cerrado, Semideciduous Forest and Semideciduous Forest in regeneration plot sizes of 200 m2, 200 m2 and 600 m2 respectively should be used to estimate any of the dendrometric variables or plot size of 200 m2 should be used for estimates of diversity only. These results are very useful for a number of environmental researches, improving forest inventory operations by preventing unnecessary sampling effort without jeopardizing accuracy.
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Slui, Benjamin Thomas. "The effect of plot co-registration error on the strength of regression between LiDAR canopy metrics and total standing volume in a Pinus radiata forest." Thesis, University of Canterbury. School of Forestry, 2014. http://hdl.handle.net/10092/10460.
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Background: The objective of this study was to verify the effect that plot locational errors, termed plot co-registration errors, have on the strength of regression between LiDAR canopy metrics and the measured total standing volume (TSV) of plots in a Pinus radiata forest.
Methods: A 737 hectare plantation of mature Pinus radiata located in Northern Hawkes Bay was selected for the study. This forest had been measured in a pre-harvest inventory and had aerial LiDAR assessment. The location of plots was verified using a survey-grade GPS. Least square linear regression models were developed to predict TSV from LiDAR canopy metrics for a sample of 204 plots. The regression strength, accuracy and bias was compared for models developed using either the actual (verified) or the incorrect (intended) locations for these plots. The change to the LiDAR canopy metrics after the plot co-registration errors was also established.
Results: The plot co-registration error in the sample ranged from 0.7 m to 70.3 m, with an average linear spatial error of 10.6 m. The plot co-registration errors substantially reduced the strength of regression between LiDAR canopy metrics and TSV, as the model developed from the actual plot locations had an R2 of 44%, while the model developed from the incorrect plot locations had an R2 of 19%. The greatest reductions in model strength occurred when there was less than a 60% overlap between the plots defined by correct and incorrect locations. Higher plot co-registration errors also caused significant changes to the height and density LiDAR canopy metrics that were used in the regression models. The lower percentile elevation LiDAR metrics were more sensitive to plot co- registration errors, compared to higher percentile metrics.
Conclusion: Plot co-registration errors have a significant effect on the strength of regressions formed between TSV and LiDAR canopy metrics. This indicates that accurate measurements of plot locations are necessary to fully utilise LiDAR for inventory purposes in forests of Pinus radiata.
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Pinter, Giselle de Souza Leite. "Estudos de padrões morfológicos de tronco, raízes e casca externa de árvores emergentes e de dossel da floresta ombrófila densa no parque estadual \'Carlos Botelho\', SP." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/41/41132/tde-02022009-154703/.
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Árvores emergentes e de dossel da Floresta Ombrófila Densa Sub-montana de uma Parcela Permanente (10,24ha) no Parque Estadual "Carlos Botelho", SP, foram estudadas e descritas morfologicamente considerando padrões de tronco, raízes e casca externa com a finalidade de auxiliar na identificação de campo. O critério de inclusão (DAP igual ou superior a 48cm) abrangeu 324 indivíduos de 64 espécies pertencentes a 36 famílias. São fornecidas descrições, ilustrações e chave de identificação para as espécies estudadas baseadas em características do tronco à altura do peito e da base; das raízes aparentes e rentes ao tronco; das raízes superficiais; e das texturas da casca externa nas regiões da árvore mencionadas. Considerando que não há uma terminologia padrão para descrição dos caracteres estudados, é proposta aqui uma nomenclatura, além de serem utilizados termos propostos por Torres et al. (1994) e Ribeiro et al. (1999), com adaptações para as variações observadas no local de estudo. O tronco foi diferenciado em cilíndrico ou acanalado, com base reta ou dilatada. As raízes variaram entre digitadas e sapopemas. Foram categorizados 13 padrões básicos de textura da casca externa: liso, áspero, sujo, rugoso, fissurado, fendido, lenticelado, reticulado, com placas, escamoso, laminado, variegado e com depressões. O uso de terminologia padronizada na descrição de características de tronco, raízes e casca permite sua aplicação e comparação com dados de estudos desenvolvidos em diferentes regiões, sendo importante ressaltar sua utilização aliada a outros caracteres da planta para uma identificação mais eficiente.<br>Emergent and canopy trees of lowmontane dense ombrophyllous forest in a permanent plot (10,24ha) in "Carlos Botelho" State Park, SP, were studied and morphologically described. Trunk, roots and outer bark patterns were considered in order to make field identification easier. A total of 324 trees, 64 species and 36 families were included (DAP ≥ 48cm) and analyzed. We provide descriptions, figures and an identification key based on the following features: trunk at breast high; trunk base; apparent roots; superficial roots; and texture of outer bark. Since there is not a standard morphological nomenclature for these patterns, we propose a nomenclature here, besides using those terms proposed by Torres et al. (1994) and Ribeiro et al. (1999) with some adaptations. Trunk are named terete or angular, straight or with an expanded base. Roots are named digitated or buttressed. Thirteen basic patterns of outer bark texture were named: entire, rough, messy, rugose, fissured, cracked, lenticellate, reticulate, flaky, scaly, laminate, variegated and dippled. Using this terminology allows its application and comparison with data from different areas. They should be used with other features, reproductive and vegetative ones, in order to allow a correct identification.
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Pardi, Mariana Meireles. "Espécies Arbustivo-arbóreas em clareiras e micro-sítios de luz em 5,12ha de Floresta de Restinga na Ilha do Cardoso, São Paulo." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-29082007-102348/.
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Estudos da dinâmica de florestas tropicais evidenciam a importância do conhecimento da relação existente entre a luz e a distribuição das espécies para o entendimento da regeneração e manutenção da diversidade dessas comunidades. Para contribuir com este conhecimento para as espécies que ocorrem nas Restingas o presente estudo descreveu a distribuição dos indivíduos arbustivo-arbóreos com DAP maior que 4,8cm em treze categorias indiretas de regime de luz em 5,12 hectares de uma Floresta de Restinga situada na Ilha do Cardoso, Município de Cananéia, SP. Estas categorias correspondem aos diferentes microsítios de luz do mosaico florestal, e são oriundas da combinação entre condições quanto ao tipo ou ausência de cobertura (cobertura decídua, cobertura perenifólia ou a pleno sol) e situações de localização dos indivíduos arbustivoarbóreos na floresta (clareira, sub-bosque, dossel). As espécies amostradas foram classificadas em grupos ecológicos de acordo com a literatura disponível em pioneiras, secundárias iniciais, sub-bosque, clímax e não classificadas para correlação com a distribuição de seus indivíduos nas categorias de luz. Foram amostrados 7.277 indivíduos arbustivo-arbóreos sendo 381 pioneiros distribuídos em 12 espécies, 4.138 secundários iniciais distribuídos em 24 espécies, 48 típicos de sub-bosque distribuídos em duas espécies, 2.133 climáxicos distribuídos em 48 espécies e 577 indivíduos distribuídos em 19 espécies permaneceram sem classificação. Das 105 espécies amostradas, 35 apresentaram uma distribuição preferencial por determinados microsítios de luz. Estes padrões de distribuição encontrados sugeriram que a quantidade de luz que chega ao subbosque das Florestas de Restinga não restringe a ocorrência de espécies pioneiras apenas às clareiras. Para algumas espécies a classificação em grupos ecológicos encontrada na literatura não foi coerente com a distribuição dos indivíduos, tendo sido sugerida uma classificação diferente de acordo com sua ocorrência nessa Floresta de Restinga, que só se confirmará através de repetições deste estudo ao longo do tempo. Foram delimitadas 77 clareiras na área de estudo durante a classificação dos indivíduos nas categorias indiretas de regime de luz, para as quais foram estimadas área, forma, composição de espécies e de indivíduos para análise da distribuição das espécies e grupos ecológicos em seu interior e favorecer futuras comparações com estudos recorrentes na área ou com estudos de regeneração natural. Repetições desse método numa mesma área, ao longo do tempo, e em diferentes áreas da mesma formação florestal proporcionarão o acúmulo de dados não só sobre a distribuição momentânea dos indivíduos, mas da dinâmica dessas florestas, promovendo o conhecimento sobre o comportamento ecológico das espécies e dos padrões de distribuição das mesmas em relação à luz.<br>Tropical Forest dynamics studies elucidate the importance of knowledge about the relationship between light and distribuition of species to understanding the regeneration and diversity mainteinence of these communities. To contribute with this knowledge to Restinga Forest species this study described the distribuition of trees with dbh (diameter at breast high) ≥4,8cm in thirteen (13) indirect light categories, in 5,12ha of a Restinga Forest in Ilha do Cardoso, Cananeia Municipal District, Sao Paulo State. These categories correspond to different light micro-sites within the forest mosaic and are derived of the combination of the type or absence of covery where the individuals can be under of (under decidual trees, under evergreen trees or under intense light) and the position which each individual can ocupy within the forest (gap, understory, canopy). All the species were classified in ecological groups according to available literature into pioneers, early secondary, understory, climax and non-classified to correlation with their individuals distribuition within the light categories. There were sampled 7.277 tree specimens represented by 381 pioneers of 12 different species, 4.138 early secondary of 24 species, 48 understory of 2 species, 2.133 climax of 48 species and 577 non-classified specimens of 19 different species. Among the 105 species sampled, 35 presented preferential distribuition for some light micro-sites. These distribuition patterns suggest that the light quantity reaching the understory doesn't restrict the occurence of pioneer species only to gaps. For some species the classification in ecological groups found in the literature were not coherent with the individuals distribuition and there were been suggested another classification according to its occurence in the Restinga Forest, which will be confirmed only through repetitions of this study among time. There were delimited 77 gaps in the study area during the classification in the indirect light categories, to which there were estimated area, shape, species and individuals compositions to assess the distribuition of species and ecological grups within these gaps and support comparisons with repeated studies in this area and with natural regeneration studies. Recurring studies using this method over the same spot during time or in different areas of the same Forest formation will provide data accumulation not only about the instantaneous distribuition of the specimens, but also about these forests dynamics, promoting the knowledge about the ecological bahaviour of species and about distribuition patterns of these species according to light regimes.
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Zinko, Ursula. "Plants go with the flow : predicting spatial distribution of plant species in the boreal forest." Doctoral thesis, Umeå : Ekologi och geovetenskap, Univ, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-315.
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Lamedica, Silvia. "FORESTE DI AREA TEMPERATA: STRUTTURE E DINAMICHE A CONFRONTO IN POPOLAMENTI VERGINI E LASCIATI A LIBERA EVOLUZIONE." Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3421643.
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A proper understanding of forest stands structure and dynamics is important in order to apply a sustainable forest management. Forest structure analysis studies the interactions between size classes of the trees, age classes, species, the role of natural and human disturbances etc. Those relationships emerge from the interpretation of different data (dbh, height, age, annual increments, deadwood, XY position of each tree in the stand…), which give information in order to assess the organization and functionality of the ecosystem. Time and space are the two main factors in the analysis of forest structure and dynamics. Concerning time, the order of magnitude should be consistent with the generation time of the ecosystems, so in forest analysis we need to carry out long-term research. In this context, permanent plots are essential instruments, since they permit the acquisition of database at regular intervals in long-term projects, which reflect the tendency of ecosystems to change slowly. The spatial scale of these plots should be set in order to catch the trends and dynamics of the vegetation. In particular, surfaces of 1-4 ha are considered large enough to capture the presence of groups and gradients, which are the expression of the ongoing dynamics in the population at a mesoscale level. This work focused on the study of forest spatial structures in some stands which are representative of different forest types with different exploitation regimes. The analyses were conducted in 4 ha permanent plots, located in the Eastern Carpathians (virgin forests) and the Alps (previously managed stands left to natural development). On the plots, all the trees taller than 1.3 m were mapped and for each tree dbh, height, height of lowest living branch, crown radii projection, increment cores, etc. were measured. The main objective was to compare virgin and managed forest, in order to assess the extent of human impact on the structure and dynamics of the latter stands. In general we found that natural areas, without major disturbances, present more complex spatial structures than the previously managed ones, even if sometimes they were left to natural development for some decades. The human impact lead towards a simplification in the stands structure and composition: signs of this impact are the unimodal diameter distributions, random spatial distribution of trees, spatial structures with almost monospecific groups. This homogeneous structure is still evident even after decades since the last human intervention. In the long term we will see if those stands will develop towards more natural structures or if they will tend to maintain their actual structure.<br>Un’appropriata comprensione della struttura e delle dinamiche dei popolamenti è basilare per una gestione forestale sostenibile. Lo studio della struttura dei popolamenti forestali passa attraverso la definizione delle relazioni tra classi dimensionali, età, specie, del ruolo dei disturbi naturali e antropici e così via. Queste relazioni emergono dall’interpretazione di dati di natura diversa (diametro, altezza, età, incrementi annuali, necromassa, posizione di ogni individuo…) che forniscono informazioni differenti ma tutte utili al fine di valutare in misura più o meno approfondita l’organizzazione e le funzionalità dell’ecosistema. Lo studio della struttura e delle dinamiche di un popolamento deve tenere in considerazione due fattori fondamentali: il tempo e lo spazio. Per quanto riguarda il primo, questo deve essere conforme con i tempi generazionali degli ecosistemi studiati e perciò nel nostro caso si parla necessariamente di lungo periodo. La predisposizione di aree di monitoraggio permanente quindi si rivela particolarmente utile ai nostri scopi, in quanto permette di disporre di database per l’acquisizione di dati a intervalli regolari nell’ambito di progetti di lunga durata, che riflettono la tendenza degli ecosistemi ad evolvere lentamente. La scala spaziale di queste aree si dovrebbe calibrare in modo tale da essere sufficiente per
evidenziare le tendenze e dinamiche della vegetazione in esame. In particolare, superfici di 1-4 ha costituiscono un livello di mesoscala sufficiente a cogliere la presenza di gruppi e gradienti che sono molto spesso espressione delle dinamiche in atto nel popolamento. Il presente lavoro si è concentrato sullo studio delle strutture spaziali di popolamenti forestali scelti in base al diverso impatto antropico subito nel corso della loro vita. Le analisi sono state effettuate all’interno di aree di monitoraggio permanente di 4 ha poste in parte in
foreste vergini dei Carpazi Orientali e in parte in popolamenti lasciati a libera evoluzione situati sulle Alpi. In ogni area sono state mappate e misurate tutte le piante con altezza superiore a 1.3 m, rilevando una serie di parametri biometrici (diametro a 1.3 m, altezza, altezza d’inserzione della chioma, proiezioni dei raggi di chioma, prelievo delle carotine legnose, ecc.) utili alla descrizione e al confronto delle strutture spaziali dei diversi popolamenti. In particolare, ci si è concentrati sul confronto tra popolamenti vergini e lasciati a libera evoluzione, per valutare in che misura l’impatto antropico abbia influito sulle strutture e le dinamiche di questi ultimi. In generale si è riscontrato che aree vergini, in assenza di disturbi naturali significativi, si esprimono in strutture spaziali più complesse e articolate rispetto ad analoghe formazioni precedentemente gestite. In quest'ultime, l’impatto antropico ha portato a una semplificazione nella composizione e nella struttura del bosco, che si manifesta, di volta in volta, in distribuzioni diametriche unimodali,distribuzioni spaziali casuali, strutture spaziali per gruppi dalla composizione omogenea. Questa struttura più omogenea è ancora evidente nonostante in alcuni casi siano passati più di quarant’anni dall’ultimo intervento. Sarà interessante approfondire queste dinamiche nel lungo periodo e verificare le traiettorie di sviluppo future, ovvero se tali popolamenti manterranno a lungo l'attuale tipologia o evolveranno verso strutture più naturaliformi.
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Massaro, Renata Alves Meira. "Viabilidade de aplicação da seleção precoce e tamanho de parcelas em testes clonais de Eucalyptus spp. /." Jaboticabal : [s.n.], 2008. http://hdl.handle.net/11449/92656.
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Orientador: Rinaldo Cesar de Paula<br>Banca: Dilermando Perecin<br>Banca: Miguel Luiz Menezes Freitas<br>Resumo: Com o objetivo de avaliar a eficiência da seleção precoce e tamanho ótimo de parcelas em Eucalyptus spp., foram usados dados de dois testes clonais avaliados quanto ao crescimento em altura (ALT), diâmetro à altura do peito (DAP) e volume individual de madeira (VOL) aos 25, 50 e 72 meses de idade. O delineamento experimental nos dois testes clonais foi o de blocos casualizados, com 30 tratamentos (clones), seis repetições, sendo um deles com seis plantas por parcelas (teste clonal 1) e o outro com 10 plantas (teste clonal 2). Foram obtidas as estimativas de coeficiente de determinação genotípico e de correlações genotípicas entre os caracteres nas idades juvenis e na idade de rotação. Para verificar a viabilidade da aplicação da seleção precoce foi simulada a seleção de 30% dos clones nas idades juvenis e na idade de rotação, para cada um dos caracteres e idades avaliadas, obtendo-se as estimativas de ganhos com a seleção direta e indireta. Para verificar o tamanho de parcelas, foi utilizado o coeficiente de repetibilidade calculado através dos métodos: Análise de Variância, dos Componentes Principais e o de Análise Estrutural, os dois últimos calculados através da matriz de correlação. Houve diferenças significativas entre os clones avaliados nos dois experimentos para todos os caracteres e idades. Com os resultados obtidos, recomenda-se a seleção precoce sobre DAP praticada em torno de dois anos de idade. O uso de seis repetições constituídas de pelo menos quatro plantas por parcela e a avaliação em apenas uma idade proporciona coeficiente de determinação superior a 80%.<br>Abstract: Aiming evaluate the Eucalyptus spp. early selection efficiency and optimum size of plots, were used data of height, diameter at breast height and individual wood volume evaluated in two clonal tests at 25, 50, and 72 months old. The experimental design in both clonal tests was randomized blocks, using 30 treatments (clones), 6 replications, at 3.0 x 3.0m spacing and linear plots, and one of them with 6 plants per plot (clonal test 1) and the other with 10 plants (clonal test 2). Variance analysis to each trait and age was done to each experiment. The estimates of genotypic determination coefficient and the correlation between the early and mature age traits were obtained. To check the viability of early selection, was simulated the selection in young and mature age, adopting 30% of selection to each one of the traits and ages evaluated, estimating the gains by the direct and indirect selection. To check the size of plots, we used the repeatability coefficient calculated by the methods: Analysis of Variance, and the Principal Components of Structural Analysis, the last two calculated through the matrix of correlation. There were significant differences among clones evaluated in the two experiments to all traits and ages. From the results obtained is suggested the practice of early selection from 2 years old age to eucalyptus clonal tests. The use of six replications consisting of at least four plants per plot and evaluation at one age provides a coefficient of determination more than 80%.<br>Mestre
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Grigalevičius, Tomas. "Miško plotų didinimo galimybės Kauno apskrityje." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100615_121405-75449.
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Miškų plotas Lietuvoje didėja nuo XX amžiaus vidurio. Mažiausias miškingumas – 19,7% užfiksuotas 1948 metais, 2009 metais siekia 32,9%. Pagal Lietuvos miškingumo didinimo programą per 2004 – 2020 m. laikotarpį bendrą šalies miškingumą planuojama padidinti 3%. Programoje numatytos miško įveisimo apimtys, atsižvelgiant į nenašių ir žemės ūkiui nenaudojamų žemės ūkio naudmenų plotus. Norint efektyviai didinti miškingumą želdinimu arba miško žėlimo skatinimu, būtina atsižvelgti į visą kompleksą aplinkos veiksnių (ekonominių, ekologinių ir socialinių – etnokultūrinių), darančių įtaką miško želdinimui ir žėlimui, želdinių ir žėlinių augimui, būklei ir miško naudojimui mažo našumo, apleistose ir pažeistose žemėse. Planuojant miško plotų didinimą Kauno apskrityje išnagrinėta žemės valstybinės apskaitos duomenys ir išduotų leidimų įveisti mišką žemės ūkio paskirties žemėje apimtys.<br>The forest area of Lithuania has been increasing from the mid-twentieth century. Minimum Forest area - 19.7% recorded in 1948 and in 2009 increased up to 32.9%. According to the Lithuanian forest improvement program through 2004 - 2020 on period, the total forest country is planned to increase by 3%. The program involves the establishment of forest volume, taking into account the low-performing agriculture and farmland quantity. From 652.7 thousand. ha of agricultural land and non-life area of 163.2 thousand. hectare (30-32 performance ratings) has been proposed temporarily to preserve, and 489.5 thousand. ha of forest produce in the future is appropriate. In order to effectively increase the forest afforestation and forestry promotion Iit should be taken into account a whole range of environmental factors (economic, environmental and social - ethnographic), affecting the forest and afforestation, plantations and Zelin on growth, condition and use of low-productivity forests, abandoned and damaged lands.
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Jakubauskaitė, Vita. "Nuosavybės teisių atkūrimas į miško žemę Alytaus apskrityje." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2009. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2009~D_20090603_094403-06443.
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Esminė žemės santykių pertvarka pradėta tik priėmus 1991 m. liepos 25 d. Žemės reformos įstatymą ir 1991 m. rugpjūčio 18 d. Įstatymą “Dėl piliečių nuosavybės teisių į išlikusį nekilnojamąjį turtą atstatymo tvarkos ir sąlygų.
Alytaus apskritis yra pati miškingiausia apskritis Lietuvoje t. p. ši teritorija išsiskiria saugomų teritorijų gausa. Miškų ūkio paskirties žemę Alytaus apskrityje 2008 m. sausio 1 d. duomenimis valdė: 42,83 proc. privatūs miškų savininkai, Nacionalinių parkų valdomos žemės nėra, 55,88 proc. visų apskrities miškų valdė miškų urėdijos, 1,29 proc. valstybinės žemės valdė kiti fiziniai ir juridiniai naudotojai. Per 2004 – 2008 m. laikotarpį privačių miškų ūkio paskirties žemės plotas Lietuvoje kasmet didėjo vidutiniškai po 22713 ha, t.y. 90850 ha per 4 metų laikotarpį, Alytaus apskrityje – po 4548 ha, t.y 18191 ha padidėjo privačių miškų. 2008 m. privatūs miškai sudarė atitinkamai 32 proc. Lietuvoje ir 43 proc. Alytaus apskrityje nuo visų miškų. Skirtingas miškų privatizavimo procentas yra dėl to, kad Alytaus apskrityje didesnius plotus užima valstybiniai parkai ir draustiniai, yra santykinai daugiau valstybinės reikšmės miškų. Atsižvelgiant į Žemės reformos įstatymu sudarytas sąlygas miškų privatizavimui, taip pat į galimybes žemės ūkiui netinkamas naudoti žemes apsodinti mišku bei esant svaiminiam apžėlimui (kas dešimt metų vykdant inventorizaciją yra randama apie 50-70 ha savaime apaugusių miškų),iki žemės reformos pabaigos išliks privačių miškų... [toliau žr. visą tekstą]<br>Adoption of the Law on Land Reform on July 25, 1991 and the Law on the Restoration of the Rights of Ownership of Citizens to the Existing Real Property on August 18, 1991 initiated the beginning of the fundamental reformation of the land relations.
Alytus District is the most forested area in Lithuania. Moreover, this territory is famous for its numerous protected areas. The data available on January 1, 2008 show that 42.83 percent of the forest areas belong to private forest owners. Pursuant to this information, the are no any territories owned by the National Parks; 55.88 % and 1.29 % of all forest lands are forestry-owned and belong to other natural persons and legal entities respectively. Within 2004-2008, the area of privately owned forests showed annual increase by 22713 ha or 90850 ha altogether. Within the period of 4 years, Alytus District expanded its territory by 4548 ha annually (or 18191 ha of privately owned forests). In 2008, the privately owned forests accounted for 32 % and 43% of all forests in Lithuania and Alytus District respectively. These forest privatization results differ because Alytus District is mostly covered by state-owned parks and sanctuaries or state forests. With reference to the forest privatization conditions following the Law on Land Reform and the possibilities to use the non-agricultural lands for forests and in the background of self-vegetation of the areas (valuation surveys carried out every 10 years show that there are about 50-70... [to full text]
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Perkowski, Matthew Paul. "An analysis of the gypsy moth event monitor modified forest vegetation simulator and the stand damage model using empirical long-term measurement plot data from the Appalachian hardwood and the Atlantic Coastal Plain mixed pine-hardwood regions." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5856.
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Thesis (M.S.)--West Virginia University, 2008.<br>Title from document title page. Document formatted into pages; contains ix, 103 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 77-79).
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Jacques, Rochelle R. "Effects of Microstegium vimineum (Trin.) A. Camus (Asian stiltgrass; Poaceae) on native hardwood seedling growth and survival." Ohio : Ohio University, 2007. http://www.ohiolink.edu/etd/view.cgi?ohiou1180715972.
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McDonald, Hannah Beth. "Tree Growth and Spatial Pattern in Two Forest Park Permanent Plots: A Look at Stand Composition and Condition." PDXScholar, 2011. https://pdxscholar.library.pdx.edu/open_access_etds/313.
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In June of 2010, two permanent research plots were established in Forest Park, based on their differing proximities to downtown Portland, Oregon. As part of a long-term ecological research project that seeks to explore the ecological status and human thumbprint on this 5,100 acre forested reserve, the 2010 tree data was investigated for emergent compositional and spatial patterns. Stand composition, tree size, growth rates, and spatial patterns were analyzed, along with ecological and land use histories. Results indicate that the Balch plot, more closely located to the urban center, has different stand composition, condition, and vegetation growth rates, compared to the more rural Miller site. This study supports findings from a study done by Broshot in 2009, where more urban plots demonstrate a different stand composition and recruitment pattern than rural sites. The study is an initial step for exploring questions regarding the ecological status of Forest Park and how land use and disturbance, past and present, shape Portland's forested reserve.
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Markovienė, Lina. "Miško plotų kaita Lietuvos respublikoje." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110614_114324-64753.
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Lietuva yra miškų zonoje, kur natūrali teritorijos būsena yra miškas. Todėl nėra jokios abejonės, kad Lietuvos miškingumas laikui bėgant dėl ūkinės žmogaus veiklos mažėjo. Prieš 200 metų miškai užėmė beveik 40% teritorijos, 1914m. – vos 20%, o 1939 m. – tik 17%. Daug miškų buvo iškirsta antrojo pasaulinio karo metais. Todėl pokario metais iškilo itin svarbus uždavinys plėsti miškų plotus, didinti medžių našumą. Jau 1984 m sausio 1 d. Lietuvos miškingumas buvo 27,9%. Miškuose vyrauja spygliuočiai, jie sudaro 64% visų medynų. Kietųjų lapuočių medynų yra 3,2%, minkštųjų lapuočių – 32,8%. Rajonų miškingumas labai nevienodas. Tai susiję su žemių derlingumu.
Miškai yra vienas svarbiausių Lietuvos gamtos turtų, turinčių didelę ekonominę, socialinę ir ekologinę reikšmę. Šiuo metu miškai užima daugiau kaip 2 milijonus hektarų arba 32,6 procentus Lietuvos Respublikos teritorijos. Pagal Lietuvos miškingumo programą yra numatyta per ateinančius 10 – 11 metų miškingumą Respublikoje padidinti dar bent 3 procentais.
Norint įgyvendinti šį tikslą mišku reikia apželdinti apie 196 tūkst. ha žemės ūkiui ir kitiems tikslams naudotų žemių, t.y. kasmet miškas turi būti įveisiamas arba savaime apželti turi vidutiniškai apie 11 tūkst. ha. Remiantis valstybinės miškų apskaitos, kurią atlieka Valstybinis miškotvarkos institutas, duomenimis, kasmet mišku savaime apželia apie 4-5 tūkst. ha ne miško žemių, todėl iki 2021 m. mišku savaime gali apaugti apie 70 – 90 tūkst. ha žemės ūkio paskirties žemės... [toliau žr. visą tekstą]<br>Lithuania is in a forest area, where the natural state of the territory is forest. Therefore, there is no doubt that over time the Lithuanian forest coverage has been declining for the economic activity of people. 200 years ago forests occupied almost 40% of the area, in 1914 - only 20%, while in 1939 - only 17%. Many areas were disforested during World War II. Therefore, the post-war period faced a crucial challenge to develop forest areas, to increase productivity of trees. Already on January 1st, 1984 Lithuanian forest coverage was 27.9%. Forests are dominated by conifers, they represent 64% of the stands. Solid hardwood stand makes 3.2%, soft deciduous - 32.8%. Districts greatly differ in forest coverage. This is related to the fertility of lands.
Forest is one of Lithuania's most important natural resources with significant economic, social and ecological implications. At present, in Lithuania forests take more than 2 million hectares, or 32.6 percent of the country territory. The program of Lithuanian forest provides the increase of forest cover by at least 3 percent in the next 10-11 year period.
To achieve this goal forest should be planted on about 196 thousand hectares of farm land and land used for other purposes, namely, each year about 11 thousand ha should be planted or naturally overgrown with forest. According to state forestry records, made by the State Forest Institute, about 4-5 thousand ha of non-forest land overgrow with forest of itself annually, so... [to full text]
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Massaro, Renata Alves Meira [UNESP]. "Viabilidade de aplicação da seleção precoce e tamanho de parcelas em testes clonais de Eucalyptus spp." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/92656.
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massaro_ram_me_jabo.pdf: 216510 bytes, checksum: 2763687448a6171d058929194d17b2a2 (MD5)<br>Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Com o objetivo de avaliar a eficiência da seleção precoce e tamanho ótimo de parcelas em Eucalyptus spp., foram usados dados de dois testes clonais avaliados quanto ao crescimento em altura (ALT), diâmetro à altura do peito (DAP) e volume individual de madeira (VOL) aos 25, 50 e 72 meses de idade. O delineamento experimental nos dois testes clonais foi o de blocos casualizados, com 30 tratamentos (clones), seis repetições, sendo um deles com seis plantas por parcelas (teste clonal 1) e o outro com 10 plantas (teste clonal 2). Foram obtidas as estimativas de coeficiente de determinação genotípico e de correlações genotípicas entre os caracteres nas idades juvenis e na idade de rotação. Para verificar a viabilidade da aplicação da seleção precoce foi simulada a seleção de 30% dos clones nas idades juvenis e na idade de rotação, para cada um dos caracteres e idades avaliadas, obtendo-se as estimativas de ganhos com a seleção direta e indireta. Para verificar o tamanho de parcelas, foi utilizado o coeficiente de repetibilidade calculado através dos métodos: Análise de Variância, dos Componentes Principais e o de Análise Estrutural, os dois últimos calculados através da matriz de correlação. Houve diferenças significativas entre os clones avaliados nos dois experimentos para todos os caracteres e idades. Com os resultados obtidos, recomenda-se a seleção precoce sobre DAP praticada em torno de dois anos de idade. O uso de seis repetições constituídas de pelo menos quatro plantas por parcela e a avaliação em apenas uma idade proporciona coeficiente de determinação superior a 80%.<br>Aiming evaluate the Eucalyptus spp. early selection efficiency and optimum size of plots, were used data of height, diameter at breast height and individual wood volume evaluated in two clonal tests at 25, 50, and 72 months old. The experimental design in both clonal tests was randomized blocks, using 30 treatments (clones), 6 replications, at 3.0 x 3.0m spacing and linear plots, and one of them with 6 plants per plot (clonal test 1) and the other with 10 plants (clonal test 2). Variance analysis to each trait and age was done to each experiment. The estimates of genotypic determination coefficient and the correlation between the early and mature age traits were obtained. To check the viability of early selection, was simulated the selection in young and mature age, adopting 30% of selection to each one of the traits and ages evaluated, estimating the gains by the direct and indirect selection. To check the size of plots, we used the repeatability coefficient calculated by the methods: Analysis of Variance, and the Principal Components of Structural Analysis, the last two calculated through the matrix of correlation. There were significant differences among clones evaluated in the two experiments to all traits and ages. From the results obtained is suggested the practice of early selection from 2 years old age to eucalyptus clonal tests. The use of six replications consisting of at least four plants per plot and evaluation at one age provides a coefficient of determination more than 80%.
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Corral, Gavin Richard. "Quantifying and Mapping Spatial Variability in Simulated Forest Plots." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/77887.
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Spatial analysis is of primary importance in forestry. Many factors that affect tree development have spatial components and can be sampled across geographic space. Some examples of spatially structured factors that affect tree growth include soil composition, water availability, and growing space. Our goals for this dissertation were to test the efficacy of spatial analysis tools in a forestry setting and make recommendations for their use. Reliable spatial analysis tools will lead to more effective statistical testing and can lead to useful mapping of spatial patterns.
The data for this project is from simulated even aged loblolly pine stands (Pinus taeda L.). These simulated stands are grown at regular spacing and we impose a range of parameters on the stands to simulate many possible scenarios. In chapter 3 of this dissertation we perform a sensitivity analysis to determine if our methods are suitable for further research and applications. In chapter 4 we perform our analysis on more realistic data generated by a spatially-explicit stand simulator, PTAEDA 4.1.
In chapter 3 we performed a statistical simulation of plantation stands without effects of competition and mortality. We used redundancy analysis (RDA) to quantify spatial variability, partial redundancy analysis (pRDA) to test for spatial dependence, and spatially constrained cluster analysis to map soil productivity. Our results indicated that RDA and pRDA are reliable methods and future evaluation is appropriate. The results from the spatially constrained cluster analysis were less clear. The success or failure of the clustering algorithm could not be disentangled from the success or failure of the selection criterion used to predict the number of clusters. Further investigations should address this concern.
In chapter 4 we used PTAEDA 4.1, a loblolly stand simulator, to simulate a range of site conditions and produce data that we could use for analysis. The results showed that RDA and pRDA were not reliable methods and ready for the field. Spatially constrained cluster analysis performed poorly when more realistic data was used and because of this further use was uncertain. It was clear from the results that levels of variation and spatial pattern complexity of microsites influenced the success rate of the methods. Both RDA and pRDA were less successful with higher levels of variation in the data and with increased spatial pattern complexity.
In chapter 5 we related the coefficient of variation from our simulations in (chapters 3 and 4) to two sets of real plot data, including a clonal set and open pollinated set. We then implemented a spatial analysis of the real plot data. Our spatial analysis results of the two comparable data sets were unaffected by genetic variability indicating that the primary source of variability across plots appears to be soil and other factors, not genetic related.<br>Ph. D.
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Fitzpatrick, Benjamin. "Ultrahigh dimensional variable selection for interpolation of geostatistical data: Case studies in soil carbon modelling." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/112365/1/Benjamin_Fitzpatrick_Thesis.pdf.
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This thesis explores statistical methodologies for predicting maps of soil carbon levels from small numbers of soil core observations. Each of these methods improves the accuracy of the mapping by discovering and exploiting empirical relationships between soil carbon observations and data on large numbers of potentially related environmental characteristics. In tandem, data visualisation techniques are applied in novel ways to represent the roles of the many environmental characteristics used in these models of soil carbon distributions. This thesis also holds relevance beyond soil carbon mapping to the widespread task of leveraging maps of potentially related, ancillary data when predicting maps from point referenced observations.
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Thérien, Guillaume. "Growth prediction of recent permanent sample plots for forest inventory projection." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/31159.
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Permanent sample plots have become the main source of information for estimating models which quantify the dynamic processes of a forest. Fitted models allow for projecting inventories, used to determine timber production and many forest management decisions. The quality of these models is largely dependent on the quality of the information provided by the permanent sample plots. However, the pool of information contained in recent permanent sample plots is limited. Efficient estimation techniques must use all the information available from such plots.
Current estimation techniques can be improved. Existing techniques employed in forestry have failed to recognize the random nature of the individual model characterizing each plot. On the other hand, techniques designed for remeasured entities in other scientific fields do not address particular forestry situations such as the small number of remeasurements or the irregularity of remeasurements. A framework for estimating forestry growth models which recognizes the individuality of each plot and special forestry situations is presented in this dissertation.
The proposed framework is a two-stage estimation technique, in which the growth rate of a permanent sample plot is considered analogous to the interest rate on a bank account. The first stage estimates the growth rate after removing the time effect. The second stage, based on Von Bertalanffy's growth curve, relates growth rate to site index and volume at the beginning of the growing season. The proposed predictor of future growth rates, the "weighted predictor," is a weighted average between the growth rate observed on a plot and the growth rate predicted from the second-stage model. The weighted predictor is then used to compound the current volume of a plot. An estimate of the variance of the prediction can also be computed.<br>Forestry, Faculty of<br>Graduate
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Dölle, Michaela. "From arable field to forest: Long-term studies on permanent plots /." Göttingen, 2008. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000252253.
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Dutch, Janet. "A comparison of denitrification in felled and unfelled plots in a Sitka spruce plantation." Thesis, University of Aberdeen, 1989. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU020972.
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There has been little work done to investigate the importance of denitrification in forest soils. This has been caused by difficulties associated with measurement of the denitrification process and from the assumption that nitrification, and hence also denitrification, was insignificant in acid environments. Nitrification can, however, occur even in the acid conditions found in coniferous forest soils, and is especially important after clear-felling when levels of nitrate in soil and drainage waters are often observed to increase. A potential exists, therefore, for gaseous losses of N <i>via</i> denitrification from such soils. This thesis describes the establishment of a suitable method for measurement of denitrification using the acetylene block technique. This method was used to monitor denitrification losses of N, both as N<SUB>2</SUB> and N<SUB>2</SUB>O, from a peaty-gley soil at Kershope Forest. The total loss of N from the standing forest through denitrification was estimated to be 3.2 kg ha<SUP>-1</SUP> over the year studied. Of this loss, approximately 80% was produced as H<SUB>2</SUB>O. Gaseous loss of N through denitrification represents approximately the same order of magnitude as the N lost from the site <i>via</i> leaching. An adjacent site, clear-felled four years previously, was also monitored for denitrification losses. Although this site was denitrifying at only a slightly greater rate than the standing forest, examination of past records from the site revealed that an estimated 9-40 kg N ha<SUP>-1</SUP>y<SUP>-1</SUP> had been lost in the two years immediately after felling. To assess the factors which controlled denitrification in the field, sub-samples of the soils used for denitrification measurements were analysed for water content, extractable nitrate, and available carbon. None of these factors, however, were found to correlate clearly with the denitrification rate. Further experiments, using laboratory amendments of soil cores, indicated that nitrate concentrations had the greatest effect on denitrification rates, although both the availability of carbon and the aeration status of the soil also affected the rates measured.
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Miranda, Ludmila Pires. "Efeito de borda no invent?rio pr?-corte de um povoamento Eucalyptus sp." UFVJM, 2016. http://acervo.ufvjm.edu.br/jspui/handle/1/1092.
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Previous issue date: 2016<br>Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG)<br>O estudo analisou a influ?ncia de alocar parcelas em diferentes pontos do talh?o com a
finalidade de um invent?rio pr?-corte, utilizando dois arranjos de intensidade amostral e
tamanho de parcela, diferentes m?todos de amostragem (Casual Simples ? ACS ou Sistem?tica
? AS), forma de parcela (retangular ou circular) e localiza??o da parcela no talh?o (borda, borda
e centro e apenas no centro). Foi realizado um censo no talh?o, onde foram mensuradas todas
as circunfer?ncias ? 1,30 metros de altura. A estimativa da altura foi obtida por meio de modelo
hipsom?trico. O ajuste do modelo foi feito com duas bases de dados para detectar a influ?ncia
do efeito de borda na altura das ?rvores: a primeira composta por dados provenientes da ?ltima
medi??o do invent?rio florestal cont?nuo (IFC) realizado no talh?o; a segunda proveniente de
cinquenta ?rvores localizadas na borda do talh?o. Com as equa??es ajustadas, utilizou-se o teste
de identidade de modelo para verificar o efeito de borda na altura. Para definir o efeito de borda
sobre o di?metro ajustou-se a fun??o Weibull de duas formas: 1) para cada uma das 10 primeiras
linhas de borda do talh?o; e 2) fez-se o ajuste das linhas de forma acumulativa, come?ando pela
linha 1 at? a d?cima linha. Conhecendo-se as estimativas dos par?metros, as distribui??es
diam?tricas foram estimadas, tomando como base a frequ?ncia observada da primeira linha de
borda. Para verificar se a distribui??o diam?trica estimada variava conforme adentrava no
talh?o utilizou-se o teste de Kolmogorov-Smirnov, a 95% de probabilidade. Para o ajuste dos
modelos volum?tricos foram usados dados de cubagem de ?rvores-amostra localizadas no
centro do talh?o. Combinando a localiza??o da parcela, m?todo de amostragem, formato da
parcela e arranjo de intensidade amostral e tamanho da parcela, foram simulados 28 cen?rios
de amostragem. A compara??o entre os procedimentos foi utilizando a precis?o e exatid?o. O
resultado do teste de identidade de modelo indicou que h? influ?ncia da borda sobre a altura
das ?rvores. Os testes de Kolmogorov-Smirnov demonstraram n?o haver diferen?a diam?trica
entre as 10 primeiras linhas de borda do talh?o. O modelo volum?trico de Schumacher e Hall
foi o que resultou nas melhores estimativas. Nos procedimentos de amostragem simulados, a
ACS foi mais precisa e eficiente para um arranjo com intensidade amostral maior e parcelas de
tamanho menores, j? a AS foi melhor com intensidade amostral menor e parcelas maiores;
quanto ao formato, tanto circular, quanto retangular obtiveram bons resultados. Em rela??o ?
localiza??o das parcelas no talh?o, os resultados foram mais exatos e precisos quando as
parcelas foram alocadas no centro do talh?o, seguidos das parcelas alocadas na borda e centro
e por fim aquelas alocadas na borda do talh?o.<br>Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016.<br>This study examined the influence of allocating plots at different points of the stand, using two
arrays of sampling intensity and plot size, different methods of sampling (Simple Casual ? ACS
or Systematic Sampling ? AS), plot format (rectangular or circular) and plot location in the
compartment (border, border and center, and only in the center). We performed a census in the
stand, where all circumferences at 1.3 meters above the ground were measured. Height
estimation was through the Hypsometric model. The model fitting was conducted with two
databases to detect the influence of the border effect at different tree heights: the first model
fitting consisted of data from the last measurement of IFC (Continuous Forest Inventory ? IFC)
conducted in the stand; the second one consisted of fifty trees located on the border of the stand.
For the adjusted model, the researcher used a model identity test to determine the effect of the
border on the height. To define the effect of the border on the diameter, the Weibull function
was fitted in two ways: 1) for each one of the first 10 borders in the stand; and 2) for the
adjustment of the lines cumulatively, beginning from the first line to the tenth line. Knowing
the parameters, we estimated diameter distributions, based on the observed frequency of the
first border. To verify if the estimated diameter distribution varied according to the plot, we
used the Kolmogorov-Smirnov test at 95% probability. For the fitting of the volumetric models,
we used cubing data of trees located in the center of the stand. So, combining the location of
the plot, the sampling method, the inventory type and the plot format, we simulated 28 sampling
scenarios. Comparison between procedures was through precision and accuracy. The result of
the model identity test indicated that the border influences tree heights. The Kolmogorov-
Smirnov tests showed no diametric difference between the first 10 border lines of the stand.
The Schumacher and Hall volumetric model was the one that got the best estimates. In the
simulated sampling procedures, ACS was more precise and efficient or an arrangement with
greater sampling intensity and smaller size plots, while AS was better with lower sampling
intensity and larger plots; as the format, either circular, or rectangular achieved good results.
Regarding the location of the plots in the stand, the results were more accurate and precise when
the plots were allocated in the center of the stand, followed by plots allocated on the border and
center and finally those allocated in the stand border.
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Hoalst-Pullen, Nancy. "Soil properties and hydrologic processes in tropical forest dynamics plots of Panama, Ecuador, and Malaysia." Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3337104.
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Urbonavičius, Svajūnas. "Brandžių medynų tūrio nustatymo metodų tikslumo tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2007. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2007~D_20070816_154623-53899.
Full textAbstract:
Darbo objektas - Telšių miškų urėdijos, Žarėnų girininkijos brandūs mišrūs eglės su lapuočiais medynai. Darbo tikslas – nustatyti dažniausiai miško inventorizacijos praktikoje naudojamų tūrio nustatymo metodų tikslumą ir išanalizuoti jį lemiančias priežastis. Darbo metodai – tūrio paklaidų, gautų lyginant medienos tūrius, nustatytus pagal sklypinės miškų inventorizacijos ir biržių atrėžimo ir įvertinimo duomenimis su pagamintos medienos duomenimis, analizė. Darbo rezultatai. Atlikus tų pačių medynų tūrio įvertinimą įvairiais metodais ir visų matavimo rezultatų analizę, paaiškėjo, kad sklypinė miškų inventorizacija tūrį Žarėnų miško masyve vidutiniškai didina 10,2 %, lyginant su ištisiniu medžių apmatavimo metodu. Įvertinę brandžių medynų tūrį, pagal pagamintą medienos produkciją, gauti rezultatai mišriuose eglės medynuose svyruoja nuo -3,0 % iki 9,9 %, bendra paklaida yra 4,9 % didesnė lyginant su ištisiniu medžių matavimo metodu. Raktažodžiai: Sklypinė miškų inventorizacija, ištisinis medžių matavimas, atrankinis medžių matavimas, medynų tūris, paklaidos.<br>OBJECT OF RESEARCH-mature mixed spruce - broadlives forests in Telšiai forest enterprise, Žarėnai forest. AIM OF RESEARCH- to determine the accuracy of most frequently applied methods to rate the volume in the practice of forest inventory and to analyze the causes that influence it. METHODS OF RESEARCH- the analysis of volume errors, got by comparing timber volumes, set according to the data of inventory of forest plots and their delimitation and the data of their evaluation with the data of manufactured timber acceptance. RESULTS OF RESEARCH-after having done the evaluation of the same timber volume using different methods and the analysis of all the results of measurement, it emerged that stand-wise forest inventory increases the volume in the array of Žarėnai forests by 10.2% when compared to the continuous forest measurement. After evaluating the volume of mature trees according to the made timber production the results in mixed fir trees range from -3,0 % to 9,9 %, a common error 4,9 % better compared to the continuous forest measurement.
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Aksamit, Dawn N. "Exotic Invasive Plants on Private Woodlands of Virginia: Effects on forest composition, structure, and wildlife habitat." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/30975.
Full textAbstract:
Exotic invasive plants have become a significant issue in the Southeastern United States for private landowners. These plants possess characteristics that allow for rapid growth and easy adaptation to many growing conditions, often outcompeting native vegetation and altering wildlife habitat, especially in disturbed areas. Disturbance, including access roads, trails, harvest sites, powerline corridors, and fence rows, is common on private land. Private landowners are often left to combat these problems without many monetary or expertise resources that are available to federal lands. Three field sites, each in a different physiographic province in Virginia, were surveyed for exotic invasive populations and sampled with nested overstory, understory, and regeneration plots and wildlife point intercept transects using paired plots during the summers of 2006 and 2007. Species richness of the overstory and understory did differ, but native percent understory cover and sapling density remained unchanged. Tree density and forest basal area were reduced with presence of exotic invasive plants. Regeneration diversity and density decreased in areas of exotic plant invasion. Eastern cottontail habitat suitability increased with the presence of exotic invasive plants. Suitability of habitat for the gray squirrel, downy woodpecker food, black-capped chickadee reproduction, and eastern wild turkey cover declined with the occurrence of exotic invasive plants. Twenty three of thirty seven total invasive plots were within twenty feet of a disturbance area. Continual assessment of impacts will help provide a better understanding of the nature of exotic invasive plants to landowners and may help them to manage and prevent plant invasions.<br>Master of Science
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Gomes, Rahul. "Incorporating Sliding Window-Based Aggregation for Evaluating Topographic Variables in Geographic Information Systems." Diss., North Dakota State University, 2019. https://hdl.handle.net/10365/29913.
Full textAbstract:
The resolution of spatial data has increased over the past decade making them more accurate in depicting landform features. From using a 60m resolution Landsat imagery to resolution close to a meter provided by data from Unmanned Aerial Systems, the number of pixels per area has increased drastically. Topographic features derived from high resolution remote sensing is relevant to measuring agricultural yield. However, conventional algorithms in Geographic Information Systems (GIS) used for processing digital elevation models (DEM) have severe limitations. Typically, 3-by-3 window sizes are used for evaluating the slope, aspect and curvature. Since this window size is very small compared to the resolution of the DEM, they are mostly resampled to a lower resolution to match the size of typical topographic features and decrease processing overheads. This results in low accuracy and limits the predictive ability of any model using such DEM data. In this dissertation, the landform attributes were derived over multiple scales using the concept of sliding window-based aggregation. Using aggregates from previous iteration increases the efficiency from linear to logarithmic thereby addressing scalability issues. The usefulness of DEM-derived topographic features within Random Forest models that predict agricultural yield was examined. The model utilized these derived topographic features and achieved the highest accuracy of 95.31% in predicting Normalized Difference Vegetation Index (NDVI) compared to a 51.89% for window size 3-by-3 in the conventional method. The efficacy of partial dependence plots (PDP) in terms of interpretability was also assessed. This aggregation methodology could serve as a suitable replacement for conventional landform evaluation techniques which mostly rely on reducing the DEM data to a lower resolution prior to data processing.<br>National Science Foundation (Award OIA-1355466)
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Arvidsson, Simon, and Marcus Gullstrand. "Predicting forest strata from point clouds using geometric deep learning." Thesis, Jönköping University, JTH, Avdelningen för datavetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-54155.
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Introduction: Number of strata (NoS) is an informative descriptor of forest structure and is therefore useful in forest management. Collection of NoS as well as other forest properties is performed by fieldworkers and could benefit from automation. Objectives: This study investigates automated prediction of NoS from airborne laser scanned point clouds over Swedish forest plots.Methods: A previously suggested approach of using vertical gap probability is compared through experimentation against the geometric neural network PointNet++ configured for ordinal prediction. For both approaches, the mean accuracy is measured for three datasets: coniferous forest, deciduous forest, and a combination of all forests. Results: PointNet++ displayed a better point performance for two out of three datasets, attaining a top mean accuracy of 46.2%. However only the coniferous subset displayed a statistically significant superiority for PointNet++. Conclusion: This study demonstrates the potential of geometric neural networks for data mining of forest properties. The results show that impediments in the data may need to be addressed for further improvements.
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Beiler, Kevin Jon. "The complex socio-spatial architecture of Rhizopogon spp. mycorrhizal networks in xeric and mesic old-growth interior Douglas-fir forest plots." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/40000.
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Mycorrhizal networks (MNs) can influence tree establishment and resource competition but little is known regarding their underlying architecture in situ. This study examined the socio-spatial architecture of MNs between Rhizopogon spp. genets and interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) trees in an old-growth forest. MN features were contrasted between plots with xeric versus mesic soil moisture regimes as a proxy for changes in site water stress anticipated with climate change. My objectives were to: (1) describe the fine-scale spatial patterns and autecological traits of R. vesiculosus and R. vinicolor mycelia systems and compare these between xeric and mesic plots; (2) describe the spatial patterns and architecture of Rhizopogon spp. MNs at the forest stand scale; (3) contrast MN architectures between phytocentric and mycocentric perspectives and between xeric and mesic plots, and identify critical determinants of MN architectures. Rhizopogon vesiculosus mycelia occurred deeper, were more spatially prolific, and colonized more tree roots than R. vinicolor mycelia. Both species were associated with moist microsites within plots, and had more prolific mycelia in mesic compared to xeric plots. The occurrence of R. vesiculosus shifted in the presence of R. vinicolor towards deeper soil horizons, suggesting competition and foraging strategy are important for niche partitioning between these species. At the forest stand scale, Rhizopogon spp. genets spanned tens of metres and colonized up to 19 trees, but R. vesiculosus genets were larger and linked more trees than R. vinicolor genets. Multiple tree cohorts were linked, with saplings and mature trees sharing the same fungal genets. Across all plots, the physical size of individual trees or fungal genets was positively related to their MN connectivity. This together with size asymmetries among different genets and trees resulted in the self-organization of complex, hierarchical scale-free MN architectures. The MNs appear robust to random perturbations but susceptible to the loss of large trees or fungal genets. No MN structural differences were found between phytocentric and mycocentric models or between xeric versus mesic plots. The pervasive mycelia and extensive MNs formed by these Rhizopogon spp. could influence interior Douglas-fir stand dynamics and resistance to water stress.
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Manogaran, Arun Prasath. "Développement du procédé de soudage par point par implusion magnétique : Assemblage hétérogène Al/Fe." Ecole centrale de Nantes, 2013. http://www.theses.fr/2013ECDN0038.
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Le soudage par impulsion magnétique est un procédé qui permet l'assemblage rapide (en quelques micro secondes) de matériaux similaires ou dissimilaires à l'état solide. Ce procédé consiste à générer des forces de Lorentz dans une pièce conductrice au moyen d'un inducteur parcouru par un courant variable et intense. Pour pouvoir réaliser une soudure il est nécessaire d'accélérer la première pièce afin qu’elle impacte à grande vitesse la seconde. Il faut donc assurer une distance suffisante entre les deux pièces (entrefer) pour permettre cette accélération. Cette technique permet classiquement d'effectuer des soudures de tubes et de tôles à condition de ménager un entrefer entre les deux pièces à assembler. Dans le cadre de cette thèse nous avons développé une nouvelle façon de souder par point deux tôles placées l'une sur l'autre sans entrefer (Magnetic Pulse Spot Welding - MPSW). Pour assurer l’entrefer entre les deux pièces à assembler nous réalisons un pré-emboutissage local appelé plot. Les tôles sont donc en contact l’une sur l’autre avant et après le soudage. Ce procédé permet d'envisager l'assemblage hétérogène de structures automobile par point ou la connexion de batteries entre elles sans chauffage. De nombreux essais et des simulations numérique sur le logiciel comsol multiphysics nous ont permis d’optimiser la géométrie du plot ainsi que celle des inducteurs. L’approche proposée a été validée en utilisant un inducteur en « I » avec une section rectangulaire et un plot rectangulaire pour l’assemblage hétérogène AA1199 / EN 355. La qualité des assemblages a été vérifiée au moyen d’essais de traction / cisaillement (quasi-statique et dynamique), d’essais de fatigue, d’essais en croix et essais de pelage. Toutes les ruptures ont lieu dans le matériau de base (Al) à la périphérie du point de soudure. D’un point de vue métallurgique les soudures sont seines avec une interface en vague caractéristique du MPW. Les observations au MEB et à l’EDX révèlent des couches d’intermétalliques (FeAl3, Fe2Al5) d’épaisseur 2 à 5 microns dans le creux des vagues de l’interface de soudage. Cette nouvelle technique de soudage ouvre de nouvelles possibilités dans le domaine de l’assemblage hétérogène par point<br>Magnetic pulse welding is a rapid process that involves applying high current on an inductor to generate Lorentz forces on to the conductive primary part (flyer). To realize the weld, it is necessary to accelerate the flyer to impact on the secondary stationary part (target) at a very high velocity attained over a certain distance called air gap between the parts. It is typically possible to perform welding of tubes and sheets provided there is an optimized standoff distance between the parts to be welded. As part of our research work, we have developed an innovative approach, Magnetic Pulse Spot Welding that eliminates the delicate task of maintaining the aforementioned air gap between the plates. A local prior stamping in the intended welding location is done on the flyer sheet called “hump” which provides the air gap. The advantage of this process is that the two sheets are always in contact with each other before and after welding. Numerical simulations using COMSOL Multiphysics allowed us to optimize the hump geometry as well as the inductor. The proposed approach was validated using an "I" shaped inductor with a rectangular cross section and a rectangular hump to join AA1199 / EN 355. The weld quality was verified by tensile/shear tests (quasi - static and dynamic), fatigue tests, cross-tension tests and peel tests. All failures occurred on the base material (Al) just along the periphery of the spot weld. From a metallurgical point of view, the weld morphology of the interface shows characteristic waves typical to MPW. The SEM and EDX observations reveal intermetallic layers (FeAl3, Fe2Al5) of thickness 2-5 μm along the wave pockets. This new method opens better prospective with regards to the heterogeneous assembly of Al/Fe
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Marinho, Neto Djalma Aranha. "Argumentos sobre a imortalidade da alma no F?don de Plat?o." Universidade Federal do Rio Grande do Norte, 2003. http://repositorio.ufrn.br:8080/jspui/handle/123456789/16524.
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Previous issue date: 2003-08-08<br>Cette recherche a pour but d ?tudier l immortalit? de l ?me dans le Ph?don de Platon. Le probl?me central consiste dans l affirmation de l immortalit? de l ?me. Pour la justifier, Platon fait une d?monstration dialectique bas?e sur la Th?orie des Formes. La trame des arguments philosophiques articul?s dans ce Dialogue sera mise en dissertation. Ces arguments sont: l argument des contraires, l argument de l Anamnese et l argument sur la cause de la g?n?ration et de la corruption<br>O presente trabalho tem como objetivo o estudo da doutrina da imortalidade da alma no F?don de Plat?o. O problema central reside na afirma??o de ser a alma imortal, para justificar tal afirma??o Plat?o lan?a m?o de uma demonstra??o dial?tica fundamentada na Teoria das Formas ou Id?ias. Ser? posto em disserta??o a trama dos argumentos filos?ficos articulados neste Di?logo, a saber: o argumento dos contr?rios; o argumento da anamnese; o argumento sobre a causa da gera??o e corrup??o
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Machado, Igor Eloi Silva. "Florística, fitossociologia e estimativa de variáveis florestais em um fragmento de cerrado stricto sensu , Gurupi-TO." Universidade Federal do Tocantins, 2018. http://hdl.handle.net/11612/957.
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O bioma Cerrado possui uma rica flora e apresenta alto nível de endemismo. Em relação ao contexto estadual, o Tocantins está situado na zona de transição geográfica entre o Cerrado e Amazônia. O objetivo desta pesquisa foi avaliar a florística, fitossociologia e aplicação de técnicas de amostragem para levantamentos florestais, tais como, tamanho e forma de parcelas, intensidade e processos amostral em uma área de Cerrado stricto senso. Por meio de um censo, em uma área de 6,7 hectares, foram identificados indivíduos arbóreos com limite de inclusão de circunferência a altura do peito (CAP) maior ou igual a 15 cm, assim também tiveram sua altura total medida. Foram amostrados 15.434 indivíduos, pertencentes a 78 espécies, 72 gêneros e 37 famílias das quais predominaram as famílias Myrtaceae e Fabaceae. A densidade total da área e área basal foram, respectivamente, de 2.303 ind.ha-1 e 14,07 m².ha-1. Na área de estudo as espécies que se destacaram em relação aos parâmetros fitossociológicos foram: Myrcia splendens, Astronium fraxinifolium, Magonia pubescens, Qualea parviflora, Protium heptaphyllum, Qualea multiflora, Vatairea macrocarpa, Tachigali aurea e Byrsonima stipulacea. Após essa etapa foram definidas variações das simulações de amostragem, considerando as combinações: dois processos de amostragem, aleatório e sistemático, diferentes tamanhos de parcelas (250, 500, 1000, 1500 m²) e formas (quadrada, retangular e circular) com as diferentes intensidades de amostragem (2,5, 5, 7,5 e 10%) avaliando três variáveis florestais: volume, área basal e número de árvores. De modo geral, o aumento da intensidade amostral apresentou estreita relação com a melhoria das estimativas das variáveis. No entanto, verificou-se que ao utilizar parcelas de 250 m², para as variáveis de interesse, apresentaram tendências de menores valores dos erros amostral e real, ao contrário do que ocorre em parcelas de tamanhos maiores. Portanto, parcelas de 250 m² tendem a captar de forma mais precisa a variação da distribuição espacial das variáveis de interesse, produzindo resultados mais confiáveis do que ao utilizar parcelas de 1.000 e 1.500 m², sob uma mesma intensidade de amostragem. De modo que, utilizando uma intensidade superior a 5%, com parcelas de 250 e 500 m², obteve erro amostral menor que 20%, resultado aceitável para área de matas nativas. Concluindo que, com base no exposto, é recomendável que, para a estimativa de variáveis florestais, sejam utilizadas parcelas pequenas, 250 ou 500 m² e intensidade amostral variável em função dos recursos de tempo e financeiros disponíveis.<br>The Cerrado biome has a rich flora and presents a high level of endemism. In relation to the state context, the Tocantins is situated in the geographical transition zone between the Cerrado and the Amazon. The objective of this research was to evaluate floristic, phytosociology and application of sampling techniques for forest surveys, such as size and shape of plots, intensity and sampling processes in an area of Cerrado stricto senso. Through a census, in an area of 6.7 hectares, arboreal individuals with a limit of inclusion of chest circumference (CAP) greater than or equal to 15 cm were identified, as well as their total height measured. We sampled 15,434 individuals belonging to 78 species, 72 genera and 37 families of which the families Myrtaceae and Fabaceae predominated. The total density of the area and basal area were, respectively, 2,303 ind.ha-1 and 14,07 m².ha-1. In the study area the species that stood out in relation to phytosociological parameters were: Myrcia splendens, Astronium fraxinifolium, Magonia pubescens, Qualea parviflora, Protium heptaphyllum, Qualea multiflora, Vatairea macrocarpa, Tachigali aurea and Byrsonima stipulacea. After this step, variations of the sampling simulations were defined, considering the combinations: two sampling processes, random and systematic, different sizes of plots (250, 500, 1.000, 1.500 m²) and shapes (square, rectangular and circular) with the different sampling intensities (2,5, 5, 7,5 and 10%) evaluating three forest variables: volume, basal area and number of trees. In general, the increase in sample intensity showed a close relationship with the improvement of the estimates of the variables. However, it was verified that when using plots of 250 m², for the variables of interest, they presented tendencies of smaller values of the sampling and real errors, unlike what occurs in plots of larger sizes. Therefore, plots of 250 m² tend to more accurately capture the variation of the spatial distribution of the variables of interest, producing more reliable results than using plots of 1,000 and 1,500 m², under the same sampling intensity. So, using an intensity of more than 5%, with plots of 250 and 500 m², obtained a sampling error of less than 20%, an acceptable result for native forest area. Based on the above, it is recommended that, for the estimation of forest variables, small plots, 250 or 500 m² are used, and the sampling intensity should be as great as the available time and money resources allow
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Dirsė, Vytautas. "Savaiminio medžių atkritimo pušynuose dėsningumų tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2005. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2005~D_20050609_161331-76056.
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There is research of regularity of free tree mortality in various age pine stands, growing in Nbl places in master work. Presented this process’s characteristics- amounts of mortality by the number and volume of the tree. We used absolute and relational parameters of free tree mortality.
An object of work- 20-140 years old pine stands, which is pure, conditionally average growing in Nbl places. Long-time investigation involved pine of the Jonava district and Berezina reserve (Belarus). Information involved free mortality from various literary sources.
Aim- fined a regularity of free tree mortality.
A method of work- Barrel method of forestry research was used in outdoor work’s. Inventory of barrel research was repeated 2-3 times in 4-7 years. Without our got information analyze from barrel research we used a method of met analyze, when various authors information of free tree mortality is united in one based object by the source of literature.
Results of work- Tree mortality research involved 20-140 years old pine, growing in Nbl places. Our investigation and results analysis shows 2-5% trees mortality (per year) registered in pine samplings; 0,3-6% - in mide-aged pine stands; 1-5% - in premature stands; 5-6% trees mortality in mature stands.
Average of size of trees mortality equal: in pine samplings- 4,2 m3/ha per year, in mide-aged stands - 2,7 m3/ha per year, in premature forests - 2,6 m3/ha per year, in mature stands - 2,7 m3/ha per year.
Our appointed average and... [to full text]
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Panitauskaitė, Enrika. "Sumedėjusios augalijos kaita Vištytgirio botaninio-zoologinio draustinio miško aikštėse." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140616_102744-88800.
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Magistro darbe tiriama sumedėjusios augalijos kaita Vištytgirio botaninio-zoologinio draustinio miško aikštėse.
Darbo objektas – miško aikštelės Vištytgirio botaniniame-zoologiniame draustinyje.
Darbo tikslas – nustatyti susidariusiose aikštėse sumedėjusios ir žolinės augalijos kaitą ir įvertinti mikroklimato įtaką Vištytgirio botaniniame-zoologiniame draustinyje.
Darbo metodai – sumedėjusiai augalijai įvertinti naudojama juostinė transekta. Sumedėjusios augalijos žėlinių tankis vertintas iki 50 cm ir virš 50 cm. Žolinės augalijos projekcinis padengimas įvertinamas vizualiai, įvertinama, kokią paviršiaus dalį (procentais) dengia kiekviena žolinių augalų rūšis. Dirvožemio temperatūra ir drėgnumas nustatytas prietaisu „Wet“, o dirvožemio rūgštingumas prietaisu „PMT 3000“. Apšvietimas įvertintas aikštelėse ir po medžių lajomis prietaisu „Hemi View Canopy System“. Taikant sumedėjusios ir žolinės augalijos bei dirvožemio temperatūros, drėgnumo ir rūgštingumo taip pat apšvietimo vertinimo metodus, nustatyta ir įvertinta miško aikščių sumedėjusios augalijos kaita, bei ją įtakojantys mikroklimatiniai veiksniai skirtingo dydžio miško aikštėse.
Darbo rezultatai. Tyrimo metu buvo įvertinta Vištytgirio botaninio-zoologinio draustinio miško aikščių sumedėjusios ir žolinės augalijos rūšinė sudėtis ir gausa. Mažose miško aikštėse nustatytos šešios savaiminukų rūšys, vidutinio dydžio – septynios, didelėse – penkios rūšys. Mažose aikštelėse vyravo šviesos trūkumą pakeliančios, vidutinio... [toliau žr. visą tekstą]<br>Changes in the woody vegetation of clearances in Vištytgitis botanical-zoological reserve are analysed in the work of master science.
Object of the work – forest observation plots in Vištytgiris botanical-zoological rezerve.
Aim of the research – to determine the changes of woody and herbaceous vegetation in stand clearings and to assess the impact of microclimate.
Method of the work – to determine woody vegetation, strip transect was used. The density of woody vegetation was measured up to 50 cm and above 50 cm. Projection coveraged was determined visually. It was determined what surface (in percentage points) is covered by each species of herbaceous plants. Soil temperature and moisture content were determined using device “Wet“ and soil acidity with device “PMT 3000“. Lighting was measured in each plot and under the trees crown using the device “Hemi View Canopy System“. Using woody and herbaceous vegetation and soil temperature, moisture content and acidity as well as lighting assessments methods to identified and evaluated vegetation changes and influencing factors in formed forest clearances.
The results of the work. After the research in Vištytgiris botanical-zoological reserve was evaluated woody and herbaceous vegetation species composition and abundance in forest plots. In small forest plots were determined 6 species of natural regeneration, in medium-sized forest plots – 7 and in large – 5 species. In small plots dominated tree species, which is not demanding to... [to full text]
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Pothrat, Claude. "Effet d'une déformation biomécanique du pied sur la marche : le cas du pied plat dynamique idiopathique de l'enfant." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4101/document.
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Le pied plat valgus dynamique idiopathique est une déformation touchant un grand nombre d’enfants. Il fait l’objet de la plupart des consultations d’orthopédie pédiatrique et donne communément lieu au port d’orthèses plantaires correctives. Le pied étant un segment dont l’architecture lui confère des propriétés de souplesse et de robustesse, une altération de sa structure, en particulier touchant à la forme de la voute plantaire, peut engendrer des modifications de la marche. Les atteintes de cette déformation sont au cœur de beaucoup d’études mais la littérature reste toujours parcellaire et centrée sur quelques variables mesurées sur le membre inférieur. En revanche, s’il est important d’évaluer la déformation localement, la marche reste une coordination de l’ensemble des segments corporels hautement hiérarchisée, dont l’évaluation de la performance nécessite des analyses plus globales. Le travail de cette thèse s’attachera à effectuer une caractérisation de l’effet de la présence d’un pied plat valgus dynamique sur la marche de l’enfant, mêlant des méthodes issues de la biomécanique classique, aux analyses de données et aus théories des systèmes dynamiques non linéaires.Les principaux résultats de ce travail concernent la multiplicité des atteintes biomécanique et les nombreuses modifications que le pied plat valgus dynamique engendre au niveau musculaire et cinématique sur le membre inférieur. Les mouvements intrinsèques du pied s’avèrent refléter particulièrement le défaut de maitrise de la marche à l’échelle du patient. Enfin, le pied s’avèrera jouer un rôle protecteur du centre de masse vis-à-vis du maintien de la stabilité dynamique lors de la marche<br>The pediatric flexible flat foot is a common deformation. It is the reason of most pediatric orthopedic consultations and commonly leads corrective foot orthotics prescription. The specific architecture of the normal foot gives it properties of adaptation, strength and flexibility. Any alteration of its structure, particularly related to the shape of the plantar arch can cause modifications in gait. A lot of studies investigated the effects of this deformation, but are generally centered on a small number of variables, only at the level of the lower limb. However, if the local deformation is important to assess, it is unlikely to represent the complex non-linear coordination of the whole body segments related to gait performance. This thesis aims at characterizing the effect of flexible flat foot on gait in children, from a biomechanical point of view at the lower limb level as well as at the global coordination level, using methods from classicla biomechanics, data analysis and non linear dynamical systems theories.The major outcomes of this work are the multiplicity of biomechanical effects and the numerous changes on muscles activities and kinematics of the lower limb caused by flexible flat foot. The intrinsic foot movements particularly reflect the lack of control of gait at the patient's level. The particular role of the trunk and contralateral leg regarding the specific locomotor pattern of patients will be detailed. Finally, the foot will appear to have a protective role of the center of mass concerning resistance to perturbations and maintaining gait dynamic stability
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Garcin, Laurent. "Techniques de mise en correspondance et détection de changements." Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2004. http://tel.archives-ouvertes.fr/tel-00133078.
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On présentera des techniques de mise en correspondance de divers types d'objets. On s'intéressera dans un premier temps à la mise en correspondance géodésique d'objets qui consiste, par le biais de l'action d'un groupe de déformation sur un ensemble d'objets, à définir une distance géodésique sur la variété riemannienne formée par l'ensemble en question, qui soit invariante par l'action de groupe considérée. Dans un premier temps, on s'intéressera à la mise en correspondance d'images sur lesquelles agissent des difféomorphismes. On en déduira un algorithme que l'on perfectionnera par une stratégie multi échelle. On adaptera cette technique de mise en correspondance géodésique à des objets tels que des points ou des vecteurs grâce à une modélisation de la déformation à base de splines. Enfin, on présentera des techniques de mise en correspondance d'ensembles de primitives avec appariement des primitives une à une.
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Philipossian, Ara, Yasa Sampurno, and Lauren Peckler. "Chemical Mechanical Planarization and Old Italian Violins." MDPI AG, 2018. http://hdl.handle.net/10150/627056.
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Previous studies have shown that spectral analysis based on force data can elucidate fundamental physical phenomena during chemical mechanical planarization (CMP). While it has not been literally described elsewhere, such analysis was partly motivated by modern violinmakers and physicists studying Old Italian violins, who were trying to discover spectral relations to sound quality. In this paper, we draw parallels between violins and CMP as far as functionality and spectral characteristics are concerned. Inspired by the de facto standard of violin testing via hammer strikes on the base edge of a violin's bridge, we introduce for the first time, a mobility plot for the polisher by striking the wafer carrier head of a CMP polisher with a hammer. Results show three independent peaks that can indeed be attributed to the polisher's natural resonance. Extending our study to an actual CMP process, similar to hammered and bowed violin tests, at lower frequencies the hammered and polished mobility peaks are somewhat aligned. At higher frequencies, peak alignment becomes less obvious and the peaks become more isolated and defined in the case of the polished wafer spectrum. Lastly, we introduce another parameter from violin testing known as directivity, , which in our case, we define as the ratio of shear force variance to normal force variance acquired during CMP. Results shows that under identical polishing conditions, increases with the polishing removal rate.