Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 39 for “"tree rings"”.
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Hydroclimatic Variability in North-central Mongolia as Inferred from Tree Rings
… at fine resolutions. Therefore, networks of tree-ring chronologies are a valuable means of assessing regional and local variability in hydroclimate while placing recent moisture trends in a historical context. Tree-ring data are particularly useful in Mongolia, where instrumental records are …
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Climate analysis using tree-rings from the Wind River Range, Wyoming
1 PDF file (ix, 94 pages)
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Relationships between tree rings and Landsat EVI in the Northeast United States
… activity of vegetation. Networks of tree ring width (TRW) chronologies provide ground-based estimates of annual net carbon (C) uptake in forests, and time series of EVI and TRW may capture common productivity signals. Robust correlations between mean TRW and EVI may enhance spatial …
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Tracking nuclear generating station emissions and fossil fuel contributions using tree rings in southern Ontario, Canada
… in southern Ontario. This study analyzes tree-ring Δ14C (the amount of 14C in a particular sample) as a proxy for atmospheric Δ14C by isolating tree-ring alpha cellulose and using accelerator mass spectrometry (AMS). Results indicate that Δ14C tree-ring signatures from white spruce (Picea …
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Applications of Box-Jenkins methods of time series analysis to the reconstruction of drought from tree rings
The lagged responses of tree-ring indices to annual climatic or hydrologic series are examined in this study. The objectives are to develop methods to analyze the lagged responses of individual tree-ring indices, and to improve upon conventional methods of adjusting for the lag in response in …
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Variation in the Bimodal Precipitation Regime of Southern Nevada, USA Measured in Tree-Ring Isotopes
… of micrometeorology, stable isotopes, and tree rings from an old-growth ponderosa pine (Pinus ponderosa) stand in southern Nevada, USA. We tested if variation in the bimodal precipitation regime could be measured in the stable isotopes of tree rings. Hourly measurements from a …
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Tracking climate signals in tropical trees
… high-resolution palaeoclimate archives, like tree rings or varved lake sediments, provide insights into the natural climate variability of the past, and thus helps improving and validating simulations of future climate changes. Centennial tree-ring stable isotope records | Within this doctoral …
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Stable carbon and oxygen isotope investigation of Pleistocene growing-season paleoclimate using tree-ring cellulose from the Missinaibi Formation, Adam Creek, James Bay Lowland, Canada
The isotopic compositions of cellulose in tree rings provide a record of seasonal and annual climatic conditions such as precipitation and temperature. We analyzed stable isotopes of carbon (δ13Ccellulose) and oxygen (δ18Ocellulose) in early-wood and late-wood of five conifer sub-fossil wood …
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Using dendrochronology to identify species-specific ice storm damage in Delaware
… that alter forest succession and retard tree growth rates throughout North America. Following a 1994 ice storm in Delaware, the Delaware Forest Service established seventy-five study plots to sample four species of trees (southern red oak [Quercus falcate ], white oak [Quercus alba], …
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Tree-ring analysis and stem biomass estimation of limba (Terminalia superba Engl. & Diels) in the framework of sustainable forest management
… tropical forests. The lack of long-term data on tree growth, wood production and carbon stocks hampers the implementation of sustainable forest management and possible financing by Kyoto Protocol related tools like REDD+ and Clean Development Mechanisms. Africa is the continent with the lowest …
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Defining the Regional and Seasonal Climatic Response of Long Douglas-Fir Tree-Ring Chronologies in Central Mexico
… from the distribution of sensitive, long-term tree-ring chronologies across Mexico's complex terrain have made it difficult to model the climate signal of tree-rings in Mexico. The objective of this research is to utilize the improved long-term, high-resolution, gridded instrumental climate …
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Advances in mixture modeling and model based clustering
… series data and show its application to annual tree rings. In the fourth chapter, we utilize the relationship between model-based clustering and the Kmeans algorithm to develop a methodology for merging clusters formed by K-means to find meaningful grouping. The final chapter is dedicated to the …
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Climatic and edaphic influences on the radial growth of eastern redcedar (Juniperus virginiana), Smoke Hole Canyon, West Virginia
The annual variability observed in tree-ring records has been used to reconstruct climate conditions at the local, regional, and global scales. Dendrochronology, the study of tree rings, has typically focused on locations where trees are limited by a single climatic variable (i.e. temperature or …
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Investigation Of The Use And Application Of Passive Sampling Methods For Understanding Potential Sources Of Mercury To Western United States
… we investigated the potential for using tree cores as a long-term record of atmospheric Hg. Tree cores have been applied to understand long-term climate change and as historical monitors for various pollutants. Tree rings were collected at 11 sites spanning the same range as the surrogate …
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EVALUATING THE PERFORMANCE OF BIOMETRIC APPROACHES FOR VERIFICATION AND MONITORING IN COMMERCIAL FOREST CARBON ACCOUNTING
… response to interannual climate variability on tree growth. Here, we performed static carbon baseline scenarios from a forest inventory approach in three flux sites in the Eastern United States. Carbon stock-centric baselines were confronted with flux tower data from those AmeriFlux sites and …
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Modeling nonlinear, nonstationary, vector time series : methods and applications.
… correspond to annual deposits, similar to tree rings. In these same layers, the ratios of carbon-13 isotopes and of oxygen-18 isotopes provide information on the types of vegetation, which in turn, gives information into the climate at the time that vegetation lived. We apply a momentum …
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Is Chir Pine Displacing Banj Oak in the Central Himalaya? Socioeconomic Implications for Local People and the Conservation of Oak Forest Biodiversity
… and the reasons behind it.</p> <p>Analysis of tree rings of chir pine indicated a positive cool season precipitation response in earlywood and a negative response to warm season precipitation in latewood, which indicate that an increase in summer rainfall associated with anthropogenic climate …
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Development of soil lead and tree-ring methods for characterizing atmospheric deposition gradients and subsequent tree growth responses
… also examined the effects of acid deposition on tree growth by sampling three tree species (Picea rubens, Liriodendron tulipifera, and Betula alleghaniensis) along spatial gradients of deposition within the eastern United States. By studying tree-rings along the gradient, I was able to examine …
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Radioanglies sklaidos biosferoje tyrimas branduolinės elektrinės aplinkoje /
… from the atmosphere during photosynthesis, tree ring analysis is an effective tool to observe operating conditions of nuclear facilities. Therefore, the main topic of this study was to determine the change in the concentration of 14C created in Ignalina nuclear power plant and compare it to …
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