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Reconstruction of the Stand-Level Disturbance History of a Temperate Coniferous Forest using LiDAR data and Geographic Object-Based Image Analysis (GEOBIA)
No full textSpatially explicit information on forest stand disturbance history is fundamental to understanding the global carbon cycle and enhancing the modelling of forest ecosystem processes. Forest disturbance records, defined in terms of Time Since Disturbance (TSD), are often incomplete for most forested areas, rarely extending before the Earth Observation satellite record. Although the spectral response of forest vegetation saturates under canopy closure, distinct horizontal and vertical forest structure features remain on the landscape for decades to centuries following a disturbance event. A stand-replacing disturbance is a mortality event (e.g., clearcut, fire, insect outbreak) that, in a short period of time, leads to complete replacement of the trees of an entire forest stand. Past stand-replacing disturbances thus result in even-aged stands, featuring only small age differences in their dominant cohort. They generally have homogenous forest canopies whose current structural development relates to TSD, as well as to the type of disturbance. In the several decades following a stand replacing disturbance, before maturity of the stand is reached and the age distribution becomes uneven, there is a strong linkage between forest structure and stand age which provides a pathway to characterize TSD from remotely sensed data. This dissertation, divided in three chapters, proposes a novel approach to reconstruct the long-term disturbance history of a temperate coniferous forest from active remotely sensed data, that can potentially complement the more established methods based on time series analysis of passive optical remotely sensed data. The methodology uses Geographic Object-Based Image Analysis (GEOBIA) and remotely sensed data from LiDAR (Light Detection and Ranging) instruments to estimate the stand level TSD. GEOBIA enables the delineation of structurally homogenous forest stands, which are used as representative units of analysis; and LiDAR data, sensitive to the three-dimensional structure of the forest canopy, are used to estimate TSD. The study area is in the Nez-Perce Clearwater National Forest (Idaho, USA), where TSD reference maps for a period of more than 140 years, and airborne LiDAR data are available. Chapter 1 proposes a two-stage evaluation strategy to semi-automatically delineate even-aged forest stands using GEOBIA on airborne LiDAR-derived data. GEOBIA has replaced traditional visual photo interpretation for forest stand delineation, but user-defined evaluation protocols are still required to identify objectively optimal delineation outputs. The study demonstrates the ability of LiDAR to discriminate stands harvested more than 50 years ago and proposes an objective and straightforward workflow that can be adapted to other study needs. In chapter 2, airborne LiDAR canopy and topographic metrics are used to estimate TSD at the stand-level using Random Forest (RF) analysis. Results demonstrate that airborne LiDAR data have enough explanatory power to categorize disturbance patterns through time. These data can be used to map disturbances that pre-date the beginning of the Earth Observation data record (up to 100 years). The integration of stand perimeters (derived from the workflow proposed in chapter 1) provides contextual information that reduces the amount of reference data required to train the RF and reduces the inherent variability of traditional cell-based analyses. Chapter 3 presents a feasibility study for the estimation of TSD from data acquired by the newly launched spaceborne LiDAR Global Ecosystem Dynamics Investigation (GEDI) instrument. GEDI is a sampling instrument, acquiring footprints of approximately 22 m diameter, each separated by ~600 m across-track and ~60 m along-track. While GEDI will soon provide billions of forest canopy measurements for tropical and temperate forests around the globe, opening a new era in the use of LiDAR for forest mapping at large spatial scales, the sampling configuration imposes some challenges for continuous spatial analysis compared to the common discrete-return airborne LiDAR. The proposed approach overcomes these challenges through data fusion between optical (Landsat) and GEDI data. The approach is tested on the same study area of chapters 1 and 2, with simulated GEDI data generated from airborne LiDAR data. Landsat data are used to generate a wall-to-wall segmentation of the study area, identifying image-objects related to forest stands, and the GEDI footprints are used to generate single point estimates of TSD. The point estimates are subsequently upscaled at the Landsat image-object scale, resulting in a wall-to-wall TSD map of the study area. The results show the potential of GEDI data for TSD estimation on even-aged forests, particularly on disturbed stands within the last 100 years.doctoral, Ph.D., Natural Resources -- University of Idaho - College of Graduate Studies, 2019-0
PHYSIOLOGICAL MECHANISMS OF NUTRITIONAL ADAPTATION TO PLANT PROTEIN DIETS BY SELECTIVE BREEDING IN RAINBOW TROUT
No full textA selected rainbow trout strain was used as a model to identify physiological parameters associated with improved performance when fed all plant-protein feed. Results from a digestibility trial showed that selection had no measurable effect on apparent digestibility coefficients of nutrients in the all plant-protein or a conventional fishmeal-based diet. While this result validated apparent digestibility as an evaluation tool for ingredient and diet quality, it demonstrated that other physiological mechanisms are responsible for the improved performance of the selected strain when fed an all plant-protein, high-soy diet. A subsequent experiment was conducted to evaluate the effects that alternate protein ingredients and plant protein mixtures with or without amino acid supplementation have on trout digestive physiology. Results from temporal plasma amino acids measurements at the absorption site (hepatic portal vein) and from the systemic blood (caudal vein) demonstrated that plasma amino acid level in the hepatic portal vein, measured at intervals following a single meal, are a valuable tool to evaluate the effects of candidate alternate proteins on fish digestive physiology. The findings showed that each ingredient affects digestive physiology of the fish in a singular manner when ingredients are fed individually. However, they do not have any predictable additive effect when fed together as a mixture. Moreover, the addition of crystalline amino acids to an all-plant protein mixture altered the plasma concentrations of all the amino acids as it did for uptake reflected in the hepatic portal vein. A major finding in the study was that the selected trout strain fed the plant protein mixture with amino acid supplemention showed a noteworthy difference compared to an unselected strain, specifically, a synchronous and homogenous decreasing pattern for all the essential amino acids over time in the hepatic portal vein. This indicates that homogeneous dietary amino acid uptake in the hepatic portal vein and rapid postprandial plasma amino acid disappearance are results of nutritional adaptation driven by selection for growth on and tolerance of all-plant protein diet. Results from gene expression of amino acid transporters, cholecystokinin and genes related with protein and amino acid metabolism supported the findings from the plasma amino acids. In conclusion, the results of the research described in this dissertation demonstrated that improved performance of the selected trout strain is associated with synchronous protein digestion of the plant protein mixture and synchronization of amino acid absorption leading to improved amino acid availability and utilization.doctoral, Ph.D., Animal and Veterinary Science -- University of Idaho - College of Graduate Studies, 2019-0
Preparing for Water Change in the Columbia River Basin: An Integrated Analysis of Vulnerability & Climate Research Review
No full textWater is fundamental to social and environmental systems, particularly throughout the Columbia River Basin (CRB). However, climate impacts and population growth pressure on water resources will affect everyone living in the Basin, but not equally and there is growing concern over whether the status quo is sustainable (Hamlet et al., 2007; Cosens et al., 2016). Significant changes to the quantity and quality of water resources are already apparent across CRB. Changing climate patterns and increased average winter temperatures have contributed to a shift from snow to rain dominant precipitation, particularly at mid-elevations (Nolin & Daly, 2006). The resultant declines in snowpack, coupled with limited water storage infrastructure, indicate risk of diminished water resources throughout the Basin (Mote et al., 2005; Payne et al., 2005). The attending changes to water volume and timing of availability have broad hydrologic, as well as social implications. The following three studies share in common exploration of regional water resource challenges and spatial analyses. From this work, we grain understanding of regional research funding patterns and conclude that there is a relative dearth of funded, peer-reviewed mountain climate research in the CRB that integrates the social and physical realms. In addition, we provide a novel approach to representing spatio-temporal distribution of social and physical vulnerability to climate change induced water resource loss at a water management scale (subbasin). Our results from two comparative methodological approaches, equal and variance weighting, uncover consistent patterns of vulnerability across the Basin, and suggest that “hotspots” of overlapping vulnerabilities also exist within the study area. We provide suggestions for further research and conclude that hotspot subbasins may be considered priority areas for next steps in targeting finite resources for integrated climate research and water loss adaptation efforts, in addition to community scale vulnerability analyses.doctoral, Ph.D., Water Resources -- University of Idaho - College of Graduate Studies, 2019-0
A new method for estimating evaporative losses from hot springs using chloride and deuterium as tracers.
No full textEstimates of the total heat budget of a thermal area is typically derived using the basic principles of mass and energy balance but the parameters neccessary to make such estimates are expensive and difficult to measure. Commonly, investigators use chemical tracers as proxies for parameters allowing the mass transfer by advective transport (flowing water) to be estimated. In spite of the available methodology for predicting advective fluxes, the heat transferred by vapor during evaporation has not yet been calculated. Evaporative processes are generally elevated in thermal areas due to large temperature gradients between surface water and the atmosphere, as well as convective transport at the spring surface by wind. The effect of evaporation on mass transfer is likely negligible but its effect on energy transfer is likely much greater and, therefore, requires further investigation. Expanding on published tracer techniques, I introduce a new method to quantify evaporation losses by intiating an instantaneous increase of two chemical tracers in two hot springs in The Borax Lake Thermal Area, one tracer is a conservative species that does not leave the liquid water to partition with vapor during evaporation (chloride) and the other is non-conservative and will partition with vapor to leave the liquid water (deuterium). By contrasting each tracers return to normal background levels, the model can predict the rates at which water is entering the spring in the subsurface, liquid water is leaving the spring, and water vapor is lost by evaporation. In addition, the model calculates the volume involved with subsurface mixing and estimates the concentration of chloride and the -values of the incoming liquid and the vapor leaving the springs. An extension of the model calculates an energy balance and indicates that the effect of evaporation on energy transfer due to the latent heat of evaportation can account for 16-20 \%\ of the advective heat transported by the liquid water. This method provides an easy, inexpensive technique to quantify the energy loss by evaporation in a thermal area.masters, M.S., Geology -- University of Idaho - College of Graduate Studies, 2019-0
Monitoring Wolf Packs by Counting Litters: Sibling Reconstruction from Genetics to Genomics
No full textParameters of reproductive success are critical to the management of wildlife populations. Genetic monitoring can provide this demographic information when traditional methods aren’t tractable. This study demonstrates a novel application of genetic data to estimate a minimum annual count of breeding packs of gray wolves (Canis lupus). Using tissue samples from wolves harvested in Idaho, 98 young of the year from 2015 and 205 from 2016 were genotyped at 18 microsatellite loci. Sibling groups for each cohort were reconstructed using COLONY, with full-sibling litters corresponding to unique packs. To assess the accuracy of relationship assignments, young of the year of known relationship from long-term study packs were added to the dataset (61 individuals from 2015 and 45 from 2016). Varied input parameters were used to evaluate the power of relationship assignments under real-world data constraints, providing insight into the use of sibship reconstruction as a tool to meet monitoring goals. Though all known relationship were correctly identified under these conditions, the number and size of assigned subgroups varied. Notably, the ability to discern between closely related non-siblings was diminished when the number of loci was reduced from 18 to 10. To further explore the impacts of different genotype data, we used RADseq to identify thousands of single nucleotide polymorphism (SNP) loci and repeated sibship analyses for 50 gray wolf YOY from 2014. Our results indicated that sibship analyses using SNP loci may be limited by missing data caused by DNA quality and quantity, and that strict filtering may yield inconsistent results. SNP and microsatellite datasets were generally concordant but produced some discrepancies in sibship assignments. To compare SNP-based sibship estimates against known relationships, we have also generated RADseq-derived SNPs in an analogous group of 86 red wolf (Canis rufus) YOY of known pedigree. Though the use of SNPs is increasing in genetic monitoring of wildlife, the strengths and trade-offs of these approaches—especially when working with legacy data sets or lower-quality DNA— should be considered in transitions to next generation methods.masters, M.S., Bioinformatics & Computational Biology -- University of Idaho - College of Graduate Studies, 2019-0
Effective Security Schemes for Wireless Implantable Medical Devices
No full textHealthcare remote devices are recognized as a promising technology for treating health related issues. Among them are the wireless Implantable Medical Devices (IMDs): These electronic devices are manufactured to treat, monitor, support or replace defected vital organs while being implanted in the human body. Thus, they play a critical role in healing and even saving lives. Current IMDs research trends concentrate on their medical reliability. However, deploying wireless technology in such applications without considering security measures may offer adversaries an easy way to compromise them. Many malicious attacks on these devices can directly affect the patient's health in a lethal way. Using insecure wireless channels for these devices offers adversaries easy ways to steal the patient's private data and hijack these systems. On the other hand, IMDs suffer from limited resources, such as the energy supply, processing power, and storage space. This renders security schemes a critical feature for implementation. A certain balance between security and efficiency must be attained in each IMD for a satisfactory and safe functioning. Therefore, we intend throughout our work to design effective security schemes to defend these IMDs. Our goal is to create or accommodate security approaches for the specific case of any IMD. We want to ensure for any IMD-user a high efficiency from the IMD to improve his health, while guaranteeing a safe use. Our plans are to decrease the computational complexity of security algorithms and authentication protocols to fit on any IMD. We also want to explore biometric features for better and safer use. We investigate all the possible scenarios (regular or urgent) to guarantee for the patient a reliable device.masters, M.S., Electrical and Computer Engineering -- University of Idaho - College of Graduate Studies, 2019-0