Present day container nursery systems for the production of Eucalyptus Dill, are reviewed and doc... more Present day container nursery systems for the production of Eucalyptus Dill, are reviewed and documented from the results of a comprehensive questionnaire distributed to 30 major Eucalyptus producing countries. The results of the survey showed that 41 Eucalyptus species were under production in 1990. Most of these species were grown in containers that varied in diameter, depth, diameter to depth ratio, and volume. The growing media, fertilizer types, fertilizer formulation, and the morphological standards used for the production of Eucalyptus stock for outplanting varied considerably. Two separate experiments were conducted with Eucalyptus globulus nursery stock. 1) The media and feeding schedule study tested the merits of Sphagnum peat, Vermiculite, and Perlite in various proportions as growing media under the exponential and replacement feeding schedules. Seedling height (cm), root collar diameter (mm), top dry weight (mg) and root dry weight (mg) were measured to study growth of ...
(one panel) are measured annually, and a moving average is used for estimating current condition ... more (one panel) are measured annually, and a moving average is used for estimating current condition and change of forest attributes while alternative methods are sought in all regions of the United States. This dissertation explored alternatives to the moving average in the Pacific Northwest using Current Vegetation Survey data collected in Oregon and Washington. Several nearest neighbor imputation methods were examined for their suitability to update plot-level forest attributes (basal area/ha, stems/ha, volume/ha, biomass/ha) to the current point in time. The results were compared to estimates obtained using a moving average and a weighted moving average. In terms of bias and accuracy, the weighted moving average performed better than the moving average. When the most recent measurements of the variables of interest were used as ancillary data, randomForest imputation outperformed both the moving average and the weighted moving average. For estimating current basal area/ha, stems/ha, volume/ha, and biomass/ha, tree-level imputation outperformed plot-level imputation. The difference in bias and
Journal: Canadian Journal of Forest Research Manuscript ID cjfr-2018-0361.R2 Manuscript Type: Art... more Journal: Canadian Journal of Forest Research Manuscript ID cjfr-2018-0361.R2 Manuscript Type: Article Date Submitted by the Author: 10-Dec-2018 Complete List of Authors: Poudel, Krishna; Mississippi State University, Department of Forestry Temesgen, Hailemariam; Oregon State University, Department of Forest Engineering, Resources, and Management Radtke, Philip; Virginia Tech, Gray, Andrew; USDA Forest Service, Pacific Northwest Research Station Keyword: Biomass, Western U.S., Dirichlet Imputation, Component Ratio Method, Carbon Is the invited manuscript for consideration in a Special Issue? : Not applicable (regular submission)
plies mathematics and statistics to efficiently analyze and quantify past, present, and future at... more plies mathematics and statistics to efficiently analyze and quantify past, present, and future attributes at all three levels. FMB offers valuable information for decisionmaking because it provides quantitative measures of current resources, means to compare differences between alternative experimental resource treatments, and methods to project future outcomes of management practices. This essay provides a brief overview of the current diversity of FMB applications using examples from business, policy analysis, and ecosystems studies. The second section gives our views on the most critical challenges facing FMB researchers and practitioners based on resource decisionmaking needs. A third section offers comments on how we think FMB professionals and academic forestry programs might cooperate in meeting these challenges. Some State-of-the-Art Applications of FMB in Forestry To illustrate the sophistication and complexity of current FMB applications in modern forestry practice, we con...
Airborne laser scanning, collected in a sampling mode, has the potential to be a valuable tool fo... more Airborne laser scanning, collected in a sampling mode, has the potential to be a valuable tool for estimating the biomass resources available to support bioenergy production in rural communities of interior Alaska. In this study, we present a methodology for estimating forest biomass over a 201,226-ha area (of which 163,913 ha are forested) in the upper Tanana valley of interior Alaska using a combination of 79 field plots and high-density airborne light detection and ranging (LiDAR) collected in a sampling mode along 27 single strips (swaths) spaced approximately 2.5 km apart. A model-based approach to estimating total aboveground biomass for the area is presented. Although a design-based sampling approach (based on a probability sample of field plots) would allow for stronger inference, a model-based approach is justified when the cost of obtaining a probability sample is prohibitive. Using a simulation-based approach, the proportion of the variability associated with sampling err...
This contribution complements Forest Ecosystems’ Thematic Series on “Forest Observational Studies... more This contribution complements Forest Ecosystems’ Thematic Series on “Forest Observational Studies”. We provide essential clarification regarding the definition and purpose of long-term field studies, review some of the extensive literature and discuss different approaches to collecting field data. We also describe two newly established forest observational networks that serve to illustrate the scope and diversity of forest field studies. The first is a large-scale network of forest observational studies in prominent natural forest ecosystems in China. The second example demonstrates observational studies in mixed and uneven-aged pine-oak forests which are selectively managed by local communities in Mexico. We summarize the potential for analysing and modeling forest ecosystems within interdisciplinary projects and provide argumentation in favour of long-term institutional commitment to maintaining forest observational field studies.
Dwarf mistletoes ( Arceuthobium species) influence many processes within forested ecosystems, but... more Dwarf mistletoes ( Arceuthobium species) influence many processes within forested ecosystems, but few studies have examined their distribution in relation to climate. An analysis of 1549 forested plots within a 14.5 million ha region of southeast Alaska provided strong indications that climate currently limits hemlock dwarf mistletoe ( Arceuthobium tsugense (Rosendahl) G.N. Jones) to a subset of the range of its primary tree host, western hemlock ( Tsuga heterophylla (Raf.) Sarg.), with infection varying from a high of 20% of trees at sea level to only 5% by 200 m elevation. Three types of modeling approaches (logistic, most similar neighbors, and random forests) were tested for the ability to simultaneously predict abundance and distribution of host and pathogen as a function of climate variables. Current distribution was explained well by logistic models using growing degree-days, indirect and direct solar radiation, rainfall, snowfall, slope, and minimum temperatures, although ac...
Regional estimation of potential forest productivity is important to diverse applications, includ... more Regional estimation of potential forest productivity is important to diverse applications, including biofuels supply, carbon sequestration, and projections of forest growth. Using PRISM (Parameter-elevation Regressions on Independent Slopes Model) climate and productivity data measured on a grid of 3356 Forest Inventory and Analysis plots in Oregon and Washington, we evaluated four possible imputation methods to estimate potential forest productivity: nearest neighbour, multiple linear regression, thin plate spline functions, and a spatial autoregressive model. Productivity, measured by potential mean annual increment at culmination, is explained by the interaction of annual temperature, precipitation, and climate moisture index. The data were randomly divided into 2237 reference plots and 1119 target plots 30 times. Each imputation method was evaluated by calculating the coefficient of determination, bias, and root mean square error of both the target and reference data set and was...
Present day container nursery systems for the production of Eucalyptus Dill, are reviewed and doc... more Present day container nursery systems for the production of Eucalyptus Dill, are reviewed and documented from the results of a comprehensive questionnaire distributed to 30 major Eucalyptus producing countries. The results of the survey showed that 41 Eucalyptus species were under production in 1990. Most of these species were grown in containers that varied in diameter, depth, diameter to depth ratio, and volume. The growing media, fertilizer types, fertilizer formulation, and the morphological standards used for the production of Eucalyptus stock for outplanting varied considerably. Two separate experiments were conducted with Eucalyptus globulus nursery stock. 1) The media and feeding schedule study tested the merits of Sphagnum peat, Vermiculite, and Perlite in various proportions as growing media under the exponential and replacement feeding schedules. Seedling height (cm), root collar diameter (mm), top dry weight (mg) and root dry weight (mg) were measured to study growth of ...
(one panel) are measured annually, and a moving average is used for estimating current condition ... more (one panel) are measured annually, and a moving average is used for estimating current condition and change of forest attributes while alternative methods are sought in all regions of the United States. This dissertation explored alternatives to the moving average in the Pacific Northwest using Current Vegetation Survey data collected in Oregon and Washington. Several nearest neighbor imputation methods were examined for their suitability to update plot-level forest attributes (basal area/ha, stems/ha, volume/ha, biomass/ha) to the current point in time. The results were compared to estimates obtained using a moving average and a weighted moving average. In terms of bias and accuracy, the weighted moving average performed better than the moving average. When the most recent measurements of the variables of interest were used as ancillary data, randomForest imputation outperformed both the moving average and the weighted moving average. For estimating current basal area/ha, stems/ha, volume/ha, and biomass/ha, tree-level imputation outperformed plot-level imputation. The difference in bias and
Journal: Canadian Journal of Forest Research Manuscript ID cjfr-2018-0361.R2 Manuscript Type: Art... more Journal: Canadian Journal of Forest Research Manuscript ID cjfr-2018-0361.R2 Manuscript Type: Article Date Submitted by the Author: 10-Dec-2018 Complete List of Authors: Poudel, Krishna; Mississippi State University, Department of Forestry Temesgen, Hailemariam; Oregon State University, Department of Forest Engineering, Resources, and Management Radtke, Philip; Virginia Tech, Gray, Andrew; USDA Forest Service, Pacific Northwest Research Station Keyword: Biomass, Western U.S., Dirichlet Imputation, Component Ratio Method, Carbon Is the invited manuscript for consideration in a Special Issue? : Not applicable (regular submission)
plies mathematics and statistics to efficiently analyze and quantify past, present, and future at... more plies mathematics and statistics to efficiently analyze and quantify past, present, and future attributes at all three levels. FMB offers valuable information for decisionmaking because it provides quantitative measures of current resources, means to compare differences between alternative experimental resource treatments, and methods to project future outcomes of management practices. This essay provides a brief overview of the current diversity of FMB applications using examples from business, policy analysis, and ecosystems studies. The second section gives our views on the most critical challenges facing FMB researchers and practitioners based on resource decisionmaking needs. A third section offers comments on how we think FMB professionals and academic forestry programs might cooperate in meeting these challenges. Some State-of-the-Art Applications of FMB in Forestry To illustrate the sophistication and complexity of current FMB applications in modern forestry practice, we con...
Airborne laser scanning, collected in a sampling mode, has the potential to be a valuable tool fo... more Airborne laser scanning, collected in a sampling mode, has the potential to be a valuable tool for estimating the biomass resources available to support bioenergy production in rural communities of interior Alaska. In this study, we present a methodology for estimating forest biomass over a 201,226-ha area (of which 163,913 ha are forested) in the upper Tanana valley of interior Alaska using a combination of 79 field plots and high-density airborne light detection and ranging (LiDAR) collected in a sampling mode along 27 single strips (swaths) spaced approximately 2.5 km apart. A model-based approach to estimating total aboveground biomass for the area is presented. Although a design-based sampling approach (based on a probability sample of field plots) would allow for stronger inference, a model-based approach is justified when the cost of obtaining a probability sample is prohibitive. Using a simulation-based approach, the proportion of the variability associated with sampling err...
This contribution complements Forest Ecosystems’ Thematic Series on “Forest Observational Studies... more This contribution complements Forest Ecosystems’ Thematic Series on “Forest Observational Studies”. We provide essential clarification regarding the definition and purpose of long-term field studies, review some of the extensive literature and discuss different approaches to collecting field data. We also describe two newly established forest observational networks that serve to illustrate the scope and diversity of forest field studies. The first is a large-scale network of forest observational studies in prominent natural forest ecosystems in China. The second example demonstrates observational studies in mixed and uneven-aged pine-oak forests which are selectively managed by local communities in Mexico. We summarize the potential for analysing and modeling forest ecosystems within interdisciplinary projects and provide argumentation in favour of long-term institutional commitment to maintaining forest observational field studies.
Dwarf mistletoes ( Arceuthobium species) influence many processes within forested ecosystems, but... more Dwarf mistletoes ( Arceuthobium species) influence many processes within forested ecosystems, but few studies have examined their distribution in relation to climate. An analysis of 1549 forested plots within a 14.5 million ha region of southeast Alaska provided strong indications that climate currently limits hemlock dwarf mistletoe ( Arceuthobium tsugense (Rosendahl) G.N. Jones) to a subset of the range of its primary tree host, western hemlock ( Tsuga heterophylla (Raf.) Sarg.), with infection varying from a high of 20% of trees at sea level to only 5% by 200 m elevation. Three types of modeling approaches (logistic, most similar neighbors, and random forests) were tested for the ability to simultaneously predict abundance and distribution of host and pathogen as a function of climate variables. Current distribution was explained well by logistic models using growing degree-days, indirect and direct solar radiation, rainfall, snowfall, slope, and minimum temperatures, although ac...
Regional estimation of potential forest productivity is important to diverse applications, includ... more Regional estimation of potential forest productivity is important to diverse applications, including biofuels supply, carbon sequestration, and projections of forest growth. Using PRISM (Parameter-elevation Regressions on Independent Slopes Model) climate and productivity data measured on a grid of 3356 Forest Inventory and Analysis plots in Oregon and Washington, we evaluated four possible imputation methods to estimate potential forest productivity: nearest neighbour, multiple linear regression, thin plate spline functions, and a spatial autoregressive model. Productivity, measured by potential mean annual increment at culmination, is explained by the interaction of annual temperature, precipitation, and climate moisture index. The data were randomly divided into 2237 reference plots and 1119 target plots 30 times. Each imputation method was evaluated by calculating the coefficient of determination, bias, and root mean square error of both the target and reference data set and was...
This contribution complements Forest Ecosystems' Thematic Series on " Forest Observational Studie... more This contribution complements Forest Ecosystems' Thematic Series on " Forest Observational Studies ". We provide essential clarification regarding the definition and purpose of long-term field studies, review some of the extensive literature and discuss different approaches to collecting field data. We also describe two newly established forest observational networks that serve to illustrate the scope and diversity of forest field studies. The first is a large-scale network of forest observational studies in prominent natural forest ecosystems in China. The second example demonstrates observational studies in mixed and uneven-aged pine-oak forests which are selectively managed by local communities in Mexico. We summarize the potential for analysing and modeling forest ecosystems within interdisciplinary projects and provide argumentation in favour of long-term institutional commitment to maintaining forest observational field studies.
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