Digital Commons Network^™

Automated Tree Mortality Detection Using Ubiquitously Available Public Data, Michael T. Huggins

Master's Theses

Understanding the dynamic interplay between fire severity, topography, and tree mortality, is crucial for predicting future forest dynamics and enhancing resilience against climate change-induced wildfire regimes. This thesis develops a multi-sensor approach for automated estimation of tree mortality, then applies it to examine trends in tree mortality over a six-year period across a fire affected study site in the Trinity River basin in Northern California. The Random Forest model uses publicly available USGS 3D Elevation Program Lidar (3DEP) and NAIP imagery as inputs and is likely to be easily adaptable to other landscapes. The model had a Receiver Operating Characteristic …

Environmental Implications Of Modern Food Production: An Analysis For The Conscious Consumer, Jessica T. Coming

Cal Poly Humboldt theses and projects

This project explores the pathways by which agriculture affects the environment and determines which foods have the greatest climate, water, and land impacts. Agricultural effects on the environment are extensive, from loss of habitat and declines in regional biodiversity to disruption of global nutrient cycles and climate change. Global food production accounts for 26-34% of annual anthropogenic greenhouse gas emissions, makes up 38-46% of habitable land, and is responsible for 70% of freshwater extraction. The effect of agriculture on the environment is most significantly dictated by what type of food is being produced. Animal-based food products consistently have the highest …

Exploring Soil Microbial Dynamics In Southern Appalachian Forests: A Systems Biology Approach To Prescribed Fire Impacts, Saad Abd Ar Rafie

Doctoral Dissertations

Prescribed fires in Southern Appalachian forests are vital in ecosystem management and wildfire risk mitigation. However, understanding the intricate dynamics between these fires, soil microbial communities, and overall ecosystem health remains challenging. This dissertation addresses this knowledge gap by exploring selected aspects of this complex relationship across three interconnected chapters.

The first chapter investigates the immediate effects of prescribed fires on soil microbial communities. It reveals subtle shifts in porewater chemistry and significant increases in microbial species richness. These findings offer valuable insights into the interplay between soil properties and microbial responses during the early stages following a prescribed fire. …

Variability In Microclimate And Carbon Dynamics In Hardwood Forests Managed With The Irregular Shelterwood Reproduction Method, Melody June Mount

Masters Theses

How do forest edges compare to intact interior forests in terms of carbon dynamics, and how is the microclimate altered through the creation of forest edges? Woody plants and trees can act as a carbon sink by using live and dead tissue to store varying amounts of carbon. However, factors such as age, species, respiration rates, and death alter the amount of carbon sequestered by the forest (Gorte, 2009). Additionally, widespread forest fragmentation has resulted in 20% of forests worldwide being located within 100 meters (m) of a forest edge (Haddad et al., 2015). Despite this fragmentation, current carbon models …

Modeling The Effect Of Neighborhood Competition On Tree Diameter Growth In The Pacific Northwest Coast Range, Htet Lin Naing

Theses and Dissertations

Trees compete for various resources such as sunlight, water, and nutrients, which can be expressed as numerical terms, called competition indices (CI). Competition between individual trees is correlated with their growth and mortality. Therefore, CIs are used as independent variables to develop, improve and modify growth and yield models. This study was conducted to test the effect of neighborhood competition on tree diameter growth among Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg) and red alder (Alnus rubra Bong.), in the Pacific Northwest Coast Range, USA. After testing seven distance-independent CIs and three distance-dependent …

Study Of Morphological And Physiological Properties And Pollinators Of The Invasive Callery Pear, Prabina Sharma

All Theses

Callery pear is an invasive tree in 15 states of United States and is currently present in 37 states. Its management has challenged landowners and land managers. Despite being listed as a noxious weed in four states, its study is limited. The accurate estimation of Callery pear biomass will give a clearer picture of the level of invasion and help land managers develop different strategies to control its population. Similarly, identifying possible pollinators of Callery pear is essential to have some insights on pollinators associated with this tree. Hence, the objectives of this study are 1) to calculate total above-ground …

Interactive Effects Of Bark Beetles, Ophiostomatoid Fungi, And Subterranean Termites On Wood Decomposition And The Biogeochemical Cycling Of Pine Forests, Kimberlyn Pace

Theses and Dissertations

A frequent source of pine tree mortality in recent years can be attributed to pine bark beetles and their vectored Ophiostomatoid fungi, an organism that has been observed to attract subterranean termites that preferentially recruit to this downed woody debris. This interaction may significantly modify biogeochemical fluxes in bark beetle mass mortality events, but studies are often limited to singular regions or single pine-dominated ecosystems. Two studies were designed to test the interactive effects of these associations on terrestrial biogeochemical cycles and decomposition processes, the first using replicated field trials in Mississippi, Arizona, and Honduras across two years and the …

Patterns, Mechanisms, And Characterization Of Carbon Cycling Stability Following Partial Forest Disturbance, Kayla C. Mathes

Theses and Dissertations

Among the most essential questions in the era of climate change is how the forest carbon (C) cycle will respond to an increase in the extent of biotic disturbances from insects and pathogens. While research has focused on stand-replacing disturbance regimes, less is known about C cycling stability following partial disturbances that produce gradients of disturbance severity. Belowground C cycling responses to disturbance are especially poorly understood, even though temperate forest soils contain up to 50% of total ecosystem C and soil respiration (R_s) accounts for more than half of temperate forest C loss. Interpreting trends and mechanisms …

Coupled Structure-Function Responses To Disturbance: High Structural Complexity Resistance Supports Primary Production Resistance, Kerstin M. Niedermaier

Theses and Dissertations

The capacity of forests to resist structural change and retain material legacies–the biotic and abiotic resources that persist through disturbance–is crucial to sustaining ecosystem functioning after disturbance. However, the role of forest structure as both a material legacy and feature supporting carbon (C) cycling stability following disturbance has not been widely investigated. We used a large-scale disturbance manipulation to ask whether LiDAR-derived canopy structures as material legacies drive 3-year responses of NPP to a range of disturbance severity levels. As part of the Forest Resilience Threshold Experiment (FoRTE) in northern Michigan, USA we simulated phloem-disrupting disturbances at a range of …

Fruit Characteristics, Defoliation, Forest Floor And Soil Properties Of Sweet Chestnut (Castanea Sativa Mill.) Forests In İstanbul-Turkey, Gülçi̇n Özer, Ender Maki̇neci̇

Turkish Journal of Agriculture and Forestry

The defoliation and fruit characteristics of natural Castanea sativa Mill. forests were annually monitored between 2014 and 2016 in İstanbul, Turkey. The soil and forest floor properties were also investigated and evaluated according to the stand development stages. Comparisons were made with ANOVA and Tukey HSD tests; the relationship between fruit yield and the properties of the soil and forest floor were tested with correlation analysis; and allometric regression models were developed for fruit yield with DBH (diameter at breast height) and (DBH)2H. The total mass was 509-652 g/m2, N mass was 7.67-9.70 g/m2 and C mass was between 165.75 …

Carbon Sequestration In A Restored West Michigan Oak Savanna: Implications For Management Practices, Jeffrey A. Heise

Masters Theses

The savanna system is an ecosystem (i.e. a transitional ecosystem) that lies between forest and grassland ecosystems. They occur across the world in various forms, but in the North American Midwest they are specifically oak savannas: systems where the open overstory is dominated by various species of oak (Quercus spp.) and the understory consists of carbon-rich prairie grasses and forbs. This ecosystem is a highly degraded ecosystem and has lost almost 99% of its former range due to agriculture and fire suppression. Since savannas are fire-evolved systems, they are maintained by and require fire as a regular disturbance to …

Patterns Of Ecosystem Structure And Wildfire Carbon Combustion Across Six Ecoregions Of The North American Boreal Forest, Xanthe J. Walker, Jennifer L. Baltzer, Laura Bourgeau-Chavez, Nicola J. Day, Catherine M. Dieleman, Jill F. Johnstone, Evan Kane, Brendan M. Rogers, Merritt R. Turetsky, Sander Veraverbeke, Michelle C. Mack

Michigan Tech Publications

Increases in fire frequency, extent, and severity are expected to strongly impact the structure and function of boreal forest ecosystems. An important function of the boreal forest is its ability to sequester and store carbon (C). Increasing disturbance from wildfires, emitting large amounts of C to the atmosphere, may create a positive feedback to climate warming. Variation in ecosystem structure and function throughout the boreal forest is important for predicting the effects of climate warming and changing fire regimes on C dynamics. In this study, we compiled data on soil characteristics, stand structure, pre-fire C pools, C loss from fire, …

Alternate Trait‐Based Leaf Respiration Schemes Evaluated At Ecosystem‐Scale Through Carbon Optimization Modeling And Canopy Property Data, R. Q. Thomas, M. Williams, M. A. Cavaleri, J.‐F. Exbrayat, T. L. Smallman, L. E. Street

Michigan Tech Publications

Leaf maintenance respiration (R_leaf,m) is a major but poorly understood component of the terrestrial carbon cycle (C). Earth systems models (ESMs) use simple sub‐models relating R_leaf,m to leaf traits, applied at canopy scale. R_leaf,m models vary depending on which leaf N traits they incorporate (e.g., mass or area based) and the form of relationship (linear or nonlinear). To simulate vegetation responses to global change, some ESMs include ecological optimization to identify canopy structures that maximize net C accumulation. However, the implications for optimization of using alternate leaf‐scale empirical R_leaf,m models are undetermined. Here we combine …

Cost Effectiveness Of Greenhouse Gas Reductions Through Afforestation Of Agricultural Land In The Arkansas Delta, Karli A. Moore

Graduate Theses and Dissertations

Sequestration of atmospheric carbon in forested lands offsets carbon emissions from other industries. Conversion of private lands, particularly agricultural tracts in marginal areas, to forests can bolster carbon abatement. The United States government agencies administer some voluntary, incentive-based programs to encourage landowners to adopt production practices with positive environmental outcomes. This policy stream can be used to increase transition of marginal agricultural land to forests, thereby creating new carbon sinks. We analyze an eleven-county study area in the Arkansas Delta to determine feasibility for a subsidy focused on carbon abatement through afforestation. This study area is significant for two reasons: …

Mechanisms Underlying Production Stability In Temperate Deciduous Forests, Shea B. Wales

Theses and Dissertations

A persistent and reliable future terrestrial carbon (C) sink will depend on how stable forest production is under more variable climate conditions. We examined how age, forest structure, and disturbance history relate to the interannual variability of above-ground wood net primary production (NPPw). Our site in northern Michigan spans two experimental forest chronosequences and three late successional stands; the chronosequences have distinct disturbance histories, originating following either clear cut harvesting (“Cut Only”) or clear cut harvesting and fire (“Cut and Burn”), and range from 21 to 108 years old. Annual NPPw was estimated using dendrochronology and site specific allometric equations. …

Uncertainty Assessment In Biomass Estimation, Isaac Lisle

Isaac Lisle

Density Management In Young Western Larch Stands: Tree Growth, Stand Yield, And Carbon Storage 54 Years After Thinning, Michael S. Schaedel

Graduate Student Theses, Dissertations, & Professional Papers

Long-term silvicultural experiments can be used to test novel ecological hypotheses and answer contemporary management questions that were not envisioned at study initiation. We used a 54-year old western larch precommercial thinning (PCT) study in northwest Montana to examine two sets of questions: (1) how different PCT regimes affect long-term stand yield and tree growth, and (2) how PCT affects total aboveground carbon (C) storage and distribution among C pools. The study has three target densities (494 trees ha^-1, 890 trees ha^-1, and 1680 trees ha^-1) and three numbers of entries to achieve those …

Ecosystem Services Of Woody Crop Production Systems, Ronald S. Zalesny Jr., John A. Stanturf, Emile S. Gardiner, James H. Perdue, Timothy M. Young, David R. Coyle, William L. Headlee, Gary S. Bañuelos, Amir Hass

USDA Forest Service / UNL Faculty Publications

Short-rotation woody crops are an integral component of regional and national energy portfolios, as well as providing essential ecosystem services such as biomass supplies, carbon sinks, clean water, and healthy soils. We review recent USDA Forest Service Research and Development efforts from the USDA Biomass Research Centers on the provisioning of these ecosystem services from woody crop production systems. For biomass, we highlight productivity and yield potential, pest susceptibility, and bioenergy siting applications. We describe carbon storage in aboveground woody biomass and studies assessing the provision of clean and plentiful water. Soil protection and wildlife habitat are also mentioned, in …

After-Effect Of Long-Term Soil Management On Soil Respiration And Otherqualitative Parameters Under Prolonged Dry Soil Conditions, Dalia Feiziene, Dalia Janusauskaite, Virginijus Feiza, Agne Putramentaite, Ausra Sinkeviciene, Skaidre Suproniene, Vytautas Seibutis, Grazina Kadziene, Irena Deveikyte, Sigitas Lazauskas, Daiva Janusauskaite, Virmantas Povilaitis

Turkish Journal of Agriculture and Forestry

Climatic conditions of environmental zone Nemoral 2 of Europe are favorable for agricultural development. However, more frequent events of hot air-waves and prolonged droughts occurring as a consequence of climate change lead to soil moisture content reduction down to the plant wilting point. Dry soil conditions may have negative consequences for soil as a habitat. The goal of this study was to evaluate the cumulative after-effect of long-term conventional (CT) and no-tillage (NT) application in combination with or without crop residues on soil physicochemical properties, microbiological activity, and soil respiration (SR) under prolonged dry soil conditions. Long-term CT with residue …

Differential Effects Of Canopy Trimming And Litter Deposition On Litterfall And Nutrient Dynamics In A Wet Subtropical Forest, Steven J. Hall, Whendee L. Silver, Grizelle González

Steven J. Hall

Humid tropical forests have the highest rates of litterfall production globally, which fuels rapid nutrient recycling and high net ecosystem production. Severe storm events significantly alter patterns in litterfall mass and nutrient dynamics through a combination of canopy disturbance and litter deposition. In this study, we used a large-scale long-term manipulation experiment to explore the separate and combined effects of canopy trimming and litter deposition on litterfall rates and litter nutrient concentrations and content. The deposition of fine litter associated with the treatments was equivalent to more than two times the annual fine litterfall mass and nutrient content in control …

Nitrogen And Carbon Dynamics In Prairie Vegetation Strips Across Topographical Gradients In Mixed Central Iowa Agroecosystems, Marlin Perez-Suarez, Michael J. Castellano, Randall Kolka, Heidi Asbjornsen, Matthew J. Helmers

USDA Forest Service / UNL Faculty Publications

Reductions of nitrogen (N) export from agricultural lands because of changes in specific N stocks andfluxes by incorporation of small amounts of prairie vegetation strips (PVS) are poorly understood. Theprimary objective of this study was to evaluate the effect of the presence and topographical position of PVSon soil and plant carbon (C) and N stocks relative to annual crop and native prairie vegetation. The studywas implemented within three small adjacent watersheds, treated with one of the following cover types:(1) 100% row-crop agriculture (CROP); (2) 20% prairie vegetation (PVS) distributed along the contouracross three topographical positions: upslope, sideslope and footslope position; …

Low Mortality In Tall Tropical Trees, R. Q. Thomas, J. R. Kellner, D. B. Clark, D. R. Peart

Dartmouth Scholarship

The dynamics of the tallest trees in tropical forests are of special interest due to their carbon content, canopy dominance, and the large canopy gaps created when they die. Known ecological mechanisms that may influence tall tree survival lead to conflicting predictions. Hydraulic stress and exposure to high winds and desiccation should increase death rates, yet the tallest trees have the greatest access to light and escape damage caused by falling boles and branches. The uncertainty in tall tree mortality rates has been difficult to address due to their low density, which makes mortality rates challenging to estimate accurately. Here, …

Carbon In The Peatlands In The Great Lakes Region, Cassandra A. Ott

Dissertations, Master's Theses and Master's Reports - Open

Peatlands cover only ~3% of the global land area, but store ~30% of the worlds' soil carbon. There are many different peat types that store different amounts of carbon. Most inventories of carbon storage in northern peatlands have been conducted in the expansive Sphagnum dominated peatlands. Although, northern white cedar peatlands (NW cedar, Thuja occidentalis L.) are also one of the most common peatland types in the Great Lakes Region, occupying more than 2 million hectares. NW cedar swamps are understudied, due in part to the difficulties in collection methods. General lack of rapid and consistent sampling methods has also …

Quantifying Carbon Allocation To Mycorrhizal Fungi By Temperate Forest Tree Species Across A Nitrogen Availability Gradient, Shersingh Joseph Tumber-Davila

Honors Theses and Capstones

Terrestrial ecosystems make up the largest carbon pool with a major portion of that being forests. With carbon being a major concern due to global climate change, being able to make accurate models is increasingly important. Studies have shown that trees may allocate up to 50% of their photosynthetically fixed carbon underground; however these values haven’t been accurately quantified and underground carbon allocation has been historically overlooked. Mycorrhizal fungi may be a large portion of underground carbon allocation, as they have a symbiotic relationship with trees where they provide the plant with water and nutrients in return for sugars (carbon). …

Forest Structure And Aboveground Biomass In The Southwestern United States From Modis And Misr, Mark Chopping, Crystal B. Schaaf, Feng Zhao, Zhuosen Wang, Anne Nolin, Gretchen G. Moisen, John V. Martonchik, Michael Bull

USDA Forest Service / UNL Faculty Publications

Red band bidirectional reflectance factor data from the NASA MODerate resolution Imaging Spectroradiometer (MODIS) acquired over the southwestern United States were interpreted through a simple geometric–optical (GO) canopy reflectance model to provide maps of fractional crown cover (dimensionless), mean canopy height (m), and aboveground woody biomass (Mg ha⁻¹) on a 250 m grid. Model adjustment was performed after dynamic injection of a background contribution predicted via the kernel weights of a bidirectional reflectance distribution function (BRDF) model. Accuracy was assessed with respect to similar maps obtained with data from the NASA Multiangle Imaging Spectroradiometer (MISR) and to contemporaneous …

Slides: Summary: Sources Of Stress And The Changing Context Of Natural Resources Law And Policy In The New West, William R. Travis

The Future of Natural Resources Law and Policy (Summer Conference, June 6-8)

Presenter: Dr. William R. Travis, Department of Geography, University of Colorado at Boulder

43 slides

Slides: Ecotrust Forests, Bettina Von Hagen

Community-Owned Forests: Possibilities, Experiences, and Lessons Learned (June 16-19)

Presenter: Bettina Von Hagen, Ecotrust Forests, OR

25 slides

Toxicity Of Aspen Wood Leachate To Aquatic Life: Laboratory Studies, Barry R. Taylor, J. Stephen Goudey, N. Bruce Carmichael

Aspen Bibliography

Trembling aspen (Populus tremuloides Michx.), a common hardwood tree throughout Canada, is being harvested at increasing rates for use in paper and building materials. Piles of aspen logs have been observed to produce a dark, watery, acutely toxic leachate. A laboratory study was undertaken to elucidate the nature, strength, and persistence of aspen leachate toxicity and the chemical composition of the leachate. Leaching from aspen chips in the laboratory was rapid, with 1% mass loss in the first 24 h. Another 2 weeks of immersion was necessary to remove all remaining leachable material (3% total)> Fresh aspen leachate derived …

Carbon Allocation And Partitioning In Aspen Clones Varying In Sensitivity To Tropospheric Ozone, M.D. Coleman, R.E. Dickson, J.G. Isebrands, D.F. Karnosky

Aspen Bibliography

No abstract provided.

Ecosystem Carbon Following Aspen Harvesting In The Upper Great Lakes, David H. Alban, D.A. Perala

Aspen Bibliography

No abstract provided.