Forest Sciences Commons^™

First Year Biomass Production Following Application Of Various Size Strip Thinnings In A Young Hardwood Stand In West Virginia., Ashlee Martin

Graduate Theses, Dissertations, and Problem Reports (ETD)

Strip thinning can reduce stand density to promote better growth of residual trees and has potential to create a woody bioenergy feedstock in addition to enhancing and maintaining early successional habitat for wildlife. However, little research has been conducted on strip thinning within young hardwood stands to determine if these are viable attributes of strip thinning. The goal of this study was to assess the first year biomass production after strip thinning among three different cut strip widths (8 ft, 12 ft, and 16 ft) in a 22-year-old mixed mesophytic hardwood stand. Woody biomass production from stump sprouts and true …

On Underestimation Of Global Vulnerability To Tree Mortality And Forest Die-Off From Hotter Drought In The Anthropocene, Craig D. Allen, David D. Breshears, Nate G. Mcdowell

United States Geological Survey: Staff Publications

Patterns, mechanisms, projections, and consequences of tree mortality and associated broadscale forest die-off due to drought accompanied by warmer temperatures—‘‘hotter drought’’, an emerging characteristic of the Anthropocene—are the focus of rapidly expanding literature. Despite recent observational, experimental, and modeling studies suggesting increased vulnerability of trees to hotter drought and associated pests and pathogens, substantial debate remains among research, management and policy-making communities regarding future tree mortality risks. We summarize key mortalityrelevant findings, differentiating between those implying lesser versus greater levels of vulnerability. Evidence suggesting lesser vulnerability includes forest benefits of elevated [CO2] and increased water-use efficiency; observed and modeled increases …

Effects Of Drought On Forests And Rangelands In The United States: A Comprehensive Science Synthesis, James M. Vose, James S. Clark, Charles H. Luce, Toral Patel-Weynand

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

This assessment provides input to the reauthorized National Integrated Drought Information System (NIDIS) and the National Climate Assessment (NCA), and it establishes the scientific foundation needed to manage for drought resilience and adaptation. Focal areas include drought characterization; drought impacts on forest processes and disturbances such as insect outbreaks and wildfire; and consequences on forest and rangeland values. Drought can be a severe natural disaster with substantial social and economic consequences. Drought becomes most obvious when large-scale changes are observed; however, even moderate drought can have long-lasting impacts on the structure and function of forests and rangelands without these obvious …

Monthly Land Cover-Specific Evapotranspiration Models Derived From Global Eddy Flux Measurements And Remote Sensing Data, Yuan Fang, Ge Sun, Peter Caldwell, Steven G. Mcnulty, Asko Noormets, Jean-Christophe Domec, John King, Zhiqiang Zhang, Xudong Zhang, Guanghui Lin, Guangsheng Zhou, Jingfeng Xiao, Jiquan Chen

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Evapotranspiration (ET) is arguably the most uncertain ecohydrologic variable for quantifying watershed water budgets. Although numerous ET and hydrological models exist, accurately predicting the effects of global change on water use and availability remains challenging because of model deficiency and/or a lack of input parameters. The objective of this study was to create a new set of monthly ET models that can better quantify landscape-level ET with readily available meteorological and biophysical information. We integrated eddy covariance flux measurements from over 200 sites, multiple year remote sensing products from the Moderate Resolution Imaging Spectroradiometer (MODIS), and statistical modelling. Through examining …

Scarification And Gap Size Have Interacting Effects On Northern Temperate Seedling Establishment, John L. Willis, Michael B. Walters, Kurt W. Gottschallk

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

After decades focused on promoting economically valuable species, management of northern temperate forests has increasingly become focused on promoting tree species diversity. Unfortunately, many formerly common species that could contribute to diversity including yellow birch (Betula alleghaniensis Britton.), paper birch (Betula papyrifera Marsh), eastern hemlock (Tsuga canadensis L.), and eastern white pine (Pinus strobus L.) are now uncommon in the seedling layer, raising concerns about our ability to use these species to increase diversity. In this study, two related seed addition experiments conducted in 45 variably-sized harvest gaps (unharvested to 6500 m^2) in adjacent mesic northern hardwood stands, Emmet County, …

Long-Term Droughtiness And Drought Tolerance Of Eastern Us Forests Over Five Decades, Matthew P. Peters, Louis R. Iverson, Stephen N. Matthews

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Droughts can influence forest composition directly by limiting water or indirectly by intensifying other stressors that affect establishment, growth, and mortality. Using community assemblages of eastern US tree species and drought tolerance characteristics assessed from literature, we examine recent drought conditions in relation to the spatial distribution of species and their tolerance to drought. First we calculate and compare a cumulative drought severity index (CDSI) for the conterminous US for the periods 1960–1986 and 1987–2013 using climate division Palmer Drought Severity Index (PDSI) values and a gridded self-calibrated PDSI dataset. This comparison indicates that drought conditions in the East tend …

N-Acetylcysteine Increased Rice Yield, Mohd Nozulaidi, Md Sarwar Jahan, Mohd Khairi, Mohammad Moneruzzaman Khandaker, Mat Nashriyah, Yusop Mohd Khanif

Turkish Journal of Agriculture and Forestry

N-acetylcysteine (NAC) biosynthesized reduced glutathione (GSH), which maintains redox homeostasis in plants under normal and stressful conditions. To justify the effects of NAC on rice production, we measured yield parameters, chlorophyll (Chl) content, minimum Chl fluorescence (Fo), maximum Chl fluorescence (Fm), quantum yield (Fv/Fm), net photosynthesis rate (Pn), photosynthetically active radiation (PAR), and relative water content (RWC). Four treatments, N1G0 (nitrogen (N) with no NAC), N1G1 (N with NAC), N0G0 (no N and no NAC), and N0G1 (no N but with NAC), were arranged in a completely randomized design with five replications. Nitrogen significantly increased yield and yield parameters of …

Effect Of Ditylenchus Dipsaci Kühn, 1857 (Tylenchida: Anguinidae) On Onionyield In Karaman Province, Turkey, Eli̇f Yavuzaslanoğlu, Abdullah Di̇ki̇ci̇, İbrahi̇m Hali̇l Elekci̇oğlu

Turkish Journal of Agriculture and Forestry

This study was conducted to investigate the effect of the stem and bulb nematode Ditylenchus dipsaci Kühn (Tylenchida: Anguinidae) on yield parameters of some onion varieties in Karaman Province, Turkey. Experiments were established in a naturally infested onion field during two consecutive years (2012-2013). Nematode population development was followed at the beginning and end of the experiment. The reproduction rate was also calculated. Onion yield and the representative average diameter and length of the onion cultivar bulbs were determined. Yield parameters of six onion varieties were compared on nematicide-treated and untreated control plots in the experiments. Nematode populations significantly decreased …

Metal Uptake, Oxidative Metabolism, And Mycorrhization In Pigeonpeaand Pea Under Arsenic And Cadmium Stress, Neera Garg, Priyanka Singla, Purnima Bhandari

Turkish Journal of Agriculture and Forestry

Presence of arsenic (As) and cadmium (Cd) at elevated levels in the soils is threatening agricultural productivity. Arbuscular mycorrhizae (AM) enhance plant resistance to metal(loid)s by sequestering them into roots, thus restricting their translocation into leaves. The present study evaluated differential responses of AM-colonized Cajanus cajan and Pisum sativum plants to As and Cd uptake and oxidative metabolism under As and Cd stress (0, 30, and 60 mg kg-1). Arsenic uptake was significantly higher than Cd uptake, which caused greater growth inhibitions and induced oxidative stress. Pea was more sensitive, with higher toxicity symptoms in roots than leaves. Mycorrhizae were …

Auxin-Mediated Growth Of Rice In Cadmium-Contaminated Soil, Hussna Farooq, Hafiz Naeem Asghar, Muhammad Yahya Khan, Muhammad Saleem, Zahir Ahmad Zahir

Turkish Journal of Agriculture and Forestry

Pollution from heavy metals is a global problem that is very dangerous to the environment. Among the heavy metals, cadmium is receiving more and more attention because it is one of the most ecotoxic, making it very harmful for biological activity in soil, biodiversity, plant metabolism, and human and animal health. Phytohormones, produced by plants, control or regulate germination, growth, metabolism, or other physiological activities, and they can alleviate the toxic effects of heavy metals on plant growth. Auxin is the most abundant natural growth hormone, controlling apical dominance, tropism, elongation of shoots, and initiation of roots in plants. However, …

Utilization Of The Pomegranate Tree (Punica Granatum L.) In The Paper Industry, Sezgi̇n Koray Gülsoy, Ayben Kiliç Pekgözlü, Asli Ceren Aktaş

Turkish Journal of Agriculture and Forestry

In this study, the chemical composition, fiber morphology, pulp, and paper properties of the pomegranate tree (Punica granatum L.) were determined. Stem and branch wood were analyzed separately. Kraft and kraft- anthraquinone (AQ) methods were used for the pulping processes. Stem wood showed superiority to branch wood with longer, wider, thicker-walled fibers. The holocellulose, $\alpha$-cellulose, and lignin contents of branch and stem wood were 72.98%-73.50%, 38.37%-39.92%, and 21.04%-25.29%, respectively. In addition, the yield of kraft pulp made from stem wood was higher than that of branch wood. However, branch wood handsheets had higher strength properties and brightness than those of …

Spectral Reflectance Indices As A Rapid And Nondestructive Phenotyping Tool For Estimating Different Morphophysiological Traits Of Contrasting Spring Wheat Germplasms Under Arid Conditions, Salah El-Hendawy, Nasser Al-Suhaibani, Abd El-Azeem Salem, Shafiq Ur Rehman, Urs Schmidhalter

Turkish Journal of Agriculture and Forestry

The aim of this study was to investigate whether spectral reflectance indices could be used to estimate different destructive morphophysiological traits of a wide and diverse range of spring wheat germplasm in a rapid and nondestructive manner. A total of 90 spring wheat germoplasms were evaluated under water shortage by applying only three irrigations during the growing cycle of germplasm with the amount of water totaling 2550 m3 ha-1. Ten selected spectral reflectance indices were related to the green leaf number per plant, green leaf area per plant, total dry weight per plant (TDW), grain yield per hectare (GY), leaf …

Effects Of Prescribed Fire On Upland Plant Biodiversity And Abundance In Northeast Florida, Peter D. Maholland

UNF Graduate Theses and Dissertations

Terrestrial ecosystems in the southeastern United States have evolved with fire as a common disturbance and as a result many natural communities require the presence of fire to persist over time. Human development precludes natural fires from occurring within these communities; however, prescribed fire is considered to be a critical tool in the effort to restore fire-dependent ecosystems after decades of fire exclusion. Direct effects of fire on individual floral and faunal species as well as benefits to biodiversity at the landscape (gamma diversity) level have largely been supported in previous research. However, information on the effects of natural and …

Effects Of The Exotic Red Imported Fire Ant (Solenopsis Invicta) On The Growth And Survival Of The Threatened Hooded Pitcher Plant (Sarracenia Minor), Edward Marques

UNF Graduate Theses and Dissertations

Plants and insects are some of the most biodiverse groups in the world and are constantly interacting. One unique interaction that has been observed occurs between carnivorous plants and insects; some plant species are capable of capturing and digesting insects for nutrients. Despite preying on these insects, there are cases where such interactions can been viewed as mutualistic. For instance, a nectar reward is produced by the plant to attract insects, and during visitation insects may fall prey to these plants. Additionally, carnivorous myrmecophytic plants may receive an added indirect benefit in the form of reduced herbivory, since ants have …

Efficacy Of The Entomopathogenic Nematode Heterorhabditis Bacteriophora Using Different Application Methods In The Presence Or Absence Of A Natural Enemy, Ramalingam Karthik Raja, Canan Hazir, Ari̇fe Gümüş, Cem Asan, Mehmet Karagöz, Selçuk Hazir

Turkish Journal of Agriculture and Forestry

Various application methods for the entomopathogenic nematode Heterorhabditis bacteriophora were evaluated under laboratory and field conditions. Four different methods of applying the infective juveniles (IJs) of the nematode to soil were assessed including (1) insect cadavers (referred to as nematode-infected cadavers), (2) subsurface injection, (3) spraying, and (4) drip irrigation. In the laboratory experiment, except for the control with no nematodes, all treatments showed more than 95% insect mortality of the bait insect (Galleria mellonella) with no significant differences among treatments. The same experimental setup was conducted with the introduction of mites, Sancassania polyphyllae (Acari: Acaridae), which are natural enemies …

Forest Fire Risk Assessment Using Point Process Modeling & Monte Carlo Fire Simulation: A Case Study In Gyeongju, South Korea, Hyeyoung Woo

Graduate Student Theses, Dissertations, & Professional Papers

Forest fire risk assessment becomes critical for developing forest and fire management strategies in Korea since the magnitude of damage from fires significantly increased over the past decades. Fire behavior probability is one of the major components in quantifying fire risk, and is often presented as burn probability. Burn probability estimation requires a proper estimation of fire occurrence probability because fire spread is largely influenced by ignition locations in addition to other environmental factors, such as weather, topography, and land covers.

The objective of this study is to assess forest fire risk over a large forested landscape in and around …

Bamboo Harvesting For Household Income Generation In The Ethiopian Highlands: Current Conditions And Management Challenges, Bridget L. Tinsley

Graduate Student Theses, Dissertations, & Professional Papers

Bamboo is a renewable resource that has been advocated as a means to alleviate poverty and foster rural development throughout the world. Ethiopia holds 67% of continental Africa’s bamboo coverage and is gaining interest by international markets. Despite great speculation about Ethiopia’s bamboo market potential, foundational information regarding household utilization and income reliance is lacking. To understand how bamboo contributes to rural Ethiopian households, a quantitative household assessment was undertaken in this study. A questionnaire census collected data from 371 households. A quantitative assessment of household incomes and assets evaluated what factors influence bamboo harvesting.

The contribution of bamboo to …

An Assessment Of Biochar Amended Soilless Media For Nursery Propagation Of Northern Rocky Mountain Native Plants, Clarice P. Matt

Graduate Student Theses, Dissertations, & Professional Papers

A study was conducted to better inform nursery practitioners of the potential benefits of biochar application in common nursery media for native plant propagation. Biochar – a carbon-rich, recalcitrant charred organic co-product of the bioenergy pyrolysis process – has emerged as a promising potential replacement for various components of soilless media, namely peat, perlite, and vermiculite, in nursery seedling propagation. A strong conceptual basis exists for biochar as a nursery media amendment, but empirical data on biochar-based plant propagation is limited. This greenhouse study examined the effects of biochar displacement of standard soilless nursery media at rates of 0%, 15%, …

Decadal Scale Responses Of Soil And Ecosystem Processes To Forest Restoration In Rocky Mountain Conifer Forests, Peter Ganzlin

Graduate Student Theses, Dissertations, & Professional Papers

Decades of fire suppression have left much of the forest in the intermountain western United States exceedingly dense, and forest restoration techniques – including thinning and prescribed fire – are increasingly being used in an attempt to mitigate the potentially disastrous effects of severe wildfire, to enhance tree growth and regeneration, and to stimulate soil nutrient cycling. While many of the short-term effects of forest restoration have been established, the long-term effects on soil biogeochemical and ecosystem processes are largely unknown. In this thesis I present two manuscripts documenting and synthesizing these long-term impacts. The first chapter focuses on the …

A Model For Determining Drivers Of Phenology In Western United States Rangelands, Joseph R. St. Peter

Graduate Student Theses, Dissertations, & Professional Papers

Plant phenology has long been used as an indicator of climate. Recent changes in plant phenology are evidence of the influence of climate change. Modeling plant phenology has become an effective tool to understand the impacts of climate change. Using machine learning techniques I developed a modeling process for accurately predicting phenology across a diverse landscape. This model uses individual site data to set site specific climate thresholds for plant phenology. This model also identifies the limiting factors to vegetation phenology for rangelands in the western United States. NDVI remotely sensed data was used to quantify land surface phenology and …