Forest Sciences Commons^™

Rocky Mountain Forests Are Poised To Recover Following Bark Beetle Outbreaks But With Altered Composition, Kyle C. Rodman, Robert A. Andrus, Amanda R. Carlson, Trevor A. Carter, Teresa B. Chapman, Jonathan D. Coop, Paula J. Fornwalt, Nathan S. Gill, Brian J. Harvey, Ashley E. Hoffman, Katharine C. Kelsey, Dominik Kulakowski, Daniel C. Laughlin, Jenna E. Morris, José F. Negrón, Katherine M. Nigro, Gregory S. Pappas, Miranda D. Redmond, Charles C. Rhoades, Monique E. Rocca, Zoe H. Schapira, Jason S. Sibold, Camille S. Stevens-Rumann, Thomas T. Veblen, Jianmin Wang, Xiaoyang Zhang, Sarah J. Hart

Geography

Amplified by warming temperatures and drought, recent outbreaks of native bark beetles (Curculionidae: Scolytinae) have caused extensive tree mortality throughout Europe and North America. Despite their ubiquitous nature and important effects on ecosystems, forest recovery following such disturbances is poorly understood, particularly across regions with varying abiotic conditions and outbreak effects. To better understand post-outbreak recovery across a topographically complex region, we synthesized data from 16 field studies spanning subalpine forests in the Southern Rocky Mountains, USA. From 1997 to 2019, these forests were heavily affected by outbreaks of three native bark beetle species (Dendroctonus ponderosae, Dendroctonus rufipennis and Dryocoetes …

Transformation Of Farmer Resistance In Conservation Areas: Land Occupation By Farmers In Mount Halimun-Salak National Park, West Java, Sulastri Sardjo, Arya Hadi Dharmawan, Dudung Darusman, Ekawati Sri Wahyuni

Masyarakat: Jurnal Sosiologi

A number of studies have shown various agrarian conflicts as a response by local farmers against the policy of national parks that prohibits them from accessing conservation forest areas. However, previous studies had not explained the dynamics of power relations between park authorities and farmers who stand in opposition to these policies. This study employs a qualitative research approach complemented by secondary data to explain the transformation of farmer resistance in the Mount Halimun-Salak National Park (TNGHS) area, namely from their repertoire of everyday resistance to practices of land occupation. Specifically, this study uses the “powercube” analytical framework to explain …

Frayed Connections: How Long-Term Nitrogen Additions Disrupt Plant-Soil Interactions And The Carbon Cycle Of A Temperate Forest, Brooke A. Eastman

Graduate Theses, Dissertations, and Problem Reports (ETD)

Forests are expected to mitigate some of the negative effects of climate change by sequestering anthropogenic carbon (C) from the atmosphere, but the degree to which they drawn down C will depend on the availability of key nutrients, such as nitrogen (N). There is a fair amount of uncertainty in the future of the forest C sink, mostly owing to the fate of soil organic matter (SOM) and soil heterotrophic respiration to future conditions. In N limited systems, plants allocate a significant amount of their photosynthate belowground for the acquisition of nutrients, but under conditions of chronic N deposition, plants …

The Impacts Of Maple Syrup Production On The Herbaceous Layer In Appalachian Hardwood Forests, Logan Scott Ferguson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Vegetation data were collected from eight maple syrup farms (sugarbushes) and eight undeveloped maple-dominated sites to examine potential differences in understory plant communities due to disturbance effects. Understory plants were identified to the species level and percent cover of aboveground leaf-area for each species was estimated within 600 total quadrats. Overstory data and environmental data were collected to help determine if they had any effect on herbaceous-layer plant communities. Species richness, Shannon diversity, and Pielou’s evenness were calculated, with the analysis showing no significant differences between the site types. The absolute cover of plant functional groups was also compared between …

Determining The Novel Pathogen Neodothiora Populina As The Causal Agent Of The Aspen Running Canker Disease In Alaska, Loretta M. Winton, Gerard C. Adams, Roger W. Ruess

Department of Plant Pathology: Faculty Publications

Neodothiora populina Crous, G.C. Adams & Winton was determined to be a new pathogen of trembling aspen (Populus tremuloides) growing in Alaska, based on completion of Koch's Postulates in replicated forest and growth chamber inoculation trials. The pathogen is responsible for severe damage and widespread rapid mortality of sapling to mature aspen (≥ 80 years) in the boreal forests of interior Alaska, due to large diffuse annual (1–2 years) cankers. Isolation of the pathogen was challenging, and identification based on cultural characters was difficult. Fruiting bodies were not found on wild diseased trees, but erumpent pycnidia were found …

The Site Evaluation Of Quercus Alba Metabolites, Zachary Alexander Byrd

Theses and Dissertations--Plant and Soil Sciences

Quercus alba has been the prominent tree species utilized in the spirits industry for decades. Of its many qualities, the ability to impart desirable flavors on spirits combined with its natural abundance makes it the ideal choice for barrels. Creating barrels is a uniform process, but variability still exists in aged spirits even when all other parameters are controlled. In this thesis, I explore how the origin of Quercus alba influences metabolite variability.

Quercus alba is a resilient species that can grow in many climates. This is seen through Quercus alba’s vast growing range, of which barrel quality white oak …

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 …

Advancing Forest Structure-Function Relationships: Linking Above- And Belowground Structure To Soil Respiration, Laura J. Hickey

Theses and Dissertations

Variation in the soil-to-atmosphere C flux, or soil respiration (Rs), is influenced by a suite of biotic and abiotic factors, including soil temperature, soil moisture, and root biomass. However, whether canopy structure is tied to soil respiration through its simultaneous influence over these drivers is not known. We assessed relationships between measures of above- and belowground vegetation density and complexity, and evaluated whether Rs is linked to remotely sensed canopy structure through pathways mediated by established biotic and abiotic mechanisms. Our results revealed that, at stand-scale, canopy rugosity–a measure of complexity–and vegetation area index were coupled to soil respiration through …

Application Of Mass Spectrometry For Characterization Of Plant-Based Phenolics And Alkaloids, Masoumeh Dorrani

Theses and Dissertations--Chemistry

Plant-derived compounds have the potential to produce value-added compounds with a variety of applications. For example, the lignin part of the lignocellulosic biomass, produced in large quantities as waste from the paper and pulp industries, is a rich source of phenolics with potential applications in the renewable energy sector, pharmaceutical, and chemical industries. On the other hand, plant alkaloids are the primary source for developing plant-derived therapeutics. Unfortunately, the recalcitrant nature of plant cell walls, low extraction yields of small secondary metabolites, and the lack of effective analytical methods for a rapid and accurate identification of plant-based compounds and plant’s …

Public Procurement Practices And Policies: Implications For Public Research And Development In The Philippines, Nelson Jose Vincent B. Querijero, Rhea L. Gumasing, Arlene C. Gutierrez, Ruth Anne T. Ruelos, Charina Krissel D. Tingson

Journal of Public Affairs and Development

This study examines procurement practices and policies that hinder or facilitate public research and development. An online survey and interviews with key informants in 44 research development institutions (RDIs) in the Philippines were conducted. Participants include Project Leaders, members of the Bids and Awards Committee (BAC), the BAC secretariat, chief accountants, technical working groups, and suppliers. The results show that some procurement policies, workflows, and capacities of the procuring entities contribute to procurement delays. A lack of qualified or suitable suppliers and a limited market of highly specialized and scientific equipment are also factors affecting procurement efficiency. It is recommended …

Revisiting Participatory Rural Appraisal (Pra) Related Studies And Exploring Pra's Success Determinants: A Content Analysis, Raquel Garcia-Agustin

Journal of Public Affairs and Development

Participatory Rural Appraisal (PRA) has shown that participation in development programs in poor communities can be empowering not only for the community members but also for the development workers. However, not all PRAs have seen successes especially in fulfilling their mission to encourage real participation. Hence, it is imperative to understand whether PRA has led to adequate understanding of indigenous perspective to call for action and the interest PRA serves. This analysis aims to provide critical insights and reflections from the experiences of previously conducted PRAs. It further aims to reveal whether PRAs were used effectively and successfully according to …

Taiwanese Perceptions Of China, Taiwan, And Us Relations From 2016 To 2021, Wan-Ling Liao, Armand Christopher C. Rola

Journal of Public Affairs and Development

In 2016, a dramatic shift in Taiwan's politics caught China's attention. After the inauguration of President Tsai Ing-wen, Beijing increased the pressure on Taiwan. Aside from limiting Taiwan's international space, Beijing had taken other steps. This study aims to review the policy regarding the relationship among Taiwan, the US, and China. The primary data were gathered through interviews with Taiwanese key informants of different age groups. Secondary data were gathered from official documents, online sources, journal and news articles, and books. Based on the analysis of informants' opinions on this issue, the study found that the majority of informants prefer …

Investigating Seed Maturation And Mortality: A Mechanism For Post-Fire Regeneration In Non-Serotinous Conifers, Madeleine A. Lopez

Cal Poly Humboldt theses and projects

Climate warming and associated dry conditions are contributing to increased fire frequency, severity, and size, for many regions in western North America. These changes in fire activity have prompted concern over the long-term persistence of some conifer species, specifically those not adapted to withstand high-severity fire. However, regeneration of non-serotinous conifer species is possible if the timing of fire occurs following seed maturation, and within a heat range that seeds can withstand, in a regenerative mechanism termed “facultative serotiny.” To address this mechanism, I determined the timing of conifer seed maturation using viability testing for four California conifer species: ponderosa …

Drought, Tree Mortality, And Regeneration In Northen California, Sophia Lb Lemmo

Cal Poly Humboldt theses and projects

The 2012-2016 California drought was the most severe in the state’s recorded history, contributing to the death of millions of trees. While the effects of this drought on forests are relatively well studied in the central and southern Sierra Nevada, less is known about its effects on the heavily timbered and diverse forests of northern California. Through sampling 54 0.25 ha plots in northern California, this study compared tree mortality and regeneration patterns before, during, and after California’s most recent record-setting drought. This study evaluated 1) the influence of habitat and competitive covariates on mortality and regeneration trends using ridge …

A Pantropical Assessment Of Deforestation Caused By Industrial Mining, Stefan Giljum, Victor Maus, Nikolas Kuschnig, Sebastian Luckeneder, Michael Tost, Laura J. Sonter, Anthony J. Bebbington

Geography

Growing demand for minerals continues to drive deforestation worldwide. Tropical forests are particularly vulnerable to the environmental impacts of mining and mineral processing. Many local- to regional-scale studies document extensive, long-lasting impacts of mining on biodiversity and ecosystem services. However, the full scope of deforestation induced by industrial mining across the tropics is yet unknown. Here, we present a biome-wide assessment to show where industrial mine expansion has caused the most deforestation from 2000 to 2019. We find that 3,264 km2 of forest was directly lost due to industrial mining, with 80% occurring in only four countries: Indonesia, Brazil, Ghana, …

Drought Responses Across Diverse Conifer Species, Habitats, And Competitive Gradients In Northern California, Gabriel J. Roletti

Cal Poly Humboldt theses and projects

Frequent and intense drought events are rapidly altering stand dynamics in western North American forests. Climate, competition, and site characteristics can affect the growth responses of individual trees to drought stress. The ecological and geographical diversity of northern California provides a unique opportunity to measure these responses across species, habitat types, and levels of competitive pressure. This study used dendrochronological techniques and linear mixed-effects models to assess growth responses to drought in four montane and two coastal conifer species across 54 study sites (nine sites per species and 540 trees total) in northern California. Growth was evaluated from 2002-2018 and …

Pyrogenic Carbon Content Of Sphagnum Peat Soils Estimated Using Diffuse Reflectance Ftir Spectrometry, Dominic Uhelski, Evan S. Kane, Rodney Chimner, Katherine A. Heckman, Jessica Miesel, Li Xie

Michigan Tech Publications, Part 1

Quantifying historical patterns of fire regimes in peatlands can help contextualise current fire behaviour and aid in planning on ecosystem and landscape scales. However, current methods for detecting the evidence of past fires in peat soils are laborious or expensive. Our goal was to develop an effective and inexpensive method for detecting pyrogenic carbon (PyC) concentration in peat which could be used to estimate the occurrence of fires by analysis of discrete soil samples. We correlated diffuse reflectance Fourier-transform infrared spectrometry (FTIR) measurements of peat, and admixtures of peat and PyC, with nuclear magnetic resonance spectrometry (NMR) estimates of PyC …

Impact Of Drought Stress On Oak Stomatal Size And Density At Thompson Farm, Nh, Emily Chen

Honors Theses and Capstones

Global climate change is likely to affect northeastern U.S. forests by increasing the frequency and severity of drought events. Historically, droughts rarely occurred in this region, so native tree species are not well-adapted to extreme moisture stress. In the future, the changing climate will likely cause unprecedented levels of low water availability which may have implications on future forest composition. It is hypothesized that trees can respond to these environmental changes by altering their functional traits, also referred to as phenotypic plasticity; for example, by producing leaves with fewer and smaller stomata.

To determine the capacity to which oak trees …

Optimization And Analytics Of Decarbonized Forest And Biomass Supply Chains, Xufeng Zhang

Graduate Theses, Dissertations, and Problem Reports (ETD)

First, a data-driven holistic analysis framework was developed to aid the industrial development of forest biomass for bioenergy to promote the regional bioeconomy. Leveraging the existing but fragmented multi-source data, four components of industrial bioenergy development were integrated into the framework including spatial statistical analysis of biomass feedstock and bioenergy production, machine learning-based suitability assessment, bioenergy plant sites identification and ranking, and socio-economic impacts assessment. A case study was conducted for forest biomass to pellet fuel in the U.S. Mid-Atlantic region. Our results indicate that the great potential of forest biomass with high variation at the county level is primarily …

Prunus Microcarpa: A Potential Rootstock For Apricots, Remzi̇ Uğur

Turkish Journal of Agriculture and Forestry

One of the most important developments in the history of fruit growing is the discovery and use of dwarf rootstocks. Today, dwarf rootstock studies continue in different fruit species including apricot. The main goal of this study was to identify new dwarfing rootstocks for apricots that limit apricot tree height and size, without altering scion production or fruit characteristics. In this study, `Hacıhaliloğlu', `Hasanbey', `Kabaaşı', and `Roxana' apricot cultivars grafted on Prunus microcarpa - a potential rootstock for apricot - were investigated. Phenological, morphological, yield, and quality traits of apricot (Prunus armeniaca L.) cultivars grafted on Prunus microcarpa seedlings and …