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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Lietuvos miško ūkio valdymo analizė / Analysis of Lithuanian forestry management

Raudonius, Darius 16 June 2005 (has links)
At the end analysis of forestry management was drew a conclusion – by financial activities was operated three models of Lithuania forestry management: budgetary financial in interwar Lithuania, budgetary and economical count financial in the period of Lithuania dependent, economical count financial in the open of Lithuania independence.
22

AUTOMATED HEIGHT MEASUREMENT AND CANOPY DELINEATION OF HARDWOOD PLANTATIONS USING UAS RGB IMAGERY

Aishwarya Chandrasekaran (9175433) 29 July 2020 (has links)
Recently, products of Unmanned Aerial System (UAS) integrated through SIFT algorithm and dense cloud matching using structure from motion has gained prominence with tree-level inventory maintenance in forestry. Various studies have been carried out by using UAS imagery to quantify and map forest structure of simple coniferous stands. However, most of the previous works employ methodologies that require manual inputs and lack of reproducibility to other forest systmes. Manual detection of trees and calculation of their attributes can be a time-consuming and complicated process which can be overcome with an automated technique applied by forest managers and/or landowners is highly desired to take full advantage of the readily available UAS remote sensing images. This study presents a methodology for automated measurements of tree height, crown area and crown diameter of hardwood species using UAS images. Different UAS platforms were employed to gather digital data of two hardwood plantations at Martell, Indiana. The resulting aerial images were used to generate the Digital Surface Model (DSM) and Digital Elevation Model (DEM) for the forest stand from which the Crown Height Model (CHM) was derived. The canopy height model can be inputted to the web platform deployed through shiny server (https://feilab.shinyapps.io/Crown/) to derive individual tree parameters automatically. The results show that this automated method provides a high accuracy in individual tree identification (F-score> 90%) and tree-level measurements (RMSEht<1.2m and RMSEcrn<1m). Moreover, tree-level parameter estimation for 4,600 trees were calculated in less than 30 minutes based on a post-processed DSM from UAS-SfM derived images with minimal manual inputs. This study demonstrates the feasibility of automated inventory and measure of tree-level attributes in hardwood plantations with UAS images.
23

UNDERSTORY RESPONSE TO SHELTERWOOD AND BURN TREATMENTS IN A DRY QUERCUS FOREST IN INDIANA

Sarah J Rademacher (12469245) 27 April 2022 (has links)
<p>  </p> <p>Alterations to the historic fire regime have contributed to widespread regeneration failure in <em>Quercus</em> L. (oak) forests of the eastern United States. Composition has shifted from <em>Quercus</em> and other fire-adapted species to dominance by mesophytic species. While land managers often focus efforts on restoring <em>Quercus</em> regeneration, the herbaceous layer experiences reduced cover and diversity of herb and graminoid species resulting from the increased woody stem density in fire-suppressed forests. Declining abundance of <em>Quercus</em> species and diversity in the herbaceous layer reduce the overall habitat quality and ecosystem functions provided by the forest. A combination of overstory harvests and prescribed burning are often conducted to restore the plant community in <em>Quercus</em> forests affected by mesophication. Initiated in 2010, our study on the Hoosier National Forest in Indiana conducted shelterwood and midstory (mechanical, chemical, or none) harvests followed by prescribed burning on a less productive site, while leaving a more productive site unburned. Our objective was to evaluate the survival and competitive response of <em>Quercus</em> spp. within the regeneration layer and whether diversity and cover increased in the herbaceous layer following treatments. Using nested circular plots, we measured seedling survival and resprout response, in addition to regeneration density before and after treatments. We measured the percent cover of herbaceous-layer species within quadrats and calculated species richness, evenness, and diversity. Using multiple mixed-effects models, ANOVA, and NMDS ordination, we evaluated woody species regeneration and herbaceous-layer composition before and after treatments. Post-treatment, monitored <em>Quercus</em> spp. seedlings at the burned site displayed greater survival (> 94%) and resprouting (> 92% of monitored stems), which exceeded most competing species, including<em> Acer</em> spp. (~ 59% survival and resprouting) and <em>Fraxinus americana </em>(72% survival and resprouting). <em>Q. alba</em> seedling (< 3.8 cm DBH) densities doubled after burning; it was one of the most abundant species (9,864 stems ha-1) at the burned site. NMDS ordination indicated a clear shift in regeneration species composition with the burn driving a shift away from mesophytic species towards greater importance of <em>Quercus</em> species. Additionally, our burned site had significantly increased herbaceous-layer richness, Shannon diversity index, and total cover compared to pre-treatment. Percent cover increased across all plant functional groups within the herbaceous layer, with trees/shrubs exhibiting the greatest increase. Herbaceous-layer composition at the burned site significantly shifted toward greater importance of graminoids and herbs post-treatment. Post-treatment, the unburned site contained fewer, and less competitive, <em>Quercus</em> seedlings compared to non-<em>Quercus</em> competitors and displayed no significant compositional shifts in seedling species composition post-harvest. Our unburned site exhibited significant, but minor, increases in herbaceous-layer richness, evenness, diversity, and total cover. Herbaceous-layer composition at the unburned site was significantly different post-treatment, shifting towards greater importance of vines, trees/shrubs, and herbs. The more-productive unburned site would likely require multiple burns to produce adequate competitive <em>Quercus</em> seedlings to perpetuate dominance in the developing stand. Burning would also likely result in greater increases in herbaceous-layer diversity compared to harvesting alone. Conversely, the shelterwood, followed by a single burn, on the less productive site had a more substantial effect on the herbaceous layer, and likely produced an adequate density of <em>Quercus</em> reproduction to ensure future dominance by the genus.</p>
24

The Establishment, Control, and Post-Control Response of Amur Honeysuckle (Lonicera maackii)

Benjamin Joseph Rivera (11205324) 29 July 2021 (has links)
<p>Amur honeysuckle (<i>Lonicera maackii</i>) is a shrub endemic to East Asia which has become invasive and nearly ubiquitous to the forest ecosystems of eastern North America. Through its extended growing season, competitive ability, and potential allelopathy, Amur honeysuckle alters native herbaceous-layer plant communities and inhibits the regeneration of native tree species. As such, it is representative of a range of invasive shrub species imported from East Asia. My thesis contributes to questions fundamental to the understanding this and other invasive shrubs: 1) How do species become invasive? 2) How can the invasions of the species be effectively controlled? 3) How does the ecosystem respond to treatment of the invasive species?</p> <p>First, I examined the role of self-compatibility within Amur honeysuckle. I compared the berry production, seed production, and germination rates between closed-pollinated and open-pollinated flowering branches of Amur honeysuckle individuals across multiple types of invasions (heavy, light, and sprouting). I found that Amur honeysuckle not only possesses the ability to self-pollinate, but that it can produce viable self-pollinated seed sets. This ability may help explain how Amur honeysuckle able to invade isolated forest patches far removed from the main invasion.</p> <p>Second, I evaluated the effectiveness of a novel herbicide adjuvant in reducing the amount of herbicide needed in the ‘cut-stump’ method of controlling Amur honeysuckle. Combining various concentrations of the most common herbicide in the world, glyphosate, with concentrations of cellulases derived from fungi, 2XL, I examined whether the cellulases improved the effectiveness of glyphosate, potentially by increasing glyphosate movement into the vascular tissue of Amur honeysuckle through the degradation of cell walls. While 2XL was not an effective adjuvant, glyphosate concentrations of less than half the recommended dosages were equally effective as higher concentrations in preventing sprouting of treated stumps. The ineffectiveness of 2XL may imply a need for protein-mitigated diffusion of glyphosate across cell walls and into the vascular tissue of the plant, which would be inhibited by the breakdown of cell walls.</p> Finally, I tested how deeper intensities of mulching-head treatments affected the sprouting response of Amur honeysuckle and the response of the herbaceous-layer plant community after treatment. I found a negative relationship between the volume of sprouting Amur honeysuckle and increasing depth of mulching-head treatment. Additionally, increasing mulching-head intensities were correlated with increased herbaceous layer diversity and conservation value as represented by Floristic Quality Index. Mulching-head treatments are a promising tool in controlling heavy invasions of non-native shrubs.
25

A LIFE CYCLE ANALYSIS OF FOREST MANAGEMENT DECISIONS ON HARDWOODS PLANTATIONS

Sayon Ghosh (15361603) 26 April 2023 (has links)
<p>In the Central Hardwood Region, the quantity and quality of hardwood timber critically depend on forest management decisions made by private landowners, since they hold the largest share of woodlands, some of which are plantations. These plantations are in a unique and critical position to provide much-needed hardwood resources. However, there is a lack of research and tools enabling rigorous assessments of profitability of long-term investments in hardwood plantations. Partially due to this, the majority of these privately held plantations remain unmanaged.</p> <p>This study aims at providing scientific evidence and tools to help promote forest management on hardwood plantations held by private landowners. To this end, I demonstrate in Chapter 1 an economic-modeling approach that minimizes establishment costs while ensuring free-to-grow status by year 5, and crown closure by year 10. Using temperate hardwoods such as black walnut and red oak as focal species, I find a black walnut plantation can attain crown closure in year six at the lowest cost ($4,540/ha) with 6 feet x 7 feet spacing, herbicide application for the first year, and fencing. For red oak, the minimum-cost option ($5,371/ ha) which achieves crown closure in year 10 requires a planting density of 6 feet x 7 feet, herbicide application for the first three years, and fencing. Modelling uncertainty in growth and mortality in a stochastic counterpart shifts optimal solutions to denser plantings for black walnut; planting more trees is, thus, risk mitigative. Based upon these research outcomes, I identify the tradeoffs between efficacy of treatments towards establishment success viz a viz their relative costs which serve as a solid foundation for the assessment of subsequent management strategies.</p> <p>Next, in chapter 2, I first calibrate growth, yield, and crown-width models for black walnut trees with existing and new tree measurements on selected Hardwood Tree Improvement and Regeneration Center (HTIRC) plots. Using spatial information on trees, I develop an individual tree level thinning model and simulate their post-thinning growth and yield. Significant predictors of annual diameter growth between years 10 to 18 include the initial tree DBH, forest edge effects, distance-dependent neighborhood competition, and tree age. Significant edge effects exist up to 3 rows and 3 trees from the non-forested edge. A tree on the perimeter rows grows 0.30 cm (0.12in.) in DBH more per year than the interior trees, between years 10 to 18. Next, I dovetail my results from the spatially explicit thinning model with the USFS Forest Vegetation Simulator (FVS) to understand the impacts of different scenarios of planting densities, site productivities, thinning treatments, and expected yields (as percentage of the total volume) of veneer sawlogs to quantify the growth and profitability from the mid-rotation until the final harvest. To support the attendant financial analyses, I incorporate risk into these projections by simulating stochastic windthrows based on certain assumptions. My projections suggest that, without the threat of windthrow damage, the net present day value (NPV) could exceed $4,900 per acre on the highest quality sites (SI =100) and high densities at planting (6 feet x 6 feet), assuming 10% or more of final volume was veneer and using a 3% discount rate. In contrast, under simulations of probable windthrow disturbances from mid-rotation to final harvest, the chances that standing timber value at harvest exceeds $5,000 per acre are 43.13% for a 96- and 90-year rotation and increase to 45.48% for 75 and further to 56.04% for 60.</p>
26

CHANGES IN TREE CANOPY CHEMICAL AND SPECTRAL PROPERTIES IN RESPONSE TO SPOTTED LANTERNFLY (Lycorma delicatula)INFESTATIONS

Elisabeth G Joll (15360469), Kelli Hoover (15360483), Matthew Ginzel (8771376), John Couture (15360486) 29 April 2023 (has links)
<p> Invasive species have developed long-term relationships with humans, especially since the start of the Industrial Revolution, and they have caused immense damage to native environments, ecosystems, and economies. An emerging invasive insect that has recently gained considerable attention is the spotted lanternfly (SLF). Early detection of SLF infestations in new areas or at low densities can lead to a more efficacious management and reduce costs associated with control them. Developing approaches to detect the presence of invasive species, favorable habitats for their establishment, and predicting potential spread will be crucial for effective management strategies to protect native environments and the economy. The goal of my thesis is to improve the understanding of how spotted lanternfly changes the spectral profile and chemical composition of host tree species. I found that spotted lanternfly feeding influences host canopy chemical and spectral properties. Specifically, I was able to use leaf-level hyperspectral measurements to differentiate SLF infestations levels in silver maple and red maple, shown by my first chapter, along with black walnut in my second chapter. Further, I was able to find differences in phenolic compounds in response to SLF infestations in red maple. The results of my study have the potential to be scaled up from leaf-level to landscape-level measurements. I have identified spectral signatures in red maple, silver maple, and black walnut that can be used to identify infestations from spectral data collected from UAVs or satellites. This potentially provides a new method for detection that is easier than traditional ones (like manual scouting and trapping). </p>
27

COMPARATIVE SILVICS OF BUTTERNUT HYBRIDS IN AFFORESTATION AND REFORESTATION PLANTINGS

Caleb E Kell (15361801) 27 April 2023 (has links)
<p>Thesis submission for Caleb Kell</p>
28

THE INFLUENCE OF LOCAL AND LANDSCAPE CHARACTERISTICS ON DEER BROWSING, AND SUBSEQUENTLY THE COMPOSITION AND STRUCTURE OF FOREST UNDERSTORIES, IN INDIANA

Richard D Sample (14204861) 02 December 2022 (has links)
<p>White-tailed deer (Odocoileus virginianus; hereafter deer) are a keystone herbivore within forest ecosystems. While deer rely on plant species for growth, reproduction, and survival, multiple external factors can dictate browsing behavior. These factors ultimately drive browsing selection, browsing intensity, and diet composition, which in turn can shape the influence deer have on forest ecosystems. To better understand the complex relationship between deer populations, their habitat, and public perception of deer, the Indiana Department of Natural Resources partnered with Purdue University to initiate the Integrated Deer Management Project (IDMP). As part of the IDMP, this dissertation evaluated the ecological condition of deer habitat to assess the influence deer have on woody and herbaceous plant species within Indiana forests. Our study aimed to i) rank woody species according to their selection by deer and evaluate how the ranking of individual species varies across the state (Chapter 2); ii) evaluate variables and spatial extents associated with differences in browsing intensity, and evaluate different indices used to assess differences in browsing intensity (Chapter 3); iii) quantify winter deer diet composition using DNA barcoding to evaluate how diets vary across a gradient of deer densities, browsing intensities, non-native plant densities, and landscape characteristics (Chapter 4); and iv) evaluate the interactive effects of deer, non-native plant species, and landscape characteristics on the herbaceous layer of forests, while further evaluating the spatial extent at which landscape characteristics are most strongly related to herbaceous-layer composition and diversity (Chapter 5). To do this, I sampled 152 woodlots over three years across three regions of Indiana, collecting data on the browsing selection of individual woody species, the browsing intensities on all woody species, and the composition of vegetation communities (Chapters 2, 3, and 5, respectively). To address diet composition (Chapter 4), we collected deer pellet groups to analyzed diet components. We ranked a total of 63 woody species regarding their browsing selection by deer. While most of these remained consistent from region to region, 16 varied greatly in selection, as deer often showed increased selection for a given species when it resided in an area that provided greater browsing opportunities. Browsing intensity was most associated with food availability, however, it was also influenced by deer density in the region with the lowest forest cover. The twig age index of browsing intensity showed promise as the most efficient and effective index for use in Indiana woodlots. Although diet composition did not differ across regions of Indiana, we found 16 that deer consumed several uncommon taxa when the greater landscape exhibited homogenous patch composition. Similarly, deer consumed different native taxa in forested landscapes with greater deer densities in comparison to agricultural landscapes with lower deer densities. Lastly, though browsing varied within and across regions landscape characteristic, and not deer, were the most influential suite of variables. Additionally, the spatial extent at which these variables exhibited their best fit varied depending on the dependent variable being evaluated and the region of analysis. Together, our results highlight that variables ranging from the woodlot to the landscape-scale influence browsing behavior. This showcases that deer respond to variables at varying scales when browsing and in general, browse more in areas that offer the greatest benefit, whether these areas offer greater food availability or quality, or offer lower risks associated with anthropogenic development. This suggests that when managing forests for deer both woodlot and landscape context should play a role in the decision process. Although differences in browsing were observed, deer had less impact on the herbaceous layer compared to other variables we examined. This suggests that, in contemporary forests, landscape characteristics may be the drivers of changes, and species composition may reflect a long-term history of deer herbivory with less variability resulting from differences in contemporary deer abundance within and across regions.  </p>
29

Quantitative Conservation Conflict Management: an Application to the Yellowwood Logging Controversy

Katelyn Elizabeth Jeffries (17547288) 05 December 2023 (has links)
<p dir="ltr">Conservation conflicts, commonly defined as “situations that occur when two or more parties with strongly held opinions clash over conservation objectives, and when one party is perceived to assert its interests at the expense of another” (Redpath et al., 2013) are expected within the realm of public land management. Conservation conflicts have been an increasing issue worldwide as the consumption of natural resources can directly oppose conservation efforts. Quantitative and qualitative approaches have been adopted in similar studies to mitigate or resolve conservation conflicts. This thesis focuses on a 2017 conflict over logging in Yellowwood State Forest in Indiana. The Social Multi-Criteria Evaluation (SMCE) framework was applied in this thesis to examine economic, ecological, and recreational criteria from multiple stakeholders' perspectives and understand how a retrospective assessment can contribute to improved conflict resolution. The study follows four steps: conducting an institutional analysis, defining criteria and potential alternative scenarios, generating an impact matrix through surveys and interviews, and aggregating results for cross-scenario comparison. The design of these steps attempts to engage stakeholders in the decision-making process and increase transparency. The ranking results reveal a clear preference for the “Shelterwood Cuts” alternative, indicating that different actions may have been a better solution. Although the methodology alone cannot make decisions, it can aid the decision-maker in creating a solution to a conservation conflict by providing guidance and bringing attention to the aspects of a conflict that require change.</p>
30

<b>Evaluating resource competition of live oak (</b><b><i>Quercus virginiana </i></b><b>) regeneration to support maritime forest restoration </b>

Brianne Nicole Innusa (18423570) 23 April 2024 (has links)
<p dir="ltr">Coastal ecosystems are critically important habitats for the services they provide on a global and local scale. Maritime forests are found within the southern Atlantic coast, and they serve as a boundary between the ocean and land. These forests stabilize coastlines, recharge groundwater, and provide a protective buffer against storm damage. Southern live oak (<i>Quercus virginiana</i>) was historically the dominant canopy species in maritime forests; however, previous land conversions to loblolly pine (<i>Pinus taeda</i>) plantations have shifted the abundance of loblolly pine to become the dominant canopy tree in maritime forests. Loblolly pines are fast growing, and they regenerate vigorously but they are not well adapted to coastal stressor. In recent decades, outbreaks of southern pine beetle (<i>Dendroctonus frontalis</i>) have provided restoration practitioners an opportunity to clear tracts of pine dominated maritime forest to restore live oak to the canopy. This research project is comprised of two experiments studying the performance of planted <i>Q. virginiana</i> seedlings on maritime forest restoration sites in coastal Georgia. The first experiment evaluated planting density (1-meter, 2-meters, 3-meters), mulch (with or without), and fertilizer (with or without). Overall seedling survival was 99% after four years. The application of fertilizer had an initial positive effect on seedling diameter after the first growing season. The application of mulch increased seedling height in the second to fourth growing seasons, diameter in third and fourth, and crown width in the fourth growing season. Planting density had no consistent effect over the first four years, and no biological significance was observed for foliar nutrient content. The second experiment examined eight different groupings of intra- and interspecific competition between <i>Q. virginiana</i> and <i>P. taeda</i> including: oak or pine alone; oak surrounded by oak, pine, or oak/pine; pine surrounded by pine, oak, or pine/oak at 0.5-m spacing between all seedlings. Two years after outplanting, survival did not vary by treatment. Oak centered competition plots were positively impacted by border tree height and diameter in year one and border height positively affected the center tree height in year two. Pine centered competition plots were positively impacted by border tree height in year one and year two. Oak centered competition plots with a mix of oak and pine on the border had significantly lower osmotic potential than other pine centric treatments after two years. Overall, oak centered treatments had lower osmotic potential than pine centered treatments. Ectomycorrhizal (EMF) species composition changed, and relative abundance increased from the initial planting to two years later but there was no variation between treatments and most EMF species were generalists. These results highlight the importance of mulch and fertilizer to reduce transplant shock and how competing seedlings can train seedlings to allocate photosynthate to shoot growth to help promote aboveground growth.</p>

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