Forest Biology Commons^™

The Ecology Of Arthropod Rain In A Tropical Forest., Andrew Robert Seiler

Electronic Theses and Dissertations

Tropical forests are structured by complex vertical linkages and nutrient exchanges between canopy and understory habitats. These linkages include the downward flux of organisms, the movement of canopy fauna, and the recycling of nutrients through litter and organic matter deposition. This dissertation investigates arthropod rain and its role in connecting the canopy and forest floor processes in a lowland tropical forest in Panama. Chapter 2 quantifies “arthropod rain”, the fall of canopy arthropods into the understory. Using pan and pole traps, I measured the composition, abundance, and biomass of arthropods falling from the canopy and assessed environmental drivers of the …

Stand Strucuture Of Planted Stands In Storm-Water Retention Basins, Jason Lanza

Electronic Theses and Dissertations

Trees assist in stormwater retention basin functionality as efficient sources of water removal, and determining stand structure and leaf area of forests can be a measure of their effectiveness. The structure of forest stands on these basins managed for runoff mitigation has received little attention. We investigated the structure and species composition/diversity (tree and herbaceous) of planted, managed stands and naturally regenerated stands on stormwater retention basins managed by Harris County Flood Control District in Harris County, Texas. We determined stand structure variables (trees per hectare, basal area per hectare, quadratic mean diameter, relative density, average tree height, and percent …

The Forest Through The Trees: Modeling The Ecological Niche And Potential Assemblage Distribution Of Oak-Hickory Forests Across The Eastern U.S., Elijah Worley

Electronic Theses and Dissertations

Understanding how tree species’ ranges and populations may shift by the end of the 21^st Century is critical for effective conservation and forest management. Ecological niche models are widely used to predict species distributions by modeling the relationships between environmental variables and species presence. While numerous models have been developed for individual tree species across the USA, there is limited research on how tree species assemblages, such as oak-hickory forests, will respond to changes in climate over time. Maxent modeling software was used to predict potential shifts in suitable habitat for the oak-hickory forest type, based on environmental variables …

Chinese Tallow Long-Term Impact On Stand Dynamics In A Bottomland Hardwood Forest Following Vegetation Management, Nicklaus R. Langlois

Electronic Theses and Dissertations

Chinese tallow (Triadica sebifera (L.) Small) is an invasive tree known to have negative impacts on bottomland hardwood forests. Chinese tallow is proficient in reproducing and surviving in bottomland hardwood forests because it is more flood and shade tolerant than most native trees. The long-term effectiveness of Chinese tallow control is an important topic to research as only a few long-term studies of Chinese tallow control have been conducted. A 10-year re-measurement of 22 paired plots installed in 2012 on the Pineywoods Mitigation Bank near Diboll, Texas following herbicide treatments examined Chinese tallow and native tree stand structure. Each …

The Role Of Forest Disturbance And Habitat Characteristics In Shaping Arthropod Ecology., Kane Alec Lawhorn

Electronic Theses and Dissertations

Disturbances in forests often generate dead wood, which is an important resource for a variety of arthropods. In tropical wet forests where fire is rare, lightning and branchfalls are common disturbances that create canopy gaps with associated large amounts of localized dead wood. By contrast, prescribed fire is a common disturbance in temperate forest that creates habitat heterogeneity and widely dispersed dead wood resources. The ecological effects of these disturbances on arthropod communities are largely unknown. This dissertation investigates how disturbance and habitat associations in both tropical and temperate forest shape arthropod ecology. Throughout, I primarily focus on beetles, ants, …

Avian Communities Monitored Along A Successional Chronosequence In Bottomland Hardwood Forests In The Lower Mississippi Alluvial Valley, Eamonn Alasdair Thurmond

Electronic Theses and Dissertations

Bottomland hardwood forests in the Lower Mississippi Alluvial Valley have been extensively reduced due to agriculture conversion and altered hydrology. Remnant forests have undergone further degradation from sources such as a lack of forest management, invasive species, and reduced regeneration of oaks (Quercus spp.). Recent restoration efforts of bottomland hardwood forests have focused on implementing wildlife forestry practices that prioritize restoring wildlife habitat while retaining profitable timber harvests. In this study I surveyed bird communities in bottomland hardwood forests in the Lower Mississippi Alluvial Valley along a successional chronosequence. Birds were sampled using automated recording units over 10 days …

Effects Of Prescribed Fire Regimes On White-Tailed Deer (Odocoileus Virginianus) Browse, Forage, And Nutrient Availability In The Pineywoods Ecoregion Of Texas, Wyatt L. Bagwell

Electronic Theses and Dissertations

Fire is a management tool for white-tailed deer (Odocoileus virginianus) habitat, influencing browse availability, herbaceous production, and nutrient content. In 2020 and 2021, this study utilized 46 plots across East Texas to assess these habitat components. A stem count index survey method was used to assess browse utilization prior to April in both years, and preferred browse species were clipped and analyzed for nutrient availability, and herbaceous production was also measured. Additionally, white-tailed deer population data, browse survey data, and recent fire history were obtained from five different wildlife management areas to examine their relationship. Deer had preferences …

Flora Of Doe Mountain Recreation Area, Johnson County, Tennessee, Benjamin Mccullough

Electronic Theses and Dissertations

A botanical inventory of Doe Mountain Recreation Area (DMRA) in northeastern Tennessee was conducted to help guide conservation-based management. A total of 484 species were found in DMRA, comprising 94 families, and 285 genera, 10 species listed in the state rare plant list, and 76 exotic species. Two species, Liatris virgata and Lycopodiella inundata, were new state records. Water in the Lycopodiella seep was an order of magnitude more acid than at other sites. An analysis of the wildland-urban interface showed that only 13% of the area was classified as uninhabited. The inventory-invasion index, introduced to quantify the relative …

Soil Quality Indicators And Vegetation Responses Following Ecological Restoration Thinning Of Ponderosa Pine On Three Soil Parent Material Types Under Grazing And Non-Grazing In Northern Arizona, Christopher Macdonald

Electronic Theses and Dissertations

This research was performed in a northern Arizona ponderosa pine (Pinus ponderosa P. & C., Lawson) forest. The objectives were to a) increase understanding of long-term vegetation responses to ecological restoration treatments on three soils types, with and without grazing, b) evaluate the responses soil physical, chemical, and biological properties to restoration treatments, with and without grazing, c) determine the utility of measured soil quality indicators to informing risks to sustainable soils management in southwestern ponderosa pine forests.

There were no significant differences in soil bulk density by soil type, treatment type, or grazing treatment. No significant differences …

Restoration Through Reassembly: Evaluating The Role Of Native Plants In Combatting Chinese Tallow, Olaniyi Ajala

Electronic Theses and Dissertations

Non-native, invasive species disrupt ecological processes and functions, posing a serious threat to natural ecosystems. By examining the growth metrics of the non-native, invasive tree, Chinese tallow (Triadica sebifera [L.] Roxb.), hereafter tallow, across different flooding and light regimes, I investigated how restructuring native communities with valuable native species will prevent the reestablishment of tallow. I studied the changes in morphological and physiological traits of tallow when growing with water tupelo (Nyssa aquatica L.), sugarberry (Celtis occidentalis L.), and green ash (Fraxinus pennsylvanica Marshall). I found that in the non-flooded and high irradiance treatments, tallow's growth …

Targeted Browsing With Goats For Eastern Redcedar (Juniperus Virginiana L.) Control, Alanna M. Hartsfield

Electronic Theses and Dissertations

As eastern redcedar (ERC) (Juniperus virginiana L.) grassland encroachment progresses, all potential control methods should be explored in the interest of Great Plains grassland health and longevity. Targeted browsing with goats has been proven as an effective control method on some juniper species; however, little is known about its ability to control ERC. These studies intend to mend knowledge gaps of how targeted browsing with goats control ERC by causing tree death without chemicals or machinery. The first study is two 3x3 Latin squares comparing protein-supplemented diets. The second study is a randomized complete block design of five 0.224 ha …

Seasonal Flammability Comparisons Of Native And Exotic Plants In The Post Oak Savannah, Blackland Prairie, And Pineywoods Ecoregions Of Texas, Michael Tiller

Electronic Theses and Dissertations

East Texas’ diverse landscape can present year-round wildfire seasons that can be influenced by seasonal and regional differences in climate and physiography. Greater insight into the fundamental thermal behavior of wildland fuels can aid in fire behavior prediction and development of fire-resistant plant lists. This study focused on estimating seasonal and regional flammability characteristics of five evergreen species: yaupon (Ilex vomitoria), Chinese privet (Ligustrum sinense), greenbrier (Smilax spp.), eastern red cedar (Juniperus virginiana), and escarpment live oak (Quercus fusiformis); and two deciduous species: Chinese tallow (Triadica sebifera) and southern …

Natural Regeneration Dynamics And Survival Influenced By Abiotic And Biotic Factors In A Bottomland Hardwood Forest, Lydia J. Voth Rurup

Electronic Theses and Dissertations

Riparian ecosystems are vital to the landscape, providing critical services including water filtration and purification, flood and erosion control, carbon sequestration, biodiversity support, and aesthetic value. Bottomland hardwood forests, however, are threatened by invasive species, land loss/conversion, inconsistent or absence of harvesting disturbances, and altered hydrological patterns, leading to reduced success of desired, native species. This research assessed regeneration dynamics and one-year survival in a seasonally-flooded bottomland hardwood forest at Boggy Slough Conservation Area in East Texas to identify abiotic and biotic factors important for successful establishment of native regeneration. Areas sampled included two that were previously treated with herbicide …

An Analysis Of Loblolly Pine And Shortleaf Pine Hybridization Using Chromatography And Geographic Information Systems: A Case Study In East Texas, Gary White

Electronic Theses and Dissertations

East Texas forests contain three native pine species known to hybridize when site conditions are suitable. Due to increased gene flow from hybridization, quantifying hybridization spatially is a growing concern as southeastern United States pine forests are increasingly influenced by improved pine genetics and warmer, drier conditions from climate change. High Performance Liquid Chromatography (HPLC) and spatial interpolation using Inverse Distance Weighted were conducted using terpenes extracted from needles of shortleaf pine (Pinus echinata), loblolly pine (Pinus taeda), and putative hybrid individuals sampled in Atlanta State Park, Tyler State Park, and Mission Tejas State Park ( …

The Ecological Resilience Of A Tropical Montane Pine Forest To Droughts, Fire, And Hurricane Disturbance, Daniel Erland Brugger Swann

Electronic Theses and Dissertations

Owing to the geographic isolation and unique climatic conditions which occur in tropical montane forests (TMFs), these systems are highly sensitive to changes in both climate and disturbance. Therefore, as ongoing climate change alters disturbance regimes – potentially facilitating multiple disturbance interactions much greater than that of isolated disturbances – TMFs may be shifted to alternate stable states. However, study of TMF resilience is essentially unknown given the lack of long-term studies in these systems. We address the resiliency of the tropical montane pine forests of the Cordillera Central, Dominican Republic using long-term climate records, remeasured vegetation data, and reconstructed …

Subalpine Forest Tree Seedling Response To Drought, Alex Goke

Electronic Theses and Dissertations

Knowledge of tree species’ ability to tolerate drought is necessary to anticipate future forest dynamics with climate change, especially at the seedling stage given their role in shaping forest structure. We used precipitation reduction shelters to mimic drought for subalpine conifer seedlings (A. lasiocarpa and P. engelmannii) in the Rocky Mountains and compared survivorship and morphological and physiological responses to assess relative degrees of drought tolerance. We detected no significant investment in morphological tolerance traits (e.g. root biomass, leaf:stem area ratio) but substantial reductions in net photosynthesis. While shading partially ameliorated drought effects when precipitation reduction was moderate, …

Comparison Of The Survival And Growth Of West Gulf Coastal Plain Pine In East Texas, Jamie Hooker

Electronic Theses and Dissertations

West Gulf Coastal Plain provenance loblolly (Pinus taeda L.), longleaf (Pinus palustris Mill.), shortleaf (Pinus echinata Mill.), and slash pines (Pinus elliottii Engelm.) were planted in East Texas to compare initial growth and survival. Containerized seedlings were planted in December 2015 on three study sites in Shelby, Houston, and Cherokee counties using a randomized complete block design. Seedlings were measured in January-February 2016 and again January-February 2017, January 2018, and January 2019. Three years after planting, survival was best (76.4%) in Houston County and was lowest in Cherokee County (26.4). Damage by Texas leafcutter ants (Atta …

Identifying An Optimal Bald Eagle Monitoring Program For Southwest Alaska National Parks, Rebecca Kolstrom

Electronic Theses and Dissertations

The Southwest Alaska Inventory and Monitoring Network includes bald eagle monitoring as part of their Vital Signs Monitoring Plan. Lake Clark National Park and Preserve, Katmai National Park and Preserve, Kenai Fjords National Park, and Wrangell – St. Elias National Park and Preserve monitor bald eagles annually, albeit slightly differently among parks. Since monitoring decisions involve multiple objectives and stakeholders, there was a need for a structured approach to identify an optimal monitoring program. We used a structured decision making process and an iterative, four-round Delphi Process to collect information about long-term bald eagle monitoring from experts. We collected information …

Monitoring Soft-Mast Production In Pine Woodland Restoration Areas On The Ouachita National Forest, Tamara B. Wood

Electronic Theses and Dissertations

The use of prescribed fire is integral to the restoration of open woodland habitats in the southeast, including shortleaf pine (Pinus echinata) woodlands in the Ouachita Mountains. Mature pine habitats maintained with recurrent disturbances have an open understory with a rich floristic diversity that provides quality habitat for many wildlife species, including the endemic and endangered red-cockaded woodpecker (Picoides borealis). Fire has many potential benefits for wildlife; however, the effects of fire on several important woody soft-mast producing species are not fully understood. Soft-mast quantity and quality is a key component in determining year-round habitat quality …

Range-Wide Prevalence And Impacts Of Pseudocercosporella Inconspicua On Lilium Grayi And An Assessment Of L. Superbum And L. Michauxii As Reservoirs, Cindy L. Barrett

Electronic Theses and Dissertations

Lilium grayi (Gray’s Lily), a southern Appalachian endemic species, is threatened by a Lilium-specific fungal pathogen, Pseudocercosporella inconspicua. The disease is characterized by tan lesions that can cause early senescence, while also lowering seed production and viability. This project tested for P. inconspicua conidia and accessed health at nine locations. The disease was present and ubiquitous across the range of L. grayi. Through identification of P. inconspicua conidia in the field, L. superbum (Turk’s Cap Lily) was identified as an additional host, while L. michauxii (Michaux’s Lily) was disease-free. However, infection was inducible in both species. With …

The Influence Of The Invasive Chinese Tallow (Triadica Sebifera) Leaf Litter On Aquatic Chemistry And Microbial Community Composition, Raymond D. Montez

Electronic Theses and Dissertations

Global climate change and anthropogenic activity have facilitated the movement and invasive potential of nonnative plants in native environments. These invasions can have negative effects on ecosystem diversity and function. The nonnative and invasive plant, Chinese Tallow (Triadica sebifera), has already invaded much of the south eastern US where it is outcompeting native tree species and changing ecosystem diversity in a variety of habitats. Leaf litter from the Chinese tallow has been shown cause changes in dissolved oxygen and pH in the aquatic environment. Turbidity is also affected when Chinese tallow litter is present in water. A series of …

Plant Community Responses To The Removal Of Lonicera Maackii From An Urban Woodland Park., Elihu H. Levine

Electronic Theses and Dissertations

Impacts of Lonicera maackii on native forest communities have been widely researched, but long-term responses of plant communities to the removal of this exotic shrub have not been extensively evaluated. The Louisville Olmsted Parks Conservancy removes exotic shrubs and vines to restore ecological processes and native species in the woodlands of Cherokee Park. Paired-plots were established in 2008 to gather baseline herb, vine, tree, and shrub community data. Honeysuckle was removed from one plot of each pair in 2009 and community data were gathered again in 2013. Native herb cover and richness, vine cover, and tree sapling abundance increased where …

Long-Term Overstory Vegetation Responses To Prescribed Fire Management For Longleaf Pine At Big Thicket National Preserve, Deanna M. Boensch

Electronic Theses and Dissertations

At the western edge of the longleaf pine (Pinus palustris) range, federal land managers have burned the forests of Big Thicket National Preserve to bring back the structure and diversity of the longleaf pine forest. In the early 1990’s, a four year study was conducted by Rice University, and the National Park Service continued monitoring the study’s fire ecology research plots. After two decades of data collection, ordination was applied to species abundance data to examine changes in vegetation communities from a variety of prescribed fire treatments and controls. The vegetation data was separated by size class to include overstory, …

Grassland And Woodland Bird Occurrence And Habitat Selection In The Prairie-Forest Transition Zone Of Minnesota, Thomas Robert Cooper

Electronic Theses and Dissertations

Numerous species of woodland and grassland nesting birds have experienced population declines in the midwestern United States. Habitat loss and habitat fragmentation are suspected to be two of the underlying causes for the population declines of woodland and grassland birds. The Minnesota Valley Wetland Management District (WMD) covers 14 counties in southeastern Minnesota in the transition zone between forested and prairie ecoregions. Little information is available relative to which birds are using grassland or woodland habitat within the WMD and how their presence or absence is related to the available habitat conditions. Therefore, my study objectives were to: 1) determine …