Forest Sciences Commons^™

The Long-Term Effects Of Wildfire Severity On Oak-Pine Communities And Their Microclimates, Scott Glenn Culbert

Theses and Dissertations--Forestry and Natural Resources

In the eastern U.S., fire-dependent tree species have historically dominated upland forest communities, but are now experiencing widespread regeneration challenges as a result of 20^th century fire suppression policies, and are being replaced by mesophytic species. Wildfires that contain areas of high burn severity may provide an important means of mitigating these challenges and facilitating fire-dependent species regeneration and recruitment into larger size classes. One mechanism by which high-severity fire can accomplish this is by modifying understory microclimate characteristics to be more conducive to these species’ growth. A wildfire within the Daniel Boone National Forest, Kentucky, USA, provided the …

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 …

The Influence Of Burn Severity On Post-Fire Spectral Recovery Of Three Fires In The Southern Rocky Mountains, Jaclyn Guz, Florencia Sangermano, Dominik Kulakowski

Geography

Increased wildfire activity and altered post-fire climate in the Southern Rocky Mountains has the potential to influence forest resilience. The Southern Rocky Mountains are a leading edge of climate change and have experienced record-breaking fires in recent years. The change in post-fire regeneration and forest resilience could potentially include future ecological trajectories. In this paper, we examined patterns of post-fire spectral recovery using Landsat time series. Additionally, we utilized random forest models to analyze the impact of climate and burn severity on three fire events in the Southern Rocky Mountains. Fifteen years following the fires, none of the burned stands …

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 …

Regenerative Effects Of Patch Cut Harvests At Natchez Trace State Forest, Joshua K. Biggerstaff

Masters Theses

Patch cutting is a harvest method with very little precedent in the Central Hardwoods Region of the United States. It is defined as a small scale clearcut of 2 to 5-acres, and it is generally prescribed in order to lessen the aesthetic impact of harvesting in highly visible areas. This study examines a change in harvesting from clearcutting to patch cutting that occurred at Natchez Trace State Forest, located in west Tennessee, in the 1990s. The objective of the study was to determine the regenerative effects of the patch cuts 25-30 years later. Various patch-cut harvest units that were harvested …

The Effects Of Fire On Oak-Forest Plant Communities Along Soil Moisture Gradients: A 25-Year Study, Rebekah Frances Shupe

Theses, Dissertations and Capstones

In the eastern U.S., fire is a natural disturbance process in Quercus (oak) forests. Fire is thought to promote oak regeneration and plant diversity by reducing competition, preparing a suitable seedbed, and increasing light availability. However, the era of fire suppression that began in the early 20^th century is thought to have negatively impacted oak regeneration and the biodiversity of the understory layer. In this study, we examined the effects of prescribed fire on tree regeneration and the understory layer over 25 years. From a study initiated in 1994, we resampled 45 permanent vegetation plots measuring 1250 m^{2 …}

Wildlife Forage Recovery Following Boreal Wildfire, Alexis Jorgensen, Jennifer Baltzer

Theses and Dissertations (Comprehensive)

Climate change is altering the boreal wildfire regime through increases in the extent and severity of burning and reductions in fire return intervals. These changes can alter the regeneration trajectory of canopy species and ground vegetation, with implications for wildlife habitat. There is some uncertainty about the timelines of when different animal species will use burned areas as their preferred forage taxa recover following fire, and how such recovery is mediated by environmental factors. Here, we aim to address these knowledge gaps through the following questions: 1) What are the main forage types consumed by boreal wildlife and how much …

Floodplain Forest Regeneration Dynamics In The Lower Mississippi River Alluvial Valley, Whitney Anne Kroschel

LSU Doctoral Dissertations

Floodplain forest species diversity is driven, in part, by variation in disturbance regime. Flood patterns create heterogeneity in microsite quality from small differences in elevation across a floodplain which, in turn, influence flood timing and duration. Differences in species’ regeneration niches in relation to hydrologic patterns can account for long-term coexistence of various species. In the past century floodplain forests have exhibited a wide range of changes in stand development and species composition as a result of altered hydrology in rivers and floodplains. I evaluated the role of regeneration in floodplain forest systems of the Lower Mississippi River Alluvial Valley …

Spatial And Temporal Patterns Of Invasive Exotic Plant Species In Response To Timber Harvesting In A Mixed Mesophytic Forest Of Eastern Kentucky, Benjamin Christopher Rasp

Theses and Dissertations--Forestry and Natural Resources

Invasive exotic species (IES) responses to silvicultural treatments eight years after timber harvesting were examined and compared to one-year post-harvest IES survey in University of Kentucky’s Robinson Forest. The temporal effects of harvesting were further compared between harvested and non-harvested watersheds. Analyses were performed to identify IES spatial distribution and determine the relationships between IES presence and disturbance effects, biological, and environmental characteristics. IES prevalence was higher in the harvested watersheds and was influenced by canopy cover, shrub cover and disturbance proximity. Ailanthus altissima and Microstegium vimineum presence in the study area has decreased over time. Comparing to the 1-yr …

Forest Islands In A Sea Of Urban Habitat, Michael J. Olejniczak

Biology Theses

Urban forests are poorly defined as ecological communities. Substantive links between anthropogenic landscape features and forest ecology are lacking. ‘Urbaness’ is commonly defined by human population density or land use classifications, but their use is inconsistent throughout the literature, and rarely is linked with ecological processes. Furthermore, it is unknown whether urban forests are functioning parts of a patchy urban woodland system or isolated islands amidst an ocean of unsuitable habitat. I first used digital satellite imagery and publicly available U.S. National Park data to link urban land use with forest processes. I then linked those land use classifications with …

Development Of Transgenic North American White Ash (Fraxinus Americana) Expressing A Bacillus Thuringiensis Protein For Management Of The Emerald Ash Borer, Eric A. Dean, Paula M. Pijut Phd., Micah E. Stevens

The Summer Undergraduate Research Fellowship (SURF) Symposium

White ash (WA), Fraxinus americana, is an integral part of the hardwood forest ecosystem. Economically, WA provides wood for important products such as baseball bats, tool handles, and hardwood flooring. Ecologically WA provides cover and mast to support wildlife. The emerald ash borer (EAB) is a significant threat to all ash species because of a lack of native resistance in North American ash trees, its rapid spread, and the ineffectiveness and expense of control measures. EAB is a non-native beetle that consumes tree vascular tissue while in the larval stage. The development of an Agrobacterium-mediated transformation protocol may …

Natural Disturbances And The Physiognomy Of Pine Savannas : A Phenomenological Model, Frank S. Gilliam, William J. Platt, Robert K. Peet

Frank S. Gilliam

Abstract. Question: The decline of the Pinus palustris ecosystems has resulted from anthropogenic influences, such as conversion to pine plantation forestry, agriculture and land development, all of which are closely related to increases in human populations. Other effects, however, have arisen from alterations in disturbance regimes that maintain the structure and function of these ecosystems. How have alterations of the disturbance regime altered the physiognomy of ‘old-growth’ stands, and what are the implications for ecosystem conservation and restoration? Methods: In contrast to models that emphasize close interactions among the vertically complex strata, we develop a conceptual phenomenological model for the …

Post-Fire Demography Of A Dry Eucalypt Forest In The Midlands, Tasmania: A Pilot Study, Christine Urbanowicz

Independent Study Project (ISP) Collection

There have been many efforts to regenerate the threatened and declining dry eucalypt forests found within the Midlands of Tasmania. This pilot study was completed as part of a larger research project on eucalypt regeneration. Researchers need to know where recruits are most successful in order to appropriately place regeneration microsites. I have begun characterizing the baseline demography of a recently burnt remnant forest. I had two objectives: 1. to characterize the stand structure where recruits are successful, and 2. to describe where the recruits are within this structure. Data on location, size, and life history stage of trees were …

Natural Disturbances And The Physiognomy Of Pine Savannas : A Phenomenological Model, Frank S. Gilliam, William J. Platt, Robert K. Peet

Biological Sciences Faculty Research

Abstract. Question: The decline of the Pinus palustris ecosystems has resulted from anthropogenic influences, such as conversion to pine plantation forestry, agriculture and land development, all of which are closely related to increases in human populations. Other effects, however, have arisen from alterations in disturbance regimes that maintain the structure and function of these ecosystems. How have alterations of the disturbance regime altered the physiognomy of ‘old-growth’ stands, and what are the implications for ecosystem conservation and restoration?

Methods: In contrast to models that emphasize close interactions among the vertically complex strata, we develop a conceptual phenomenological model for the …

Some Effects Of Cover Over Coniferous Seedbeds In Southern New England, James W. Toumey, Ernest J. Neethling

Yale School of the Environment Bulletin Series

The object of the study as at first conceived was to secure experimental data under the climatic conditions of southern Connecticut: 1. On the effect of shade as compared with full light on the time required for germination, and on germination values in representative conifers, and on survival and growth during the first season. 2. On the effect of mulch as compared with exposed soil on the time required for germination, and on germination values in representative conifers, and on survival and growth during the first season.