Life Sciences Commons^™

A Tree-Ring Record Of Historical Fire Activity In A Piedmont Longleaf Pine (Pinus Palustris Mill.) Woodland In North Carolina, Usa, Monica T. Rother, Thomas W. Patterson, Paul A. Knapp, Tyler J. Mitchell, Nell Allen

Faculty Publications

CO₂ capture from industrial point source waste streams represents an important need for achieving the global goal of carbon-neutrality. Compared with conventional liquid sorbents, solid sorbents can exhibit several distinct advantages, including enhanced lifetime and reduced energy consumption for sorbent regeneration. Considering that reducing CO₂ emission is a great challenge, reaching approximately 37 billion metric tons just in 2021, ideal sorbent solutions should not only exhibit a high capture performance but also enable large scale manufacturing using low-cost precursors and simple processes. In this work, we demonstrate the use of a commodity polymer, polystyrene-block-polyisoprene-block-polystyrene …

Facilitation Differentially Affects Competitive Responses Of Aspen And Subalpine Fir Through Stages Of Stand Development, Rebecca Lee Molinari, Matthew F. Bekker, Benjamin D. St. Clair, Jason Bartholomew, R. Justin Derose, Stanley G. Kitchen, Samuel B. St. Clair

Aspen Bibliography

Spatial interactions between trees influence forest community succession. The objective of this study was to investigate how shifts in forest composition and proximity between tree species affect stand development over time in mixed forest systems. At six locations across the Fishlake National Forest, Utah, USA, in stands where facilitation has been documented previously, tree-ring samples were collected from aspen and subalpine fir trees. Basal area increment was calculated to characterize the effects of the proximity of overstory trees on multidecadal growth responses of aspen and subalpine fir in aspen-dominant and mixed aspen–conifer stands. Subalpine fir seedlings were established next to …

Tree-Ring Based Reconstruction Of Historical Fire In An Endangered Ecosystem In The Florida Keys, Lauren A. Stachowiak, Maegen L. Rochner, Elizabeth A. Schneider, Grant L. Harley, Savannah A. Collins-Key, Hunter A. Bonawitz

SHU Faculty Publications

Big Pine Key, Florida, is home to one of Earth’s largest swaths of the critically-endangered dry forests. Known as pine rocklands, this fire-adapted ecosystem must experience regular fire to persist and remain healthy. Pine rocklands are composed of a sole canopy species: the South Florida slash pine (Pinus elliottii var. densa), along with a dense understory of various woody and herbaceous species, and minimal surface moisture and soil development. Slash pine record wildfire activity of the surrounding area via fire scars preserved within the annual tree rings formed by the species. Our study used dendrochronology to investigate the fire history …

Using Dendrochronology To Create A Timescale Of Succession On Nurse Logs In The Olympic Temperate Rainforest, Sean Grealish

Summer Research

Previous work on the Olympic peninsula in Washington State has shown that recently fallen trees provide a germination location for seeds that cannot do so on the forest floor due to thick moss mats. My field work over two summers dating and surveying nurse logs yielded a crossover at ~70 years where ground mosses start to dominate over tree mosses and seedling abundance begins to decrease.

Using Tree-Ring Growth And Stable Isotopes To Explore Ponderosa Pine Ecophysiological Responses To Climate Variability And The 2012-2015 California Drought, Rachel M. Keen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Climate warming in recent decades has resulted in more frequent and severe drought events in the western United States. These changes are projected to continue, making it exceedingly important to understand how forests respond to severe drought stress, and how we can manage these forests to reduce mortality during future events. The 2012-2015 California drought is a recent example of a severe, multi-year drought that was coupled with an epidemic-scale outbreak of western pine beetle, killing nearly 90% of ponderosa pines in the central and southern Sierra Nevadas. In the first portion of this study, we compared pairs of surviving …

Fire History Of A Georgia Montane Longleaf Pine (Pinus Palustris) Community, Nathan Klaus

Georgia Journal of Science

Montane longleaf pine forests, woodlands, and savannas are endangered, fire-dependent ecosystems of the Piedmont, Ridge and Valley, Appalachian, and Cumberland Plateau physiographic provinces of Georgia, Alabama, and North Carolina. Compared to other longleaf pine ecosystems, e.g., longleaf pine-wiregrass, little has been published about montane longleaf pine ecosystems. Understanding the historic fire regimes that once maintained montane longleaf pine ecosystems is an important first step toward achieving restoration and conservation goals for this ecosystem. I used two approaches to investigate historic fire regimes: 1) a dendrochronological study of fire scars on Sprewell Bluff Natural Area and 2) calculations of the average …

Detecting Balsam Woolly Adelgid Infestations Using Tree Rings, Morgan Lane Leef

Graduate Theses, Dissertations, and Problem Reports

Balsam woolly adelgid (BWA), Adelges piceae(Ratzeburg), is a sap-sucking, exotic invasive insect that arrived in North America from central Europe around 1900. Since then, its range has expanded from New Brunswick, Canada to the southern Appalachian Mountains. It is a threat to all North American true-fir species, but populations can be controlled by cold continental winters. Adelgid feeding leaves noticeable traces on the wood tissue (“rotholz”) and causes a temporary positive radial growth response among affected trees. The purpose of this research was to determine dates of initial outbreaks, balsam fir radial growth change during outbreaks, and the relationship …

Evaluating Climate And Environmental Drivers Of Tree Species’ Growth Within The Northern Forest, Rebecca Stern

Graduate College Dissertations and Theses

Northeastern forests are in a period of immense change. While forests are inherently dynamic ecosystems, a range of environmental challenges may cause unique and uncertain transformations within forests moving forward. How trees in northern forests respond to these environmental and anthropogenic changes remains uncertain; reductions and increases in the growth of various species and shifts in current species’ ranges may take place.

I analyzed associations between tree growth (assessed using xylem increment cores) and a range of site, climate, and pollution deposition variables for seven major tree species in Vermont. First, I looked at red oak (Quercus rubra L.), a …

The Impact Of Climate And Elevation On The Growth And Mortality Of Piñon Pine, Alice M. Fretz

Biology ETDs

The Southwestern United States is currently experiencing severe drought, resulting in the mortality of many tree species. Piñon-juniper woodlands are an extensive biome in the Southwest, and are highly vulnerable to extended periods of drought that lead to tree mortality. Specifically, Pinus edulis populations are decreasing due to increasingly arid conditions. I used dendrochronology to investigate how tree growth rings of Pinus edulis reflect severe drought in living and dead trees. I also investigated how severe drought affects Pinus edulis along an altitudinal gradient. Tree core samples were taken from currently living and dead trees, as well as from trees …

Quantifying Tree Response To Alterations In Pollution Deposition And Climate Change In The Northeastern Us, Alexandra M. Kosiba

Graduate College Dissertations and Theses

Understanding tree physiological responses to climate change is critical for quantifying forest carbon, predicting species' range change, and forecasting growth trajectories. Continued increases in temperature could push trees into conditions to which they are ill adapted -- such as decreased depth of winter snow cover, altered water regimes, and a lengthened effective growing season. A complicating factor is that in the northeastern United States, climate change is occurring on a backdrop of acid deposition and land-use change. In this dissertation, I used three studies to investigate the spatiotemporal nuances of resultant tree and sapling physiology to environmental change.

First, I …

Assessing Growth Response To Climate Controls In A Great Basin Artemisia Tridentata Plant Community, Lorenzo F. Apodaca

UNLV Theses, Dissertations, Professional Papers, and Capstones

An assessment of the growth response of key vegetative species to climatic variability is vital to identifying possible local impacts on ecosystems faced with imminent climate change. With current climate projections in Nevada predicting a shift to an even more arid climate with greater year-to-year variability, the imperative exists to identify the effects of specific climatic controls on plant growth and to research methods to assess large-scale vegetative changes, especially in more remote areas where readily available data sets may be lacking. This study utilized annual growth ring indices constructed from big sagebrush (Artemisia tridentatassp.tridentata) stems collected in Spring Valley, …

Evaluating The Influence Of Disturbance And Climate On Red Spruce (Picea Rubens Sarg.) Community Dynamics At Its Southern Range Margin, Relena R. Ribbons

Masters Theses 1911 - February 2014

Picea rubens(red spruce) populations experienced a synchronous rangewide decline in growth and vigor starting in the 1960’s, which was likely caused by climate change or environmental disturbances (e.g., acid deposition); However, it is yet unknown if populations continue to decline or have recovered. In the context of global warming, red spruce is a species of concern because it is at its southern continuous range margin in Massachusetts. This study uses tree-ring data coupled with population data from permanent plots to quantify the status of red spruce in Massachusetts. Tree cores were extracted from red spruce and used to examine …

Age, Forest Structure, And Disturbance History Of Five Potential Old-Growth Forests In Eastern Kentucky's Cumberland Plateau, Adrienne Michelle Cooper

Online Theses and Dissertations

The Cumberland Plateau (CP) is an ecoregion of global importance, yet its extent of old- growth forest (OG) is not well known. Due to its rarity and importance, understanding what OG remains is needed to deduce the region's health. This study described five potential OG forests in eastern Kentucky. Sites possessing >5 trees/ha established prior to 1780, and being similar in disturbance history and forest structure to other regional OG were to be considered OG. Shillalah Creek (SC) and Hensley-Pine Mountain (HP) possess no in plot trees established prior to 1780, show evidence of stand-wide disturbance during the 1930's, are …

Multicentury Fire And Forest Histories At 19 Sites In Utah And Eastern Nevada, Emily K. Heyerdahl, Peter M. Brown, Stanley G. Kitchen, Marc H. Weber

Aspen Bibliography

Our objective is to provide site-specific fire and forest histories from Utah and eastern Nevada that can be used for land management or additional research. We systematically sampled fire scars and tree-recruitment dates across broad gradients in elevation and forest type at 13 sites in Utah and 1 in eastern Nevada to characterize spatial and temporal variation in historical fire regimes as well as forest structure and composition. We collected similar data non-systematically at five additional sites in Utah. These 19 sites include a broad range of forest types (from pinyon-juniper woodlands to spruce-fir forests) and fire regime types. In …

Changes In Nitrogen Cycling During The Past Century In A Northern Hardwood Forest, Kendra K. Mclauchlan, Joseph M. Craine, W. Wyatt Oswald, Peter R. Leavitt, Gene E. Likens

Dartmouth Scholarship

Nitrogen (N) availability, defined here as the supply of N to terrestrial plants and soil microorganisms relative to their N demands, limits the productivity of many temperate zone forests and in part determines ecosystem carbon (C) content. Despite multidecadal monitoring of N in streams, the long-term record of N availability in forests of the northeastern United States is largely unknown. Therefore, although these forests have been receiving anthropogenic N deposition for the past few decades, it is still uncertain whether terrestrial N availability has changed during this time and, subsequently, whether forest ecosystems have responded to increased N deposition. Here, …