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Full-Text Articles in Life Sciences

Dendrochronology In The Blackwater Ecological Preserve, Sarah Durham, Arvind Bhuta Jan 2023

Dendrochronology In The Blackwater Ecological Preserve, Sarah Durham, Arvind Bhuta

College of Sciences Posters

The Blackwater Ecological Preserve (BEP), located in southeastern Virginia, holds significant ecological importance as it contains the northernmost intact community of Pinus palustris, longleaf pine. At the BEP, we cored longleaf pine and recorded sample data including tree height and diameter at breast height (DBH). Two sites on the BEP, the 20’s series and 40’s series, were found to correlate within, but not between, sites. Statistical and qualitative analyses were conducted to find differences between the sites significant enough to affect correlation within a chronology. This data is being incorporated into a larger dendrochronology and climate analysis study on …


Preliminary Assessment Of Climatic Sensitivity Of Riparian Old-Growth Eastern Hemlock, John B. Holden Iv, Sophan Chhin, Andrew Hirsch, Eric Yetter Jun 2021

Preliminary Assessment Of Climatic Sensitivity Of Riparian Old-Growth Eastern Hemlock, John B. Holden Iv, Sophan Chhin, Andrew Hirsch, Eric Yetter

Mountaineer Undergraduate Research Review

Eastern hemlock is a long-lived, slow growing climax species in North America currently undergoing a major decline in population due to a combination of effects derived from hemlock woolly adelgid (HWA) as well as changing climate patterns. Data was collected in an old-growth, riparian hemlock forest within the West Virginia University Research Forest to understand the effect of monthly climate factors (mean temperature, mean precipitation, and climate moisture index (CMI)) on hemlock radial growth. Results indicated that March mean temperature and May CMI of the current growth year are positively associated with hemlock growth whereas prior year summer conditions of …


Climatic Drivers Of Growth In Mixed Conifer Forests Of The Sierra Nevada For Different Tree Sizes And Thinning Treatments, Andrew M. Hirsch Jan 2021

Climatic Drivers Of Growth In Mixed Conifer Forests Of The Sierra Nevada For Different Tree Sizes And Thinning Treatments, Andrew M. Hirsch

Graduate Theses, Dissertations, and Problem Reports

The Mediterranean region of northern California is projected to get increasingly warmer under all Intergovernmental Panel on Climate Change (IPCC) emission scenarios, with future precipitation projections not showing much of a trend. This poses a problem to the already dry summers that are experienced in the Mediterranean region of California. If precipitation does not increase alongside temperatures, the dry seasons will likely only get drier. The use of dendroclimatology to assess how mixed conifer species in the Sierra Nevada responded to past climate is a key resource that can be used to infer how trees may respond to a future …


Using Dendrochronology To Create A Timescale Of Succession On Nurse Logs In The Olympic Temperate Rainforest, Sean Grealish Jan 2020

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.


Stand Location Variance As An Indicator Of Disturbance Regime In A Monotypic Tsuga Canadensis Forest, Cole J. Doolittle May 2019

Stand Location Variance As An Indicator Of Disturbance Regime In A Monotypic Tsuga Canadensis Forest, Cole J. Doolittle

Honors Program Projects

Disturbance regimes, which are critical components of forest ecosystems, influence forest morphology, biodiversity, and regeneration. The heterogeneity of disturbance regimes are not well understood on small scales. In this study I analyzed tree cores from five sites within a Tsuga canadensis (Eastern hemlock) forest in northern Wisconsin to investigate disturbance regimes through mean growth release criteria. This study investigated the following questions: 1) Are disturbance regimes in T. canadensis stand level or site specific? 2) If disturbances are site specific, is site location an indicator of disturbance regime? 3) Do site characteristics such as density and tree diameter at breast …


Assessment Of The Ponderosa Woodlands In Nebraska's Wildcat Hills: Implications For Juniperus Encroachment And Management, Allie Victoria Schiltmeyer Jul 2018

Assessment Of The Ponderosa Woodlands In Nebraska's Wildcat Hills: Implications For Juniperus Encroachment And Management, Allie Victoria Schiltmeyer

School of Natural Resources: Dissertations, Theses, and Student Research

Ponderosa pine (Pinus ponderosa) is a dominant tree species across western North America. Its eastern distribution includes three populations in western Nebraska. This study assesses the distribution, structure and age of ponderosa pine woodlands in one of those regions, the Wildcat Hills. The Wildcat Hills have escaped severe wildfires seen in recent decades in other ponderosa pine regions. Nevertheless, the Wildcat Hills woodlands face multiple threats including climate change, wildfire, drought, pine beetles, and invasive species. Key to these threats is the stand structure of pine woodlands, which have increased in density across much of ponderosa pine’s range. …


Growth Dynamics Of Black Spruce (Picea Mariana) Across Northwestern North America, Anastasia E. Sniderhan Jan 2018

Growth Dynamics Of Black Spruce (Picea Mariana) Across Northwestern North America, Anastasia E. Sniderhan

Theses and Dissertations (Comprehensive)

The impacts of climate change have been widely documented around the world. One of the most rapidly changing areas is the boreal forest of North America. The extent of change has been such that there have been shifts in long-standing climate-growth relationships in many boreal tree species; while the growth of many of these high-latitude forests were formerly limited by temperature, warming has increased the evapotranspirative demands such that there is widespread drought stress limiting productivity in the boreal forest. With the importance of the boreal forest as a global carbon sink, it is imperative to understand the extent of …


A 1,461-Year Growing Season Precipitation Reconstruction For The Carolina Coastal Plain, Kathryn Perkins Wolff May 2012

A 1,461-Year Growing Season Precipitation Reconstruction For The Carolina Coastal Plain, Kathryn Perkins Wolff

Graduate Theses and Dissertations

A recollection and dating of ancient cypress trees and subfossil logs was performed at Black River, North Carolina, and the separate Black River, South Carolina. The new updated and expanded chronologies date from AD 365 to 2010 and 549 to 2010, respectively. Baldcypress ring-width chronologies are dominated by high inter-annual to decadal variability and do not tend to capture century scale fluctuations in tree-ring growth that could be associated with centennial scale change in climate. The tree-ring chronologies were standardized with a technique designed to preserve low frequency variance known as regional curve standardization. The two chronologies were averaged into …


Evaluating The Influence Of Disturbance And Climate On Red Spruce (Picea Rubens Sarg.) Community Dynamics At Its Southern Range Margin, Relena R. Ribbons Jan 2011

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 …


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 May 2007

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, …


Tree-Ring Dating, Waldo S. Glock May 1953

Tree-Ring Dating, Waldo S. Glock

Journal of the Minnesota Academy of Science

No abstract provided.