Carolyn Copenheaver - Academia.edu (original) (raw)

Papers by Carolyn Copenheaver

NACTA journal, May 18, 2024

The acknowledgements section of a doctoral dissertation provides a rare view into the student-adv... more The acknowledgements section of a doctoral dissertation provides a rare view into the student-advisor relationship. The gendered differences for how doctoral students acknowledge male and female advisors was examined in 208 dissertations from a U.S. land-grant university. Doctoral students used a greater number and diversity of words when acknowledging female advisors. Nine hierarchical thematic roles and obligations of advisors were identified and were equally represented in acknowledging male and female advisors. Doctoral students described the roles and obligations of their doctoral advisor independently of gender; however, they used gendered language, which highlights the persistence of gendered norms within academic culture.

Forest Ecology and Management, Feb 1, 2009

Natural Areas Journal, Nov 24, 2020

ABSTRACT Invasional meltdown hypothesizes that invasive species facilitate the establishment of s... more ABSTRACT Invasional meltdown hypothesizes that invasive species facilitate the establishment of subsequent invaders, with cascading consequences for ecosystem structure and function, including the extirpation of native species. However, meltdown has rarely been tested empirically with large regional data sets, leading to somewhat equivocal support. Recently, the USDA Forest Service initiated sampling of nonnative plants within a subset of their Forest Inventory and Analysis (FIA) plots, presenting an ideal dataset to evaluate meltdown and its consequences across large geographies. We used FIA data from 963 plots across 11 northeastern states to test the predictions of invasional meltdown and to examine the mechanism through which invasion impacts native tree seedling richness. Remeasured plots showed a significant increase in the number and cover of invasive species over time. We provide support for invasional meltdown, finding a pattern of accelerating invasive species richness over 4–5 y in plots with higher initial invasive species richness. Also, we found that plots with higher levels of invasive abundance corresponded to decreased native tree species richness at one point in time and that the magnitude of the relationship appeared to be stronger after 4–5 y. Our results suggest that evidence of invasional meltdown is more clearly evident when examining invasive plant species richness over time; further, invader abundance (measured as cover) is a better predictor of impacts than invader richness, which supports growing evidence that invasive abundance is an important driver of ecological impact.

AGU Fall Meeting Abstracts, Dec 1, 2019

Mentoring & Tutoring: Partnership in Learning, Mar 15, 2022

ABSTRACT Two faculty mentors maintained weekly journals of their experiences supervising three co... more ABSTRACT Two faculty mentors maintained weekly journals of their experiences supervising three consecutive cohorts of summer undergraduate research interns, with the objective of recording the faculty mentors’ experiences and tracking potential transitions in their experiences across time. One common theme was the importance of creating a mentoring team of other faculty members, university administrators, and departmental staff to assist with the summer interns. One of the foundational experiences during the summer internship was the week-long field trip, which defined each person’s position within the research team. One of the largest challenges for the faculty mentors was balancing the needs of interns with different levels of motivation. Overall, as the faculty mentors gained experience and benefited from working as a team, they were able to increase their satisfaction with the success of the internships and maintain their own levels of academic productivity.

Canadian Journal of Forest Research, Aug 1, 2010

Compression tests and specific gravity analyses were conducted to investigate the impacts of grow... more Compression tests and specific gravity analyses were conducted to investigate the impacts of growth suppression and growth release on wood quality in yellow-poplar ( Liriodendron tulipifera L.). Growth ring widths in 23 increment cores were determined and the years of minimum suppression and maximum release were identified based on a modified radial growth averaging technique. Three specimens (1 mm × 1 mm × 4 mm) from both minimum suppression and maximum release years were prepared from each increment core. Data analysis using paired-samples t tests revealed that the mean ultimate crushing stress of the maximum release years was significantly higher than that of the minimum suppression years, yet the mean specific gravity was not significantly different. Even though there was no statistical difference in specific gravity for the two growth conditions studied, the ultimate crushing stress was statistically higher for the release growth specimens. This finding provides support for the concept that growth rate can have an added effect on strength properties that is not entirely captured by specific gravity. Thus, to improve wood quality in yellow-poplar stands, forest managers might consider increasing the likelihood of periods of growth release by controlling the competition experienced by the trees.

In 1994, two ice storms hit the ridge-and-valley region of southwestern Virginia. Large-diameter ... more In 1994, two ice storms hit the ridge-and-valley region of southwestern Virginia. Large-diameter trees experienced high levels of branch breakage and many small-diameter trees were bent under the weight of the ice. To right themselves, the conifers formed compression wood. The objective of this study was to quantify the influence of stem diameter, age, crown class, tree location, and influence of nearest neighbor on compression wood formed following the 1994 ice storms in eastern white pine (Pinus strobus, L.). Pinus strobus within a 50 x 100 m plot were destructively sampled at Virginia Techs’ Fishburn Forest in southwestern Virginia and cross-sectional disks were removed at stump height. Disks were sanded, cross-dated, and scanned. Tree locations were spatially mapped with a laser transit, along with distance and attributes of the nearest neighboring trees. The images of the scanned disks were imported into Photoshop and the amount of compression wood formed in the years following 1994 was measured as a percentage of total area in the cross-section. The white pine exhibited a two-age structure with younger trees establishing in 1990s and older trees in the 1960s. Through a comparison of these two age classes, the formation of compression wood appeared to be age independent; however diameter and crown class were related to amount of compression wood formed by the white pines following the 1994 ice storms with smaller diameter and lower crown classes forming relatively more compression wood compared to larger, dominant individuals

Forest Ecology and Management, Dec 1, 2015

Abstract Riparian forested wetlands improve downstream water quality by trapping suspended sedime... more Abstract Riparian forested wetlands improve downstream water quality by trapping suspended sediment from adjacent waterways. Waters that transport sediment and nutrients into adjacent wetlands also create wet and dry hydrologic periods and thus, have the potential to impact site productivity. In this study, we used a dendrogeomorphic technique with green ash (Fraxinus pennsylvanica Marsh.) to estimate sediment accretion for two time periods (1881–2012 and 1987–2012) along a natural levee (35 m from river) and backswamp (75 m from river) and identified the influence of hydrology and climate on radial growth in green ash and water tupelo (Nyssa aquatica L.) along the Tensaw River in southwestern Alabama. We detected significantly higher sediment accretion rates for the 1987–2012 time period along the natural levee (p = 0.00; 1.6 cm yr−1) and backswamp (p = 0.03; 1.2 cm yr−1) than for the 1881 to 2012 period (0.4 and 0.5 cm yr−1). Using previously measured (2010) soil bulk density for the site, estimated mass of sediment trapped per unit area ranged from 55–135 Mg ha−1 yr−1 for the 1987–2012 period and 17–61 Mg ha−1 yr−1 for the 1881–2012 period. We identified positive, significant correlations between green ash radial growth and the number of days the backswamp was flooded (1.4 m stage), days the Tensaw River was at bankfull (2.1 m), and average daily river stage during the overall growing season (April to August) and for the month of April. Green ash radial growth also illustrated a positive, significant response to April precipitation totals demonstrating the overall role of moisture availability just prior to the onset of xylem formation. Green ash trees along the natural levee and backswamp were more responsive to hydrology and climate than water tupelo trees located further in the backswamp, illustrating the potential resistance of water tupelo to perturbations. This study illustrates the important role forested wetlands play in improving water quality through quantification of sediment accretion rates and the potential impact that introduced disturbances (i.e., forest harvest-related disturbances) can have on ecosystem services.

Journal of The Torrey Botanical Society, 2011

To evaluate the compression wood response in eastern white pine (Pinus strobus L.) following a se... more To evaluate the compression wood response in eastern white pine (Pinus strobus L.) following a severe ice storm in 1994, 47 trees were felled in 2007 and cross-sectional samples were collected at 0.5 (±0.2) m stem height. The disks were sanded and digitally scanned, and the cross-sectional area (mm 2) of compression wood within each tree-ring was quantified using image analysis software. Topographic data (slope, aspect, and elevation) were also recorded for each P. strobus tree, along with a modified competition index. Wood anatomical features were also quantified in the three years before and after the storm along a tree diameter gradient. Although tree age was relatively constant in this stand, tree size was influenced by topographic position; larger trees grew in the valley while smaller trees were found growing in thin soils at the mid-slope position. When the cohort was about 25 years old, ice deposition caused a heterogeneous compression wood response which was highly related to tree size. In the thirteen years following the ice storm, the 6-9 cm (2007) diameter class formed significantly more compression wood area than any other, followed by the 10-13 cm (2007) diameter class. The tree diameter range that formed the most post-storm compression wood was 4-8 cm at the time of the storm, suggesting that this diameter range was most affected by 8.5 cm of ice loading in P. strobus. Trees > 18 cm in 1994 did not form any compression wood after the storm, but many experienced a growth release to fill canopy gaps. Topographic variables did not influence compression wood formation directly, but only one plot was iii sampled so these results are tenuous. However, topography did influence tree size which was the most important predictor in compression wood. There was no relationship between compression wood area and competition index. Due to compression wood formation after the ice storm, cell wall thickness and cell circularity were significantly higher in the 1994 tree-ring than in other rings examined (1991-1993, 1995, and 1996). Tracheid and lumen diameters were significantly smaller in compression wood cells (30.5 and 19.5 μm, respectively) than in normal wood (36.8 and 28.4 μm, respectively); opposite wood cells were intermediate in size (32.4 and 24.4 μm, respectively). Due to small tracheid size, compression wood contained significantly more cells mm-1 (33) than normal wood (27), but no significant differences in cell wall area. Therefore, cumulative cell wall area occupied 47% of the cross-section in compression wood tissue on average, compared to 31% in normal wood. Dispersing tree weight across a greater surface area may help compression wood to prop up a bent tree, but reduced lumen area may also impact hydraulic conductivity in the stem. v Table of Contents ABSTRACT .

Mountain Research and Development, Nov 1, 2014

Topographically isolated communities of the southern Appalachian Mountains provide an ideal area ... more Topographically isolated communities of the southern Appalachian Mountains provide an ideal area in which to examine the impact of environmental and social connections on the economy of land sales. Our objective was to identify whether the price of land in a small Appalachian county of southwestern Virginia, USA, from 1786 to 1830, was influenced by area, month or year of sale, water availability, presence of tree species that were proxies of site quality, grantor/grantee residency, or familial relationship between grantor and grantee. The multiple regression model identified four significant factors that influenced the price of land during early European settlement of the southern Appalachian Mountains. Larger areas of land sold for lower prices. Landowners sold land to relatives at a lower price than to nonrelatives. The presence of surface water or red maple (Acer rubrum) on the property was associated with lower land prices. The negative relationship between water and price of land was likely a reflection that the parcels sold at the highest prices were in towns where streams or rivers were no longer relied upon as a water source. The model explained 39% of the variation and demonstrated a blend of environmental and social factors that influenced land sale patterns during early European settlement of the Appalachian Mountains.

Journal of natural resources and life sciences education, 2009

Environmental Management, Jan 28, 2004

/ Analysis of long-term study data indicates deadwood C production in loblolly pine plantations a... more / Analysis of long-term study data indicates deadwood C production in loblolly pine plantations averages between 50 and 1700 kg/ha/year in stands age 15 to 35 years. In order to accurately predict deadwood carbon stocks over the life of individual stands, information is needed on the size distribution of deadwood and the rates of decay of varioussize deadwood pieces. Effects of management activities on mortality and subsequent decay should also be accounted for in model predictions of deadwood C. We describe a proposal for augmenting a loblolly pine stand-level growth and yield model to account for deadwood C production and yield over an entire rotation. Deadwood size distributions are predicted from stand-level variables. Decay rates after mortality are predicted from stand attributes and piece-size information and are used to predict C accumulation in deadwood. The resulting model will be used to predict aboveground carbon stocks in loblolly pine stands, or in regional assessments when linked to geographic databases.

Water Resources Research

Trees, mostly sycamore (Platanus occidentalis L.), are growing in the channel of the lower 7 km o... more Trees, mostly sycamore (Platanus occidentalis L.), are growing in the channel of the lower 7 km of Sinking Creek in the Appalachian Mountains of Virginia. Sinking Creek is a gravel‐bedded stream that disappears into a subsurface cave network and for its lower 7 km, flows intermittently throughout the year, exposing a dry streambed. We hypothesize that there have been low‐flow periods in the past conducive to tree‐seedling establishment. We describe this system and test our hypothesis through an analysis of hydrologic, dendrochronological, and geomorphic data to better understand the conditions leading to tree establishment and persistence in the stream channel. To our knowledge, this is the first study on trees growing in the channel of an intermittent stream in a temperate environment. Most riparian vegetation studies along intermittent rivers and ephemeral streams focus on dryland areas, where trees have also been observed growing in the channel. Our results show that sycamores ar...

We used dendrochronology and vegetation sampling to examine climatic response and stand dynamics ... more We used dendrochronology and vegetation sampling to examine climatic response and stand dynamics at two slope positions (350 m asl and 520 m asl) on No Business Mountain in the southwestern Piedmont of Virginia. Modeling plant response to climate change requires an understanding of the influence of small-scale environmental change. We sampled vegetation and developed pitch pine and Virginia pine tree-ring chronologies from the midslope and the mountaintop. A higher species richness and more hickory and black gum were found at the mountaintop. Significant correlations existed between tree-ring growth and temperature in the late fall and precipitation from the prior years' summer months; however, the same dendroclimatological response existed for both species at both slope postions. According to the dendroecological analysis, pitch pine entered the sites after agricultural abandonment in the early 1900s, and Virginia pine entered the sites following a release event in the 1940s. R...

Dendrochronologia, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Natural Sciences Education, 2013

Journal of Forestry, 2017

American chestnut (Castanea dentate) has been described as a towering giant dominating eastern de... more American chestnut (Castanea dentate) has been described as a towering giant dominating eastern deciduous forests. To determine whether this portrayal was accurate, we compared pre-and postblight descriptions of American chestnut. Preblight sources most frequently reported maximum height of mature American chestnut as 100 ft whereas postblight descriptions most frequently report a maximum height of 120 ft. In preblight sources, the maximum diameter reported for American chestnut was 13 ft, and in postblight sources 17 ft was regularly identified as the maximum diameter. We hypothesize that confusion between tree circumference and diameter and the inability to correct false descriptions with measurements has resulted in an increase in the reported maximum size of American chestnut in postblight sources.

... 197-203 DEVELOPMENT OF A WHITE OAK CHRONOLOGY USING LIVE TREES AND A POST-CIVIL WAR CABIN IN ... more ... 197-203 DEVELOPMENT OF A WHITE OAK CHRONOLOGY USING LIVE TREES AND A POST-CIVIL WAR CABIN IN SOUTH-CENTRAL VIRGINIA ZACHARY J. BORTOLO!&quot;, CAROLYN A. COPENHEAVER,1 ROBERT L. LONGE and JAN AN ... 1995; Krause 1997; Therrell 2000 ...

Journal of Agricultural Education

Many universities and professional associations recognize excellence in teaching with awards; how... more Many universities and professional associations recognize excellence in teaching with awards; however, research findings on the impact of an award on teaching identity are mixed. The objective of this study was to qualify the impact of receiving a National or Regional United States Department of Agriculture Teaching, Extension, and Research Award (TERA) on teaching identity. Secondarily, this study explored how well award-winning teachers’ self-identities and behaviors corresponded with recognized characteristics of excellent teaching. A phenomenological approach utilizing semistructured interviews and researcher reflexivity was used to gather information from 12 TERA recipients. Findings indicate that faculty members recognized for excellence in teaching demonstrate known characteristics of effective teachers, seek guidance from the Scholarship of Teaching and Learning, and feel that teaching continues to be less valued than research in their institutional cultures. Results suggest...