Browsing by Author "Emrick, Verl III"

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    Biological Surveys for Fries Hydroelectric Project in the Upper New River, Grayson County, Virginia
    Carey, Caitlin; Orth, Donald J.; Emrick, Verl III (FERC, 2018-04)
    Operated by Aquenergy Systems, LLC (the Licensee; a subsidiary of Enel Green Power North America, Inc.) and licensed by the Federal Energy Regulatory Commission (FERC), the Fries Hydroelectric Project (the Project; FERC No. 2883) is currently undergoing relicensing using FERC’s Traditional Licensing Process (TLP). The current license for the Project was issued June 10th, 1980 and is set to expire May 31st, 2020. In compliance with the first stage of FERC’s TLP, the Licensee filed its Notice of Intent (NOI) and Pre-Application Document (PAD) with FERC (May 2015; Aquenergy Systems, LLC 2015), conducted a joint meeting and site visit with resource agencies and members of the public to solicit input on information needs and study plans (September 2015), and received written comments from stakeholders identifying information gaps and necessary studies to be performed. Pursuant to input provided from resource agencies and the public, the Licensee prepared and distributed a draft outline of proposed studies and methodology to agencies on March 18, 2016. The Licensee held a follow-up joint agency conference call (March 24th, 2016) to receive feedback on the proposed study plans and to reach an agreement on all reasonable and necessary studies as requested by the agencies. Agency comments and changes were incorporated into study plans and a revised outline was distributed to the agencies on April 15th, 2016...
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    Characterization of golden-cheeked warbler Dendroica chrysoparia habitat at Fort Hood, Texas, USA
    Emrick, Verl III (2019-05-26)
    The golden-cheeked warbler Dendroica chrysoparia is a federally endangered, neotropical-nearctic migrant songbird that breeds in central Texas, USA, and prefers mature, closed canopy oak–Ashe juniper woodlands for nesting and foraging. Fort Hood is an 87 890 ha military reservation located in central Texas in Bell and Coryell Counties on the eastern edge of the Edwards Plateau ecoregion. We surveyed for golden-cheeked warblers and measured habitat variables at 95 separate locations in a 56.6 km2 research area that supports a golden-cheeked warbler breeding population. We detected golden-cheeked warblers on 34 of 95 (36%) point count locations. Principal component analysis was used to reduce the 27 habitat variables to a set of uncorrelated variables. This analysis resulted in the identification of 4 principal components that accounted for 52% of the variance. Logistic regression identified one principal component (ratio of Ashe juniper to other woody species) that was strongly related to golden-cheeked warbler occurrence. Our data indicate that a 4:1 ratio of Ashe juniper to other woody species is an important feature of occupied golden cheeked warbler habitat, particularly in the mid- to upper canopy at Fort Hood.
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    Disturbance, Functional Diversity and Ecosystem Processes: Does Species Identity Matter?
    Emrick, Verl III (Virginia Tech, 2013-05-24)
    The role of disturbance is widely recognized as a fundamental driver of ecological organization from individual species to entire landscapes. Anthropogenic disturbances from military training provide a unique opportunity to examine effects of disturbance on vegetation dynamics, physicochemical soil properties, and ecosystem processes. Additionally, plant functional diversity has been suggested as the key to ecosystem processes such as productivity and nutrient dynamics. I investigated how disturbance and functional composition both singly and in combination affect vegetation dynamics, soil physicochemical properties, and ecosystem processes. I conducted my research at Fort Pickett, Virginia, USA to take advantage of the spatially and temporally predictable disturbance regime. In order to investigate the effect of plant functional composition on ecosystem properties, I used functional groups comprised of species with similar physiology and effects on ecosystem processes (C4 grasses, C3 grasses, legumes, forbs, woody plants). My study showed that two distinct disturbances associated with military training, vehicle maneuvers, and fire; affect functional group abundance, within functional group richness, and total species richness. I found strong effects of vehicle maneuvers on soil physical properties including an increase in bulk density and reduction in soil porosity. Fire also influenced soil physical properties but more indirectly through the reduction of above ground litter inputs. Though many of the measured physicochemical soil properties at Fort Pickett exhibited statistically significant effects of disturbance, the strength of these relationships appears to be modulated by influences of previous land use. I found statistically significant (P < 0.05) effects of disturbance on chlorophyll fluorescence, and effect of functional composition on available soil N- NH4+. In addition, I detected a significant interactive effect of disturbance class and functional composition on soil CO2 flux. The interactive effects of disturbance and functional composition on soil CO2 flux demonstrated how the loss of functional diversity could lead to instability in ecosystem processes in disturbed ecosystems.    In a dynamic ecosystem, I demonstrated that the abundance and diversity of plant functional groups was significantly influenced by disturbance. By experimentally altering the abundance and diversity of these functional groups in a disturbance-mediated ecosystem, I showed that functional groups and presumably species influence key ecosystem processes.
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    Final Report: Vegetation Map for Brookhaven National Labs
    Klopfer, Scott D.; Emrick, Verl III (Virginia Tech, 2002-01)
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    Freshwater Mussel Assessment in the Upper Nottoway River and its Tributaries on Fort Pickett, Virginia
    Carey, Caitlin; Wolf, Eric; Emrick, Verl III (2014-09)
    The upper reaches of the Nottoway River and its tributaries on Fort Pickett, Virginia are located within one of the most diverse river basins of the Atlantic Slope region. Freshwater mussels are vital components of these aquatic ecosystems and are often referred to as ecosystem engineers. Mussel surveys on Fort Pickett have historically concentrated on the central reaches of the Nottoway below the reservoir. Thus, assessments in tributaries and sites above the reservoir were needed. We evaluated a total of 68 sites across Fort Pickett and implemented a two-phase sampling design using time-constrained and quadrat-based surveys at a sub-set of these sites. We documented a total of 9 mussel species, including the state threatened Atlantic pigtoe and state species of concern eastern lampmussel. We found that mussels were patchily distributed and densities and species richness varied greatly between sites. Generally, species richness was lower and densities were higher in the tributaries compared to the main-stem of the Nottoway. Our findings of local mussel populations in the tributaries suggest that these areas may serve as spatial refugia for populations of several species. We found little evidence of recent recruitment across species, even at sites with high densities, indicating the need for water-quality testing and host fish surveys to identify management actions needed to support long-term population viability across species. Riparian and habitat protection should extend to the tributaries as well as to the main-stem of the Nottoway. Furthermore, we recommend additional surveys above the reservoir and in the Controlled Access Area, routine monitoring for Atlantic pigtoe and eastern lampmussel, as well as water quality assessments.
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    The Influence of Switchgrass Establishment on Soil Organic Matter Pools in an Agricultural Landscape
    Pryatel, Margaret Jane (Virginia Tech, 2015-08-27)
    Agricultural activities have significant impacts on global biogeochemical cycles, particularly carbon and nitrogen. Conventional row-crop agriculture accelerates the decomposition of soil organic matter, contributing to atmospheric carbon and declining soil fertility. Planting perennial warm season grasses is a useful management alternative to row crop agriculture because these species have been shown to be effective at increasing soil carbon storage and retaining nitrogen. The objectives of this research were to examine how converting row crops to a native perennial warm season grass (Panicum virgatum L., common name switchgrass) influences the recovery of soil organic matter fractions and nitrogen retention within an agricultural watershed in the Shenandoah Valley of Virginia. Soil samples were analyzed for total carbon and nitrogen, three particulate organic matter fractions, root biomass, mineralizable carbon and nitrogen pools, and microbial biomass. Surprisingly, I observed significant declines in bulk soil organic matter and surface particulate organic matter pools following switchgrass establishment. There were no differences in mineralizable carbon and microbial biomass pools between row crop and switchgrass soils, but labile carbon pools and nitrogen immobilization increased as switchgrass stands matured. These results are potentially due to switchgrass litter inputs stimulating microbial communities and accelerating the decomposition of recalcitrant soil organic matter, leading to declines in soil organic carbon stocks. The results from this study will be used to understand the environmental and economic benefits of implementing switchgrass plantings in agricultural watershed as a means to mitigate agriculturally-induced effects on carbon storage and nitrogen retention in soils.
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    Integrative Science and Solutions for Freshwater Systems Concept Paper - A plan to build a signature-strength in Freshwater Systems
    Benham, Brian L.; Czuba, Jonathan A.; Hession, W. Cully; Krometis, Leigh-Anne H.; Scott, Durelle T.; Stephenson, Stephen Kurt; Thompson, Theresa M.; Bork, Dean R.; Hester, Erich T.; Polys, Nicholas F.; Ivory, James Dee; Angermeier, Paul L.; Castello, Leandro; Dolloff, C. Andrew; Emrick, Verl III; Jones, Jess W.; McLaughlin, Daniel L.; Meyers, R. B.; Orth, Donald J.; Schoenholtz, Stephen H.; Snodgrass, Joel W.; Hotchkiss, Erin R.; Smith, Eric P. (Virginia Tech, 2017-05-15)
    Virginia Tech is poised to become a global leader in the pursuit and application of new knowledge to inform management and restoration of waterbodies and their watersheds. Despite our notable strengths in specific disciplines, we have not yet facilitated nor nurtured an interdisciplinary program whereby a holistic perspective of freshwater systems can permeate into VT-shaped students and bridge the gaps among water-relevant biophysical, social sciences, and the arts. We know of no other major research university with a signature-strength in integrated freshwater systems science...
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    Removal, Propagation, and Transplantation of Michaux’s Sumac (Rhus michauxii) Colonies from the Infantry Platoon Battle Course, Fort Pickett –Maneuver Training Center, Virginia
    Emrick, Verl III; Fields, Matthew; Fitzpatrick, Jessica (2018-05-01)
    Michaux’s sumac (Rhus michauxii Sarg.) is a rare and federally endangered, densely pubescent, rhizomatous shrub found in periodically disturbed habitats in the inner Coastal plain and piedmont of the southeastern United States. At Fort Pickett, conflicts between military training and Michaux’s sumac are uncommon. Current management of the Fort Pickett population restricts all military activity, with the exception of foot traffic, within colonies of Michaux’s sumac. However, the dynamic and constantly evolving military mission has resulted in range expansion and alteration thus isolating small colonies of Michaux’s sumac. At Fort Pickett, six colonies of Michaux’s sumac occurred within two active firing ranges. The goal of the research project was the careful excavation of Michaux’s sumac rhizomes from up to six small, isolated colonies on two active direct fire ranges at Fort Pickett, propagation of these individuals in a controlled greenhouse setting, and the subsequent transplantation of the propagated individuals to suitable habitat on Fort Pickett. In March 2017, while the plants were dormant, all rhizomes in colonies were excavated by digging with a hand trowel. We planted 168 bare rhizomes in 1-gallon plastic greenhouse pots with equal parts of peat, clay, and perlite, along with 25 grams of soil from the original colony location to ensure inoculation by native mycorrhizae. Approximately ½ of the individuals showed signs of stress and wilting by May of 2017. The source was a soil-borne pathogen, Rhizoctonia solani. All plants, including the healthy individuals, were treated with fungicides registered for control of rhizoctonia. On April 26-27, 2018, 39 of the greenhouse grown Michaux’s sumac were successfully planted in DF6. The remaining 20 grown outside under shade cloth will be planted in the fall of 2018. In July 2018, all 39-transplanted individuals were alive and vigorous with, 17 (44%) individuals producing female flowers and one (2.5%) male flowers. While these procedures were specifically researched and developed for the removal and transplantation of Michaux’s sumac stems from Range 12 and the IPBC, they can serve as the basis for any future propagation of Michaux’s sumac rhizomes for conservation and recovery.