Spatial Variation In Carbon And Nitrogen In Cultivated Soils In Henan Province, China: Potential Effect On Crop Yield, Xuelin Zhang, Qun Wang, Frank S. Gilliam, Yilun Wang, Feina Cha, Chaohai Li
Improved management of soil carbon (C) and nitrogen (N) storage in agro-ecosystems represents an important strategy for ensuring food security and sustainable agricultural development in China. Accurate estimates of the distribution of soil C and N stores and their relationship to crop yield are crucial to developing appropriate cropland management policies. The current study examined the spatial variation of soil organic C (SOC), total soil N (TSN), and associated variables in the surface layer (0–40 cm) of soils from intensive agricultural systems in 19 counties within Henan Province, China, and compared these patterns with crop yield. Mean soil C ...
In Situ Nitrogen Mineralization, Nitrification, And Ammonia Volatilization In Maize Field Fertilized With Urea In Huanghuaihai Region Of Northern China, Xuelin Zhang, Qun Wang, Jun Xu, Frank S. Gilliam, Nicolas Tremblay, Chaohai Li
Nitrogen (N) fertilization potentially affects soil N mineralization and leaching, and can enhance NH3 volatilization, thus impacting crop production. A fertilizer experiment with five levels of N addition (0, 79, 147, 215 and 375 kg N ha-1) was performed in 2009 and 2010 in a maize field in Huanghuaihai region, China, where > 300 kg N ha-1 has been routinely applied to soil during maize growth period of 120 days. Responses of net N mineralization, inorganic N flux (0–10cm), NH3 volatilization, and maize yield to N fertilization were measured. During the growth period, net N mineralization and nitrification varied seasonally ...
Effect Of Spatial Influence On Endophyte Diversity Within Alnus Rubra, 2017 Portland State University
Effect Of Spatial Influence On Endophyte Diversity Within Alnus Rubra, Sebastian L. Singleton
Student Research Symposium
Red alders (Alnus rubra) of the Pacific Northwest are characterized as actinorhizal dicotyledons; plants that possess that ability to form symbiotic relationships with endophytic organisms, which result in nitrogen-fixing nodules. In Alders of the order Fagales, such a symbiotic relationship with Frankia bacteria allows these plants to play crucial environmental roles as pioneer species able to colonize and enrich nutrient-deficient soils. This ability has a major impact on ecological succession by enabling other species to establish. Although inoculation with frankia bacteria is known to increase symbiotic nitrogen fixation capabilities of actinorhizal plants, whether they could confer the same benefit to ...
Variation In Density Dependent Seedling Survival Across Forests Of Different Successional Age And Hunting Protection Status, 2017 University of Nebraska-Lincoln
Variation In Density Dependent Seedling Survival Across Forests Of Different Successional Age And Hunting Protection Status, Nohemi Huanca-Nunez
Dissertations and Theses in Biological Sciences
Over 50% of the original extent of tropical forests has been cleared. Restoration of secondary forests is important for maintaining the ecosystem services that mature tropical forests provide. Density dependence (DD) is thought to be a major mechanism for shaping forest community structure and may cause reduced spatial aggregation among individuals of the same species, allowing for maintenance of diversity. While much research has focused on DD in mature tropical forests, few studies have examined how DD may influence community structure in secondary forests, many of which are also exposed to hunting. There are several important agents of negative and ...
Flight Activity, Oviposition Pit Distribution, And Emergence Densities Of Monochamus Titillator And M. Carolinensis In The Ozark-St. Francis National Forest In Arkansas, 2017 University of Arkansas, Fayetteville
Flight Activity, Oviposition Pit Distribution, And Emergence Densities Of Monochamus Titillator And M. Carolinensis In The Ozark-St. Francis National Forest In Arkansas, Jake Bodart
Theses and Dissertations
Monochamus (Coleoptera: Cerambycidae) are a genus of longhorn beetles commonly known as pine sawyers. They have a worldwide distribution coincident with pines (Pinaceae) and are vectors of the pinewood nematode (Bursaphelenchus xylophilus). In the United States, there are eight known Monochamus species and they have a sympatric distribution with at least one other Monochamus species throughout their range. Monochamus are known to attack stressed, dead, and dying conifers especially pines. In the Ozark- St. Francis National Forest in Arkansas, there are two species of pine sawyers and they share this sympatric distribution observed throughout the United States, M. titillator (southern ...
Building A Comprehensive Collection Of Ash Germplasm, 2017 United States Department of Agriculture
Building A Comprehensive Collection Of Ash Germplasm, Mark P. Widrlechner
Mark P. Widrlechner
This paper summarizes a presentation from the Congress Symposium, “The Introduction of the Emerald Ash Borer in North America, A Case Study of Invasive Species Epidemiology and Conservation of the Host Species.” It briefly discusses the state of Fraxinus (ash) taxonomy, ash as a landscape and forest tree, some of its specialized uses, including those by Native Americans, and its role in supporting other organisms. The devastation caused to native, North American ash populations by the introduction of Agrilus planipennis (emerald ash borer; EAB) to the Detroit, Michigan area has already led to the loss of tens of millions of ...
Timber Talk, Vol. 55, No. 1, March 2017, 2017 University of Nebraska - Lincoln
Timber Talk, Vol. 55, No. 1, March 2017
Timber Talk: Nebraska Forest Industry Newsletter
In This Issue
Lumber Market Reports 1
Hardwood Lumber Prices 2
Hardwood Lumber Market History 3
Bringing Innovative Timber Construction to Nebraska 4
Using Biochar to Reduce Cattle Emissions 5
Nebraska Forest Industry Spotlight 6
Timber Appraisals 6
Nebraska Wood Energy Team Conducting Statewide Analysis 7
Trading Post 8
An Artificial Neural Network For Real-Time Hardwood Lumber Grading, 2017 USDA Forest Service
An Artificial Neural Network For Real-Time Hardwood Lumber Grading, Edward Thomas
USDA Forest Service / UNL Faculty Publications
Computerized grading of hardwood lumber according to NHLA rules would permit fast assessment of sawn lumber and the evaluation of potential edging and trimming operations to improve lumber value. More importantly, to enable optimization of the hardwood lumber sawing process, a fast means of evaluating the potential value of boards before they are sawn is necessary. As log and lumber scanning systems become prevalent and common, these needs become more pressing. From an automation perspective, the NHLA lumber grades are difficult to implement efficiently in a computer program. Exhaustive approaches that examine every potential cutting size and combination to determine ...
Interactions Between White-Tailed Deer Density And The Composition Of Forest Understories In The Northern United States, 2017 University of Minnesota
Interactions Between White-Tailed Deer Density And The Composition Of Forest Understories In The Northern United States, Matthew B. Russell, Christopher W. Woodall, Kevin M. Potter, Brian F. Walters, Grant M. Domke, Christopher M. Oswalt
USDA Forest Service / UNL Faculty Publications
Forest understories across the northern United States (US) are a complex of tree seedlings, endemic forbs, herbs, shrubs, and introduced plant species within a forest structure defined by tree and forest floor attributes. The substantial increase in white-tailed deer (Odocoileus virginianus Zimmerman) populations over the past decades has resulted in heavy browse pressure in many of these forests. To gain an objective assessment of the role of deer in forested ecosystems, a region-wide forest inventory across the northern US was examined in concert with white-tailed deer density information compiled at broad scales. Results indicate that deer density may be an ...
Residential Building Energy Conservation And Avoided Power Plant Emissions By Urban And Community Trees In The United States, David J. Nowak, Nathaniel Appleton, Alexis Ellis, Eric Greenfield
USDA Forest Service / UNL Faculty Publications
Urban trees and forests alter building energy use and associated emissions from power plants by shading buildings, cooling air temperatures and altering wind speeds around buildings. Field data on urban trees were combined with local urban/community tree and land cover maps, modeling of tree effects on building energy use and pollutant emissions, and state energy and pollutant costs to estimate tree effects on building energy use and associated pollutant emissions at the state to national level in the conterminous United States. Results reveal that trees and forests in urban/community areas in the conterminous United States annually reduce electricity ...
Roosting Behavior, Habitat Use, And Relative Abundance Of The Northern Long-Eared Bat (Myotis Septentrionalis) Following Arrival Of White-Nose Syndrome To Mammoth Cave National Park, 2017 University of Kentucky
Roosting Behavior, Habitat Use, And Relative Abundance Of The Northern Long-Eared Bat (Myotis Septentrionalis) Following Arrival Of White-Nose Syndrome To Mammoth Cave National Park, Marissa M. Thalken
Theses and Dissertations--Forestry
White-Nose Syndrome (WNS; Pseudogymnoascus destructans) is responsible for the regional population collapse of many cave-hibernating bat species, including the northern long-eared bat (Myotis septentrionalis), in eastern United States and Canada. I evaluated roosting behavior, habitat selection, and landscape-scale distribution of roosts of the northern long-eared bat during spring emergence and the early maternity season in Mammoth Cave National Park, Kentucky, USA, from 2015 to 2016. Logistic regression analysis comparing habitat features of roosts with random plots indicated selection of roosts reflected the costs of energetic demands by sex and reproductive status. Relative abundance of local bat species was assessed pre- ...
Invasion Dynamics Of The Exotic Liana Euonymus Fortunei (Turcz.) Hand.-Mazz. (Wintercreeper), 2017 University of Kentucky
Invasion Dynamics Of The Exotic Liana Euonymus Fortunei (Turcz.) Hand.-Mazz. (Wintercreeper), Todd J. Rounsaville
Theses and Dissertations--Biology
Elevated atmospheric CO2 has been implicated as a driver of increased liana abundance worldwide. Known as disturbance creators and beneficiaries, lianas possess the potential to significantly influence forest ecosystems. I investigated the early-invasion dynamics of Euonymus fortunei (wintercreeper), an evergreen liana that is invading forests in eastern North America, disrupting native plant communities and ecosystem functions.
Wintercreeper is widely cultivated as an ornamental groundcover, frequently invading natural areas via asexual stem growth. Invasion of remote natural areas is dependent upon seed transport and may occur less frequently. I examined the mechanisms of seed dormancy by conducting a ‘move-along’ experiment ...
Short-Term Wildfire Impacts In A Rocky Mountain Catchment: Searching For Evidence Of Riverine Black Carbon Transport After The Cold Springs Wildfire, 2017 University of Colorado, Boulder
Short-Term Wildfire Impacts In A Rocky Mountain Catchment: Searching For Evidence Of Riverine Black Carbon Transport After The Cold Springs Wildfire, Dillon Mcclintock Ragar
Undergraduate Honors Theses
Black Carbon (BC) is a long-lasting and ubiquitous product of combustion. It is found nearly everywhere on the Earth’s surface, oceans, and atmosphere. It was originally considered to be very stable in soils, but is now understood to be mobile in terrestrial and aquatic environments. The magnitude of BC flux into oceans via riverine transport has been established, but the exact conditions under which transport occurs are unknown. This research monitored surface water sites to determine if a pulse of BC could be identified from a recently burned forested area in the Colorado Rocky Mountains. BC was shown to ...
The Effects Of Abandoned Mines On Tree Health In Boulder Canyon, Co And An Analysis Of Abandoned Mine Lands Mitigation Policies, 2017 University of Colorado, Boulder
The Effects Of Abandoned Mines On Tree Health In Boulder Canyon, Co And An Analysis Of Abandoned Mine Lands Mitigation Policies, Dakota Anderson
Undergraduate Honors Theses
This thesis examines the effects of abandoned mines on tree health in Boulder Canyon, CO and also analyses national and state policy regarding abandoned mine lands mitigation. Abandoned mines are a prevalent issue throughout the nation and in the state of Colorado. Research has shown that abandoned mines leak heavy metal pollutants that can have an adverse effect on ecosystems. I used a line intercept sampling method to determine the mean diameter at breast height and percentage of dead trees at 13 mined and 13 control areas. The results showed that the presence of a mine had no effect on ...
Modeling The Spread Of Sudden Oak Death Across A Heterogeneous Landscape In Redwood National Park Using A Spatially-Explicit Epidemiological Model, Laura A. Morgan
The pathogen Phytophthora ramorum, the causal agent of Sudden Oak Death (SOD), is responsible for the deaths of millions of oak (Quercus spp.) and tanoak (Notholithocarpus densiflorus) trees in California and Oregon (USA). A recent infection in Redwood National Park (RNP) in California (USA) provided an opportunity to adapt an existing SOD model to assess the efficacy of current and proposed management strategies. A common method of SOD treatment includes killing both infected and uninfected hosts in the area of infection, as well as the area surrounding the infection to create buffers to account for undetected or cryptic infections. I ...
Characterization Of Genic Microsatellite Markers (Est-Ssrs) In The Endangered Oak Species Quercus Georgiana M.A.Curtis, 2017 Michigan Technological University
Characterization Of Genic Microsatellite Markers (Est-Ssrs) In The Endangered Oak Species Quercus Georgiana M.A.Curtis, Priyanka Dipak Kadav
Dissertations, Master's Theses and Master's Reports
Quercus is important ecologically and economically because it provides food and habitat for wildlife, wood and paper products for humans. Oaks are endangered due to various factors like shifting climates, habitat loss, drought, pathogens and genetic swamping. Quercus georgiana (M.A. Curtis) is an endangered and restricted oak species which is remaining only in the southeastern part of the US. Efforts are required to conserve this endangered species from extinction. Conservation of this species can be done through these methods: ex-situ conservation (arboretum and botanical garden) and in-situ conservation strategies which protect the species in its natural habitat. For this ...
Occam's Razor Vol. 7 - Full (2017), 2017 Western Washington University
Occam's Razor Vol. 7 - Full (2017)
No abstract provided.
Effectiveness Of Chemical Defense In A Tropical Millipede Species On A Potential Predator, The Tarantula Megaphobema Mesomelas, 2017 Western Washington University
Effectiveness Of Chemical Defense In A Tropical Millipede Species On A Potential Predator, The Tarantula Megaphobema Mesomelas, Maya L. Klem
Millipedes are known to have a variety of physical and chemical defenses to deter predators. Some species of tropical millipedes have considerably reduced primary defenses when compared to other tropical millipedes, but do retain chemical defense mechanisms. This study uses the tarantula Megaphobema mesomelas to test the effectiveness of a secondary defense mechanism, cyanide and benzaldehyde, from a species lacking a robust primary defense. Five tarantulas were found and collected around Monteverde, Costa Rica and brought into the Monteverde Biological Station. They were housed in tanks to allow for controlled feeding trials. Two treatment groups were created: millipedes with cyanide ...
Molecular Diversity Of Foliar Fungal Endophytes In Relation To Defense Strategies And Disease In Whitebark Pine, 2017 University of Montana, Missoula
Molecular Diversity Of Foliar Fungal Endophytes In Relation To Defense Strategies And Disease In Whitebark Pine, Lorinda Bullington 5474413
Graduate Student Theses, Dissertations, & Professional Papers
An invasive fungal pathogen, Cronartium ribicola (the causative agent of white pine blister rust) infects and kills whitebark pine (Pinus albicaulis) throughout the western US. Blister rust has decreased whitebark pine populations by over 90% in some areas. Whitebark pine, a keystone species, has been proposed for listing under the Endangered Species Act in the U.S., and the loss of this conifer is predicted to have severe impacts on forest composition and function in high elevations. Hundreds of asymptomatic fungal species live inside whitebark pine tissue, and recent studies suggest that these fungi can influence the frequency and severity ...
The Influence Of The Invasive Chinese Tallow (Triadica Sebifera) Leaf Litter On Aquatic Chemistry And Microbial Community Composition, 2016 Stephen F Austin State University
The Influence Of The Invasive Chinese Tallow (Triadica Sebifera) Leaf Litter On Aquatic Chemistry And Microbial Community Composition, Raymond D. Montez
Electronic Theses and Dissertations
Global climate change and anthropogenic activity have facilitated the movement and invasive potential of nonnative plants in native environments. These invasions can have negative effects on ecosystem diversity and function. The nonnative and invasive plant, Chinese Tallow (Triadica sebifera), has already invaded much of the south eastern US where it is outcompeting native tree species and changing ecosystem diversity in a variety of habitats. Leaf litter from the Chinese tallow has been shown cause changes in dissolved oxygen and pH in the aquatic environment. Turbidity is also affected when Chinese tallow litter is present in water. A series of experiments ...