Digital Commons Network^™

Science At Engineer Cantonment, Hugh H. Genoways, Brett C. Ratcliffe, Carl R. Falk, Thomas E. Labedz, Paul R. Picha, John R. Bozell

University of Nebraska State Museum: Mammalogy Papers

Conclusions

It is our contention that Thomas Say, Titian Peale, Edwin James, and their colleagues of the Stephen Long Expedition of 1819–1820 were heavily engaged in scientific research, which took the form of the first biodiversity inventory undertaken in the United States. This accomplishment has been overlooked both by biologists and historians, but it should rank among the most significant accomplishments of the expedition. The results of this inventory continue to inform us today about environmental, faunal, and floral changes along the Missouri River in an area that is known to be an ecotone between the deciduous forests of the …

Drivers Of Post-Fire Vascular Plant Regeneration In The Conifer-Dominated Boreal Forest Of Southern Northwest Territories, Alison White

Theses and Dissertations (Comprehensive)

In recent years, climate warming has led to an increase in the severity and frequency of naturally occurring fires in boreal ecosystems globally. In 2014, an unprecedented 3.4 million hectares of boreal forest burned in the Northwest Territories (NWT). While much research has focused on post-fire succession of serotinous tree species such as Picea mariana (black spruce) and Pinus banksiana (jack pine), the understory community of vascular plants play an important role in ecosystem functioning but less is known about the response of this component of the system to changing fire regimes. Regeneration strategies such as the ability to resprout …

Effects Of Management On Functional Diversity In Restored Tallgrass Prairie Plant Communities, Anna K. Farrell

Graduate Research Theses & Dissertations

While recent studies have embraced evaluating ecosystems through functional diversity, the focus on interspecific trait changes may limit their usefulness and application. Functional traits (traits that explain species’ responses to environmental conditions and their ecosystem roles) can provide a more nuanced understanding of how disturbances shape plant communities and the functions they perform. Further, the inclusion of intraspecific trait responses can explain a significant portion of these relationships. In ecosystem restorations, management strategies can act as environmental drivers and disturbances that affect community structure. This study examined how three environmental drivers (grazer presence, prescribed fire, and age) in restored grasslands …

Conflicting Hydraulic Effects Of Xylem Pit Structure Relate To The Growth-Longevity Tradeoff In A Conifer Species, Beth Roskilly

Graduate Student Theses, Dissertations, & Professional Papers

Consistent with a ubiquitous life history tradeoff, trees exhibit a negative relationship between growth and longevity among and within species. However, the mechanistic basis of this life history tradeoff is not well understood. In addition to tradeoffs among multiple traits based on resource allocation conflicts, life history tradeoffs may arise from tradeoffs based on single traits under opposing selection. While a myriad of factors likely contribute to the growth-longevity tradeoff in trees, we hypothesized that conflicting functional effects of xylem structural traits contribute to the growth-longevity tradeoff. We tested this hypothesis by examining the extent to which xylem morphological traits …

The Cotesia Sesamiae Story: Insight Into Host-Range Evolution In A Hymenoptera Parasitoid And Implication For Its Use In Biological Control Programs, L. Kaiser, S. Dupas, A. Branca, E. A. Herniou, C. W. Clarke, C. Capdevielle Dulac, J. Obonyo, R. Benoist, J. Gauthier, P. A. Calatayud, J. F. Silvain, B. P. Le Ru

All Peer-Reviewed Publications

This review covers nearly 20 years of studies on the ecology, physiology and genetics of the Hymenoptera Cotesia sesamiae, an African parasitoid of Lepidoptera that reduces populations of common maize borers in East and South Africa. The first part of the review presents studies based on sampling of C. sesamiae from maize crops in Kenya. From this agrosystem including one host plant and three main host borer species, studies revealed two genetically differentiated populations of C. sesamiae species adapted to their local host community, and showed that their differentiation involved the joint evolution of virulence genes and sensory mechanisms of …

Functional Predictions Of Microbial Communities In Soil As Affected By Long‐Term Tillage Practices, Janani Hariharan, Aditi Sengupta, Parwinder Grewal, Warren A. Dick

School of Earth, Environmental, & Marine Sciences Faculty Publications

Core Ideas

• Microbial function is important but difficult to assess in soil.
• An omics‐driven tool, PICRUSt, was used to characterize functions of soil microbial communities.
• No‐tillage compared with plow tillage was functionally enriched for most nutrient cycles.
• Many other functions integral to soil health can be explored by the PICRUSt omics approach.

Soil microbial communities affect the soil's biological, chemical, and physical properties, but there is still a knowledge gap regarding the long‐term impact of tillage practices on soil microbial dynamics. Additionally, the accurate identification of belowground microbial functions is a topic of active interest. In this study, microbial community …

Influence Of An Internal Parasite Control On Cattle Grazing Behavior And Production, Jace Stott

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Six herds of 45 to 90 cow/calf pairs grazing on upland range were used to examine the efficacy of an injectable extended release eprinomectin parasite control on production traits, activity behavior, and efficacy against internal parasitism. In 2016, treatment cows were given a subcutaneous injection of LongRange^tm. In 2017, all cows in the study were treated with a short acting Synanthic^tm treatment and only treatment cows were given an additional LongRange^tm treatment. In both 2016 and 2017, fecal egg counts were significantly lower (P < 0.05) in eprinomectin treated cows compared to control cows. Calf gains were 4.8 kg and 8.7 kg greater (P < 0.1) for the calves of dams treated with eprinomectin compared to calves of control cows in 2016 and 2017, respectively. Activity characteristics of cattle were inconclusive, with treated cows having lower (P < 0.01) grazing and traveling times compared to control cows in 2016, and more (P < 0.01) grazing and traveling in 2017.

Differences in grazing behaviors based on time within pasture at different times …

The Interacting Roles Of Climate, Soils, And Plant Production On Soil Microbial Communities At A Continental Scale, M. P. Waldrop, J. M. Holloway, D. B. Smith, M. B. Goldhaber, Rebecca E. Drenovsky, K. M. Scow, R. Dick, D. Howard, B. Wylie, J. B. Grace

2017 Faculty Bibliography

Soil microbial communities control critical ecosystem processes such as decomposition, nutrient cycling, and soil organic matter formation. Continental scale patterns in the composition and functioning of microbial communities are related to climatic, biotic, and edaphic factors such as temperature and precipitation, plant community composition, and soil carbon, nitrogen, and pH. Although these relationships have been well explored individually, the examination of the factors that may act directly on microbial communities vs. those that may act indirectly through other ecosystem properties has not been well developed. To further such understanding, we utilized structural equation modeling (SEM) to evaluate a set of …

Divergence In Life History Traits Between Two Populations Of A Seed-Dimorphic Halophyte In Response To Soil Salinity, Fan Yang, Jerry M. Baskin, Carol C. Baskin, Xuejun Yang, Dechang Cao, Zhenying Huang

Biology Faculty Publications

Production of heteromorphic seeds is common in halophytes growing in arid environments with strong spatial and temporal heterogeneity. However, evidence for geographic variation (reflecting local adaptation) is almost nonexistent. Our primary aims were to compare the life history traits of two desert populations of this halophytic summer annual Suaeda corniculata subsp. mongolica and to investigate the phenotypic response of its plant and heteromorphic seeds to different levels of salt stress. Dimorphic seeds (F₁) of the halophyte S. corniculata collected from two distant populations (F₀) that differ in soil salinity were grown in a common environment under …

Ultramafic Geoecology Of South And Southeast Asia, M.L. Galey, A. Van Der Ent, M.C.M. Iqbal, N. Rajakaruna

Biological Sciences

Globally, ultramafic outcrops are renowned for hosting foras with high levels of endemism, including plants with specialised adaptations such as nickel or manganese hyperaccumulation. Soils derived from ultramafic regoliths are generally nutrient-deficient, have major cation imbalances, and have concomitant high concentrations of potentially phytotoxic trace elements, especially nickel. The South and Southeast Asian region has the largest surface occurrences of ultramafic regoliths in the world, but the geoecology of these outcrops is still poorly studied despite severe conservation threats. Due to the paucity of systematic plant collections in many areas and the lack of georeferenced herbarium records and databased information, …

Chapter 2 - Protozoa, Janice M. Glime

Bryophyte Ecology Volume 2: Bryological Interaction

Explore the contents of Bryophyte Ecology, Volume 2, Chapter 2 - Protozoa by clicking the links above. For the Contents section of this ebook, as well as Volumes 1 through 5, please visit the Bryophyte Ecology Main Page.

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Ebook sponsored by Michigan Technological University and the International Association of Bryologists.

Chapter 13 - Fish, Janice M. Glime

Bryophyte Ecology Volume 2: Bryological Interaction

Explore the contents of Bryophyte Ecology, Volume 2, Chapter 13 - Fish by clicking the link above. For the Contents section of this ebook, as well as Volumes 1 through 5, please visit the Bryophyte Ecology Main Page.

Use CTRL+F to easily search within PDF files.

Ebook sponsored by Michigan Technological University and the International Association of Bryologists.

Chapter 1 - Introduction, Janice M. Glime

Bryophyte Ecology Volume 1: Physiological Ecology

Explore the contents of Bryophyte Ecology, Volume 1, Chapter 1 - Introduction by clicking the link above. For the Contents section of this ebook, as well as Volumes 1 through 5, please visit the Bryophyte Ecology Main Page.

Use CTRL+F to easily search within PDF files.

Ebook sponsored by Michigan Technological University and the International Association of Bryologists.

Volume 1, Chapter 4-5: Adaptive Strategies: Growth And Life Forms, Janice M. Glime

Bryophyte Ecology Subchapters

No abstract provided.

Climate Dynamics, Invader Fitness, And Ecosystem Resistance In An Invasion-Factor Framework, Stephen L. Young, David R. Clements, Antonio Ditommaso

West Central Research and Extension Center, North Platte

As researchers and land managers increasingly seek to understand plant invasions and the external (climate) and internal (plant genetics) conditions that govern the process, new insight is helping to answer the elusive question of what makes some invasions successful and others not. Plant invasion success or failure is based on a combination of evolutionary and ecological processes. Abiotic (e.g., climate) and biotic (e.g., plant competition) conditions in the environment and plant genetics (e.g., fitness) combine in either decreasing or increasing invasion, yet it has proven challenging to know exactly which of these conditions leads to success for a given species, …

Population Structure And Genetic Diversity Of Bromus Tectorum Within The Small Grain Production Region Of The Pacific Northwest, Nevin C. Lawrence, Amber L. Hauvermale, Amit Dhingra, Ian C. Burke

Department of Agronomy and Horticulture: Faculty Publications

Bromus tectorum L. is an invasive winter annual grass naturalized across the United States. Numerous studies have investigated B. tectorum population structure and genetics in the context of B. tectorum as an ecological invader of natural areas and rangeland. Despite the wealth of information regarding B. tectorum, previous studies have not focused on, or made comparisons to, B. tectorum as it persists in individual agroecosystems. The objectives of this study were to assess the genetic diversity and structure, the occurrence of generalist and specialist genotypes, and the influence of climate on distribution of B. tectorum sourced exclusively from within …

Taxonomic Position Of Abies Equi-Trojani On The Basis Of Needlecharacters By Comparison With Different Fir Species, Anna Katarzyna Jasinska, Katarzyna Sekiewicz, Tolga Ok, Angel Romo, Adam Boratynski, Krystyna Boratynska

Turkish Journal of Botany

The needles from 25 trees of Abies equi-trojani from Kazdağı (Mount Ida) were compared with those from four populations of A. alba, two of A. cephalonica, and three of each of A. xborisii-regis, A. bornmuelleriana, and A. nordmanniana, each represented by 29-31 individuals. Thirty-nine morphological and anatomical needle characters (26 main and 13 estimated ones) were examined biometrically to verify the systematic position of A. equi-trojani. To evaluate the relationships among taxa, Student's t-test for independent samples, the Mann-Whitney U test, and discrimination and clustering analyses were applied. The differences between taxa were statistically significant for several characters, but the …

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 …

Regeneration And Invasion Of Cottonwood Riparian Forest Following Wildfire, Carissa L. Wonkka, Dirac L. Twidwell Jr., Christine H. Bielski, Craig R. Allen, Michael C. Stambaugh

Department of Agronomy and Horticulture: Faculty Publications

Populus deltoides is considered to be a weak resprouter and highly susceptible to wildfire, but few post-wildfire studies have tracked P. deltoides response and resprouting within the Great Plains of North America. Following a wildfire in southwestern Kansas, U.S.A., we surveyed burned and unburned areas of a cottonwood riparian forest along the Cimarron River that included a major understory invader, tamarisk (Tamarix ramosissima Ledeb.). We tested the following hypotheses, which are consistent with the current understanding of P. deltoides response to wildfire in the Great Plains: (1) regeneration of P. deltoides will be low in areas burned by the …

Taxonomic Revision Of Dendrobium Sw. Section Stachyobium Lindl. (Orchidaceae) In Thailand, Phataravee Prommanut

Chulalongkorn University Theses and Dissertations (Chula ETD)

Taxonomic revision of Dendrobium Sw. section Stachyobium Lindl. in Thailand has been conducted from 2015-2018 based on natural habitats observation in Thailand as well as various herbaria visits, i.e. BCU, BK, BKF, BM, C, CMUB, E, K, KKU and QBG. Key to species, taxonomic descriptions, ecological data, illustrations and geographical distribution of all taxa are provided. Twenty four taxa with including 21 species and 3 varieties were recognized. Among these, two species namely Dendrobium chiangdaoense and D. obchantiae are new to Thailand and two species viz. Dendrobium sp.2 and Dendrobium sp.3 are being proposed as new species. Besides, Dendrobium sp.1 …

Are Weevils Picky Eaters? Community Structure And Host Specificity Of Neotropical Saproxylic Beetles (Coleoptera: Curculionidae), Jhunior A. Morillo

Dissertations and Theses

Abstract Primary saproxylic beetles play a major role in forest nutrient cycling and making deadwood accessible to other decomposers. Understanding beetle host preferences and patterns of community assembly is critical for their conservation, and for predicting which species might become invasive. This project aims to investigate the ecological and host specificity, as well as the community composition of curculionids in a mosaic of old-growth (OG) and secondary forest on the Osa Peninsula, Costa Rica. The subfamily Scolytinae was expected to be the most species-rich and abundant. Ambrosia beetles were expected to have more generalist species than other curculionids. Old growth …

Diversity Of Mosses In Phu Kradueng National Park, Loei Province, Patsakorn Ajintaiyasil

Chulalongkorn University Theses and Dissertations (Chula ETD)

The study of mosses diversity in Phu Kradueng National Park, Loei Province was explored from December 2014 to December 2016. The samples were collected along the 6 natural trails. A total of 501 samples were identified into 30 families, 55 genera, 100 species, 5 subspecies, and 9 varieties. Three families of mosses namely Sphagnaceae, Fissidentaceae, and Leucobryaceae were common families which included 11, 9 and 7 taxa, respectively. Additionally, the most common microhabitat was saxicolous with 45 species. The second and third common microhabitats were terrestrial and corticolous with 43 and 37 species, respectively. Additionally, there are 4 species which …

Integration Of Plant Defense Traits With Biological Control Of Arthropod Pests: Challenges And Opportunities, Julie A. Peterson, Paul J. Ode, Camila Oliveira-Hofman, James D. Harwood

Department of Entomology: Faculty Publications

Crop plants exhibit a wide diversity of defensive traits and strategies to protect themselves from damage by herbivorous pests and disease. These defensive traits may be naturally occurring or artificially selected through crop breeding, including introduction via genetic engineering. While these traits can have obvious and direct impacts on herbivorous pests, many have profound effects on higher trophic levels, including the natural enemies of herbivores. Multi-trophic effects of host plant resistance have the potential to influence, both positively and negatively, biological control. Plant defense traits can influence both the numerical and functional responses of natural enemies; these interactions can be …

Volume 2, Chapter 12-17: Terrestrial Insects: Holometabola - Diptera Biology And Habitats, Janice M. Glime

Bryophyte Ecology Subchapters

No abstract provided.

Morphological And Molecular Identification And Characterization Of Dry Bean Fungal Root Rot Pathogens In Zambia, Chikoti Mukuma

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Dry bean is among the most important food legume crops for direct human consumption in Latin America and Africa. Recently, root and crown rot (RCR) has emerged as an important production constraint. Root and crown rot often involve fungal complexes. Thus, the straw, detached leaf, cup and stem tests were compared on their ability to detect the most common pathogens reported to be associated with RCR: Fusarium solani, Fusarium oxysporum, Pythium ultimum, Rhizoctonia solani and Macrophomina phaseolina.Significant differences (P

Next Generation Sequencing (NGS), conventional Polymerase Chain Reaction (PCR), and classical fungal culturing methods were compared in identification of …

The Plight Of Aspen: Emerging As A Beneficiary Of Wolf Restoration On Yellowstone’S Northern Range, John Klaptosky

Aspen Bibliography

No abstract provided.

A Comparative Study Of The Flora And Soils Of Great Duck And Little Duck Islands, Maine, Usa, Luka Negoita, Matthew Dickinson, Glen H. Mittlehauser, N. Rajakaruna

Biological Sciences

Strong environmental gradients and varied land-use practices have generated a mosaic of habitats harboring distinct plant communities on islands on the coast of Maine. Botanical studies of Maine’s islands, however, are generally limited in number and scope. Baseline studies of Maine’s islands are necessary for assessing vegetation dynamics and changes in habitat conditions in relation to environmental impacts imposed by climate change, rising sea levels, invasive species, pests and pathogens, introduced herbivores, and human disturbance. We conducted a survey of the vascular plants and soils of forest, field, and ocean-side communities of Great Duck and Little Duck Islands, ME. These …

Evolutionary Responses Of Invasive Grass Species To Variation In Precipitation And Soil Nitrogen, Monica A. Nguyen, Amy E. Ortega, Quoc L. Nguyen, Sarah Kimball, Michael L. Goulden, Jennifer L. Funk

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

1.Global climate models suggest that many ecosystems will experience reduced precipitation over the next century and the consequences for invasive plant performance are largely unknown. Annual invasive species may be able to quickly evolve traits associated with drought escape or tolerance through rapid genetic changes.

2.We investigated the influence of five years of water and nitrogen manipulations on trait values in a southern California grassland system. Seeds from two annual grass species (Avena barbata, Bromus madritensis) were collected from experimental plots and grown in a common environment over two generations. We measured 14 physiological, morphological, phenological, and …

Stenocarpella Maydis: Identification, Management, And Population Diversity, Martha P. Romero Luna

Open Access Dissertations

Diplodia ear rot (DER) has been a persistent corn disease across the Midwest, and in recent years it has become an annual problem. The objectives of this study were to i) develop a molecular assay for the identification of Stenocarpella maydis, causal agent of DER, ii) evaluate the effect of crop rotation and tillage on DER severity, iii) determine the survival period of S. maydis in corn residue at different soil depths in a corn field, and iv) identify genetic diversity among S. maydis isolates collected from the Midwestern and Southern United States. The genus Stenocarpella contains two species, S. …

From Planning To Execution To The Future: An Overview Of A Concerted Effort To Enhance Biological Control In Apple, Pear, And Walnut Orchards In The Western U.S., Vincent P. Jones, Nicholas J. Mills, Jay F. Brunner, David R. Horton, Elizabeth H. Beers, Thomas R. Unruh, Peter W. Shearer, Jessica R. Goldberger, Steven P. Castagnoli, Nadine Lehrer, Eugene R. Milickzy, Shawn A. Steffan, Kaushalya G. Amarasekare, Ute Chambers, Angela N. Gadino, R. Karina Gallardo, Wendy E. Jones

Agricultural and Environmental Sciences Faculty Research

We embarked on a large project designed to help enhance biological control in apple, pear and walnut orchards in the western U.S., where management programs were in the midst of a transition from older organo-phosphate insecticides to mating disruption and newer reduced-risk insecticides. A “pesticide replacement therapy” approach resulted in unstable management programs with unpredictable outbreaks of spider mites and aphids. Our project was designed to provide growers and pest managers with information on the effects of newer pesticide chemistries on a suite of representative natural enemies in both the laboratory and field, potential of new monitoring tools using herbivore-induced …