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Full-Text Articles in Ecology and Evolutionary Biology

Chapter 3 - Slime Molds, Janice M. Glime Jan 2019

Chapter 3 - Slime Molds, Janice M. Glime

Bryophyte Ecology Volume 2: Bryological Interaction

Explore the contents of Bryophyte Ecology, Volume 2, Chapter 3 - Slime Molds 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.

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


H.B. Bozeman Collection, University Archives And Special Collections, Prescott Memorial Library, Louisiana Tech University Jan 2019

H.B. Bozeman Collection, University Archives And Special Collections, Prescott Memorial Library, Louisiana Tech University

Manuscript Finding Aids

Specimen of petrified palm wood found by Estes B. Bozeman in 1962-63 on the southeast flank of the Sikes Salt Dome, Winn Parish, Louisiana. Palm trees grew in the Winn Parish area 30-40 million years ago during the Tertiary Period of the Cenozoic Era.


Increasing Warm-Season Native Grass Biomass Using Fire, Herbicide, And Nitrogen Applications, Sharon A. Clay, Alexander Smart, David E. Clay Jan 2019

Increasing Warm-Season Native Grass Biomass Using Fire, Herbicide, And Nitrogen Applications, Sharon A. Clay, Alexander Smart, David E. Clay

Native Plant Focused Publications

The North American Great Plains tallgrass prairie was once a system of native cool and warm season grasses, which have been degraded by non-native invasive plants. Native grass restoration is highly desirable to improve ecosystem functions and productivity. In this two-year study, the impact of fire, herbicide, and nitrogen on productivity and the presence of invasive species [primarily the cool season grass, smooth brome (Bromus inermis Leyss.)] and native warm season native grass species [big bluestem (Andropogon gerardii Vitman), sideoats and blue grama (Bouteloua curtipendula (Michx.) Torr.), and B. gracilis (Willd. Ex Kunth) Lag. ex Griffiths] were investigated. Spring fire …


Cropping Systems Research Summary 2019: Soybean And Soygreen Research Reports, Charles Burr Jan 2019

Cropping Systems Research Summary 2019: Soybean And Soygreen Research Reports, Charles Burr

West Central Research and Extension Center, North Platte

Project Titles

Soybean Seeding Rates

Soygreen® Treatments for Iron Deficiency Chlorosis


Cropping Systems Research Summary 2019: Agroecosystems Entomology Project Research Reports, Samantha R. Daniel, Andrea Rilaković, Katharine A. Swoboda Bhattarai, M. G. Sacilotto, C. A. Deans, S. Behmer, Julie A. Peterson Jan 2019

Cropping Systems Research Summary 2019: Agroecosystems Entomology Project Research Reports, Samantha R. Daniel, Andrea Rilaković, Katharine A. Swoboda Bhattarai, M. G. Sacilotto, C. A. Deans, S. Behmer, Julie A. Peterson

West Central Research and Extension Center, North Platte

Investigating the role of spiders in integrated pest Management for biological control of Nebraska crop pests, Samantha R. Daniel. Advisors: Julie A. Peterson and Robert Wright

Simulating larval movement of Western bean cutworm in blended refuges by laboratory feeding on non-Bt, Cry1F and Vip3A maize, Andrea Rilaković and Katharine Swoboda Bhattrai

Determining western bean cutworm Striacosta albicosta (Lepidoptera: Noctuidae) optimal nutritional intake via choice studies, M. G. Sacilotto, Katharine Swosoda Battharai, C. A. Deans, S. Behmer, and Julie A. Peterson


Weed Science Research Summary 2019: Weed Control And Spray Drift Jan 2019

Weed Science Research Summary 2019: Weed Control And Spray Drift

West Central Research and Extension Center, North Platte

Weed Science

Large-scale off-target movement assessment of dicamba in Nebraska, Guilherme S. Alves, Kasey Schroeder, Jeff Golus, Greg R. Kruger

Spray drift from aerial application in South Dakota, Guilherme S. Alves, Kasey Schroeder, Arthur F. T. Duarte, Daniel A. Doretto, Greg R. Kruger

Dicamba spray drift as influenced by wind speed and nozzle type, Guilherme S. Alves, Greg R. Kruger, João Paulo A. R. da Cunha, Denise G. de Santana, Luís André T. Pinto, Frederico Guimarães, and Milos Zaric

Spray drift and droplet spectrum from dicamba sprayed alone or mixed with adjuvants using air-induction nozzles, Guilherme S. Alves, Greg R. …


Assessment Of Cover Crop Management Strategies In Nebraska, Us, Maxwel C. Oliveira, Liberty Butts, Rodrigo Werle Jan 2019

Assessment Of Cover Crop Management Strategies In Nebraska, Us, Maxwel C. Oliveira, Liberty Butts, Rodrigo Werle

West Central Research and Extension Center, North Platte

Adoption of cover crops has the potential to increase agricultural sustainability in the US and beyond. In 2017, a survey was conducted with Nebraska stakeholders in an attempt to evaluate current cover crop management strategies adopted in soybean (Glycine max [L.] Merr.), field corn (Zea mays L.), and seed corn production. Eighty-two Nebraska stakeholders answered the survey, of which 80% identified themselves as growers. Eighty-seven percent of respondents manage cover crops, and the average cover crop ha planted on a per farm basis is 32%. The primary method of establishing cover crops following soybeans and field corn is …


Developmental And Reproductive Characteristics Of Beef Heifers Classified By Number Of Estrous Cycles Experienced By Start Of First Breeding, Andy Roberts, Jaclyn N. Ketchum, Richard N. Funston Jan 2019

Developmental And Reproductive Characteristics Of Beef Heifers Classified By Number Of Estrous Cycles Experienced By Start Of First Breeding, Andy Roberts, Jaclyn N. Ketchum, Richard N. Funston

West Central Research and Extension Center, North Platte

A retrospective analysis was conducted to evaluate the effect of number of estrous cycles exhibited before breeding on growth and reproductive performance of replacement beef heifers fed ad-libitum or restricted by 20% less than ad-libitum during postweaning development over a 9-yr period. Progesterone concentration in blood samples collected at 9- to 11-d intervals were used to assign heifers into groups by number of estrous cycles exhibited before the start of breeding: 0 (nonpubertal; n = 395), 1 (n = 205), 2 (n = 211), 3 (n = 116), or >3 (n = 249). Heifers (P …


Evaluation Of Foliar Insecticides For The Control Of Western Bean Cutworm In Field Corn, 2018, Katharine A. Swoboda-Bhattarai, Samantha R. Daniel, Julie A. Peterson Jan 2019

Evaluation Of Foliar Insecticides For The Control Of Western Bean Cutworm In Field Corn, 2018, Katharine A. Swoboda-Bhattarai, Samantha R. Daniel, Julie A. Peterson

West Central Research and Extension Center, North Platte

The objectives of this field trial were to evaluate the efficacy of single applications of foliar insecticides at preventing feeding damage by the western bean cutworm (WBC), an important pest of corn and dry beans that has undergone a rapid range expansion into the eastern Corn Belt during the last 18 yr. This study was conducted within the historic range of WBC, at the University of Nebraska-Lincoln’s Henry J. Stumpf International Wheat Center in Perkins County, NE (40.856851°N, −101.701335°W). An RCB design with a total of 16 treatments (including an untreated check) and four replications was used. Plots measured 20 …


Fungicide Application Technology For Controlling The Sugarcane Orange Rust, Thales Cassemiro Alves, João Arantes Rodrigues Da Cunha, Rafael Marcão Tavares, Guilherme Sousa Alves, Sérgio Macedo Silva Jan 2019

Fungicide Application Technology For Controlling The Sugarcane Orange Rust, Thales Cassemiro Alves, João Arantes Rodrigues Da Cunha, Rafael Marcão Tavares, Guilherme Sousa Alves, Sérgio Macedo Silva

West Central Research and Extension Center, North Platte

With the epidemic onset of the sugarcane orange rust, fungicide applications of the Strobilurins and Triazoles groups have become necessary in susceptible varieties. This study aimed at evaluating the operational conditions of fungicide application in sugarcane (SP81-3250 variety), in relation to the spray deposition on the upper canopy and the effectiveness of the orange rust control. Treatments consisted of two application volumes (30 L ha-1 or 40 L ha-1) and three nozzle deflection angles (0 º, 90 º or 135 º), plus a ground application at the rate of 200 L ha-1, sprayed with a uniform flat spray nozzle of …


Response Of Amaranthus Spp. Following Exposure To Sublethal Herbicide Rates Via Spray Particle Drift, Bruno C. Vieira, Joe D. Luck, Keenan L. Amundsen, Todd A. Gaines, Rodrigo Werle, Greg Kruger Jan 2019

Response Of Amaranthus Spp. Following Exposure To Sublethal Herbicide Rates Via Spray Particle Drift, Bruno C. Vieira, Joe D. Luck, Keenan L. Amundsen, Todd A. Gaines, Rodrigo Werle, Greg Kruger

West Central Research and Extension Center, North Platte

The adverse consequences of herbicide drift towards sensitive crops have been extensively reported in the literature. However, little to no information is available on the consequences of herbicide drift onto weed species inhabiting boundaries of agricultural fields. Exposure to herbicide drift could be detrimental to long-term weed management as several weed species have evolved herbicide-resistance after recurrent selection with sublethal herbicide rates This study investigated the deposition of glyphosate, 2,4-D, and dicamba spray particle drift from applications with two different nozzles in a low speed wind tunnel, and their impact on growth and development of Amaranthus spp. Herbicide drift …


Droplet Size And Nozzle Tip Pressure From A Pulse–Width Modulation Sprayer, Thomas R. Butts, Liberty E. Butts, Joe D. Luck, Bradley K. Fritz, Wesley C. Hoffmann, Greg R. Kruger Jan 2019

Droplet Size And Nozzle Tip Pressure From A Pulse–Width Modulation Sprayer, Thomas R. Butts, Liberty E. Butts, Joe D. Luck, Bradley K. Fritz, Wesley C. Hoffmann, Greg R. Kruger

West Central Research and Extension Center, North Platte

Pulse-width modulation (PWM) sprayers can improve application accuracy through flow control, turn compensation, and high-resolution overlap control by pulsing an electronically-actuated solenoid valve which controls the relative proportion of time each solenoid valve is open (duty cycle). The objective of this experiment was to identify the droplet size distribution and nozzle tip pressure when influenced by PWM duty cycle, nozzle technology, and gauge pressure to provide PWM guidelines. The experiment was conducted in a low-speed wind tunnel at the Pesticide Application Technology Laboratory using a SharpShooter® PWM system. In general, for non-venturi nozzles, as duty cycle decreased, droplet size slightly …


Approaches To Evaluating Grower Irrigation And Fertilizer Nitrogen Amount And Timing, Tsz Him Lo, Daran Rudnick, Charles Burr, Matt Stockton, Rodrigo Werle Jan 2019

Approaches To Evaluating Grower Irrigation And Fertilizer Nitrogen Amount And Timing, Tsz Him Lo, Daran Rudnick, Charles Burr, Matt Stockton, Rodrigo Werle

West Central Research and Extension Center, North Platte

Diversity in the knowledge, mindset, strategies, and tools that growers use to manage irrigation and fertilizer nitrogen culminates in diversity in profitability and environmental impact among farms. As growers, academia, and industry strive together to tackle the technological and non-technological challenges impeding better irrigation and fertilizer nitrogen management, a science-based evaluation of grower input amount and timing becomes an important initial step in the process. Providing such valuable feedback to growers is a high-priority objective for the University of Nebraska-Lincoln Testing Ag Performance Solutions (UNL-TAPS) farm management competition. In this competition, each team of mostly growers made management decisions for …


Droplet Size Impact On Efficacy Of A Dicamba-Plus-Glyphosate Mixture, Thomas R. Butts, Chase A. Samples, Lucas X. Franca, Darrin M. Dodds, Daniel B. Reynolds, Jason W. Adams, Richard K. Zollinger, Kirk A. Howatt, Bradley K. Fritz, W. Clint Hoffmann, Joe D. Luck, Greg R. Kruger Jan 2019

Droplet Size Impact On Efficacy Of A Dicamba-Plus-Glyphosate Mixture, Thomas R. Butts, Chase A. Samples, Lucas X. Franca, Darrin M. Dodds, Daniel B. Reynolds, Jason W. Adams, Richard K. Zollinger, Kirk A. Howatt, Bradley K. Fritz, W. Clint Hoffmann, Joe D. Luck, Greg R. Kruger

West Central Research and Extension Center, North Platte

Chemical weed control remains a widely used component of integrated weed management strategies because of its cost-effectiveness and rapid removal of crop pests. Additionally, dicamba-plus-glyphosate mixtures are a commonly recommended herbicide combination to combat herbicide resistance, specifically in recently commercially released dicamba-tolerant soybean and cotton. However, increased spray drift concerns and antagonistic interactions require that the application process be optimized to maximize biological efficacy while minimizing environmental contamination potential. Field research was conducted in 2016, 2017, and 2018 across three locations (Mississippi, Nebraska, and North Dakota) for a total of six site-years. The objectives were to characterize the efficacy of …


Weed Science Research Summary 2019: Progress Report Of Phd Student Regarding Weed Control, Jesaelen Gizotti De Moraes Jan 2019

Weed Science Research Summary 2019: Progress Report Of Phd Student Regarding Weed Control, Jesaelen Gizotti De Moraes

West Central Research and Extension Center, North Platte

2017-2018 Interaction of Lactofen with Glyphosate or Glufosinate for Weed Control as Affected by Adjuvants and Droplet Size

2018 Effect of Adjuvants on Physical Properties of Glyphosate and PPO-Inhibiting Herbicide Spray Mixtures

2019 Management of Troublesome Weeds in XtendFlex® Soybeans

2019-2020 Soybean Symptomatology and Yield Response to Sub-Labeled Doses of Dicamba and 2,4-D


Evaluation Of Foliar Insecticide Application Timing For The Control Of Western Bean Cutworm In Field Corn, 2018, Katharine A. Swoboda-Bhattarai, Samantha R. Daniel, Julie A. Peterson Jan 2019

Evaluation Of Foliar Insecticide Application Timing For The Control Of Western Bean Cutworm In Field Corn, 2018, Katharine A. Swoboda-Bhattarai, Samantha R. Daniel, Julie A. Peterson

West Central Research and Extension Center, North Platte

The objective of this field trial was to determine if application timing affects the efficacy of single applications of foliar insecticides at preventing feeding damage by the western bean cutworm (WBC), an important pest of corn and dry beans in the North American Corn Belt. This study was located at the University of Nebraska- Lincoln’s Henry J. Stumpf International Wheat Center in Perkins County, NE (40.856851°N, −101.701335°W). The experimental design used was an RCB design with a total of 10 treatments (three insecticides applied at three application timings, plus an untreated check) and four replications; the treatment design was an …


Eucosma Giganteana (Riley) And Sliphium Perfoliatum L., Morphological Variation In An Insect-Plant Association In Eastern South Dakota, Paul J. Johnson, Arvid Boe, Abigail P. Martens Jan 2019

Eucosma Giganteana (Riley) And Sliphium Perfoliatum L., Morphological Variation In An Insect-Plant Association In Eastern South Dakota, Paul J. Johnson, Arvid Boe, Abigail P. Martens

Native Plant Focused Publications

Silphium perfoliatum L., cup plant, has potential as a new multi-purpose crop. It is pollinator-friendly and has biodiversity enhancement, conservation, economic, and medical potential. In eastern South Dakota, S. perfoliatum can produce more than 20 Mg (million grams) ha-1 of biomass and 0.09 Mg ha-1 of seed in agronomic plantings. The giant eucosma moth, Eucosma giganteana (Riley), is a major pest of agronomic S. perfoliatum in the region. We provide a summary of this insect and its association with its host. Our experimental objectives were to determine if the frequency of rhizome occupation by late instar larvae and if their …


Testing The Competition-Colonization Trade-Off And Its Correlations With Functional Trait Variations Among Subtropical Tree Species, Yue Bin, Guojun Lin, Sabrina E. Russo, Zhongliang Huang, Yong Shen, Honglin Cao, Juyu Lian, Wanhui Ye Jan 2019

Testing The Competition-Colonization Trade-Off And Its Correlations With Functional Trait Variations Among Subtropical Tree Species, Yue Bin, Guojun Lin, Sabrina E. Russo, Zhongliang Huang, Yong Shen, Honglin Cao, Juyu Lian, Wanhui Ye

School of Biological Sciences: Faculty Publications

The competition-colonization trade-off, by which species can partition spatial niches, is a potentially important mechanism allowing the maintenance of species diversity in plant communities. We examined whether there was evidence for this trade-off among tree species in a subtropical forest and how it correlated with eight functional traits. We developed and estimated a metric for colonization ability that incorporates both fecundity and seed dispersal based on seed trap data and the sizes and distributions of adult trees. Competitive ability was estimated as survival probability under high crowding conditions based on neighborhood models. Although we found no significant relationship between colonization …


Quantifying Signpost Usage By Captive Male White-Tailed Deer, Cassie L. Auxt, Eric S. Michel, Jonathan A. Jenks Jan 2019

Quantifying Signpost Usage By Captive Male White-Tailed Deer, Cassie L. Auxt, Eric S. Michel, Jonathan A. Jenks

The Prairie Naturalist

White-tailed deer (Odocoileus virginianus) use rubbing of signpost structures to communicate during the breeding season. Rubbing of signpost structures allows deer to communicate via visual and chemical cues, which allows them to establish dominance hierarchies and maintain hierarchal status throughout the breeding season (Moore and Marchinton 1974, Miller et al. 1981, Hewitt 2011). Once a living tree is rubbed, the exposed light-colored sapwood creates a stark contrast in wooded areas, increasing visibility and further enticing deer to investigate the structure (Oehler et al. 1995). Anatomically, the tubular apocrine sudoriferous glands of white-tailed deer are located at the antler …


Haplotype Diversity And Population Genetic Structure Of Antistrophus Gall Wasps Associated With Two Silphium Species And Implication For Host Mediated Speciation, Jiaxin Deng Jan 2019

Haplotype Diversity And Population Genetic Structure Of Antistrophus Gall Wasps Associated With Two Silphium Species And Implication For Host Mediated Speciation, Jiaxin Deng

Masters Theses

Gall making insects form a special feeding guild of phytophagous animals, and by manipulating host plant tissue differentiation, are able to avoid plant chemical defenses and thus have no need for counter defense mechanisms. Host plant selection is crucial to the evolution of these insects because successful gall formation is largely dependent on host plant ability to respond to stimuli. In Illinois and neighboring states, Antistrophus gall wasps associated with the rosin weed (S. integrifolium) and the cup plant (S. perfoliatum) are morphologically indistinguishable and thus have been treated as belonging to single species. However, the wasps from the host …


Diversifying Cornfields By Interseeding Cover Crops: Practical Implications And The Response Of Invertebrate Communities, Michael Bredeson Jan 2019

Diversifying Cornfields By Interseeding Cover Crops: Practical Implications And The Response Of Invertebrate Communities, Michael Bredeson

Electronic Theses and Dissertations

The lack of suitable habitat conditions for beneficial organisms in simplified agroecosystems leads to unstable invertebrate communities and overreliance on chemical control of herbivores. It is possible to manage pest populations without agrichemicals by manipulating farmland so that herbivores are impaired by plant-driven bottom-up and enemy-driven top-down antagonisms. Interseeding cover crops between established crop rows is a method used by farmers to improve habitat suitability for natural enemies and hinder host-finding, feeding and movement by herbivores. Here I address three important research gaps related to interseeding cover crops. A calcium carbonate seed coating, used to improve seed-broadcasting efficiency, was tested …


Stoichiometric Homeostasis In Two Native And Two Invasive South Dakotan Grasses, Joshua Thonas Harvey Jan 2019

Stoichiometric Homeostasis In Two Native And Two Invasive South Dakotan Grasses, Joshua Thonas Harvey

Electronic Theses and Dissertations

Increased nutrient availability has been widely linked to the success of invasive plants, however a general mechanism explaining these observations is lacking. Stoichiometric homeostasis (H), which is the regulation of internal nutrient concentrations, has been used to explain changes in plant community diversity under alterations in nutrient availability. One hypothesis holds that plants with high regulation (larger H) decrease in abundance in nutrient enriched conditions but are stable in nutrient deficient and drought conditions, likely due to extensive root systems. Additionally, plants with low regulation (lower H) increase in abundance under nutrient enriched conditions but are sensitive to drought …


Influence Of Shaded Conditions On Development Of Asteraceae Species Native To Kansas, Aline Rodrigues De Queiroz Jan 2019

Influence Of Shaded Conditions On Development Of Asteraceae Species Native To Kansas, Aline Rodrigues De Queiroz

Master's Theses or Doctor of Nursing Practice

to the heterogeneity of habitats, all plants are exposed to at least some degree of shade during their lifetime. Reduced light intensity, drops in R:FR ratio, and limited blue light are cues for plants to perceive competition; the shade avoidance syndrome (SAS) is common for grassland species while shade tolerance (ST) is common for forest species when competition is perceived. SAS is characterized by elongation of stems and petioles, reduced branches, decreased leaf area, decreased shoot biomass, and increased number of ramets. ST is characterized by little elongation of stems and petioles, high chlorophyll content and high chlorophyll a/b ratio …


Island Invasion: The Silent Crisis In Hawaii, Sophia Janssen Jan 2019

Island Invasion: The Silent Crisis In Hawaii, Sophia Janssen

Pomona Senior Theses

Keeping out invasive species may, upon first review, seem like a trivial environmental cry from ecologists and deep environmentalists; a belated wish to return to an undeveloped world where nature was pristine. However invasive species create problems that impact all of us and can have far more severe consequences than changing a stunning landscape. These problems are heightened in islands like Hawaii, where the fragile ecosystems have developed over centuries of evolution and adaptation. The introduction of a disease-carrying mosquito can put the people of Hawaii at risk to many vector-born illnesses and create an epidemic, taking human life. The …


Fire And Road Disturbance Impacts On Forest Plant Species And Seed Rain In Table Mountain Fire Arai, Kittitas County, Washington, Jonathan A. Betz Jan 2019

Fire And Road Disturbance Impacts On Forest Plant Species And Seed Rain In Table Mountain Fire Arai, Kittitas County, Washington, Jonathan A. Betz

All Master's Theses

Forest communities are in a constant state of change. Disturbance events can alter the physical landscape and create conditions favorable to some species while negatively impacting others. Fire has been a natural, reoccurring source of disturbance in Pacific Northwest forests. Over the past centuries the fire paradigm has changed in favor of fire suppression. Forest roads permit access provide greater access but further fracture forest community’s continuity. The 2012 Table Mountain Fire and road influence have altered the plant community’s seed rain and vegetation. This study measured dispersed seeds and understory vegetation cover as functions of roads and fire intensity. …


Intraspecific Variation In Dehydration Tolerance: Insights From The Tropical Plant Marchantia Inflexa, Rose A. Marks Jan 2019

Intraspecific Variation In Dehydration Tolerance: Insights From The Tropical Plant Marchantia Inflexa, Rose A. Marks

Theses and Dissertations--Biology

Plants are threatened by global change, increasing variability in weather patterns, and associated abiotic stress. Consequently, there is an urgent need to enhance our ability to predict plant community dynamics, shifts in species distributions, and physiological responses to environmental challenges. By building a fundamental understanding of plant stress tolerance, it may be possibly to protect the ecological services, economic industries, and communities that depend on plants. Dehydration tolerance (DhT) is an important mechanism of water stress tolerance with promising translational applications. Here, I take advantage natural variation in DhT to gain a deeper insight into this complex trait. In addition, …


Foraging Preferences Of Barnacle Geese On Endophytic Tall And Red Fescues, Tuuli-Marjaana Koski, Kari Saikkonen, Tero Klemola, Marjo Helander Jan 2019

Foraging Preferences Of Barnacle Geese On Endophytic Tall And Red Fescues, Tuuli-Marjaana Koski, Kari Saikkonen, Tero Klemola, Marjo Helander

Human–Wildlife Interactions

Many grasses (Poaceae) have symbiotic fungal endophytes, which affect livestock by producing unpalatable or harmful secondary compounds. Less is known about the repelling effects of fungal endophytes on avian grazers despite potential wildlife management implications. Herbivorous goose (Branta spp.) species may become a nuisance in recreational use areas via fecal littering. Planting these areas with grasses that avian grazers avoid may help mitigate this damage. In 2016, we studied the foraging preference of the barnacle geese (B. leucopsis) with endophytic (E+) or endophyte-free (E-) red fescue (Festuca rubra) and/or tall fescue (Schedonorus phoenix) in …


Ectomycorrhizal Fungal Community Assembly On Seedlings Of A Neotropical Monodominant Tree, Carolyn Delevich Jan 2019

Ectomycorrhizal Fungal Community Assembly On Seedlings Of A Neotropical Monodominant Tree, Carolyn Delevich

Cal Poly Humboldt theses and projects

Formation of ectomycorrhizae may facilitate early seedling survival of ectomycorrhizal tree species due to enhanced nutrient acquisition. This could be especially important in heavily shaded understories of tropical monodominant forests where host plant photosynthetic capacity is limited. Little information is available on ectomycorrhizal (ECM) fungal colonization or community development of monodominant seedling cohorts, which have high survival rates. Following a 2016 mast seeding event, we sequentially measured percent colonization and species composition of ECM fungi on live and recently dead seedlings of the tropical monodominant tree Dicymbe corymbosa. We also compared seedling ECM fungi to those of nearby adult …


Quantifying The Morphological And Physiological Effects Of Drought, Grass Invasion, And Fire On Longleaf, Loblolly, And Slash Pine, Laura Young Jan 2019

Quantifying The Morphological And Physiological Effects Of Drought, Grass Invasion, And Fire On Longleaf, Loblolly, And Slash Pine, Laura Young

College of Graduate Studies: Theses & Dissertations

Climate change is altering ecosystems on a global scale, creating novel ecological scenarios with which plant species must cope. Factors such as altered precipitation and fire regimes and non-native plant invasion may negatively affect native plant species, while interactions between these stressors could magnify their impacts. The complexity of multiple stressors and the effects they have on native pine seedlings are difficult to predict without evaluating their combinations in field experiments. In a multi-year study, I investigated the effects of drought and plant invasion on three southeastern pine species under pre and post-fire conditions. We planted longleaf (Pinus palustris …


Biogeochemical Response To Vegetation And Hydrologic Change In An Alaskan Boreal Fen Ecosystem, Danielle L. Rupp Jan 2019

Biogeochemical Response To Vegetation And Hydrologic Change In An Alaskan Boreal Fen Ecosystem, Danielle L. Rupp

Dissertations, Master's Theses and Master's Reports

Boreal peatlands store approximately one third of the earth’s terrestrial carbon, locked away in currently waterlogged and frozen conditions. Peatlands of boreal and arctic ecosystems are affected increasingly by shifting hydrology caused by climate change. The consequences of these relatively rapid ecosystem changes on carbon cycling between the landscape and the atmosphere could provide an amplifying feedback to climate warming. Alternatively, the advancement of terrestrial vegetation into once waterlogged soils could uptake carbon as a sink. Previous work suggests that fens will become an increasingly dominant landscape feature in the boreal. However, studies investigating fens, their response to hydrologic and …