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Weed Science

2015

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Full-Text Articles in Life Sciences

Prioritizing The Management Of Arundo Donax: Recommendations For Removal And Revegetation In California Riparian Habitats, Matthew S. Waterworth Dec 2015

Prioritizing The Management Of Arundo Donax: Recommendations For Removal And Revegetation In California Riparian Habitats, Matthew S. Waterworth

Master's Projects and Capstones

The highly invasive grass species, giant reed (Arundo donax), has been a major contributor to riparian habitat degradation in California for over 50 years. Several modes of vegetative reproduction have allowed this alien species to take advantage of fluvial processes and rapidly spread within California watersheds. A. donax dramatically alters hydrologic regimes, displaces native vegetation, and removes food and habitat for native wildlife. It is widely accepted that removal of this invasive on a watershed scale is critical to restore natural riparian processes and facilitate the reestablishment of native flora and fauna. The following study analyzed the efficacy of …


Book Reviews: Bumble Bees Of North America. Paul H. Williams, Robbin W. Thorp, Leif L. Richardson, And Sheila R. Colla., Samuel O’Dell Dec 2015

Book Reviews: Bumble Bees Of North America. Paul H. Williams, Robbin W. Thorp, Leif L. Richardson, And Sheila R. Colla., Samuel O’Dell

The Prairie Naturalist

Bumblebee identification is generally considered straight- forward, yet mistakes often are made due to the degree of similarity between the color patterns of different species. Bumble Bees of North America aims to improve the accuracy of identifications by both casual observers and professionals through the use of intuitive diagrams, descriptions, and the more technical dichotomous keys. In addition to providing the first complete field guide to North American bumblebees, the authors make efficient use of the reader’s attention by summarizing taxonomic history, favored food plants, and environmental issues concerning bumblebees.

Bumble Bees of North America is organized into three distinct …


North Shore: A Natural History Of Minnesota’S Superior Coast, Janet R. Keough Dec 2015

North Shore: A Natural History Of Minnesota’S Superior Coast, Janet R. Keough

The Prairie Naturalist

Many readers of The Prairie Naturalist have lived along or visited Lake Superior’s coast. Like me, you have probably wondered about the geology and history of this beautiful and dramatic feature of northeastern Minnesota. Chel Anderson and Adelheid Fischer have written an accessible book that comprehensively describes the history and geology of the coast, surrounding highlands, and Lake Superior itself. In addition, the authors have provided fascinating subchapters on some of the most interesting species that are key elements of the region.

This rather large but beautiful book is arranged in five major chapters that cover the dominant geological units …


Remembering Paul B. Kannowski, Robert Seabloom Dec 2015

Remembering Paul B. Kannowski, Robert Seabloom

The Prairie Naturalist

I am saddened to report that Dr. Paul Kannowski passed away 3 September 2015, succumbing to cancer. He was 88. A native of Grand Forks, Paul attended the University of North Dakota for his B.S. and M.S. degrees, and the University of Michigan for his Ph.D. He joined the University of North Dakota Biology Department in 1957, retiring in 1990 after 33 years of service

Paul chaired UND’s Biology Department twice, totaling 13 years, considered to be a remarkable achievement by many of us who have been exposed to that task! His leadership was instrumental in the nearly exponential growth …


Variability In The Selection Patterns Of Pronghorn: Are They Really Native Prairie Obligates?, Paul F. Jones, Mike Grue, Mike Suitor, Darren J. Bender, Cormack Gates, Dale Eslinger, Julie Landry-Deboer Dec 2015

Variability In The Selection Patterns Of Pronghorn: Are They Really Native Prairie Obligates?, Paul F. Jones, Mike Grue, Mike Suitor, Darren J. Bender, Cormack Gates, Dale Eslinger, Julie Landry-Deboer

The Prairie Naturalist

In Canada, pronghorn (Antilocapra americana) are primarily considered a native prairie obligate because of their reliance on open grassland vegetation communities, although an assessment of local ecological knowledge suggests that pronghorn in Alberta select a variety of habitat from native prairie to cultivated lands. The primary objective of our study was to assess whether pronghorn in Alberta and Saskatchewan are native prairie obligates. Specifically, we addressed the following questions: 1) do individual pronghorn show similar selection patterns for native prairie and, therefore, support the notion that they are prairie obligates; 2) do pronghorn show consistent resource selection patterns …


Notes: Woodpecker Forage Availability In Habi- Tat Disturbances Of The Black Hills, Brian E. Dickerson, Angie K. Ambourn, Mark A. Rumble, Kurt K. Allen, Chad P. Lehman Dec 2015

Notes: Woodpecker Forage Availability In Habi- Tat Disturbances Of The Black Hills, Brian E. Dickerson, Angie K. Ambourn, Mark A. Rumble, Kurt K. Allen, Chad P. Lehman

The Prairie Naturalist

Habitat disturbance events are critical to ecological systems in which some bird species have become specialized. The vegetation community, reduced competition, ability to avoid predators, nest-site characteristics, and forage opportunities within a disturbed ecosystem are all aspects that make it desirable for selection by particular species (Svärdson 1949, Cody 1981, Martin 1998). Specifically, avian species rely on the forest conditions created by fire, insects, and disease (Brawn et al. 2001, Hunter et al. 2001, Devictor et al. 2008). In the Black Hills National Forest (BHNF) of South Dakota,two major types of natural disturbances include wildfires and mountain pine beetle (Dendroctonus …


Estimating Herbaceous Biomass Of Grassland Vegetation Using The Reference Unit Method, Eric D. Boyda, Jack L. Bulter, Lan Xu Dec 2015

Estimating Herbaceous Biomass Of Grassland Vegetation Using The Reference Unit Method, Eric D. Boyda, Jack L. Bulter, Lan Xu

The Prairie Naturalist

Aboveground net primary production provides valuable information on wildlife habitat, fire fuel loads, and forage availability. Aboveground net primary production in herbaceous plant communities is typically measured by clipping aboveground biomass. However, the high costs associated with physically harvesting plant biomass may prevent collecting sufficient data to account for natural spatial and temporal variability of vegetation at a landscape scale. Various double-sampling techniques have been developed to increase sample size while reducing cost. We applied a biomass estimation technique previously developed for estimating shrub biomass using representative samples or “reference units” to estimate herbaceous grassland biomass. Our reference units consisted …


Effects Of Short-Term Soil Conditioning By Cheatgrass And Western Wheatgrass, James J. O'Connor, Janet S. Prevey Dec 2015

Effects Of Short-Term Soil Conditioning By Cheatgrass And Western Wheatgrass, James J. O'Connor, Janet S. Prevey

The Prairie Naturalist

The exotic grass Bromus tectorum (cheatgrass) is a ubiquitous invader in the western USA. Cheatgrass is a proficient competitor, frequently displacing native plants, forming monotypic stands and reducing biodiversity in ecosystems it invades. Our experiment tested whether short-term soil modification by cheatgrass and a predominant native grass, Pascopyrum smithii (western wheatgrass), affected subsequent growth of both species. We compared productivity of cheatgrass and western wheatgrass by harvesting aboveground biomass of plants grown in either cheatgrass- or western wheatgrass-conditioned soils over two simulated growing seasons. Results indicated that cheatgrass soils do not inhibit the productivity of the native grass, but do …


Sage-Grouse Nests In An Active Conifer Mastication Site, Charles P. Sandford, David K. Dahlgren, Terry A. Messmer Dec 2015

Sage-Grouse Nests In An Active Conifer Mastication Site, Charles P. Sandford, David K. Dahlgren, Terry A. Messmer

The Prairie Naturalist

Greater sage-grouse (Centrocercus urophasianus; sage-grouse) have experienced long-term range-wide population declines and now may occupy less than 50% of their historic range (Schroeder et al. 2004). Conifer encroachment into sagebrush (Artemisia spp.) habitat was identified as a major conservation threat by the United States Fish and Wildlife Service (USFWS) as the agency reviewed the listing status of the species for possible protection under the Endangered Species Act of 1973 (USFWS 2013).

Conifer encroachment into sagebrush habitats negatively impacts sage-grouse at landscape scales (Doherty et al. 2008, Casazza et al. 2011, Baruch-Mordo et al. 2013). Sage-grouse will utilize …


Potential Interaction Between Pre- And Post-Emergence Herbicides And The Efficacy Of Insecticide And Fungicide Seed Treatments In Cotton, Cory Joseph Vineyard Dec 2015

Potential Interaction Between Pre- And Post-Emergence Herbicides And The Efficacy Of Insecticide And Fungicide Seed Treatments In Cotton, Cory Joseph Vineyard

Masters Theses

An apparent reduction in the performance of neonicotinoid seed treatments in controlling thrips, especially in cotton, has been observed, which has coincided with the increased use of both pre- and post-emergence herbicides to control glyphosate-resistant weeds. The objective of this research was to evaluate the potential interactions of both pre- and post-emergence herbicides on the efficacy of insecticide and fungicide seed treatments in cotton

Aldicarb along with imidacloprid and thiamethoxam seed treatments reduced thrips numbers compared with non-treated seed. However, thiamethoxam did not provide effective control. Some pre-emergence herbicide treatments reduced plant health. While there was evidence that thrips injury …


Distribution And Occurrence Of Bat Species In North Dakota, Josiah J. Nelson, Paul R. Barnhart, Erin H. Gillam Dec 2015

Distribution And Occurrence Of Bat Species In North Dakota, Josiah J. Nelson, Paul R. Barnhart, Erin H. Gillam

The Prairie Naturalist

Prior to 2009, a detailed survey of occurrence and distribution of bats in North Dakota had not been conducted. Localized surveys, occurrence reports, and museum specimens provided the only records of bats in the state. Ongoing habitat loss, exploitation of natural resources, and the impending spread of white-nose syndrome to the western United States are major threats to bat populations of the region. The objective of this study was to document presence and distributions of bat species resident in North Dakota. From 2009 to 2012, multiple mist-netting and acoustic surveys were conducted to document species presence across North Dakota. A …


North Shore: A Natural History Of Minnesota’S Superior Coast, Janet R. Koeugh Dec 2015

North Shore: A Natural History Of Minnesota’S Superior Coast, Janet R. Koeugh

The Prairie Naturalist

Many readers of The Prairie Naturalist have lived along or visited Lake Superior’s coast. Like me, you have probably wondered about the geology and history of this beautiful and dramatic feature of northeastern Minnesota. Chel Anderson and Adelheid Fischer have written an accessible book that comprehensively describes the history and geology of the coast, surrounding highlands, and Lake Superior itself. In addition, the authors have provided fascinating subchapters on some of the most interesting species that are key elements of the region.

This rather large but beautiful book is arranged in five major chapters that cover the dominant geological units …


Remembering The Days Of Old: Data Exploration And Simple Statistics, Christopher N. Jacques Dec 2015

Remembering The Days Of Old: Data Exploration And Simple Statistics, Christopher N. Jacques

The Prairie Naturalist

Greetings GPNSS members! By the time you read this editorial, most of you will probably be enjoying spectacular seasonal changes in the outdoors this autumn and a hint of winter in the air (for those of us in the northern Great Plains region). I write this editorial during my favorite time of year, deer hunting in the Midwest. Temperatures are finally start- ing to resemble the fall and the Christmas Holiday season is just around the corner. Much like my children have images of Santa dancing in their heads on Christmas Eve, each fall I replay images of a trophy …


Use Of Hppd-Inhibiting Herbicides For Control Of Common Weeds In Arkansas And Current Status Of Herbicide-Resistance Among Echinochloa Populations In Arkansas, Clay Starkey Dec 2015

Use Of Hppd-Inhibiting Herbicides For Control Of Common Weeds In Arkansas And Current Status Of Herbicide-Resistance Among Echinochloa Populations In Arkansas, Clay Starkey

Graduate Theses and Dissertations

Herbicide-resistant weeds in Arkansas cause problems for growers. Up-to-date information and new technologies can help plan mitigation strategies to slow resistant weeds. The objectives of this research were to provide a ‘snapshot’ of herbicide-resistant Echinochloa spp. in rice producing counties, determine how much resistance has spread across the state, and understand the effectiveness of 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicides for control of glyphosate-resistant (GR) Palmer amaranth relative to commercial standards currently labeled in soybean. To assess the prevalence of Echinochloa spp. resistance, 82 samples were collected from 23 rice producing counties in 2010. The samples were tested for resistance to commonly …


Confirming Resistance To Prodiamine And Glyphosate In A Single Annual Bluegrass (Poa Annua L.) Biotype From Tennessee, Shane Matthew Breeden Dec 2015

Confirming Resistance To Prodiamine And Glyphosate In A Single Annual Bluegrass (Poa Annua L.) Biotype From Tennessee, Shane Matthew Breeden

Masters Theses

Annual bluegrass (Poa annua L.; POAAN) is a cool-season weed that commonly infests warm-season turfgrasses during winter dormancy. In spring 2012, poor POAAN control (<50%) was reported on golf course roughs in Alcoa, TN (35.75 °N, -83.88 °W) following treatment with a tank mixture of prodiamine (1120 g ha-1[hectare]) and glyphosate (840 g ae ha-1) during bermudagrass dormancy. The objective of this research was to determine if this POAAN biotype was resistant to prodiamine and glyphosate.

Using mature plants from the field, 81 of the 100 selections were not controlled by glyphosate and prodiamine; 96 of the 100 selections were not controlled by glyphosate, while 84 were unaffected by prodiamine. Only a single plant sampled was susceptible to both herbicides. …


Variation Between Peripheral And Center Achene Morphology And Attributes Of Achene Germination In The Invasive Species, Centaurea Melitensis, Kandee Bain Dec 2015

Variation Between Peripheral And Center Achene Morphology And Attributes Of Achene Germination In The Invasive Species, Centaurea Melitensis, Kandee Bain

Electronic Theses, Projects, and Dissertations

Invasive species are often successful and problematic because of their ability to persist in disturbed and undisturbed environments despite weed management practices. Understanding reproduction and dispersal strategies in these species can aid in developing management approaches to help control their spread. Centaurea melitensis, a nonnative invasive with European origins, is found in disturbed areas of southern California. It produces three different types of flower heads that develop at different times and at different locations on the plant during the growing season. The chasmogamous (CH) flower heads are located at the top of the plant, the initial cleistogamous (iCL) heads …


Predicting Invasive Range Of Eucalyptus Globulus In California, Anthony J. Lopez Dec 2015

Predicting Invasive Range Of Eucalyptus Globulus In California, Anthony J. Lopez

Master's Theses

Eucalyptus globulus is the subject of intense debate in California. Its invasive potential, aggressive growth, reproductive biology, and association with fire make the prediction of spread important in California. Two modeling simulations, Climex and Maxent, will illustrate the distribution and potential growth range of E. globulus in California based on climate and presence. Modeling the potential range of growth will predict invasive spread. The anticipated result is the continued spread of E. globulus in coastal regions with adequate moisture and suitable climate. Predicting the range of E. globulus in California dictates management strategy and is key for preventing further introduction, …


Canola: A Modern Crop For A Modern Era, Kenneth J. Roché Nov 2015

Canola: A Modern Crop For A Modern Era, Kenneth J. Roché

Doctor of Plant Health Program: Dissertations and Student Research

The University of Nebraska-Lincoln Doctor of Plant Health program is a professional doctorate program with a comprehensive approach to plants and agriculture. The program emphasizes a broad interdisciplinary education across all plant-related disciplines, practical learning, research, and experience through internships. For my final required internship, I worked as a senior agricultural research intern with Research Designed for Agriculture (RD4AG) in Montana. RD4AG is a contract research organization based in Yuma, AZ with over thirty-years of experience. During my three month internship at RD4AG in Montana, a large portion of my responsibilities centered on managing regulated canola trials that were undertaken …


Enhancing The Effectiveness Of Biological Control Programs Of Invasive Species By Utilizing An Integrated Pest Management Approach, Invasive Species Advisory Committee Oct 2015

Enhancing The Effectiveness Of Biological Control Programs Of Invasive Species By Utilizing An Integrated Pest Management Approach, Invasive Species Advisory Committee

National Invasive Species Council

Conclusion

Biological control has been shown on many occasions to be the most cost-effective invasive species management tool available. However, integrating biological control projects with the full breadth of other integrated pest management (IPM) tools, expanding post-re- lease monitoring to maximize efficacy, adaptive management, and incorporating new and innovative ecological, and genetic technologies may provide private and public land managers greater opportunities for long-term success in suppression of established invasive species.


Impact Of The Biological Control Agent Tetramesa Romana (Hymenoptera: Eurytomidae) On Arundo Donax (Poaceae: Arundinoideae) Along The Rio Grande River In Texas, John A. Goolsby, Patrick J. Moran, Alexis Racelis, Kenneth R. Summy, Maricela Martinez Jimenez, Ronald D. Lacewell Oct 2015

Impact Of The Biological Control Agent Tetramesa Romana (Hymenoptera: Eurytomidae) On Arundo Donax (Poaceae: Arundinoideae) Along The Rio Grande River In Texas, John A. Goolsby, Patrick J. Moran, Alexis Racelis, Kenneth R. Summy, Maricela Martinez Jimenez, Ronald D. Lacewell

Biology Faculty Publications and Presentations

Five years post-release of the arundo gall wasp, Tetramesa romana, into the riparian habitats of the lower Rio Grande River, changes in the health of the invasive weed, Arundo donax, or giant reed, have been documented. These changes in plant attributes are fairly consistent along the study area of 558 river miles between Del Rio and Brownsville, TX, and support the hypothesis that the arundo wasp has had a significant impact as a biological control agent. Plant attributes were measured prior to release in 10 quadrats at each of 10 field sites in 2007, and measured again …


Assessing Multiple-Herbicide Resistance In A 2,4-D Resistant Waterhemp (Amaranthus Tuberculatus) Biotype From Nebraska – Student Research, Roberto Crespo Oct 2015

Assessing Multiple-Herbicide Resistance In A 2,4-D Resistant Waterhemp (Amaranthus Tuberculatus) Biotype From Nebraska – Student Research, Roberto Crespo

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

A waterhemp biotype was recently reported resistant to 2,4-D in Nebraska. In addition to the repeated use of 2,4-D, atrazine and imazathapyr were reported to be frequently used to control broadleaf weeds. Greenhouse experiments were conducted to confirm 2,4-D resistance and test for resistance to growth regulator herbicides and other herbicide modes-of-action (MoA). A single dose-response experiment showed reduced sensitivity in all three waterhemp biotypes to atrazine, imazethapyr and lactofen; therefore, they were generally considered resistant to those three herbicide MoA. None of the biotypes contained the Ser264 target-site mutation. Since the ametryn dose-response experiment resulted in all susceptible biotypes, …


When An Invasive Plant Fails To Invade, Stephen L. Young Oct 2015

When An Invasive Plant Fails To Invade, Stephen L. Young

West Central Research and Extension Center, North Platte

In 2012, much of the US Midwest was gripped in one of the most severe droughts on record. While conducting experimental fieldwork at a site in Nebraska during June of that year, I noticed a single musk thistle (Carduus nutans; Figure 1) that appeared to be in the bolt or early flowering stage, which is typical for the species at that time. Here, however, two things were unusual: this plant was less than 1 meter tall (with adequate moisture and light, musk thistle typically grows to heights of 1–2.5 meters before flowering), and was only 3 months old (the bolt …


Prescribed Fire Monitoring Report, Tallgrass Prairie National Preserve 2014 (Iqcs Fire Number 285382, 285383, 266782, 285677), Sherry A. Leis, Sarah E. Hinman Sep 2015

Prescribed Fire Monitoring Report, Tallgrass Prairie National Preserve 2014 (Iqcs Fire Number 285382, 285383, 266782, 285677), Sherry A. Leis, Sarah E. Hinman

United States National Park Service: Publications

Introduction

In 2014, the preserve’s federal and NGO partners conducted prescribed fires during March, April, and October that encompassed 8129.8 acres of Tallgrass Prairie National Preserve (TAPR). This was a unique burn year in that prescribed burns occurred in the spring, the traditional burn season, and the fall. Fall burns were conducted to support needed archaeological surveys as part of the environmental compliance for a symphony event scheduled for June 2015 at the preserve. Burns at TAPR were coordinated with local US Fish and Wildlife Service (USFWS), The Nature Conservancy (TNC), and various units of the National Park Service.

Burns …


A Field Guide For Grasses And Grass-Like Plants Of Idaho, Justin J. Trujillo, Eva K. Strand (Mentor) Aug 2015

A Field Guide For Grasses And Grass-Like Plants Of Idaho, Justin J. Trujillo, Eva K. Strand (Mentor)

Idaho Conference on Undergraduate Research

The purpose of this project is to develop a user-friendly field guide to grasses and grass-like plants in Idaho, specifically geared to those with limited background in botany. The guide will feature 60 Idaho grasses and grass-like plants, intended for K-16 educators and students, ranchers, land owners, recreationists, and nature enthusiasts, with accompanying K-12 lesson plans. In the form of both a printed book and an offline app for iPhones and Androids, the guide will include colorful images showing detailed characteristics and vegetative features of each grass, an easy-to-use dichotomous key, and information on each plant’s history, forage value, and …


Weed Dynamics During Transition To Conservation Agriculture In Western Kenya Maize Production, Judith A. Odhiambo, Urszula Norton, Dennis Ashilenje, Emmanuel C. Omondi, Jay B. Norton Aug 2015

Weed Dynamics During Transition To Conservation Agriculture In Western Kenya Maize Production, Judith A. Odhiambo, Urszula Norton, Dennis Ashilenje, Emmanuel C. Omondi, Jay B. Norton

Agricultural and Environmental Sciences Faculty Research

Weed competition is a significant problem in maize (Zea mays, L.) production in Sub-Saharan Africa. Better understanding of weed management and costs in maize intercropped with beans (Phaseolus vulgaris, L.) during transition to conservation agricultural systems is needed. Changes in weed population and maize growth were assessed for a period of three years at Bungoma where crops are grown twice per year and at Trans-Nzoia where crops are grown once per year. Treatments included three tillage practices: minimum (MT), no-till (NT) and conventional (CT) applied to three cropping systems: continuous maize/bean intercropping (TYPICAL), maize/bean intercropping with relayed mucuna after bean …


The Effects Of Fire On Spore Viability Of Lygodium Microphyllum (Old World Climbing Fern), Nicole Sebesta Jul 2015

The Effects Of Fire On Spore Viability Of Lygodium Microphyllum (Old World Climbing Fern), Nicole Sebesta

FIU Electronic Theses and Dissertations

Lygodium microphyllum, native to the Old World tropics, has invaded central and southern Florida, destroying native habitats, reducing biodiversity and altering fire regimes. Prescribed fire, one of several methods used to manage L. microphyllum infestations, reduces fern biomass over large areas, but its effects on spore viability are unknown. To provide tools to evaluate whether fire-dispersed spores are viable, this research determined how heat affects spore viability. Spores were exposed to temperatures of 50°C to 300°C for durations of 5 seconds to 1 hour, then allowed to germinate on agar in petri plates. Percent germination was assayed after two …


Plant Community Associations Of Two Invasive Thistles, Emily S.J. Rauschert, Katriona Shea, Sarah Goslee Jun 2015

Plant Community Associations Of Two Invasive Thistles, Emily S.J. Rauschert, Katriona Shea, Sarah Goslee

Biological, Geological, and Environmental Faculty Publications

In order to combat the growing problems associated with biological invasions, many researchers have focused on identifying which communities are most vulnerable to invasion by exotic species. However, once established, invasive species can significantly change the composition of the communities that they invade. The first step to disentangling the direction of causality is to discern whether a relationship with other vegetation exists at all. Carduus nutans and C. acanthoides are similar invasive thistles, which have caused substantial economic damage worldwide. We assessed the associations between the thistles and the standing flora in four sites in central Pennsylvania in which they …


Food Habits Of Fall-Collected Age-0 Walleyes In Eastern South Dakota Gla- Cial Lakes, Benjamin J. Schall, Matthew J. Phayvanh, Jeffrey D. Grote, Daniel J. Dembkowski, Melissa R. Wuellner Jun 2015

Food Habits Of Fall-Collected Age-0 Walleyes In Eastern South Dakota Gla- Cial Lakes, Benjamin J. Schall, Matthew J. Phayvanh, Jeffrey D. Grote, Daniel J. Dembkowski, Melissa R. Wuellner

The Prairie Naturalist

Food habits of age-0 fishes can influence their growth and survival prior to the first winter (Hoxmeier et al. 2006, Shoup and Wahl 2011). Ontogenetic diet shifts in juvenile piscivorous fishes result in a transition in consumption from zooplankton to macroinvertebrates and eventually fish throughout development (Mittelbach and Persson 1998). Certain food items may be more energetically beneficial to fishes than others as consumption of prey fishes may lead to faster growth rates of predators, decreased overwinter starvation, avoidance of competition, and reduced predation risk (Werner and Gilliam 1984). By the time age-0 walleyes (Sander vitreus) have reached lengths of …


Inter- And Intra-Specific Interactions In Germination And Seedling Establishment Of Cheatgrass And Russian Wildrye, Erin K. Espeland Jun 2015

Inter- And Intra-Specific Interactions In Germination And Seedling Establishment Of Cheatgrass And Russian Wildrye, Erin K. Espeland

The Prairie Naturalist

Cheatgrass (Bromus tectorum) is an invasive species in the arid and semi-arid west of the USA, and is weedy in disturbed prairie landscapes. Perennial Russian wildrye (Psathyrostachys juncea) limits population growth of cheatgrass, but the mechanism is unclear. I conducted glasshouse and greenhouse experiments to test if intra- and interspecific competitive interactions of seeds and seedlings of cheatgrass and Russian wildrye were different across a geographic soil gradient with different cultivation legacies in eastern Montana, USA. Seed-seed interactions occurred in both species. Cheatgrass and Russian wildrye inhibited one another’s emergence in one edaphic condition in one experiment. Cheatgrass growth was …


Bot Fly Infestation Of Thirteen-Lined Ground Squirrels In Colorado Shortgrass Steppe, Kim Conway, Paul Stapp Jun 2015

Bot Fly Infestation Of Thirteen-Lined Ground Squirrels In Colorado Shortgrass Steppe, Kim Conway, Paul Stapp

The Prairie Naturalist

We studied prevalence of bot fly infestation of thirteen-lined ground squirrels (Ictidomys tridecemlineatus) trapped during 13 years of population monitoring in shrub and grassland habitats in northern Colorado. We also investigated effects of prescribed burning, a common habitat management practice in grasslands, on bot fly prevalence. Infested squirrels were rarely located on shrub sites and during spring (May–Jun) trapping. Across all summers, mean prevalence in grasslands was 7.9% (range: 2.1–23.8%), with years of highest prevalence corresponding to years when the fewest hosts were captured in spring. Infested squirrels had from one to seven warbles, with 46.7% having only one warble. …