Life Sciences Commons^™

Hawai‘I Forest Review: Synthesizing The Ecology, Evolution, And Conservation Of A Model System, Kasey E. Barton, Andrea Westerband, Rebecca Ostertag, Elizabeth Stacy, Kawika Winter, Donald R. Drake, Lucas Berio Fortini, Creighton M. Litton, Susan Cordell, Paul Krushelnycky, Kapua Kawelo, Kealoha Feliciano, Gordon Bennett, Tiffany Knight

Life Sciences Faculty Research

As the most remote archipelago in the world, the Hawaiian Islands are home to a highly endemic and disharmonic biota that has fascinated biologists for centuries. Forests are the dominant terrestrial biome in Hawai‘i, spanning complex, heterogeneous climates across substrates that vary tremendously in age, soil structure, and nutrient availability. Species richness is low in Hawaiian forests compared to other tropical forests, as a consequence of dispersal limitation from continents and adaptive radiations in only some lineages, and forests are dominated by the widespread Metrosideros species complex. Low species richness provides a relatively tractable model system for studies of community …

Leaf Micromorphology Aids Taxonomic Delineation Within The Hypervariable Genus Metrosideros (Myrtaceae) On O'Ahu, Gary L. Sur, Richard Keating, Elizabeth Stacy

Life Sciences Faculty Research

Variation in leaf micromorphology can aid delimitation of taxonomically difficult groups. The woody genus Metrosideros (Myrtaceae) dominates Hawai'i's native forests and comprises striking, predominantly infraspecific, macromorphological variation, including many forms unrecognized in current taxonomic treatments. On taxonomically rich O'ahu, 10 taxa (varieties or unnamed morphotypes of M. polymorpha and other species) occur in a predictable sequence with overlapping ranges from low to high elevation along the numerous leeward ridges of the Ko'olau Range. We used scanning electron and light microscopy to examine mature, nonsenescing sun leaves from each of these 10 taxa. Parametric and nonparametric tests were used to compare …

The Role Of Oswrky71 And Its Interacting Proteins In Seed Germination And Early Growth Of Cereal Grains, Margaret Ja Shin

UNLV Theses, Dissertations, Professional Papers, and Capstones

During seed germination and early seedling growth, complex molecular and physiological events occur in rice (Oryza sativa) and other cereal grains. As the seed transitions to vegetative tissue, it responds to both favorable and unfavorable environmental conditions and is vulnerable to attack by predation and disease. Although seeds are relatively small and tender in size, extensive and sophisticated molecular networks enables the immobile seed to grow, survive and adapt in its environment. One of the networks I am interested in is in the crosstalk between the gibberellin (GA) and abscisic acid (ABA) signaling pathways. These pathways are interesting because they …

Bryoecology In The American Southwest: Patterns Of Biodiversity And Responses To Global Change, John Carroll Brinda

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation combines investigation of the large-scale responses of bryophyte species diversity and distribution with small-scale physiological adaptations to global change. These two areas of inquiry are linked because one way to predict plant species responses to global change is to examine their distribution across current ecological gradients produced by factors such as latitude and elevation. By examining these biogeographic patterns one can identify those species that have a narrow tolerance and therefore are most sensitive to change. Selected bryophytes might then be used as indicator species in long-term monitoring programs. Where historical data exist, these can be used to …

Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis: Final Report, Scott R. Abella

Fire Science

Species selection can make the difference between successful revegetation projects and costly failures. Candidate native species for revegetating burned arid lands in the southwestern United States must meet at least two criteria. These species must: (1) be competitive in postfire environments typically dominated by exotic grasses, and (2) be able to become established reliably by seeding or planting. In response to Manager’s Request Task 3 (reestablishment of native vegetation after fires on arid lands) in the 2006 JFS announcement for proposals, this research tackled the problem of selecting native species with the greatest chance of revegetation success by conducting synergistic …

Joint Fire Science Program – Lake Mead National Recreation Area Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis: Quarterly Progress Report, Time Period: July 1 — September 30, 2010, Margaret N. Rees

Fire Science

• Article entitled “Competitive Hierarchy of Native Desert Plants with Red Brome (Bromus rubens): Towards Identifying Invasion-Reducing Species" was revised and re-submitted to the Invasive Plant Science and Management journal.
• Final data collection on soils and nursery plots is complete. Data are awaiting analysis.

The Endosymbiotic Relationship Of Leguminosae (Fabaceae) And Rhizobium, Sabrina Mcgee, Dolores Maceda, Maria Bustos, Maryknoll Palisoc, Rachel Dahl

Undergraduate Research Opportunities Program (UROP)

This project will look at The Endosymbiotic Relationship of Leguminosae (Fabaceae) and Rizobioum. Endoysmbiosis Theory is the concept that mitochondria and chloroplasts are the result of years of evolution initiated by the endocytosis, (the process by which cells absorb material through their cell membrane) of bacteria and algae which, instead of becoming digested, became symbiotic.The mitochondria of eukaryotes evolved from aerobic bacteria, probably rickettsias, living within their host cell and the chloroplasts from cyanobacteria, also known as blue-green algae. Endoysmbiosis is a type of symbiosis in which one organism lives inside the body of another and both function as a …

Temporal And Spatial Assessment Of Evaporation, Transpiration, And Soil Moisture Redistribution, Brian M. Bird

UNLV Theses, Dissertations, Professional Papers, and Capstones

At a native stand of creosote bush (Larrea tridentata) in North Las Vegas, a rainfall simulation study was conducted over a 12 month period from October 2005 to October 2006. Simulated rainfall occurred during the winter, spring, summer, and fall periods. Rainfall simulation systems were positioned on each of 12 plots, each containing a single creosote bush. Simulated rainfall events occurred at night with multiple short pulses designed to maximize infiltration while minimizing ponding. Yearly simulated rainfall amounts were set at 0, 15, 30 and 60 cm (replicated three times) and were approximately 0, 1.5, 3.0 and 6.0 times the …

Joint Fire Science Program – Lake Mead National Recreation Area Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis: Quarterly Progress Report, Time Period: May 1 — June 30, 2010, Margaret N. Rees

Fire Science

• Article entitled “Competitive Hierarchy of Native Desert Plants with Red Brome (Bromus rubens): Towards Identifying Invasion-Reducing Species" was submitted to the Invasive Plant Science and Management journal.
• Maintained nursery plots and added installment of nitrogen treatment.
• Took measurements in nursery (competition) plots and harvested biomass.

Joint Fire Science Program – Lake Mead National Recreation Area Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis: Quarterly Progress Report, Time Period: January 1 — April 30, 2010, Margaret N. Rees

Fire Science

• Article entitled “Competitive Hierarchy of Native Desert Plants with Red Brome (Bromus rubens): Towards Identifying Invasion-Reducing Species" was submitted to the Invasive Plant Science and Management journal
• Maintained nursery plots and added installment of nitrogen treatment.
• Took measurements in nursery (competition) plots and harvested biomass.

Research Poster: Eco-Hydrological Pathways Inferred From Stable Isotopes In A Pinus Ponderosa And Pinus Monophylla Woodland Of The Sheep Range, Southern Great Basin, Usa, Kelli Hoover, Simon Poulson, Franco Biondi, Jeffrey Underwood

2010 Annual Nevada NSF EPSCoR Climate Change Conference

Research poster

Joint Fire Science Program – Lake Mead National Recreation Area Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis: Quarterly Progress Report, Time Period: October 1 — December 31, 2009, Margaret N. Rees

Fire Science

• Article accepted for publication in Journal of Arid Environments.

• Recharged irrigation gel packs for outplanting and watered seed plots at Goodsprings site.

• Completed full year of seed granivory trials at Goodsprings site.

• Presented information on this Task Agreement to 4th International Fire Ecology and Management Congress.

• Maintained nursery plots and added installment of nitrogen treatment.

Joint Fire Science Program – Lake Mead National Recreation Area Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis: Quarterly Progress Report, Time Period: July 1 — September 30, 2009, Margaret N. Rees

Fire Science

• Weighed biomass for competitive hierarchy study.
• Completed more seed granivory trials at Goodsprings.
• Monitored and maintained nursery plots.
• Submitted revised article to Journal of Arid Environments.

Joint Fire Science Program – Lake Mead National Recreation Area: Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis, Quarterly Progress Report, April 1 — June 30, 2009, Margaret N. Rees

Fire Science

• Initiated a competitive hierarchy study.
• Monitored and maintained outplanting at Goodsprings.
• Completed more seed granivory trials at Goodsprings.
• Mentored student to completion of undergraduate research project.
• Monitored and maintained nursery plots.
• Revising article submitted to Journal of Arid Environments.

Investigation Of Plant Water Use In The Great Basin, Nv, Benjamin Conrad

UNLV Theses, Dissertations, Professional Papers, and Capstones

Global climate change in addition to a growing population can have a strong impact on our natural resources. In particular, cities in the semi-arid and arid southwestern US are currently faced with the challenge of providing sustainable fresh water to a growing population. In Las Vegas, dwindling water levels in Lake Mead have forced water managers to seek water resources from Spring Valley and Snake Valley, NV, which are located 402 km north of the city. The goals of this research were to investigate the water use of shrubs located in these valleys by using a large aperture scintillometer (LAS) …

Joint Fire Science Program – Lake Mead National Recreation Area: Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis, Quarterly Progress Report, January 1— March 31, 2009, Margaret N. Rees

Fire Science

• Monitored and watered native plants in nursery plots.

• Exotic grasses seeded into nursery plots.

• Nitrogen treatment applied to nursery plots.

• Granivory study trials performed each month and corresponding abstract submitted to ESA.

• Competitive hierarchy study germination trials are underway.

• Monitored seeding and outplanting experiments at Goodsprings.

• Submitted article to Mojave Applied Ecology Notes newsletter updating on JFS work.

• Mentoring UNLV undergraduate student in research project for ENV 492.

• Prepared presentation materials for two scientific meetings.

Joint Fire Science Program – Lake Mead National Recreation Area: Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis, Quarterly Progress Report, October 1 — December 31, 2008, Margaret N. Rees

Fire Science

• Presented poster at Natural Areas Conference in Nashville, TN

• Initiated granivory study at Goodsprings.

• Outplanted 2376 plants for Experiment 1 at Lake Mead nursery.

• Presented poster at Wildfires and Invasive Plants in American Deserts conference in Reno, NV.

• Submitted manuscript covering our distance from road - microsite invasibility study to Journal of Arid Environments.

Joint Fire Science Program – Lake Mead National Recreation Area: Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis, Quarterly Progress Report, July 1 — September 30, 2008, Margaret N. Rees

Fire Science

• Cones monitored and reseeded to obtain plants for nursery study.

• Goodsprings revegetation studies monitored.

• Website developed for JFS study.

• Writing short communication for Journal of Arid Environments.

• Working on poster for NAA conference in October.

Gender Variation In The Prezygotic Reproductive Effort Of The Common Silver Moss, Kimberley Horsley, Lloyd Stark

Undergraduate Research Opportunities Program (UROP)

The bryophyte Bryum argenteum is a vigorous moss with a cosmopolitan distribution and high tolerance to desiccation and temperature stress. Due to its widespread nature, B. argenteum has been highly investigated (e.g., Chopra and Bhatla 1981). However, very little research has been done on the reproductive aspects of this moss with respect to gender differences. This project will address the prefertilization reproductive efforts of the moss, and look for any differences in the rate of growth and sexual expression between the sexes. The hypothesis to be tested is that males actually have a higher prefertilization reproductive effort than females and …

Decoding The Protein Interaction Network - An Approach Integrating Biology And Math, Ryan Huang, Lingkun Gu, Qingxi J. Shen

Undergraduate Research Opportunities Program (UROP)

The WRKY super family is known to play a major role during the plant stress response and development. My project focuses on the protein-protein interaction of an Oryzasativa (rice) transcription factor, OsWRKY71 which functions as the repressor of gibberellins signaling pathway. Previous literature revealed that OsWRKY71 can interact with itself or OsWRKY51 to form dimmers by using bimolecular fluorescence complementation (BiFC). To confirm this result, we use yeast two-hybrid system. As our data showed, OsWRKY71 seems to suppress the reporter gene expression of the conventional yeast two-hybrid system, so we use a modified yeast two-hybrid, Mating-based Split Ubiquitin System (MbSUS). …

Joint Fire Science Program – Lake Mead National Recreation Area: Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis: Quarterly Progress Report, April 1— June 30, 2008, Margaret N. Rees

Fire Science

• Cones seeded for competition experiment at Lake Mead nursery.

• Cones monitored for seedling establishment.

• Goodsprings revegetation studies monitored.

• Invasibility data being entered and analyzed.

• Abstract for NAA conference submitted.

• Joint Fire Science update article submitted to Mojave Applied Ecology Notes newsletter.

Joint Fire Science Program – Lake Mead National Recreation Area: Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis: Quarterly Progress Report, January 1— March 31, 2008, Margaret N. Rees

Fire Science

• Fence built.

• Seeds and plants obtained.

• Seeding experiment initiated at Goodsprings burn site.

• Three hundred twenty plants, comprising eight species, planted at the Goodsprings burn site on February 12, 2008.

• First of a series of Joint Fire Science update articles submitted to Mojave Applied Ecology Notes newsletter.

Joint Fire Science Program – Lake Mead National Recreation Area: Revegetating Burned Arid Lands: Identifying Successful Native Species Using Trait And Competition Analysis, Quarterly Progress Report, October 1, 2007 To December 31, 2007, Margaret N. Rees

Fire Science

The task agreement was awarded to UNLV on October 1, 2007. This report covers the period October 1, 2007 to December 31, 2007. The following activities have been conducted toward meeting or exceeding deliverables in the statement of work: hiring and project start and experimental set-up

Lake Mead National Recreation Area Vegetation Monitoring And Management: Quarterly Progress Report, Period Ending December 31, 2006, Margaret N. Rees

Vegetation Monitoring

Executive Summary

• Two new Weed Sentry research assistants were hired.
• Weed Sentry staff surveyed for exotic species on 89 miles of roads on NPS and BLM land and treated more than 21,000 exotic plants in incipient populations.
• A grid-based rare plant monitoring method was tested this quarter.
• A manuscript detailing vegetation succession on a water pipeline at Lake Mead NRA was submitted for review to the journal Crossosoma.
• New integrative projects undertaken this quarter included establishing a competition study between a native grass and the exotic Sahara mustard, salvaging plants for research purposes from private sites with permission from landowners, …

Lake Mead National Recreation Area Vegetation Monitoring And Management: Final Close-Out Report, Time Period: October 1, 2005 To September 30, 2006, Margaret N. Rees

Vegetation Monitoring

The National Park Service (NPS) at Lake Mead National Recreation Area (LAME) entered into a cooperative agreement with the University of Nevada, Las Vegas (UNLV) to accomplish vegetation monitoring and management activities. This report summarizes activities that took place by UNLV under this task agreement between October 1, 2005, and September 30, 2006. The activities included:

• Weed Sentry mapping and treating incipient populations of exotic invasive plants throughout Clark County, including along shorelines of Lakes Mead and Mohave;
• Monitoring of targeted rare native plant species;
• Sahara mustard research; and
• Providing technical assistance upon request to the NPS vegetation manager.

In …

Effects Of Smoke And Fire-Related Cues On Panstemon Barbatus Seeds, Scott R. Abella

Public Policy and Leadership Faculty Publications

Previous research has found that exposure to fire-related cues enhances germination of some plant species, and such species may exist in frequent-fire southwestern United States Pinus ponderosa forests. I performed four greenhouse experiments with Penstemon barbatus, a perennial forb common in P. ponderosa forests, testing seed responses to liquid and air smoke, charred P. ponderosa wood and leachate, heat and emergence substrates. Liquid smoke increased P. barbatus emergence to as high as 63%, 44% greater than controls, and enhanced emergence in all 4 experiments. Air smoke produced by burning P. ponderosa litter for 15 min appeared to increase emergence similar …

Lake Mead National Recreation Area Vegetation Monitoring And Management: Quarterly Progress Report, Period Ending December 31, 2005, Margaret N. Rees

Vegetation Monitoring

Executive Summary

• Required reports on sticky buckwheat (Eriogonum viscidulum) and threecorner milkvetch (Astragalus geyeri var. triquetrus) to be submitted through appropriate protocols by December 30, 2005
• Summary report on several other rare plants to be submitted through appropriate protocols by December 30, 2005
• Invasive perennial pepperweed (also called tall whitetop; Lepidium latifolium) documented and treated by Weed Sentry within Black Canyon, Lake Mojave

Age And Sex-Specific Rates Of Leaf Regeneration In The Mojave Desert Moss Syntrichia Caninervis, Lloyd Stark, L. Nichols, Nicholas N. Mcletchie, S. D. Smith, C. Zundel

Life Sciences Faculty Research

The extremely skewed female-biased sex ratio in the desert moss Syntrichia caninervis was investigated by assessing the regeneration capacity of detached leaves. Juvenile, green, yellow-green, and brown leaves equating to approximately 0, 2, 6, and 12 yr of age, respectively, were detached from individuals of S. caninervis collected from 10 field populations and grown in a growth chamber for 58 d at a light intensity of 33–128 µmol · m–2 · s–1. Younger leaves (0–2 yr old) tended to have a greater viability, regenerate more quickly, extend their protonemal filaments farther, produce shoots (gametophores) more quickly, produce more shoots, and …

Integrated Weed Management Plan For The Lower Las Vegas Wash, Elizabeth Bickmore

Publications (WR)

The Las Vegas Wash (Wash) is the primary drainage for the metropolitan Las Vegas Valley, eventually finding its way into the Colorado River watershed system. Pursuant to the recommendations of the Water Quality Citizens Advisory Committee, the Las Vegas Wash Coordination Committee (LVWCC) was formed in 1998 to develop a comprehensive plan for the long-term stabilization and management of the Wash. Consisting of representatives from 28 government agencies, businesses, environmental groups and citizens, the LVWCC formulated the Las Vegas Wash Comprehensive Adaptive Management Plan (CAMP) and designated the Southern Nevada Water Authority (SNWA) as the lead agency for the implementation …

On The Relationship Between Stomatal Characters And Atmospheric Co2, C. D. Reid, H. Maherali, H. B. Johnson, S. D. Smith, S. D. Wullschleger, R. B. Jackson

Life Sciences Faculty Research

Leaf stomatal characters influence the response of terrestrial evapotranspiration to climate change and are used as proxies for the reconstruction of past atmospheric [CO2]. We examined the phenotypic response of stomatal index (SI), density (SD) and aperture (AP) to rising atmospheric CO2 in 15 species after four years exposure to a field CO2 gradient (200 to 550 μmol mol−1 atmospheric [CO2]) or at three Free Air CO2 Enrichment (FACE) sites. Along the CO2 gradient, SI and SD showed no evidence of a decline to increasing [CO2], while AP decreased slightly. There was no significant change in SI, SD or AP …