Environmental Sciences Commons^™

Investigating Three Decades Of Vegetation Change In A Mojave Desert Mountain Range, Chris Lee Roberts

UNLV Theses, Dissertations, Professional Papers, and Capstones

This project is a vegetation change study spanning 29 years in the Newberry Mountains of Southern Nevada. Long term monitoring data are crucial for understanding the effects of climate change on vegetation dynamics. Successful management intervention in vegetation change will require identification of early indicator plant species and their responses to climatic cues. This project is one of the oldest comparisons of resurveyed Mojave vegetation community plots with repeatable methodology and the longest survey interval reported for the southeastern Mojave Desert. 103 plots were relocated and resurveyed based on data methods in Jim Holland's thesis titled "A Vegetative Analysis of …

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: 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.

29 Years Of Vegetation Community Change Across Environmental Gradients In A Mojave Desert Mountain Range, Christopher L. Roberts, James S. Holland, Scott R. Abella

Graduate Research Symposium (GCUA) (2010 - 2017)

There is a great deal of uncertainty as to how biological communities respond to changes in land use and climate change, a situation particularly relevant in protected areas such as national parks that were designated to conserve specific biological features. Utilizing extant vegetation data sets with repeatable methodology can provide opportunities for insight into previous vegetation change and provide base line data for long-term monitoring projects useful for modeling vegetation community trajectories. We have relocated and resurveyed 106 sites from a vegetation community study initiated in 1979 in the Newberry Mountains, southern Nevada, within Lake Mead National Recreation Area managed …

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Final Project Report, Scott R. Abella, Margaret N. Rees

Vegetation Monitoring

Vegetation Monitoring and Analysis at Lake Mead National Recreation Area (NRA) was funded by the Multi-Species Habitat Conservation Plan, Southern Nevada Public Land Management Act, Lower Colorado River Multi-Species Conservation Program, and Lake Mead NRA base-funds. This Cooperative Task Agreement was awarded to the Public Lands Institute (PLI) at the University of Nevada, Las Vegas (UNLV) on September 30, 2006 with the term ending December 31, 2009, as modified. The primary purpose of this Task Agreement was to work within an interagency framework towards the accomplishment of three main vegetation management objectives. These three goals were to: (1) inventory, research …

Biotic Responses To Climate Change In The Great Basin And Mojave Desert: Vegetation, David Charlet, Patrick Leary

2010 Annual Nevada NSF EPSCoR Climate Change Conference

84 PowerPoint slides Convener: Franco Biondi, UNR & Michael Young, DRI Session 4: Ecological Change and Water Resources Abstract: -The Problem -To detect changes in vegetation as it responds to changes in climate, we must first know where the vegetation is now -GAP (Geographic Approach to Protection of Biodiversity) map --National project to map land cover throughout the US. --Nevada map (Edwards et al. 1996) -Southwest ReGAP map --Land cover map for southwestern US (Prior-Magee et al. 2007) to correct problems identified in GAP map

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.

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, July 1, 2009 To September 30, 2009, Margaret N. Rees

Vegetation Monitoring

Executive Summary

• Weed Sentry staff surveyed over 55 miles and 311 acres (most of which was conducted by foot) this quarter.
• Planning for future Brassica tournefortii research projects has been implemented through collaboration between PLI and NPS staff.
• Preliminary results from ongoing Brassica tournefortii projects indicate little effect of disturbance on abundance of the species, but, as expected, the species benefitted with increased water availability
• Rare plant data monitoring and data entry for this season is complete.
• Pre-planning activities for the upcoming Northshore Road restoration plantings and evaluation were initiated.
• Gypsum restoration research is ongoing, data are being analyzed and …

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, April 1, 2009 To June 30, 2009, Margaret N. Rees

Vegetation Monitoring

Executive Summary

• The Weed Sentry program surveyed over 187 miles (1,342 acres) of federal land by vehicle and foot in Clark County for incipient populations of exotic plants.
• Weed Sentry staff continue to survey never before surveyed sites, and trails and regions within Upper Las Vegas Wash CTA and Sloan Canyon NCA as requested by BLM managers
• In 2009 rare plant monitoring was completed. Data entry and analysis are in progress.

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, January 1, 2009 To March 31, 2009, Margaret N. Rees

Vegetation Monitoring

Executive Summary

• The Weed Sentry program surveyed over 126 miles (981 acres) of federal land by vehicle and foot in Clark County for incipient populations of exotic plants.
• Weed Sentry staff continue to survey never before surveyed sites, and trails and regions within Red Rock and Sloan Canyon NCAs requested by BLM managers.
• The 2009 rare plant monitoring was initiated and in progress.
• Northshore Road reconstruction monitoring was initiated and active monitoring and care of salvaged plants was performed by UNLV staff.
• Rana onca vegetation monitoring and reporting was completed.

Consequences Of More Extreme Precipitation Regimes For Terrestrial Ecosystems, S. D. Smith, C. Beier, Aimee T. Classen, Melinda D. Smith, Jana L. Heisler, S. W. Leavitt, Alan K. Knapp, D. Briske, Y. Luo, M. Reichstein, J. E. Bell, Philip A. Fay, R. Sherry, Benjamin Smith

Life Sciences Faculty Research

Amplification of the hydrological cycle as a consequence of global warming is forecast to lead to more extreme intra-annual precipitation regimes characterized by larger rainfall events and longer intervals between events. We present a conceptual framework, based on past investigations and ecological theory, for predicting the consequences of this underappreciated aspect of climate change. We consider a broad range of terrestrial ecosystems that vary in their overall water balance. More extreme rainfall regimes are expected to increase the duration and severity of soil water stress in mesic ecosystems as intervals between rainfall events increase. In contrast, xeric ecosystems may exhibit …

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Year-End Progress Report, October 1, 2007 To September 30, 2008, Margaret N. Rees

Vegetation Monitoring

Executive Summary

• The Weed Sentry program surveyed over 335 miles and 2,610 acres of transportation corridors on federal land in Clark County for incipient populations of exotic plants.
• 18 manuscripts attained in-press or published status and one manuscript was submitted for review this year. Among published manuscripts, are one documenting Sahara mustard germination patterns (Western North American Naturalist), one assessing exotic species distributions in Clark County (Environmental Monitoring and Assessment), and another is a synthesis of burro effects on Mojave Desert vegetation (Environmental Management), and one assessing vegetation in grassy remnants of the Las Vegas Valley (Desert Plants)
• Staff delivered …

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, April 1, 2008 To June 30, 2008, Margaret N. Rees

Vegetation Monitoring

Executive Summary

• The Weed Sentry program surveyed over 182 miles of transportation corridors on federal land in Clark County for incipient populations of exotic plants.
• Five manuscripts attained published or in-press status this quarter. The published manuscripts are (1) assessing vegetation in grassy remnants of the Las Vegas Valley (Desert Plants), (2) assessing exotic species distributions in Clark County (Environmental Monitoring and Assessment), (3) a synthesis of burro effects on Mojave Desert vegetation (Environmental Management), and (4) examining canopy-tree influences along a soil parent material gradient in (Journal of the Torrey Botanical Society).
• Staff delivered eight presentations this quarter at …

Limnological Assistance For The Lake Mead National Recreation Area In Meeting The Challenge Of The Water 2025 Initiative: Annual Report, Period Ending May 31, 2008, Margaret N. Rees

Limnological Studies

Hiring: Limnologist Dr. Wai Hing (David) Wong was hired and officially reported to work on 5/15/2008.

Project 1 and Project 2: Dr. Wong has commenced work on Projects 1 and 2.

Project 3: Dr. Wong has commenced work on Project 3. A comprehensive zebra/quagga mussel bibliography has been completed and published to the 100th Meridian Web site. Six interagency, multi-disciplinary quagga mussel meetings have been held. A quagga mussel substrate project has been initiated and, through the coordination efforts of this project, two other studies have been selected and refined to help determine the ecological impacts of quagga mussel infestation …

Limnological Assistance For The Lake Mead National Recreation Area In Meeting The Challenge Of The Water 2025 Initiative: Quarterly Progress Report, Period Ending: April 1, 2008, Margaret N. Rees

Limnological Studies

Hiring: A decision is anticipated in the upcoming weeks regarding the hiring of a limnologist. Two candidates were selected from among three qualified applicants for telephone interviews; they were subsequently interviewed in-person.

Project 1: Review of the draft Boulder Basin Adaptive Management Plan is on-going. Meetings of the Systems Conveyance and Operations Program (SCOP) Technical Advisory Teams were attended.

Project 2: Development of a white paper expressing the joint needs of the entities involved in Water 2025 projects is on-going; scientific review of data and reports related to bacteria in high-use areas of Lake Mead is underway.

Project 3: Discussions …

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, January 1— March 31, 2008, Margaret N. Rees

Vegetation Monitoring

Executive Summary

• The Weed Sentry program surveyed 104 miles of transportation corridors on federal land in Clark County for incipient populations of exotic plants.
• Seven manuscripts attained in-press or published status and two manuscripts were submitted for review this quarter. Among other in-press manuscripts, are one documenting Sahara mustard germination patterns (Western North American Naturalist), one assessing exotic species distributions in Clark County (Environmental Monitoring and Assessment), and another is a synthesis of burro effects on Mojave Desert vegetation (Environmental Management).
• Staff delivered four presentations this quarter at conferences or at agency meetings. Twenty-six Las Vegas bearpoppy sites were assessed …

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, October 1, 2007 To December 31, 2007, Margaret N. Rees

Vegetation Monitoring

Executive Summary

• The Weed Sentry program surveyed more than 750 miles of federal lands in Clark County for invasive, exotic plant species.
• Weed Sentry also removed more than 600,000 individual invasive plants from federal
  lands. These removals represent pro-active efforts that may have forestalled large
  infestations difficult and costly to eradicate.
• In response to a request by the manager of the Fish and Wildlife Service Desert National
  Wildlife Refuge, a major effort of surveying springs for plant community composition
  and invasive plants provided unique knowledge services by the Weed Sentry program.
  No such baseline information existed for the Sheep Range. …

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Year-End Progress Report, October 1, 2006 To September 30, 2007, Margaret N. Rees

Vegetation Monitoring

Executive Summary

• The Weed Sentry program surveyed more than 750 miles of federal lands in Clark County for invasive, exotic plant species.
• Weed Sentry also removed more than 600,000 individual invasive plants from federal
  lands. These removals represent pro-active efforts that may have forestalled large
  infestations difficult and costly to eradicate.
• In response to a request by the manager of the Fish and Wildlife Service Desert National
  Wildlife Refuge, a major effort of surveying springs for plant community composition
  and invasive plants provided unique knowledge services by the Weed Sentry program.
  No such baseline information existed for the Sheep Range. …

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, Period Ending March 31, 2007, Margaret N. Rees

Vegetation Monitoring

Executive Summary

• Weed Sentry staff surveyed for exotic species on 208 miles of roads on NPS land and on 61 miles of BLM land. Due to sparse precipitation this winter, exotic species are much less abundant this year compared to last year at this time.
• Other exotic species projects initiated this quarter included an assessment of invasion patterns below native shrubs for early detection of potential invasion “hotspots,” and a community invasibility experiment established near the NPS nursery with substantial involvement from NPS ATR Ms. Alice Newton.
• A manuscript detailing several experiments with the invasive species Sahara mustard was submitted …

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 …

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

Monitoring Temporal Change In Riparian Vegetation Of Great Basin National Park, E. A. Beever, D. A. Pyke, J. C. Chambers, F. Landau, S. D. Smith, K. Murray

Life Sciences Faculty Research

Disturbance in riparian areas of semiarid ecosystems involves complex interactions of pulsed hydrologic flows, herbivory, fire, climatic effects, and anthropogenic influences. We resampled riparian vegetation within ten 10-m × 100-m plots that were initially sampled in 1992 in 4 watersheds of the Snake Range, east central Nevada. Our finding of significantly lower coverage of grasses, forbs, and shrubs within plots in 2001 compared with 1992 was not consistent with the management decision to remove livestock grazing from the watersheds in 1999. Change over time in cover of life-forms or bare ground was not predicted by scat counts within plots in …

Vegetation Characteristics Associated With Small Mammal Populations In The Las Vegas Wash, Christine Therese Herndon

UNLV Theses, Dissertations, Professional Papers, and Capstones

Percent litter, average litter depth, percent bare ground, vegetation density, vegetation canopy, and distance to an ecotone boundary were measured and compared to small mammal capture locations in the Las Vegas Wash. Neotoma lepida appear to be greatly dependent upon the foliage litter of T. ramosissima. Alternatively, ecotone boundaries appear to be the most important factor affecting Dipodomys merriami distributions. Peromyscus eremicus distributions may be predicted based on vegetation density and increased canopy during shorter, winter torpor periods. Chaetodipus penicillatus were consistently associated with dense, seed-bearing vegetation, although C. penicillatus is extremely opportunistic and vegetation density should not limit their …

A Study Of Invasive Species Cover Near Roads In A Red Rock Canyon Blackbrush Community, Christopher Keough

UNLV Theses, Dissertations, Professional Papers, and Capstones

The monitoring of Mojave Desert plant communities during and following disturbance is an important process that could provide invaluable information about disturbance/recovery regimes in similar arid environments across the globe. Blackbrush communities are of particular interest because of their low replacement rate, which makes them highly susceptible to disturbance. Roads in the Mojave Desert have been associated with soil compaction resulting in a lack of vegetation as well as an increase in invasive species cover in the immediate proximity. To investigate these statements, eight fifty-foot line transects were established in each of three plot types (perpendicular to dirt roads, perpendicular …

Riparian Plant Water Relations Along The North Fork Of The Kings River, California, J. L. Nachlinger, S. D. Smith, R. J. Risser

Life Sciences Faculty Research

Plant water relations of five obligate ripar-ian species were studied along California's North Fork Kings River. Diurnal stomatal conductance, transpi-ration, and xylem pressure potentials were measured throughout the 1986 growing season and in mid-season in 1987. Patterns were similar for all species although absolute values varied considerably. Maximum stomatal conductance occurred early in the day and season during favorable environmental conditions and decreased as air temperature and the vapor pressure difference between the leaf and air increased. Maximum transpiration rates occurred in mid-morning and mid-summer resulting in estimated daily water losses per unit sunlit leaf area of 163-328 mol H2O …