Weed Science Commons^™

Addressing Water Hyacinth (Pontederia Crassipes) Impacts On Aquatic Biota In Lake Okeechobee, Joseph Salerno

All HCAS Student Capstones, Theses, and Dissertations

The incursion of water hyacinth, Pontederia crassipes in Lake Okeechobee has resulted in management systems to be implemented to reduce the coverage of the invasive macrophyte. Its residence in the Lake Okeechobee ecosystem and the effects it has on organisms in the lake, whether it be positive or harmful is unknown. This study attempted to assess the potential effects that water hyacinth has on aquatic biota in Lake Okeechobee. Biotic data were collected on open water, water hyacinth covered, and native vegetation covered habitats via hook-and-line fishing, electrofishing, baited minnow traps, and the sampling of plant roots over a thirteen-month …

Managing Forest Disturbances: Effects On Mule Deer And Plant Communities In Montana's Northern Forests, Teagan Ann Hayes

Graduate Student Theses, Dissertations, & Professional Papers

Mule deer (Odocoileus hemionus) are frequently the focus of population and habitat management in the western United States. Land and wildlife managers use disturbance to reset forests to earlier successional stages and improve the quality and quantity of forage available to mule deer. However, the effects of management practices on nutrition and selection vary widely, so the implementation of management practices raises ecological as well as management-related concerns. This work investigated how disturbance from wildfire, prescribed fire, and timber harvest influences the spatial and temporal distribution of nutritional resources in mule deer summer range, and therefore, how the …

Farmer Attitudes Toward Cooperative Approaches To Herbicide Resistance Management: A Common Pool Ecosystem Service Challenge, David E. Ervin, Elise H. Breshears, George B. Frisvold, Terrance M. Hurley, Katherine E. Dentzman, Jeffrey L. Gunsolus, Raymond A. Jussaume, Micheal D. K. Owen, Jason Norsworthy, Mustofa Mahmud Al Mamun, Wesley Everman

Environmental Science and Management Faculty Publications and Presentations

Dramatic growth in herbicide-resistant (HR) weeds in the United States threatens farm profitability and may undercut environmentally beneficial farming practices. When HR weeds move across farm boundaries due to ecological processes or human action, a common pool resource challenge emerges, requiring farmer cooperation to manage such weeds effectively. We investigate the scope for cooperative management using responses to a national survey on HR weed issues to test a recursive model of three preconditions for collective action: (1) concern about HR weeds migrating from nearby lands; (2) communication with neighbors about HR weeds; and (3) belief that cooperation is necessary for …

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 …

Survey Of Invasive Lantana Camara At Makirovana-Tsihomanaomby Forest Complex, Eliza Pessereau

Independent Study Project (ISP) Collection

Lantana camara is a shrub known globally as an invasive pest that grows primarily in degraded areas. The species is known to exist at Makirovana-Tsihomanaomby, a forest complex in northeastern Madagascar with 167 endemic species of flora and fauna, several of which are on the IUCN Red List. The complex, specifically Tsihomanaomby forest, is used as a resource for the three rural communes that live on its outskirts, meaning that it experiences much human activity. The objective of this study was to survey the population of L. camara at two sites: one just outside of the Tsihomanaomby forest and one …

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: 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.

Assessing Invasive Plant Species As Threats In Mojave Desert Parks, Sara L. Mcpherson, Donovan J. Craig, Scott R. Abella

Graduate Research Symposium (GCUA) (2010 - 2017)

The invasion and persistence of exotic plant species threatens the natural features that national parks are designed to protect. For example, park managers have witnessed an increase in the frequency, extent and intensity of fires along with a reduction in native species richness and diversity. Many park managers are familiar with a suite of highly invasive plants, but lack a comprehensive and systematic way of prioritizing invasive plant species based on potential threats to the parks’ resources. We have entered into a collaborative project with the National Park Service’s Inventory and Monitoring program to develop an invasive plant early detection …

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 …

Native Species Interactions With Red Brome: Suggestions For Burn-Area Revegetation, Scott R. Abella

Public Policy and Leadership Faculty Publications

In deserts, native perennial plants often actually facilitate the establishment of exotic annual grasses. One of our focal areas of research is to identify native species for use in revegetation projects that reduce the establishment of exotic annual grasses, or at least do not strongly facilitate exotic species establishment. An initial research effort involving a competition experiment of red brome with native species and a correlational field study of brome distribution among native perennial plants is in press with the journal Invasive Plant Science and Management.

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.

Progress In Strategic Research Areas, Scott R. Abella

Public Policy and Leadership Faculty Publications

Three years ago through conversations with resource managers, assessing the status of knowledge of the scientific literature, and our own interests, we set forth several strategic research areas that we believed would be timely for advancing Mojave Desert conservation and management.

Early Post-Fire Recovery On A Heavily Visited Mojave Desert Burn: Red Rock Canyon Near Las Vegas, Nevada, Scott R. Abella, E. Cayenne Engel, Christina L. Lund, Jessica E. Spencer

Fire Science Presentations

Wildfire has become widespread in southwestern USA deserts. In a record 2005 fire season in the Mojave Desert, for example, more than 385,000 hectares burned (Brooks and Matchett 2006). This burned area is approximately 3% of the entire Mojave Desert. Fueled in large part by exotic annual grasses, these fires burned desert ecosystems thought to have only burned infrequently historically. Burns now occupy significant portions of desert landscapes, posing prominent management challenges. Improving our understanding of plant recovery on desert burns is important for evaluating future fire hazard, whether natural revegetation will meet management objectives, and for planning active revegetation …

Post-Fire Plant Recovery In The Mojave And Sonoran Deserts Of Western North America, Scott R. Abella, Public Lands Institute, Department Of Environmental Studies, University Of Nevada, Las Vegas

Fire Science Presentations

Fire is thought to have been generally rare historically in the Mojave and Sonoran Deserts. However, invasion by exotic grasses (e.g., Schismus spp.) has increased fuel continuity, promoting fire in these deserts. Succession and recovery are not well understood processes in deserts, nonetheless for a novel disturbance like fire. In addition to helping build theories of desert succession and recovery, information on post-fire recovery has numerous practical implications (e.g., determining whether active revegetation is needed). Systematic reviews provide a means for obtaining literature using reproducible search criteria. This approach facilitates a balanced appraisal of available information, synthesizes scattered literature, and …

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 …

An Overview Of The Vegetation Research Program: Knowledge Services For Land Management, Scott R. Abella

Fire Science Presentations

• Provide knowledge services about the ecology and management of southwestern dryland ecosystems
• Specialize in working with resource managers to conduct applied research
• Conduct and provide research, monitoring, scientific literature synthesis, and technical assistance

Plant Community Response To Fire: A Chronosequence Study, Scott R. Abella, E. Cayenne Engel

Public Policy and Leadership Faculty Publications

Fires are becoming more prevalent events across the landscape in the southwestern US. Over the next several decades the already arid southwest is predicted to become warmer and drier, with longer summers, and an increase of “extreme” weather events such as lightening inducing thunderstorms. While the “hotter and drier” forecast may indicate less abundant plant life, and thus less available biomass for fuel, exotic invasive plant species are becoming more dominant across the landscape with increases in human travel and commerce. Exotic species (particularly many of the invasive grasses) are adding fuel for the fires to burn when the annuals …

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 …

Implications For Management Prioritization Of Exotic Annual Weed Monitoring Near Roadsides In The Eastern Mojave Desert, Usa, Donovan J. Craig, Jill E. Craig, Scott R. Abella, Public Lands Institute,

Vegetation Monitoring Presentations

Invasive exotic plants provide an unnatural conduit for fires in the Mojave Desert. For the last five years, roadside monitoring for exotic invasive species has been a common practice for documenting distributions in Clark County, Nevada (Abella et al., in press). Yet, studies have shown that weed relationships to road corridors differ depending upon the natural system (Hansen and Clevenger, 2005). In the Mojave Desert, it is unknown whether exotic species are limited to or even predominant along roadsides.

Compounding this uncertainty, fertile islands under shrubs are known to enhance conditions for many annuals (Thompson et al., 2005). Thus, a …

Response Of Sahara Mustard (Brassica Tournefortii) To Water Addition And Soil Disturbance, Alexis Suazo, Jessica E. Spencer, Scott R. Abella

Vegetation Monitoring Presentations

Invasive exotic species can have a significant impact on the structure, function, and diversity of ecological communities. Sahara mustard (Brassica tournefortii) is one of the top exotic invasive species spreading through the southwestern deserts of North America. In arid environments, it is well documented that species abundance is sensitive to rainfall (Beatly 1974, Ernest et al. 2000). In the Mojave Desert, winter precipitation can trigger massive germination events (Beatly 1974). As a winter annual, Sahara mustard may have a positive response to winter precipitation by germinating, growing, and reproducing before native annuals, monopolizing soil moisture and nutrients, and potentially changing …

Seeding Effectiveness And Natural Regeneration Of Mojave Desert Plant Communities After 2005-2006 Wildland Fires, E. Cayenne Engel, Scott R. Abella, Christina L. Lund

Fire Science Presentations

1) Assessment of BLM seeding effectiveness in mid-elevation burn where pre-burn plant communities were dominated by blackbrush, Joshua trees, and creosote.

2) Patterns driving fire recovery at the landscape scale:

• Link initial vegetation, environment, and soils
• Are there patterns that can be gleaned that can then be applied to management prescriptions?

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 …

Vegetation Re-Establishment Of Mojave Desert Plant Communities After 2005-2006 Wildland Fires, E. Cayenne Engel, Scott R. Abella

Fire Science Presentations

Examine biotic and abiotic patterns that determine vegetative regrowth after wildfires to better inform land managers about what to expect after fires and how to manage restoration efforts.

Seeding Effectiveness For Eight Mojave Desert Perennials After A 2005 Wildfire, E. Cayenne Engel, Scott R. Abella, Christina L. Lund

Fire Science Presentations

To assess BLM seeding effectiveness in a mid-elevation burn where pre-burn plant communities were dominated by blackbrush, Joshua trees, and creosote.

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, …