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Physical Sciences and Mathematics Commons™

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University of Nevada, Las Vegas

Public Policy and Leadership Faculty Publications

2008

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Articles 1 - 12 of 12

Full-Text Articles in Physical Sciences and Mathematics

Managing Gambel Oak In Southwestern Ponderosa Pine Forests: The Status Of Our Knowledge, Scott R. Abella Nov 2008

Managing Gambel Oak In Southwestern Ponderosa Pine Forests: The Status Of Our Knowledge, Scott R. Abella

Public Policy and Leadership Faculty Publications

Gambel oak (Quercus gambelii) is a key deciduous species in southwestern ponderosa pine (Pinus ponderosa) forests and is important for wildlife habitat, soil processes, and human values. This report (1) summarizes Gambel oak’s biological characteristics and importance in ponderosa pine forests, (2) synthesizes literature on changes in tree densities and fire frequencies since Euro-American settlement in pine-oak forests, (3) suggests management prescriptions for accomplishing various oak management objectives (for example, increasing diameter growth or acorn production), and (4) provides an appendix containing 203 Gambel oak literature citations organized by subject. Nine studies that reconstructed Gambel oak density changes since settlement …

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Chronic Disease, Homeland Security, And Sailing To Where There Be Dragons, David M. Hassenzahl Oct 2008

Chronic Disease, Homeland Security, And Sailing To Where There Be Dragons, David M. Hassenzahl

Public Policy and Leadership Faculty Publications

The five papers in this special issue share the perspective that attitudes toward risk are strongly shaped by social context, and that understanding context can help us understand how risk decisions are made, and thereby how to make them better.

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New Book Chapter Reviewing Mojave Desert Revegetation Practices Is Forthcoming, Scott R. Abella Oct 2008

New Book Chapter Reviewing Mojave Desert Revegetation Practices Is Forthcoming, Scott R. Abella

Public Policy and Leadership Faculty Publications

I was invited to write a chapter for a forthcoming book on Arid Environments to be published by Nova Science Publishers. This book is anticipated to appear in late 2008 or early 2009, and we will be able to provide additional details about the entire book at that time. I co-authored our chapter on revegetation with Alice Newton, Vegetation Manager at Lake Mead National Recreation Area. We systematically reviewed 23 published studies of planting or seeding native species in the Mojave Desert.

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Gambel Oak Growth Forms: Management Opportunities For Increasing Ecosystem Diversity, Scott R. Abella Sep 2008

Gambel Oak Growth Forms: Management Opportunities For Increasing Ecosystem Diversity, Scott R. Abella

Public Policy and Leadership Faculty Publications

Gambel oak (Quercus gambelii) clones have several different growth forms in southwestern ponderosa pine (Pinus ponderosa) forests, and these growth forms each provide unique wildlife habitat and resource values. The purposes of this note are to review published growth-form classifications for Gambel oak, provide examples of ecological effects of different growth forms, and summarize management strategies for promoting desired growth forms. Four different growth-form classifications have been published, which generally recognize variants of three basic forms: shrubby thickets of small-diameter stems, pole-sized clumps, and large trees. These growth forms exemplify ecological and management tradeoffs. For example, shrubby forms provide browse …

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Changes In Gambel Oak Densities In Southwestern Ponderosa Pine Forests Since Euro-American Settlement, Scott R. Abella, Peter Z. Fule Sep 2008

Changes In Gambel Oak Densities In Southwestern Ponderosa Pine Forests Since Euro-American Settlement, Scott R. Abella, Peter Z. Fule

Public Policy and Leadership Faculty Publications

Densities of small-diameter ponderosa pine (Pinus ponderosa) trees have increased in southwestern ponderosa pine forests during a period of fire exclusion since Euro-American settlement in the late 1800s. However, less well known are potential changes in Gambel oak (Quercus gambelii) densities during this period in these forests. We reviewed published literature to summarize changes in oak density in ponderosa pine forests over the past 140 years and evaluated the possibility that large-diameter oaks have decreased in density. All nine studies examining oak density changes found that densities of small-diameter oaks have escalated. Increases ranged from 4- to more than 63-fold. …

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Estimating Soil Seed Bank Characteristics In Ponderosa Pine Forests Using Vegetation And Forest-Floor Data, Scott R. Abella, Judith D. Springer Sep 2008

Estimating Soil Seed Bank Characteristics In Ponderosa Pine Forests Using Vegetation And Forest-Floor Data, Scott R. Abella, Judith D. Springer

Public Policy and Leadership Faculty Publications

Soil seed banks are important for vegetation management because they contain propagules of species that may be considered desirable or undesirable for site colonization after management and disturbance events. Knowledge of seed bank size and composition before planning management activities facilitates proactive management by providing early alerts of exotic species presence and of abilities of seed banks to promote colonization by desirable species. We developed models in ponderosa pine (Pinus ponderosa) forests in northern Arizona to estimate the size and richness of mineral soil seed banks using readily observable vegetation and forestfloor characteristics. Regression models using three or fewer predictors …

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Plant Recruitment In A Northern Arizona Ponderosa Pine Forest: Testing Seed- And Leaf Litter- Limitation Hypotheses, Scott R. Abella Aug 2008

Plant Recruitment In A Northern Arizona Ponderosa Pine Forest: Testing Seed- And Leaf Litter- Limitation Hypotheses, Scott R. Abella

Public Policy and Leadership Faculty Publications

Seed availability and leaf litter limit plant establishment in some ecosystems. To evaluate the hypothesis that these factors limit understory plant recruitment in Pinus ponderosa forests, I conducted a seeding and litter removal experiment at six thinned sites in the Fort Valley Experimental Forest, northern Arizona. Experimental seeding of four native species (Penstemon virgatus, Erigeron formosissimus, Elymus elymoides, and Festuca arizonica) and raking of litter occurred in 2005. Seeding resulted in a substantial recruitment of 14 to 103 seedlings/m2 (1 to 10/ft2) one month after seeding for two species (P. virgatus and E. elymoides), but these densities subsequently declined by …

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We're Moving Into Unlv's New Science And Engineering Building, Scott R. Abella Jul 2008

We're Moving Into Unlv's New Science And Engineering Building, Scott R. Abella

Public Policy and Leadership Faculty Publications

Our research group is one of the few select groups that is moving into the new, $113-million UNLV Science and Engineering Building. The building is exclusively dedicated to research, and its four stories contain 200,000 square feet of research laboratories, faculty offices, and auditorium space for research symposia. Located on North Campus just northeast of the Biology Building, the building is anticipated to obtain LEED (Leadership in Energy and Environmental Design) certification.

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Fire Effects On Gambel Oak In Southwestern Ponderosa Pine-Oak Forests, Scott R. Abella, Peter Z. Fule Apr 2008

Fire Effects On Gambel Oak In Southwestern Ponderosa Pine-Oak Forests, Scott R. Abella, Peter Z. Fule

Public Policy and Leadership Faculty Publications

Gambel oak (Quercus gambelii) is ecologically and aesthetically valuable in southwestern ponderosa pine (Pinus ponderosa) forests. Fire effects on Gambel oak are important because fire may be used in pine-oak forests to manage oak directly or to accomplish other management objectives. We used published literature to: (1) ascertain historical fire regimes in pine-oak forests, (2) discern prescribed burning effects on Gambel oak survival and diameter growth, and (3) provide suggestions for using fire to manage oak. Frequent fire is part of Gambel oak’s historical environment, as historical fire return intervals often averaged less than 10 years in pine-oak forests. More …

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Plant Community Response To Fire: A Chronosequence Study, Scott R. Abella, E. Cayenne Engel Apr 2008

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 …

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Fire History And Forest Structural Change In The Spring Mountains, Scott R. Abella Jan 2008

Fire History And Forest Structural Change In The Spring Mountains, Scott R. Abella

Public Policy and Leadership Faculty Publications

Since early 2006 we have been working to develop a partnership with the Spring Mountains District of the Humboldt-Toiyabe National Forest to provide science support for understanding fire history and forest structural changes in support of ecologically based management strategies. We teamed up with the Ecological Restoration Institute (ERI) at Northern Arizona University and the University of Arizona Tree Ring Lab to deliver a workshop on March 6, 2008 at the interagency office in Las Vegas, Nevada. On September 16-18, we again teamed up with colleagues at ERI to conduct a preliminary field assessment of forest change at 10 sites …

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Opportunities For New Collaborative Projects, Scott R. Abella, Jill E. Craig Jan 2008

Opportunities For New Collaborative Projects, Scott R. Abella, Jill E. Craig

Public Policy and Leadership Faculty Publications

The Research Group is currently working in successful partnerships with Lake Mead National Recreation Area, BLM Las Vegas, Desert National Wildlife Refuge (U.S. Fish and Wildlife Service), Joshua Tree National Park, and in collaboration with the Ecological Restoration Institute, the U.S. Forest Service (Region 3).

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