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Full-Text Articles in Physical Sciences and Mathematics

Renewable Energy Projects In Southwestern Deserts – Update On Our Involvement, Scott R. Abella Jul 2010

Renewable Energy Projects In Southwestern Deserts – Update On Our Involvement, Scott R. Abella

Public Policy and Leadership Faculty Publications

Like many in the conservation field, we have a good understanding of the urgent need for alternative energy sources, but also of the negative environmental tradeoffs of placing renewable energy developments on vast tracts of public lands in southwestern deserts as currently envisioned. We also understand political and economic reasons, good or bad, for not doing some obvious things that make sense for renewable energy like placing solar arrays on building tops in cities, within multi-use contexts such as crops, and on already impacted land when alternative energy projects (right or wrong) are to be placed on public land.


Trying To Beat The Brome: Understanding Establishment Thresholds And Choosing Competitive Native Species At Parashant National Monument, Scott R. Abella, E. Cayenne Engel Jan 2010

Trying To Beat The Brome: Understanding Establishment Thresholds And Choosing Competitive Native Species At Parashant National Monument, Scott R. Abella, E. Cayenne Engel

Public Policy and Leadership Faculty Publications

Desert fires fueled by exotic grasses like the omnipresent red brome (Bromus rubens) can be intense and cause widespread mortality of native vegetation. Native desert scrub communities such as those dominated by blackbrush (Coleogyne ramosissima) do not readily reestablish after fire (Abella 2009) and may even become more abundant in the post-burn landscape initiating a fire cycle that occurs at a greater frequency than the recovery time of the long-lived desert perennial community.


Native Species Interactions With Red Brome: Suggestions For Burn-Area Revegetation, Scott R. Abella Jan 2010

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.


Synthesis Completed Of Post-Fire Recovery Of Native Perennials In The Mojave, Sonoran Deserts, Scott R. Abella Jul 2009

Synthesis Completed Of Post-Fire Recovery Of Native Perennials In The Mojave, Sonoran Deserts, Scott R. Abella

Public Policy and Leadership Faculty Publications

Literature syntheses to develop status of knowledge reports are important to integrate and summarize the scattered scientific literature on a particular topic. The isolation and fragmentation of scientific literature on a topic is not necessarily a shortcoming of science. Rather, it is simply a consequence of having (1) research published in a diverse array of journals, (2) articles build on each other and therefore articles relevant to a particular topic can be published decades apart, and (3) funding virtually impossible to secure to do these periodic assessments of what we know and don’t know (competitive science grants want researchers to …


Progress In Strategic Research Areas, Scott R. Abella Jan 2009

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.


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 …


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. …


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 …


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 …