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Full-Text Articles in Life Sciences

Effects Of Habitat Restoration On Soil Retention On Santa Rosa Island, Michael Perez, Kathryn Mceachern, Ken Niessen Jan 2017

Effects Of Habitat Restoration On Soil Retention On Santa Rosa Island, Michael Perez, Kathryn Mceachern, Ken Niessen

STAR (STEM Teacher and Researcher) Presentations

Ranching began on Santa Rosa Island in the 1840’s, consequently introducing nonnative megafauna that put novel selective grazing pressures on endemic plant species. Their movement patterns also altered substrate integrity as the land became denuded of any stabilizing vegetation. Dense groves of island oak (Q. tomentella) are known to aid in sediment deposition and retention. The groves also function to collect water during periods of intense fog common to the island. This experiment sought to determine whether sediment is being lost or deposited on a ridge in the middle of the island containing a grove of Q. tomentella. The ...


Weights And Balances: Integrating Models For Prevention And Response To Southern California Offshore Oil Spills, Carmen Watts Clayton, Amoret Bunn Oct 2016

Weights And Balances: Integrating Models For Prevention And Response To Southern California Offshore Oil Spills, Carmen Watts Clayton, Amoret Bunn

STAR (STEM Teacher and Researcher) Presentations

Licensing offshore oil and gas reserves in the United States waters are overseen by the U.S. Department of the Interior’s Bureau of Safety and Enforcement (BSEE). The licensing application includes planning for any worst-case oil spill scenario between BSEE and the applicant based on lessons learned from historic offshore spills such as the Deepwater Horizon (2010), Exxon Valdez (1989), and the Union Oil Platform Blowout (1969). The process for planning to respond to oil spills involves coordination with multiple agencies, trustees, and stakeholders to ensure that oil spill responses consider multiple factors, including ecologically sensitive species, commercial transportation ...


Testing Predictions Used To Build An Agrivoltaics Installation On A Small-Scale Educational Model, Katie Kinney, Rebecca Minor, Greg Barron-Gafford Oct 2016

Testing Predictions Used To Build An Agrivoltaics Installation On A Small-Scale Educational Model, Katie Kinney, Rebecca Minor, Greg Barron-Gafford

STAR (STEM Teacher and Researcher) Presentations

Models are valuable tools for explaining and testing systems. Small-scale models can be especially useful for educational purposes. For models to be useful, they have to accurately depict the larger system that they are describing. A novel man-made system, known as an agrivoltaic structure, is being constructed at Biosphere 2 near Oracle, Arizona. The word agrivoltaic is a combination of agriculture and photovoltaics, or solar farming. My research involved creating a small-scale version of this system for educational purposes. The model of this system tested two predictions: that plants will grow better in the shade of a panel and that ...


The Effect Of Drought On Stomatal Conductance In The Biosphere 2 Rainforest, Justin Gay, Joost Van Haren Aug 2015

The Effect Of Drought On Stomatal Conductance In The Biosphere 2 Rainforest, Justin Gay, Joost Van Haren

STAR (STEM Teacher and Researcher) Presentations

Drought is a major climate change concern for the Earth’s rainforests; however little is currently known about how these forests and individual plants will respond to water stress. At the individual level, the ability of plants to regulate their stomatal conductance is an important preservation mechanism that helps to cool leaves, regulate water loss, and uptake carbon dioxide. At the ecosystem level, transpiration in rain forests is a major contributor to the feedback loop that returns moisture to the atmosphere for continued rains. Nearly 60% of atmospheric moisture in the Amazon rain forests has been traced back to origins ...


Radiocarbon Isotopic Classification Of Deep Tropical Forest Soils, Brooke Butler, Karis J. Mcfarlane, Jennifer Pett-Ridge, Katherine A. Heckman Aug 2015

Radiocarbon Isotopic Classification Of Deep Tropical Forest Soils, Brooke Butler, Karis J. Mcfarlane, Jennifer Pett-Ridge, Katherine A. Heckman

STAR (STEM Teacher and Researcher) Presentations

Tropical forest soils have an important role in global carbon (C) stocks. Small changes in the cycling of C could drastically affect atmospheric carbon dioxide (CO2) concentrations and active cycling of carbon in a forest community. Currently, little is understood of how tropical forest soils will respond to the increasing global temperatures. To examine the effects of warming/ drought on losses of older versus younger soil C pools, we implemented radiocarbon (14C) isotopic characterization of various soil plot samples and depths from the Luquillo Experimental Forest, Puerto Rico. 14C was measured using Accelerated Mass Spectrometry (AMS) from catalytically condensed carbon ...


Evaluation Of Anthropogenic Marine Debris And Sargassum Fluitans And Its Potential Impact On Sea Turtle Hatchlings At Sandy Point National Wildlife Refuge, Christina Macmillan Aug 2015

Evaluation Of Anthropogenic Marine Debris And Sargassum Fluitans And Its Potential Impact On Sea Turtle Hatchlings At Sandy Point National Wildlife Refuge, Christina Macmillan

STAR (STEM Teacher and Researcher) Presentations

Anthropogenic debris, particularly plastic, has become a significant threat for marine species with the increased use of plastics over the years. Marine birds and sea turtles, mostly green, loggerhead and leatherback turtles, are especially vulnerable to mistaking plastic debris for food and ingesting it. There has been a rise in the incidence of turtles having plastic fragments in their GI tracts; even small amounts of plastic may have major long-term health and reproductive effects. On the nesting beaches, both adults and hatchlings may become entangled in debris or have trouble navigating around beach debris during their crawl to the sea ...


Light Pollution Research Through Citizen Science, John Kanemoto Aug 2014

Light Pollution Research Through Citizen Science, John Kanemoto

STAR (STEM Teacher and Researcher) Presentations

Light pollution (LP) can disrupt and/or degrade the health of all living things, as well as, their environments. The goal of my research at the NOAO was to check the accuracy of the citizen science LP reporting systems entitled: Globe at Night (GaN), Dark Sky Meter (DSM), and Loss of the Night (LoN). On the GaN webpage, the darkness of the night sky (DotNS) is reported by selecting a magnitude chart. Each magnitude chart has a different density/number of stars around a specific constellation. The greater number of stars implies a darker night sky. Within the DSM iPhone ...


Growing Conditions For Algae, Angeles Mora, Tamar Melkonian, Alejandro Calderon-Urrea Aug 2014

Growing Conditions For Algae, Angeles Mora, Tamar Melkonian, Alejandro Calderon-Urrea

STAR (STEM Teacher and Researcher) Presentations

With the growing demands of water in California and the increasing cost of fossil fuels to operate water-cleaning equipment, Algae was cultivated in different concentrations of Nitrogen, Phosphorus, and Potassium (NPK) during different trails to identify the best growing conditions for the removal water contaminates. Before testing algae in waste water, the Algae: Dunaliella Primolecta, Chlorella Vulgaris, and Scenedesmus Dimorphus were cultivated in four different media containing distilled water and plant vitamins. The different mediums used include: Orchid Grow More (20-20-20), Miracle Grow (30-10-10), Murashige & Skoog, and Orchid Bloom Boster (11-35-15). As a result of the investigation, the algae, Scenedesmus ...


Salinity And Temperature Distribution Of Jellyfish In The San Francisco Estuary, Trisha Huynh, Brooke Bemowski, Lindsay Sullivan, Wim Kimmerer Aug 2014

Salinity And Temperature Distribution Of Jellyfish In The San Francisco Estuary, Trisha Huynh, Brooke Bemowski, Lindsay Sullivan, Wim Kimmerer

STAR (STEM Teacher and Researcher) Presentations

Jellyfish are generally characterized by their jelly-like bodies and internal lining (two tissue layers). They found both in the phylum Ctenophora and the phylum Cnidaria. Ctenophores differ from cnidarians primarily due to the rows of “combs”, or cilia, which are used for transportation. Additionally, ctenophores possess sticky cells while cindarians possess stinging cells. Jellyfish depend on zooplankton (small floating aquatic animals) as a food source; as a result, they are potential competitors and predators to plankton-eating fish and may negatively impact fish populations.

As recently as 1950, jellyfish have entered the San Francisco Bay from the Mediterranean Sea (probably in ...


Zooplankton Trophic Ecology In The San Francisco Estuary During Summer As Determined By Stable Isotope Analysis, Kyla Bradylong, Steven Westbrook, Julien Moderan, Wim Kimmerer Aug 2013

Zooplankton Trophic Ecology In The San Francisco Estuary During Summer As Determined By Stable Isotope Analysis, Kyla Bradylong, Steven Westbrook, Julien Moderan, Wim Kimmerer

STAR (STEM Teacher and Researcher) Presentations

Declines in the abundance of several pelagic fish species in the upper San Francisco Estuary have prompted investigation into food web interactions within the estuary and delta (the lower Sacramento and San Joaquin Rivers). This area is characterized by low primary production and pelagic food webs much longer and reticulated than previously thought, implying low efficiency in the energy transfers from primary producers to planktivorous fish. We determined the carbon and nitrogen stable isotope (SI) composition of zooplankton samples collected monthly between June 2012 and February 2013 at eight stations along the salinity gradient. As consumers SI composition reflects that ...


Juxtaposing Nasa’S Aeronet Aod With Carb Pm Data Over The San Joaquin Valley To Facilitate Multi-Angle Imaging Spectroradiometer (Misr) Pm Pollution Research, John Kanemoto Aug 2013

Juxtaposing Nasa’S Aeronet Aod With Carb Pm Data Over The San Joaquin Valley To Facilitate Multi-Angle Imaging Spectroradiometer (Misr) Pm Pollution Research, John Kanemoto

STAR (STEM Teacher and Researcher) Presentations

Airborne particulate matter (PM) has been shown to increase the risk for asthma, chronic bronchitis, cardiopulmonary complications, and respiratory cell membrane damage/infection/leakage. PM levels are currently analyzed from two perspectives: stationary land-based monitoring (LBM) sites and total Aerosol Optical Depth (AOD) atmospheric column measurements. Both perspectives often leave miles of space between measuring locations and will have a continually increasing cost from introducing/maintaining sites. The Multi-angle Imaging SpectroRadiometer (MISR) satellite team hopes to begin investigating/archiving PM levels comprehensively via inputting MISR AOD measurements into a function/model which predicts the amount of ground level PM.

In ...


Optimizing Electrode Design For Microbial Fuel Cells Used For Wastewater Treatment, Lindsay Nichols, John A. Hogan Jan 2013

Optimizing Electrode Design For Microbial Fuel Cells Used For Wastewater Treatment, Lindsay Nichols, John A. Hogan

STAR (STEM Teacher and Researcher) Presentations

Microbial fuel cells (MFC) utilize bacteria to generate an electrical current that can be used in the decomposition of sludge and human urine. In a MFC there is an anode (for oxidation of organic compounds), cathode (reduction of oxygen or carbon dioxide), and a proton exchange membrane (PEM, allows protons to migrate); reduction-oxidation reactions between the anode and cathode produce a measurable current. Bacteria that are found in sludge can be used to produce electrons in a voltaic cell, but optimizing conditions for harnessing the energy is crucial to making a MFC efficient. Research has shown that the ratios of ...


Structure And Development Of Pitch Canker Infected Monterey Pine Stands At Ano Nuevo, California, Douglas D. Piirto, Sauli Valkonen Jul 2005

Structure And Development Of Pitch Canker Infected Monterey Pine Stands At Ano Nuevo, California, Douglas D. Piirto, Sauli Valkonen

Natural Resources Management and Environmental Sciences

The sustainability of indigenous Monterey pine (Pinus radiata D. Don)at Ano Nuevo stands in the central coast of California was examined. The foremost management objective in these stands is to establish and maintain stand structures that ensure a sustainable presence of the species in terms of uneven-aged management. The major threats are the proliferation of shade-tolerant tree species and the pitch canker ( Fusarium circinatum) disease. The study was based on data from 17 systematically placed sample plots, measured once, in one stand with a very high degree of variation in stand structure and species composition. The results indicated that ...


Fire Regimes And Resultant Forest Structure In Native Ano Nuevo Monterey Pine (Pinus Radiata) Forest, California, Scott L. Stephens, Douglas D. Piirto, Domenico F. Caramagno Jul 2004

Fire Regimes And Resultant Forest Structure In Native Ano Nuevo Monterey Pine (Pinus Radiata) Forest, California, Scott L. Stephens, Douglas D. Piirto, Domenico F. Caramagno

Natural Resources Management and Environmental Sciences

Native Monterey pine (Pinus radiata) forests occur in five populations on the west coast of North America. High severity fire has been reported to be the main disturbance agent that initiates seedling establishment for this species. To investigate the impacts of fire in this ecosystem, age structure and fire history data were collected from the native Ano Nuevo Monterey pine forest near Santa Cruz California. Stump cross-sections were removed from 10 randomly placed openings, and each was dated to determine tree age and fire history. Average mean fire return intervals were 11.2-20.1 y. Fifty-one percent of the Monterey ...


An Ecological Basis For Managing Giant Sequoia Ecosystems, Douglas D. Piirto, Robert R. Rogers Jul 2002

An Ecological Basis For Managing Giant Sequoia Ecosystems, Douglas D. Piirto, Robert R. Rogers

Natural Resources Management and Environmental Sciences

A strategy for management of giant sequoia groves is formulated using a conceptual framework for ecosystem management recently developed by Region Five of the USDA Forest Service. The framework includes physical, biological, and social dimensions. Environmental indicators and reference variability for key ecosystem elements are discussed in this paper. The selected ecosystem elements include: 1) attitudes, beliefs, and values; 2) economics and subsistence; 3) stream channel morphology; 4) sediment; 5) water; 6) fire; 7) organic debris; and 8) vegetation mosaic. Recommendations are made for the attributes of environmental indicators that characterize these elements. These elements and associated indicators will define ...


Communicating The Role Of Science In Managing Giant Sequoia Groves, Douglas D. Piirto, Robert R. Rogers, Mary C. Bethke May 1997

Communicating The Role Of Science In Managing Giant Sequoia Groves, Douglas D. Piirto, Robert R. Rogers, Mary C. Bethke

Natural Resources Management and Environmental Sciences

Management of giant sequoia groves has been and continues to be a hotly debated issue. The debate has reached Congress, with all parties seeking resolution as to what constitutes an ecologically and publicly acceptable management approach. Determining the correct management approach and communicating that approach to the general public is the crux of the problem. Emerging concepts and principles of forest ecosystem management may provide a mechanism to seek resolution of these management problems related to giant sequoia. The Memorandum of Understanding between the members of the recently formed Giant Sequoia Ecology Cooperative provided the impetus for the development of ...


Efficacy Of Herbicide Application Methods Used To Control Tanoak (Lithocarpus Densiflorus) In An Uneven-Aged Coast Redwood Management Context, Douglas D. Piirto, Brenda Smith, Eric K. Huff, Scott T. Robinson Mar 1996

Efficacy Of Herbicide Application Methods Used To Control Tanoak (Lithocarpus Densiflorus) In An Uneven-Aged Coast Redwood Management Context, Douglas D. Piirto, Brenda Smith, Eric K. Huff, Scott T. Robinson

Natural Resources Management and Environmental Sciences

Three methods of tanoak (Lithocarpus densiflorus [Hook. & Arn.] Rehd.) control involving the application of the amine or ester form of triclopyr were evaluated in this coast redwood uneven-aged forest management study of herbicides. A cut-stump application with the amine form of triclopyr (Garlon 3A), frill cut with the amine form of triclopyr, basal-bark (outer surface) with the ester form of triclopyr (Garlon 4), and an untreated control were replicated three times. The tanoak control results in Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) and/ or coast redwood (Sequoia sempervirens [D. Don] Endl.) predominated stands obtained in earlier studies in northern California and ...


Giant Sequoia Insect, Disease, And Ecosystem Interactions, Douglas D. Piirto Jun 1992

Giant Sequoia Insect, Disease, And Ecosystem Interactions, Douglas D. Piirto

Natural Resources Management and Environmental Sciences

Individual trees of giant sequoia (Sequoia gigantea [Lindl.] Decne.) have demonstrated a capacity to attain both a long life and very large size. It is not uncommon to find old-growth giant sequoia trees in their native range that are 1,500 years old and over 15 feet in diameter at breast height. The ability of individual giant sequoia trees to survive over such long periods of time has often been attributed to the species high resistance to disease, insect, and fire damage. Such a statement, however, is a gross oversimplification, given broader ecosystem and temporal interactions. For example, why isn ...


Cost-Effective Wilderness Fire Management: A Case Study In Southern California, Christian A. Childers, Douglas D. Piirto Mar 1990

Cost-Effective Wilderness Fire Management: A Case Study In Southern California, Christian A. Childers, Douglas D. Piirto

Natural Resources Management and Environmental Sciences

Federal wilderness fire management policies have been scrutinized since the catastrophic fires in the Greater Yellowstone Area in 1988. While wilderness tire management objectives are still aimed at recreating natural fire regimes, all USDA Forest Service fire management programs must be cost-effective. Since current Forest Service economic analyses do not fully represent the value of fire to wilderness, a cost-effectiveness analysis was developed to compare wilderness fire management options. The analytical procedure is briefly reviewed, illustrated through a southern California case study and case study results are discussed. These results suggest that containment of some tires may be more cost-effective ...


Cost-Effective Fire Management For Southern California's Chaparral Wilderness: An Analytical Procedure, Chris A. Childers, Douglas D. Piirto Oct 1988

Cost-Effective Fire Management For Southern California's Chaparral Wilderness: An Analytical Procedure, Chris A. Childers, Douglas D. Piirto

Natural Resources Management and Environmental Sciences

Fire management has always meant fire suppression to the managers of the chaparral covered southern California National Forests. Today, Forest Service fire management programs must be cost effective, while wilderness fire management objectives are aimed at recreating natural fire regimes. A cost-effectiveness analysis has been developed to compare fire management options for meeting these objectives in California's chaparral wilderness. This paper describes the analytical procedure using examples from a study currently being conducted for the Los Padres National Forest, and discusses some preliminary results.


Wood Of Giant Sequoia: Properties And Unique Characteristics, Douglas D. Piirto May 1985

Wood Of Giant Sequoia: Properties And Unique Characteristics, Douglas D. Piirto

Natural Resources Management and Environmental Sciences

Wood properties of giant sequoia (Sequoia gigantea [Lindl.] Decne.) were compared with those for other coniferous tree species. Wood properties such as specific gravity, various mechanical properties, extractive content, and decay resistance of young-growth giant sequoia are comparable to or more favorable than those of coast redwood (Sequoia sempervirens [D. Don] Endl.). It is recommended that giant sequoia be considered for planting stock in managed production forests to increase future supplies of wood having the characteristics so highly valued in coast redwood and other decay-resistant species


Poria Incrassata In Giant Sequoia, Douglas D. Piirto, John R. Parmeter, W. Wayne Wilcox Jan 1977

Poria Incrassata In Giant Sequoia, Douglas D. Piirto, John R. Parmeter, W. Wayne Wilcox

Natural Resources Management and Environmental Sciences

No abstract provided.