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Articles 1 - 14 of 14

Full-Text Articles in Life Sciences

Ecological And Organic Life Safety Concerns Of Hfo-1234yf, Alberni V. Ruiz Aug 2017

Ecological And Organic Life Safety Concerns Of Hfo-1234yf, Alberni V. Ruiz

STAR (STEM Teacher and Researcher) Presentations

While at NOAA my research was directed by the inquiry of whether or not HFO-1234yf, a new compound being introduced into coolant system and replacing greenhouse gases HFC, is harmful to organic life. Using the computer program Matlab I was able to develop figures that represented the concentration of HFO-1234yf (HFO) in 12 different tower locations throughout the country. Comparing and contrasting concentrations of this HFO compound at each site led me to the question the possible harmful side effects this compound could bring to organic life due to the fact that concentration levels are increasing, with one factor being ...


Citizen Science Sensor Development - Smap | Soil Moisture Active Passive, Hagop Hovhannesian Aug 2016

Citizen Science Sensor Development - Smap | Soil Moisture Active Passive, Hagop Hovhannesian

STAR (STEM Teacher and Researcher) Presentations

“Detailed monitoring of soil moisture provides a view of how our whole Earth system works.”

The Soil Moisture Active Passive (SMAP) satellite mission was launched in January 2015; its main purpose is to acquire global measurements of soil moisture. SMAP partnered with the GLOBE program (Global Learning and Observations to Benefit the Environment), which is an international program where students collect environmental variables in a scientifically methodical way. SMAP readings and maps have various uses in various fields, which include monitoring drought, predicting floods, assisting in crop productivity, and linking water, energy and carbon cycles. The goal of this project ...


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 ...


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.