29,331 research outputs found
The Oxford Handbook of Environmental History edited by Andrew C. Isenberg
Review of Andrew C. Isenberg\u27s The Oxford Handbook of Environmental History
Examining the Effects of Urbanization on Soil Characteristics in Portland, Oregon\u27s Forest Park
Studies by Dr. Nancy Broshot in Forest Park, an urban forest in Portland, Oregon, have shown high tree mortality and low concomitant recruitment. Lichen surveys conducted in 2013 revealed a shift in the lichen community to one typified by nitrogen-tolerant and nitrogen-thriving species. To ascertain if nitrogenous air pollution could be a cause of low recruitment, soil samples were collected from 32 previously established study sites in Forest Park and at 3 control sites established in 2014 in the Mount Hood National Forest, a rural forest in the Clackamas River Basin. At each site, the soil O horizon depth was measured, and soil samples were collected from the A horizon, which were subsequently dried and sieved. The resulting soil samples were analyzed at the Central Analytical Laboratory at OSU to determine carbon and nitrogen concentration, as well as carbon to nitrogen ratios. The results of the soil analysis show that soil samples from the control sites had significantly higher concentrations of carbon and a significantly higher carbon to nitrogen ratio than the sites in Forest Park. These findings are quite exciting and suggest a number of possible avenues for further research
Where Have All the Young Trees Gone? A Big Picture Look at the Lack of Seedlings and Saplings in Urban Forests
We take a big picture look at the lack of seedlings, saplings and young trees in urban forests using our research in Forest Park in Portland, Oregon. Broshot, who measured vegetation at 25 sites in Forest Park, recorded significantly fewer live seedlings, saplings and young trees and significantly more dead seedlings, saplings and young trees in 2003 than in 1993. The percent mortality of western red cedar seedlings that were planted at 9 sites in Forest Park in 2005 ranged from less than 5% to over 70%. Investigations into the cause of seedling death has discounted predation by deer, elk or invertebrates, leaf disease, soil moisture, site aspect, and light as factors. The site with the highest mortality is located directly above the St John’s Bridge, suggesting air pollution. More recent work with lichens has provided evidence that nitrogen deposition related to air pollution may be the cause. We outline our past work and report preliminary results from our 2012 lichen survey analysis to support our hypothesis that pollution is a cause of the lack of young trees
Soil Nitrogen and Carbon in Urban and Rural Forests
Previous work by Dr. Nancy Broshot has revealed high tree mortality and low recruitment (new seedlings) in an urban forest (Forest Park in Portland, Oregon). A series of lichen surveys in 2013 showed the lichen community has shifted to one dominated by lichens tolerant of and thriving on high nitrogen levels. To ascertain if nitrogenous air pollution could be a cause of low recruitment, we measured the level of nitrogen and carbon in the soil at 32 sites in Forest Park (24 permanent sites and 8 conifer recruitment sites). We also added 3 control sites in the Mount Hood National Forest above Estacada along an apparent air pollution gradient. The plant community was measured at three transects at each control site and lichen surveys were conducted. Four soil samples were collected at each site, dried at 35oC until weight remained constant and sieved to reduce to fine soil particle size. The samples will be assessed using an elemental analyzer to determine total nitrogen and total carbon
The impact of information and communication technology on family carers of older people and professionals in Sweden
Government policy in Sweden, as in other developed countries, pays increasing attention as to how best to support the family carers of older people. New and innovative means of support, such as information and communication technology, are emerging. This paper explores the perceived benefits of, and barriers to, information technology as a means of supporting family carers of older people.
Following a brief overview of the care-giving literature, with particular reference to the Swedish context, interview and questionnaire data collected from 34 families who took part in the Swedish ACTION project are used to explore the role of user-friendly information and communication technology to inform and enable family carers of older people to exercise choice, to care more effectively and to work in partnership with professionals. Interview data from two groups of professionals that utilised ACTION are also examined to throw light on its potential benefits for both carers and professionals. Consideration is given to the barriers to using information technology, and to identifying those carers most likely to benefit. Areas for further development are the need for practitioners' education and a wider range of programmes to address carers' diverse needs. Clearly, lessons learned from the Swedish project have wider relevance, given that new forms of support are being developed in most technically advanced countries
Writing about accessibility
In this forum we celebrate research that helps to successfully bring the benefits of computing technologies to children, older adults, people with disabilities, and other populations that are often ignored in the design of mass-marketed products.
--- Juan Pablo Hourcade, Editor
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Radar signal return from near-shore surface and shallow subsurface features, Darien Province, Panama
The AN/APQ-97 radar imagery over eastern Panama is analyzed. The imagery was directed toward extraction of geologic and engineering data and the establishment of operational parameters. Subsequent investigations emphasized landform identification and vegetation distribution. The parameters affecting the observed return signal strength from such features are considered. Near-shore ocean phenomena were analyzed. Tidal zone features such as mud flats and reefs were identified in the near range, but were not detectable in the far range. Surface roughness dictated the nature of reflected energy (specular or diffuse). In surf zones, changes in wave train orientation relative to look direction, the slope of the surface, and the physical character of the wave must be considered. It is concluded that the establishment of the areal extent of the tidal flats, distributary channels, and reefs is practical only in the near to intermediate range under minimal low tide conditions
Risk aversion and bidding theory
Theory of bidding behavior and formation of bidding model with risk aversio
CHANGE AND CONFLICT IN LAND AND WATER USE: RESOURCE VALUATION IN CONFLICT RESOLUTION AMONG COMPETING USERS
Resource /Energy Economics and Policy,
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