Evaluation Models Viewpoints on Educational and Human Services Evalu
Evaluation Models is an up-to-date revision of the classic text first published in 1983. Organized in three sections, the first includes a historical perspective on the growth of evaluation theory and practice and two comparative analyses of the various a
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Distinguishing natural from anthropogenic stress in plants: physiology, fluorescence and hyperspectral reflectance Julie C. Zinnert & Stephen M. Via & Donald R Young
Received: 12 March 2012 / Accepted: 2 August 2012 # Springer-Verlag (outside the USA) 2012
Abstract Background and Aims Explosives released into the environment from munitions production, processing facilities, or buried unexploded ordnances can be absorbed by surrounding roots and induce toxic effects in leaves and stems. Research into the mechanisms with which explosives disrupt physiological processes could provide methods for discrimination of anthropogenic and natural stresses. Our objectives were to experimentally evaluate the effects of natural stress and explosives on plant physiology and to link differences among treatments to changes in hyperspectral reflectance for possible remote detection. Methods Photosynthesis, water relations, chlorophyll fluorescence, and hyperspectral reflectance were measured following four experimental treatments (drought, salinity, trinitrotoluene and hexahydro1,3,5-trinitro-l,3,5-triazine) on two woody species. Principal Components Analyses of physiological and
hyperspectral results were used to evaluate the differences among treatments. Results Explosives induced different physiological responses compared to natural stress responses. Stomatal regulation over photosynthesis occurred due to natural stress, influencing energy dissipation pathways of excess light. Photosynthetic declines in explosives were likely the result of metabolic dysfunction. Select hyperspectral indices could discriminate natural stressors from explosives using changes in the red and near-infrared spectral region. Conclusions These results show the possibility of using variations in energy dissipation and hyperspectral reflectance to detect plants exposed to explosives in a laboratory setting and are promising for field application using plants as phytosensors to detect explosives contamination in soil. Keywords Drought . Salinity . RDX . TNT . Hyperspectral reflectance . Chlorophyll fluorescence . Photosynthesis
Responsible Editor: Juan Barcelo. J. C. Zinnert US Army ERDC, Fluorescence Spectroscopy Lab, 7701 Telegraph Road, Alexandria, VA 22315, USA J. C. Zinnert (*) : S. M. Via : D. R. Young Department of Biology, Virginia Commonwealth University, Richmond, VA 23284, USA e-mail: [email protected]
Introduction Plants have evolved numerous mechanisms to protect against excess light energy under natural stress conditions (Flexas et al. 2002; Flexas and Medrano 2002; Flexas et al. 2004); however, plants are not adapted to withstand the numerous anthropogenic disturbances to which they are often exposed. For example, millions
Plant Soil
of hectares in the United States alone are contaminated with various explosives (Winfield et al. 2004). Vegetative cover plays an important role in the movement of explosives through the soil. Since plants are rooted in soil substrate, they are considered indicators of the local environmen
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