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Full-Text Articles in Physical Sciences and Mathematics

Productivity, Absorbed Photosynthetically Active Radiation, And Light Use Efficiency In Crops: Implications For Remote Sensing Of Crop Primary Production, Anatoly A. Gitelson, Yi Peng, Timothy J. Arkebauer, Andrew E. Suyker Feb 2015

Productivity, Absorbed Photosynthetically Active Radiation, And Light Use Efficiency In Crops: Implications For Remote Sensing Of Crop Primary Production, Anatoly A. Gitelson, Yi Peng, Timothy J. Arkebauer, Andrew E. Suyker

Papers in Natural Resources

Vegetation productivity metrics such as gross primary production (GPP) at the canopy scale are greatly affected by the efficiency of using absorbed radiation for photosynthesis, or light use efficiency (LUE). Thus, close investigation of the relationships between canopy GPP and photosynthetically active radiation absorbed by vegetation is the basis for quantification of LUE. We used multiyear observations over irrigated and rainfed contrasting C3 (soybean) and C4 (maize) crops having different physiology, leaf structure, and canopy architecture to establish the relationships between canopy GPP and radiation absorbed by vegetation and quantify LUE. Although multiple LUE definitions are reported in the literature, …


Simultaneous Cr(Vi) Reduction And Methylene Blue Removal By Bacillus Sp. Jh2-2 Isolated From Mining Site Soil, Jaehong Shim, Patrick Shea, Jeong-Muk Lim, Byung-Taek Oh Jan 2015

Simultaneous Cr(Vi) Reduction And Methylene Blue Removal By Bacillus Sp. Jh2-2 Isolated From Mining Site Soil, Jaehong Shim, Patrick Shea, Jeong-Muk Lim, Byung-Taek Oh

Papers in Natural Resources

A Bacillus sp. strain (JH2-2), isolated from soil at an abandoned mine site, reduced Cr(VI) to Cr(III) under aerobic conditions. At pH 7, the strain reduced essentially all of the Cr(VI) in M9 minimal medium to Cr(III) at initial concentrations ≤50 mg Cr(VI) L−1 within 100 h. The X-ray diffraction pattern of the Cr(III) precipitate matched chromium (III) hydrogen phosphate (CrH2P3O10∙2H2O). The JH2-2 strain showed high tolerance to other heavy metal (loid)s, with minimal inhibitory concentrations in liquid medium of (mg L−1): As (500), Cd (100), Cu (350), Ni (300), Zn …


A Combined Chemical And Biological Approach To Transforming And Mineralizing Pahs In Runoff Water, Chainarong Sakulthaew, Steve D. Comfort, Chanat Chokejaroenrat, Clifford Harris, Xu Li Jun 2014

A Combined Chemical And Biological Approach To Transforming And Mineralizing Pahs In Runoff Water, Chainarong Sakulthaew, Steve D. Comfort, Chanat Chokejaroenrat, Clifford Harris, Xu Li

Papers in Natural Resources

The water quality of lakes, rivers and streams associated with metropolitan areas is declining from increased inputs of urban runoff that contain polycyclic aromatic hydrocarbons (PAHs). Our objective was to transform and mineralize PAHs in runoff using a combined chemical and biological approach. Using 14C-labeled phenanthrene, 14C-benzo(a)pyrene and a mixture of 16 PAHs, we found that ozone transformed all PAHs in a H2O matrix within minutes but complete mineralization to CO2 took several weeks. When urban runoff water (7.6 mg C L−1) replaced H2O as the background matrix, some delays in degradation rates …


Data-Driven Diagnostics Of Terrestrial Carbon Dynamics Over North America, Jingfeng Xiao, Scott V. Ollinger, Steve Frolking, George Hurtt, David Y. Hollinger, Kenneth J. Davis, Yude Pan, Xiaoyang Zhang, Feng Deng, Jiquan Chen, Dennis D. Baldocchi, Beverly E. Law, M. Altaf Arain, Ankur R. Desai, Andrew D. Richardson, Ge Sun, Brian Amiro, Hank Margolis, Lianhong Gu, Russell L. Scott, Peter D. Blanken, Andrew E. Suyker Jan 2014

Data-Driven Diagnostics Of Terrestrial Carbon Dynamics Over North America, Jingfeng Xiao, Scott V. Ollinger, Steve Frolking, George Hurtt, David Y. Hollinger, Kenneth J. Davis, Yude Pan, Xiaoyang Zhang, Feng Deng, Jiquan Chen, Dennis D. Baldocchi, Beverly E. Law, M. Altaf Arain, Ankur R. Desai, Andrew D. Richardson, Ge Sun, Brian Amiro, Hank Margolis, Lianhong Gu, Russell L. Scott, Peter D. Blanken, Andrew E. Suyker

Papers in Natural Resources

The exchange of carbon dioxide is a key measure of ecosystem metabolism and a critical intersection between the terrestrial biosphere and the Earth’s climate. Despite the general agreement that the terrestrial ecosystems in North America provide a sizeable carbon sink, the size and distribution of the sink remain uncertain. We use a data-driven approach to upscale eddy covariance flux observations from towers to the continental scale by integrating flux observations, meteorology, stand age,aboveground biomass, and a proxy for canopy nitrogen concentrations from AmeriFlux and Fluxnet-Canada Research Network as well as a variety of satellite data streams from the MODIS sensors. …


On The Role Of Budget Sufficiency, Cost Efficiency, And Uncertainty In Species Management, Max Post Van Der Burg, Bartholomew B. Bly, Tammy Vercauteren, James B. Grand, Andrew J. Tyre Jan 2014

On The Role Of Budget Sufficiency, Cost Efficiency, And Uncertainty In Species Management, Max Post Van Der Burg, Bartholomew B. Bly, Tammy Vercauteren, James B. Grand, Andrew J. Tyre

Papers in Natural Resources

Many conservation planning frameworks rely on the assumption that one should prioritize locations for management actions based on the highest predicted conservation value (i.e., abundance, occupancy). This strategy may underperform relative to the expected outcome if one is working with a limited budget or the predicted responses are uncertain. Yet, cost and tolerance to uncertainty rarely become part of species management plans. We used field data and predictive models to simulate a decision problem involving western burrowing owls (Athene cunicularia hypugaea) using prairie dog colonies (Cynomys ludovicianus) in western Nebraska. We considered 2 species management strategies: …


Landsat-8: Science And Product Vision For Terrestrial Global Change Research, David P. Roy, M. A. Wulder, T. R. Loveland, C. E. Woodcock, R. G. Allen, M. C. Anderson, D. Helder, J. R. Irons, D. M. Johnson, R. Kennedy, T. A. Scambos, C. B. Schaaf, J. R. Schott, Y. Sheng, E. F. Vermote, A. S. Belward, R. Bindschadler, W. B. Cohen, F. Gao, J. D. Hipple, P. Hostert, Desert Research Institute, Reno, Nv, C. O. Justice, Ayse Kilic, V. Kovalskyy, Z. P. Lee, L. Lymburner, J. G. Masek, J. Mccorkel, Y. Shuai, R. Trezza, J. Vogelmann, R. H. Wynne, Z. Zhu Jan 2014

Landsat-8: Science And Product Vision For Terrestrial Global Change Research, David P. Roy, M. A. Wulder, T. R. Loveland, C. E. Woodcock, R. G. Allen, M. C. Anderson, D. Helder, J. R. Irons, D. M. Johnson, R. Kennedy, T. A. Scambos, C. B. Schaaf, J. R. Schott, Y. Sheng, E. F. Vermote, A. S. Belward, R. Bindschadler, W. B. Cohen, F. Gao, J. D. Hipple, P. Hostert, Desert Research Institute, Reno, Nv, C. O. Justice, Ayse Kilic, V. Kovalskyy, Z. P. Lee, L. Lymburner, J. G. Masek, J. Mccorkel, Y. Shuai, R. Trezza, J. Vogelmann, R. H. Wynne, Z. Zhu

Papers in Natural Resources

Landsat 8, a NASA and USGS collaboration, acquires global moderate-resolution measurements of the Earth's terrestrial and polar regions in the visible, near-infrared, short wave, and thermal infrared. Landsat 8 extends the remarkable 40 year Landsat record and has enhanced capabilities including new spectral bands in the blue and cirrus cloud-detection portion of the spectrum, two thermal bands, improved sensor signal-to-noise performance and associated improvements in radiometric resolution, and an improved duty cycle that allows collection of a significantly greater number of images per day. This paper introduces the current (2012–2017) Landsat Science Team's efforts to establish an initial understanding of …


Estimation Of Crop Gross Primary Production (Gpp): FaparChl Versus Mod15a2 Fpar, Qingyuan Zhang, Yen-Ben Cheng, A. I. Lyapustin, Yujie Wang, Feng Gao, Andrew E. Suyker, Shashi B. Verma, Elizabeth M. Middleton Jan 2014

Estimation Of Crop Gross Primary Production (Gpp): FaparChl Versus Mod15a2 Fpar, Qingyuan Zhang, Yen-Ben Cheng, A. I. Lyapustin, Yujie Wang, Feng Gao, Andrew E. Suyker, Shashi B. Verma, Elizabeth M. Middleton

Papers in Natural Resources

Photosynthesis (PSN) is a pigment level process in which antenna pigments (predominately chlorophylls) in chloroplasts absorb photosynthetically active radiation (PAR) for the photochemical process. PAR absorbed by foliar non-photosynthetic components is not used for PSN. The fraction of PAR absorbed (fAPAR) by a canopy/vegetation (i.e., fAPARcanopy) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) images, referred to as MOD15A2 FPAR, has been used to compute absorbed PAR (APAR) for PSN (APARPSN) which is utilized to produce the standard MODIS gross primary production (GPP) product, referred to as MOD17A2 GPP. In this study, the fraction of PAR …


Modeling Vulnerability Of Groundwater To Pollution Under Future Scenarios Of Climate Change And Biofuels-Related Land Use Change: A Case Study In North Dakota, Usa, Ruopu Li, James W. Merchant Mar 2013

Modeling Vulnerability Of Groundwater To Pollution Under Future Scenarios Of Climate Change And Biofuels-Related Land Use Change: A Case Study In North Dakota, Usa, Ruopu Li, James W. Merchant

Papers in Natural Resources

Modeling groundwater vulnerability to pollution is critical for implementing programs to protect groundwater quality.Most groundwater vulnerability modeling has been based on current hydrogeology and land use condi- tions. However, groundwater vulnerability is strongly dependent on factors such as depth-to-water, recharge and land use conditions thatmay change in response to future changes in climate and/or socio-economic condi- tions. In this research, a modeling framework, which employs three sets of models linked within a geographic information system (GIS) environment, was used to evaluate groundwater pollution risks under future climate and land use changes in North Dakota. The results showed that areas with …


Maximizing A New Quantity In Sequential Reserve Selection, Adam W. Schapaugh, Andrew J. Tyre Jan 2013

Maximizing A New Quantity In Sequential Reserve Selection, Adam W. Schapaugh, Andrew J. Tyre

Papers in Natural Resources

The fundamental goal of conservation planning is biodiversity persistence, yet most reserve selection methods prioritize sites using occurrence data. Numerous empirical studies support the notion that defining and measuring objectives in terms of species richness (where the value of a site is equal to the number of species it contains, or contributes to an existing reserve network) can be inadequate for maintaining biodiversity in the long term. An existing site-assessment framework that implicitly maximized the persistence probability of multiple species was integrated with a dynamic optimization model. The problem of sequential reserve selection as a Markov decision process was combined …


Rural Inhabitant Perceptions Of Sandhill Cranes In Wintering Areas Of Northern Mexico, Ingrid Barcelo, Juan Carlos Guzmán-Aranda, Felipe Chávez-Ramírez, Larkin A. Powell Jan 2012

Rural Inhabitant Perceptions Of Sandhill Cranes In Wintering Areas Of Northern Mexico, Ingrid Barcelo, Juan Carlos Guzmán-Aranda, Felipe Chávez-Ramírez, Larkin A. Powell

Papers in Natural Resources

Trends in the mid-continent population of sandhill cranes (Grus canadensis) indicate that the species is increasing. A large proportion of this population winters in northern Mexico where possible conflicts between local inhabitants and cranes can occur. We conducted interviews of 40 rural inhabitants living near wetlands used by cranes in three Mexican states. All interviewees had knowledge of cranes and were capable of describing them. The arrival of cranes affected 43% of interviewees. The negative effects were mainly destroyed crops with a subsequent diminished production. Seventy percent of those affected implemented scare tactics to deter the birds, while others (15%) …


A Century Of Climate Change For Fairbanks, Alaska, Gerd Wendler, Martha Shulski Jan 2009

A Century Of Climate Change For Fairbanks, Alaska, Gerd Wendler, Martha Shulski

Papers in Natural Resources

Climatological observations are available for Fairbanks, Interior Alaska, for up to 100 years. This is a unique data set for Alaska, insofar as it is of relatively high quality and without major breaks. Applying the best linear fit, we conclude that the mean annual temperature rose from -3.6°C to -2.2°C over the century, an increase of 1.4°C (compared to 0.8°C worldwide). This comparison clearly demonstrates the well-known amplification or temperature change for the polar regions. The observed temperature increase is neither uniform over the time period nor uniform throughout the course of a year. The winter, spring, and summer seasons …