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- Nebraska (4)
- Remote sensing (4)
- Turbid productive waters (4)
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- Evapotranspiration (3)
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- MODIS (3)
- Reflectance (3)
- MEdium Resolution Imaging Spectrometer (MERIS) (2)
- Chlorophyll-a (chl-a) (2)
- Great Plains (2)
- Leaf area index (2)
- Leaves (2)
- MERIS (2)
- Spectral algorithm (2)
- Water potential (2)
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- Above-water reflectance (1)
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- Alphavirus; Cliff Swallow; disease emergence; host–pathogen dynamics; House Sparrow; infectious disease; Oeciacus vicarius; Passer domesticus; Petrochelidon pyrrhonota; vector biology; virus ecology; virus evolution. (1)
- Andropogon gerardii Vitman (1)
- Animal waste lagoon (1)
- Anthocyanins (1)
- Anthosyanins (1)
- Argusianus argus (1)
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Articles 1 - 30 of 54
Full-Text Articles in Physical Sciences and Mathematics
Satellite Estimation Of Chlorophyll-A Concentration Using The Red And Nir Bands Of Meris—The Azov Sea Case Study, Wesley J. Moses, Anatoly A. Gitelson, Sergey Berdnikov, Vasiliy Povazhnyy
Satellite Estimation Of Chlorophyll-A Concentration Using The Red And Nir Bands Of Meris—The Azov Sea Case Study, Wesley J. Moses, Anatoly A. Gitelson, Sergey Berdnikov, Vasiliy Povazhnyy
School of Natural Resources: Faculty Publications
We present here the results of calibrating and validating a three-band model and, its special case, a two-band model, which use MEdium Resolution Imaging Spectrometer (MERIS) reflectances in the red and near-infrared spectral regions for estimating chlorophyll-a (chl-a) concentration in inland, estuarine, and coastal turbid productive waters. During four data collection campaigns in 2008 and one campaign in 2009 in the Taganrog Bay and the Azov Sea, Russia, water samples were collected, and concentrations of chl-a and total suspended solids were measured in the laboratory. The data collected in 2008 were used for model calibration, and the …
Corrections To “Satellite Estimation Of Chlorophyll-A Concentration Using The Red And Nir Bands Of Meris—The Azov Sea Case Study”, Wesley J. Moses, Anatoly A. Gitelson, Sergey Berdnikov, Vasiliy Povazhnyy
Corrections To “Satellite Estimation Of Chlorophyll-A Concentration Using The Red And Nir Bands Of Meris—The Azov Sea Case Study”, Wesley J. Moses, Anatoly A. Gitelson, Sergey Berdnikov, Vasiliy Povazhnyy
School of Natural Resources: Faculty Publications
We correct here some errors that appear in our paper: W.J. Moses, A.A. Gitelson, S. Berdnikov, and V. Povazhnyy, “Satellite estimation of chlorophyll-a concentration using the red and NIR bands of MERIS—The Azov Sea case study,” IEEE Geoscience and Remote Sensing Letters, volume 6, number 4, pp. 845–849, October 2009.
Estimation Of Chlorophyll-A Concentration In Case Ii Waters Using Modis And Meris Data—Successes And Challenges, Wesley Moses, Anatoly Gitelson, Sergey Berdnikov, Vasiliy Povazhnyi
Estimation Of Chlorophyll-A Concentration In Case Ii Waters Using Modis And Meris Data—Successes And Challenges, Wesley Moses, Anatoly Gitelson, Sergey Berdnikov, Vasiliy Povazhnyi
School of Natural Resources: Faculty Publications
We present and discuss here the results of our work using MODIS (moderate resolution imaging spectroradiometer) and MERIS (medium resolution imaging spectrometer) satellite data to estimate the concentration of chlorophyll-a (chl-a) in reservoirs of the Dnieper River and the Sea of Azov, which are typical case II waters, i.e., turbid and productive. Our objective was to test the potential of satellite remote sensing as a tool for near-real-time monitoring of chl-a distribution in these water bodies. We tested the performance of a recently developed three-band model, and its special case, a two-band model, which use the reflectance at red and …
Retrieval Of Foliar Information About Plant Pigment Systems From High Resolution Spectroscopy, Susan L. Ustin, Anatoly A. Gitelson, Stéphane Jacquemoud, Michael Schaepman, Gregory P. Asner, John A. Gamon, Pablo Zarco-Tejada
Retrieval Of Foliar Information About Plant Pigment Systems From High Resolution Spectroscopy, Susan L. Ustin, Anatoly A. Gitelson, Stéphane Jacquemoud, Michael Schaepman, Gregory P. Asner, John A. Gamon, Pablo Zarco-Tejada
School of Natural Resources: Faculty Publications
Life on Earth depends on photosynthesis. Photosynthetic systems evolved early in Earth history and have been stable for 2.5 billion years, providing prima facie evidence for the significance of pigments in plant functions. Photosynthetic pigments fill multiple roles from increasing the range of energy captured for photosynthesis to protective functions. Given the importance of pigments to leaf functioning, greater effort is needed to determine whether individual pigments can be identified and quantified in vivo using high fidelity spectroscopy. We review recent advances in detecting plant pigments at the leaf level and discuss successes and reasons why challenges remain for robust …
Photosynthetic Performance Of Invasive Pinus Ponderosa And Juniperus Virginiana Seedlings Under Gradual Soil Water Depletion, Saadia Bihmidine, N. M. Bryan, K. R. Payne, M. R. Parde, Jane A. Okalebo, Sharon E. Cooperstein, Tala Awada
Photosynthetic Performance Of Invasive Pinus Ponderosa And Juniperus Virginiana Seedlings Under Gradual Soil Water Depletion, Saadia Bihmidine, N. M. Bryan, K. R. Payne, M. R. Parde, Jane A. Okalebo, Sharon E. Cooperstein, Tala Awada
School of Natural Resources: Faculty Publications
Changes in climate, land management and fire regime have contributed to woody species expansion into grasslands and savannas worldwide. In the USA, Pinus ponderosa P. & C. Lawson and Juniperus virginiana L. are expanding into semiarid grasslands of Nebraska and other regions of the Great Plains. We examined P. ponderosa and J. virginiana seedling response to soil water content, one of the most important limiting factors in semiarid grasslands, to provide insight into their success in the region. Photosynthesis, stomatal conductance, maximum photochemical efficiency of PSII, maximum carboxylation velocity, maximum rate of electron transport, stomatal limitation to photosynthesis, water potential, …
Wilderness Serendipity: Planning And Assessing Learning During An Experiential Field Course, Larkin A. Powell, Andrew J. Tyre, Scott E. Hygnstrom, David A. Wedin, P. R. Hanson, Mark S. Kuzila, James B. Swinehart
Wilderness Serendipity: Planning And Assessing Learning During An Experiential Field Course, Larkin A. Powell, Andrew J. Tyre, Scott E. Hygnstrom, David A. Wedin, P. R. Hanson, Mark S. Kuzila, James B. Swinehart
School of Natural Resources: Faculty Publications
Experiential learning opportunities promote skill in problem-solving and critical thinking, but they require unique assessment methods because traditional approaches are difficult to implement in the field. We have conducted a study tour course involving a canoe trip in a wilderness area in northern Minnesota since 2004. Here, we describe how we developed our course's learning experiences, ensured the learning experiences materialized, and assessed the student learning objectives. Proper planning can result in valuable, spontaneous learning experiences. We used a student journal, field-based quiz, and participation grade to effectively assess the breadth of student learning that was inherent in our course. …
Quality Control Of Soil Water Data In Applied Climate, Jinshing You, Kenneth Hubbard, Rezaul Mamood, Venkataramana Sridhar, Dennis Todey
Quality Control Of Soil Water Data In Applied Climate, Jinshing You, Kenneth Hubbard, Rezaul Mamood, Venkataramana Sridhar, Dennis Todey
School of Natural Resources: Faculty Publications
Abstract: Soil moisture is a key state variable from both climate and hydrologic cycle assessment perspectives. Recently, automated measurements of soil moisture with sensors deployed at sites in a real-time monitoring network have provided valuable new data to monitor the soil water resource. However, to assure the quality of the data, quality control QC tools are needed. Earlier studies left little literature on the QC of soil water data as measurements were generally not part of a network that routinely collected measurements. This paper presents a systematic QC analysis and methodology to evaluate the performance of candidate QC techniques using …
Tree Canopy Effect On Grass And Grass/Legume Mixtures In Eastern Nebraska, Michael El. L. Perry, Walter H. Schacht, Gregory A. Ruark, James R. Brandle
Tree Canopy Effect On Grass And Grass/Legume Mixtures In Eastern Nebraska, Michael El. L. Perry, Walter H. Schacht, Gregory A. Ruark, James R. Brandle
School of Natural Resources: Faculty Publications
A study to determine the feasibility of producing forage for grazing livestock under trees was conducted as a step toward evaluating the potential for silvopasture systems in the northern and central Great Plains. The effects of overstory leaf area index (LAI), percentage understory light transmittance (LT), and soil moisture (SM) on yield and crude protein (CP) of big bluestem [Andropogon gerardii Vitman; (BB)], smooth bromegrass [ Bromus inermis Leyss.; (SB)], and mixtures with birdsfoot trefoil [ Lotus corniculatus L.; (BFT)] were examined. The study was conducted in both Scotch pine (Pinus sylvestris L.) and green ash (Fraxinus …
Avian Foraging Patterns In Crop Field Edges Adjacent To Woody Habitat, Heidi L. Puckett, James R. Brandle, Ron J. Johnson, Erin E. Blankenship
Avian Foraging Patterns In Crop Field Edges Adjacent To Woody Habitat, Heidi L. Puckett, James R. Brandle, Ron J. Johnson, Erin E. Blankenship
School of Natural Resources: Faculty Publications
As natural predators of pest insects, woodland birds provide biological pest suppression in crop fields adjacent to woody edges. Although many birds using these habitats forage widely, earlier studies have found that most foraging activity occurs within 50 m of the woody edge. The goals of this study were to determine the primary area of use, or functional edge, for birds foraging in crop fields adjacent to woody edges, and to evaluate their foraging distance patterns. During the summers of 2005 and 2006, avian foraging behavior was observed at 12 research sites in east central Nebraska that contained either a …
Phylogeography Of The Rufous-Naped Wren (Campylorhynchus Rufinucha): Speciation And Hybridization In Mesoamerica, Hernan Vazquez-Miranda, Adolfo G. Navarro-Siguenza, Kevin E. Omland
Phylogeography Of The Rufous-Naped Wren (Campylorhynchus Rufinucha): Speciation And Hybridization In Mesoamerica, Hernan Vazquez-Miranda, Adolfo G. Navarro-Siguenza, Kevin E. Omland
School of Natural Resources: Faculty Publications
The Rufous-naped Wren (Campylorhynchus rufinucha) is a sedentary, morphologically variable species distributed in the dry forests of Mesoamerica. It ranges from Colima, Mexico, south to Costa Rica along the Pacific slope, with a disjunct population in central Veracruz. Populations of two forms on the Pacific slope intergrade in Chiapas, Mexico, apparently as a result of secondary contact. We sequenced a mitochondrial DNA (mtDNA) gene to explore phylogeographic patterns and hybridization. We found three divergent lineages, two geographically spanning the Isthmus of Tehuantepec and a disjunct Veracruz population. Analyses of molecular variation and statistics are consistent with genetically distinct …
A Comparison Between Above-Water Surface And Subsurface Spectral Reflectances Collected Over Inland Waters, Asif M. Bhatti, Donald Rundquist, John Schalles, Luis Ramirez, Seigo Nasu
A Comparison Between Above-Water Surface And Subsurface Spectral Reflectances Collected Over Inland Waters, Asif M. Bhatti, Donald Rundquist, John Schalles, Luis Ramirez, Seigo Nasu
School of Natural Resources: Faculty Publications
The objective of the research was to undertake a quantitative comparison of spectral-reflectance measurements made slightly above the surface of water bodies with the measurements made slightly below the surface. The study is focused on three rivers; two in Georgia, USA and one in Japan. As expected, the differences in reflectance are not constant and vary with the wavelength. The contribution of surface-reflection effects to the surface reflectance measured slightly above the water is both pronounced and highly variable, but although they do alter the magnitude of the upwelling signal, they do not change the general shape of the spectral …
Evapotranspiration Of Irrigated And Rainfed Maize–Soybean Cropping Systems, Andrew E. Suyker, Shashi Verma
Evapotranspiration Of Irrigated And Rainfed Maize–Soybean Cropping Systems, Andrew E. Suyker, Shashi Verma
School of Natural Resources: Faculty Publications
We have been making year-round measurements of mass and energy exchange in three cropping systems: (a) irrigated continuous maize, (b) irrigated maize–soybean rotation, and (c) rainfed maize–soybean rotation in eastern Nebraska since 2001. In this paper, we present results on evapotranspiration (ET) of these crops for the first 5 years of our study. Growing season ET in the irrigated and rainfed maize averaged 548 and 482 mm, respectively. In irrigated and rainfed soybean, the average growing season ET was 452 and 431 mm, respectively. On average, the maize ET was higher than the soybean ET by 18% for irrigated crops …
Development Of A Healthy Farm Index To Assess Ecological, Economic, And Social Function On Organic And Sustainable Farms In Nebraska's Four Agroecoregions., James R. Brandle
Development Of A Healthy Farm Index To Assess Ecological, Economic, And Social Function On Organic And Sustainable Farms In Nebraska's Four Agroecoregions., James R. Brandle
School of Natural Resources: Faculty Publications
No abstract provided.
An Evaporation Estimation Method Based On The Coupled 2-D Turbulent Heat And Vapor Transport Equations, Jozsef Szilagyi, Janos Jozsa
An Evaporation Estimation Method Based On The Coupled 2-D Turbulent Heat And Vapor Transport Equations, Jozsef Szilagyi, Janos Jozsa
School of Natural Resources: Faculty Publications
The analytical solution of the coupled turbulent diffusion equations of heat and vapor transport across a moisture discontinuity under near-neutral atmospheric conditions and constant energy available at the evaporating surface yields a simple equation (i.e., the wet-surface equation [WSE]) that relates the change in surface temperature to the change in the land surface moisture content as the environment dries. With the help of percent possible sunshine, air temperature, and humidity measurements at selected weather stations as well as land surface temperature values from MODIS data, monthly, warm-season evaporation rates were estimated for five rectangular regions across the contiguous U.S. employing …
Complementary Relationship Of Evaporation And The Mean Annual Water-Energy Balance, Jozsef Szilagyi, Janos Jozsa
Complementary Relationship Of Evaporation And The Mean Annual Water-Energy Balance, Jozsef Szilagyi, Janos Jozsa
School of Natural Resources: Faculty Publications
By combining the complementary relationship of evaporation with the coupled long-term water-energy balance of Porporato et al. (2004) in a Budyko-type framework, one can, from atmospheric measurements alone, derive important ecosystem characteristics, such as the mean effective relative soil moisture and the maximum soil water storage, as well as predict changes in the rooting depth of vegetation as a response to climate variations.
Comment On ‘‘Power Law Catchment-Scale Recessions Arising From Heterogeneous Linear Small-Scale Dynamics’’ By C. J. Harman, M. Sivapalan, And P. Kumar, Jozsef Szilagyi
Comment On ‘‘Power Law Catchment-Scale Recessions Arising From Heterogeneous Linear Small-Scale Dynamics’’ By C. J. Harman, M. Sivapalan, And P. Kumar, Jozsef Szilagyi
School of Natural Resources: Faculty Publications
It is demonstrated that a near-linear subsurface runoff response from a short and relatively steep slope segment and a nonlinear response at the watershed scale may primarily arise from geometry rather than from an assumed linear nature of the subsurface runoff response from the hillslope, as Harman et al. [2009] employed for the Panola Mountain Research (PMR) catchment in Georgia. The authors caution in their paper that hydraulic theory (exemplified by the study of Brutsaert and Nieber [1977]) cannot generally account for the heterogeneity in the watershed scale and therefore should be used with certain reservation when employing it for …
Movements, Distribution, And Abundance Of Great Argus Pheasants (Argusianus Argus) In A Sumatran Rainforest, Nurul L. Winarni, Timothy G. O'Brien, John P. Carroll, Margaret F. Kinnaird
Movements, Distribution, And Abundance Of Great Argus Pheasants (Argusianus Argus) In A Sumatran Rainforest, Nurul L. Winarni, Timothy G. O'Brien, John P. Carroll, Margaret F. Kinnaird
School of Natural Resources: Faculty Publications
We used radiotelemetry, habitat sampling, camera trapping, and line-transect surveys to explore movement patterns, distribution, and abundance of Great Argus Pheasants (Argusianus argus) in Sumatra, Indonesia. We radiotracked six adult and one subadult males. Territories averaged 14.5 ± 8.5 ha, and home-range size did not vary by month or by relative abundance of selected plant foods. Daily travel distance (849 ± 211 m) varied significantly between months but did not reflect changes in plant foods. Territories were used almost exclusively by resident males. Males preferentially used undisturbed forest (habitat I). Vegetation structure at male display sites and random points indicated …
A Phylogenetic Supertree Of The Fowls (Galloanserae, Aves), Soo Hyumg Eo, Olaf R.P. Bininda-Emonds, John P. Carroll
A Phylogenetic Supertree Of The Fowls (Galloanserae, Aves), Soo Hyumg Eo, Olaf R.P. Bininda-Emonds, John P. Carroll
School of Natural Resources: Faculty Publications
The fowls (Anseriformes and Galliformes) comprise one of the major lineages of birds and occupy almost all biogeographical regions of the world. The group contains the most economically important of all bird species, each with a long history of domestication, and is an ideal model for studying ecological and evolutionary patterns. Yet, despite the relatively large amount of systematic attention fowls have attracted because of their socio-economic and biological importance, the species-level relationships within this clade remain controversial. Here we used the supertree method matrix representation with parsimony to generate a robust estimate of species-level relationships of fowls. The supertree …
Modeling Lakes And Reservoirs In The Climate System, M. D. Mackay, P. J. Neale, C. D. Arp, L. N. De Senerpont Domis, X. Fang, G. Gal, K. D. Johnk, G. Kirillin, J. D. Lenters, E. Litchman, S. Macintyre, P. Marsh, J. Melack, W. M. Mooij, F. Peeters, A. Quesada, S. G. Schladow, M. Schmid, C. Spence, S. L. Stokes
Modeling Lakes And Reservoirs In The Climate System, M. D. Mackay, P. J. Neale, C. D. Arp, L. N. De Senerpont Domis, X. Fang, G. Gal, K. D. Johnk, G. Kirillin, J. D. Lenters, E. Litchman, S. Macintyre, P. Marsh, J. Melack, W. M. Mooij, F. Peeters, A. Quesada, S. G. Schladow, M. Schmid, C. Spence, S. L. Stokes
School of Natural Resources: Faculty Publications
Modeling studies examining the effect of lakes on regional and global climate, as well as studies on the influence of climate variability and change on aquatic ecosystems, are surveyed. Fully coupled atmosphere–land surface–lake climate models that could be used for both of these types of study simultaneously do not presently exist, though there are many applications that would benefit from such models. It is argued here that current understanding of physical and biogeochemical processes in freshwater systems is sufficient to begin to construct such models, and a path forward is proposed. The largest impediment to fully representing lakes in the …
First Record Of Pseudorabies In Feral Swine In Nebraska, Sam Wilson, Alan R. Doster, Justin D. Hoffman, Scott E. Hygnstrom
First Record Of Pseudorabies In Feral Swine In Nebraska, Sam Wilson, Alan R. Doster, Justin D. Hoffman, Scott E. Hygnstrom
School of Natural Resources: Faculty Publications
In 2007, two new populations of feral swine were discovered in Nance and Valley counties, Nebraska, USA. Necropsies and serologic testing was done on two individuals from the Nance County herd. Results indicated that a lactating sow had positive antibodies for pseudorabies virus (PRV). Investigations conducted by Nebraska Game and Parks Commission Law Enforcement division confirmed that the infected individual was transported illegally to Nebraska, USA, from Texas, USA. All domestic swine herds located within an 8 km radius of the infected individual tested negative for antibodies to PRV. Our results provide a clear example of how diseases can spread …
A Modified Advection-Aridity Model Of Evapotranspiration, Jozsef Szilagyi, Michael T. Hobbins, Janos Jozsa
A Modified Advection-Aridity Model Of Evapotranspiration, Jozsef Szilagyi, Michael T. Hobbins, Janos Jozsa
School of Natural Resources: Faculty Publications
No abstract provided.
Analytical Solution Of The Coupled 2-D Turbulent Heat And Vapor Transport Equations And The Complementary Relationship Of Evaporation, Jozsef Szilagyi, Janos Jozsa
Analytical Solution Of The Coupled 2-D Turbulent Heat And Vapor Transport Equations And The Complementary Relationship Of Evaporation, Jozsef Szilagyi, Janos Jozsa
School of Natural Resources: Faculty Publications
No abstract provided.
Estimating Spatially Distributed Monthly Evapotranspiration Rates By Linear Transformations Of Modis Daytime Land Surface Temperature Data, J. Szilagyi, J. Jozsa
Estimating Spatially Distributed Monthly Evapotranspiration Rates By Linear Transformations Of Modis Daytime Land Surface Temperature Data, J. Szilagyi, J. Jozsa
School of Natural Resources: Faculty Publications
No abstract provided.
Nutrient Uptake And Mineralization During Leaf Decay In Streams – A Model Simulation, J. R. Webster, J. D. Newbold, Steven A. Thomas, P. J. Mulholland
Nutrient Uptake And Mineralization During Leaf Decay In Streams – A Model Simulation, J. R. Webster, J. D. Newbold, Steven A. Thomas, P. J. Mulholland
School of Natural Resources: Faculty Publications
We developed a stoichiometrically explicit computer model to examine how heterotrophic uptake of nutrients and microbial mineralization occurring during the decay of leaves in streams may be important in modifying nutrient concentrations. The simulations showed that microbial uptake can substantially decrease stream nutrient concentrations during the initial phases of decomposition, while mineralization may produce increases in concentrations during later stages of decomposition. The simulations also showed that initial nutrient content of the leaves can affect the stream nutrient concentration dynamics and determine whether nitrogen or phosphorus is the limiting nutrient. Finally, the simulations suggest a net retention (uptake > mineralization) of …
Characterizing The Seasonal Dynamics Of Plant Community Photosynthesis Across A Range Of Vegetation Types, Lianhong Gu, Wilfred M. Post, Dennis D. Baldocchi, T. Andrew Black, Andrew E. Suyker, Shashi Verma, Timo Vesala, Steve C. Wofsy
Characterizing The Seasonal Dynamics Of Plant Community Photosynthesis Across A Range Of Vegetation Types, Lianhong Gu, Wilfred M. Post, Dennis D. Baldocchi, T. Andrew Black, Andrew E. Suyker, Shashi Verma, Timo Vesala, Steve C. Wofsy
School of Natural Resources: Faculty Publications
The seasonal cycle of plant community photosynthesis is one of the most important biotic oscillations to mankind. This study built upon previous efforts to develop a comprehensive framework to studying this cycle systematically with eddy covariance flux measurements. We proposed a new function to represent the cycle and generalized a set of phenological indices to quantify its dynamic characteristics. We suggest that the seasonal variation of plant community photosynthesis generally consists of five distinctive phases in sequence each of which results from the interaction between the inherent biological and ecological processes and the progression of climatic conditions and reflects the …
Spring Home Ranges Of White Bass In Irrigation Reservoirs Of The Republican River Basin, Nebraska, D. R. Martin, Larkin A. Powell, Kevin L. Pope
Spring Home Ranges Of White Bass In Irrigation Reservoirs Of The Republican River Basin, Nebraska, D. R. Martin, Larkin A. Powell, Kevin L. Pope
School of Natural Resources: Faculty Publications
Fishery biologists have documented small home ranges, relative to available habitat, for many littoral freshwater fishes. Home ranges for pelagic species, such as white bass Morone chrysops, are generally not well described, yet are thought to be large. We studied white bass movement using acoustic telemetry in two irrigation reservoirs of the Republican River basin in south-western Nebraska. Acoustic transmitters were implanted in fall of the previous year and tracking occurred a minimum of once per week throughout spring (mid-March to May) 2007 and 2008. Linear home ranges were calculated from observed locations of individual fish. Twelve of the …
Latitudinal Patterns Of Magnitude And Interannual Variability In Net Ecosystem Exchange Regulated By Biological And Environmental Variables, Wenping Yuan, Yiqi Luo, Andrew D. Richardson, Ram Oren, Sebastiaan Luyssaert, Ivan A. Janssens, Reinhart Ceulemans, Xuhui Zhou, Thomas Grünwald, Marc Aubinet, Christian Berhofer, Dennis D. Baldocci, Jiquan Chen, Allison L. Dunn, Jared L. Deforest, Danilo Dragoni, Allen H. Goldstein, Eddy Moors, J. William William Munger, Russell K. Monson, Andrew E. Suyker, Gregory Starr, Russell L. Scott, John Tenhunen, Shashi Verma, Timo Vesala, Steven C. Wofsy
Latitudinal Patterns Of Magnitude And Interannual Variability In Net Ecosystem Exchange Regulated By Biological And Environmental Variables, Wenping Yuan, Yiqi Luo, Andrew D. Richardson, Ram Oren, Sebastiaan Luyssaert, Ivan A. Janssens, Reinhart Ceulemans, Xuhui Zhou, Thomas Grünwald, Marc Aubinet, Christian Berhofer, Dennis D. Baldocci, Jiquan Chen, Allison L. Dunn, Jared L. Deforest, Danilo Dragoni, Allen H. Goldstein, Eddy Moors, J. William William Munger, Russell K. Monson, Andrew E. Suyker, Gregory Starr, Russell L. Scott, John Tenhunen, Shashi Verma, Timo Vesala, Steven C. Wofsy
School of Natural Resources: Faculty Publications
Over the last two and half decades, strong evidence showed that the terrestrial ecosystems are acting as a net sink for atmospheric carbon. However the spatial and temporal patterns of variation in the sink are not well known. In this study, we examined latitudinal patterns of interannual variability (IAV) in net ecosystem exchange (NEE) of CO2 based on 163 site-years of eddy covariance data, from 39 northern-hemisphere research sites located at latitudes ranging from ~29°N to ~ 64°N. We computed the standard deviation of annual NEE integrals at individual sites to represent absolute interannual variability (AIAV), and the corresponding …
Seasonal Changes In Depth Of Water Uptake For Encroaching Trees Juniperus Virginiana And Pinus Ponderosa And Two Dominant C4 Grasses In A Semiarid Grassland, Kathleen D. Eggemeyer, Tala Awada, F. Edwin Harvey, David A. Wedin, Xinhua Zhou, C. William Zanner
Seasonal Changes In Depth Of Water Uptake For Encroaching Trees Juniperus Virginiana And Pinus Ponderosa And Two Dominant C4 Grasses In A Semiarid Grassland, Kathleen D. Eggemeyer, Tala Awada, F. Edwin Harvey, David A. Wedin, Xinhua Zhou, C. William Zanner
School of Natural Resources: Faculty Publications
We used the natural abundance of stable isotopic ratios of hydrogen and oxygen in soil (0.05–3 m depth), plant xylem and precipitation to determine the seasonal changes in sources of soil water uptake by two native encroaching woody species (Pinus ponderosa P. & C. Lawson, Juniperus virginiana L.), and two C4 grasses (Schizachyrium scoparium (Michx.) Nash, Panicum virgatum L.), in the semiarid Sandhills grasslands of Nebraska. Grass species extracted most of their water from the upper soil profile (0.05–0.5 m). Soil water uptake from below 0.5 m depth increased under drought, but appeared to be minimal in …
Landscape Structure Control On Soil Co2 Efflux Variability In Complex Terrain: Scaling From Point Observations To Watershed Scale Fluxes, Diego Andrés Riveros-Iregui, Brian L. Mcglynn
Landscape Structure Control On Soil Co2 Efflux Variability In Complex Terrain: Scaling From Point Observations To Watershed Scale Fluxes, Diego Andrés Riveros-Iregui, Brian L. Mcglynn
School of Natural Resources: Faculty Publications
We investigated the spatial and temporal variability of soil CO2 efflux across 62 sites of a 393-ha complex watershed of the northern Rocky Mountains. Growing season (83 day) cumulative soil CO2 efflux varied from ~300 to ~2000 g CO2 m—2, depending upon landscape position, with a median of 879.8 g CO2 m—2. Our findings revealed that highest soil CO2 efflux rates were observed in areas with persistently high soil moisture (riparian meadows), whereas lower soil CO2 efflux rates were observed on forested uplands (98% of watershed area). Furthermore, upslope accumulated …
Differential Soil Respiration Responses To Changing Hydrologic Regimes, Vincent J. Pacific, Brian L. Mcglynn, Diego Andrés Riveros-Iregui, Howard E. Epstein, Daniel J. Welsch
Differential Soil Respiration Responses To Changing Hydrologic Regimes, Vincent J. Pacific, Brian L. Mcglynn, Diego Andrés Riveros-Iregui, Howard E. Epstein, Daniel J. Welsch
School of Natural Resources: Faculty Publications
Soil respiration is tightly coupled to the hydrologic cycle (i.e., snowmelt and precipitation timing and magnitude). We examined riparian and hillslope soil respiration across a wet (2005) and a dry (2006) growing season in a subalpine catchment. When comparing the riparian zones, cumulative CO2 efflux was 33% higher, and peak efflux occurred 17 days earlier during the dry growing season. In contrast, cumulative efflux in the hillslopes was 8% lower, and peak efflux occurred 10 days earlier during the drier growing season. Our results demonstrate that soil respiration was more sensitive to drier growing season conditions in wet (riparian) …