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Full-Text Articles in Natural Resources and Conservation

Insights From Characterizing Extinct Human Gut Microbiomes, Raul Y. Tito, Dan Knights, Jessica Metcalf, Alexandra J. Obregon-Tito, Lauren Cleeland, Fares Najar, Bruce Roe, Karl Reinhard, Kristin Sobolik, Samuel Belknap, Morris Foster, Paul Spicer, Rob Knight, Cecil M. Lewis, Jr. Dec 2012

Insights From Characterizing Extinct Human Gut Microbiomes, Raul Y. Tito, Dan Knights, Jessica Metcalf, Alexandra J. Obregon-Tito, Lauren Cleeland, Fares Najar, Bruce Roe, Karl Reinhard, Kristin Sobolik, Samuel Belknap, Morris Foster, Paul Spicer, Rob Knight, Cecil M. Lewis, Jr.

School of Natural Resources: Faculty Publications

In an effort to better understand the ancestral state of the human distal gut microbiome, we examine feces retrieved from archaeological contexts (coprolites). To accomplish this, we pyrosequenced the 16S rDNA V3 region from duplicate coprolite samples recovered from three archaeological sites, each representing a different depositional environment: Hinds Cave (~8000 years B.P.) in the southern United States, Caserones (1600 years B.P.) in northern Chile, and Rio Zape in northern Mexico (1400 years B.P.). Clustering algorithms grouped samples from the same site. Phyletic representation was more similar within sites than between them. A Bayesian approach to source-tracking was used to …


Evolutionary And Practical Implications Of Pseudo-Estrus Behavior In Florida Panthers (Puma Concolor Coryi), John F. Benson, Mark A. Lotz, E. Darrell Land, Dave P. Onorato Nov 2012

Evolutionary And Practical Implications Of Pseudo-Estrus Behavior In Florida Panthers (Puma Concolor Coryi), John F. Benson, Mark A. Lotz, E. Darrell Land, Dave P. Onorato

School of Natural Resources: Faculty Publications

Estrus behavior by females for reasons other than reproduction (pseudo-estrus) has been reported in species of primates and felids, and alternative hypotheses have been put forth to explain its evolution and function. We observed 3 separate cases of pseudo-estrus behavior by 2 Puma concolor coryi (Florida Panther) females while they were nursing young (old) kittens. We used VHF and GPS telemetry data, genetic pedigree analysis, and visual observations to provide insight into the evolutionary and practical implications of this behavior for Panthers. We suggest that female Panthers likely consort with males while nursing kittens to maintain amicable relations with these …


Comparative Transcriptome Analysis Of Two Olive Cultivars In Response To Nacl-Stress, Christos Bazakos, Maria E. Manioudaki, Ioannis Therios, Demetrios Voyiatzis, Dimitris Kafetzopoulos, Tala Awada, Panagiotis Kalaitzis Aug 2012

Comparative Transcriptome Analysis Of Two Olive Cultivars In Response To Nacl-Stress, Christos Bazakos, Maria E. Manioudaki, Ioannis Therios, Demetrios Voyiatzis, Dimitris Kafetzopoulos, Tala Awada, Panagiotis Kalaitzis

School of Natural Resources: Faculty Publications

Background: Olive (Olea europaea L.) cultivation is rapidly expanding and low quality saline water is often used for irrigation. The molecular basis of salt tolerance in olive, though, has not yet been investigated at a system level. In this study a comparative transcriptomics approach was used as a tool to unravel gene regulatory networks underlying salinity response in olive trees by simulating as much as possible olive growing conditions in the field. Specifically, we investigated the genotype-dependent differences in the transcriptome response of two olive cultivars, a salt-tolerant and a salt-sensitive one.

Methodology/Principal Findings: A 135-day long …


Flow, Nutrients, And Light Availability Influence Neotropical Epilithon Biomass And Stoichiometry, Tyler J. Kohler, Thomas N. Heatherly Ii, Rana W. El-Sabaawi, Eugenia Zandona, Michael C. Marshall, Alexander S. Flecker, Catherine M. Pringle, David N. Reznick, Steven A. Thomas Aug 2012

Flow, Nutrients, And Light Availability Influence Neotropical Epilithon Biomass And Stoichiometry, Tyler J. Kohler, Thomas N. Heatherly Ii, Rana W. El-Sabaawi, Eugenia Zandona, Michael C. Marshall, Alexander S. Flecker, Catherine M. Pringle, David N. Reznick, Steven A. Thomas

School of Natural Resources: Faculty Publications

Light, nutrient availability, and flow are strong factors controlling the elemental composition and biomass of epilithon in temperate stream ecosystems. However, comparatively little is known about these relationships in tropical streams. We investigated how gradients of light and nutrient availability, seasonality, and habitat influenced epilithon biomass, chlorophyll a, and nutrient ratios in montane streams of Trinidad, West Indies. We sampled 4 focal tributaries of a single river, 2 of which had canopies experimentally thinned, every other month over a 2-y period to observe temporal dynamics and light effects on epilithon. We also sampled 18 sites across Trinidad’s Northern Range Mountains …


Denitrification By Sulfur-Oxidizing Bacteria In A Eutrophic Lake, Amy J. Burgin, Stephen K. Hamilton, Stuart E. Jones, Jay T. Lennon Jul 2012

Denitrification By Sulfur-Oxidizing Bacteria In A Eutrophic Lake, Amy J. Burgin, Stephen K. Hamilton, Stuart E. Jones, Jay T. Lennon

School of Natural Resources: Faculty Publications

Understanding the mechanistic controls of microbial denitrification is of central importance to both environmental microbiology and ecosystem ecology. Loss of nitrate (NO3 ) is often attributed to carbon-driven (heterotrophic) denitrification. However, denitrification can also be coupled to sulfur (S) oxidation by chemolithoautotrophic bacteria. In the present study, we used an in situ stable isotope (15NO3 ) tracer addition in combination with molecular approaches to understand the contribution of sulfur-oxidizing bacteria to the reduction of NO3 in a eutrophic lake. Samples were incubated across a total dissolved sulfide (H2S) gradient (2 to …


The General Ensemble Biogeochemical Modeling System (Gems) And Its Applications To Agricultural Systems In The United States, Shuguang Liu, Zhengxi Tan, Mingshi Chen, Jinxun Liu, Anne Wein, Zhengpeng Li, Shengli Huang, Jennifer Oeding, Claudia Young, Shashi Verma, Andrew Suyker, Stephen Faulkner, Gregory W. Mccarty Jan 2012

The General Ensemble Biogeochemical Modeling System (Gems) And Its Applications To Agricultural Systems In The United States, Shuguang Liu, Zhengxi Tan, Mingshi Chen, Jinxun Liu, Anne Wein, Zhengpeng Li, Shengli Huang, Jennifer Oeding, Claudia Young, Shashi Verma, Andrew Suyker, Stephen Faulkner, Gregory W. Mccarty

School of Natural Resources: Faculty Publications

The General Ensemble Biogeochemical Modeling System (GEMS) (Liu, 2009; Liu et al., 2004c) was developed to integrate well-established ecosystem biogeochemical models with various spatial databases for the simulations of biogeochemical cycles over large areas. Figure 18.1 shows the overall structure of the GEMS. Some of the key components are described below.

General Ensemble Biogeochemical

Modeling System (GEMS) 310

Multiple Underlying Biogeochemical Models 310

Monte Carlo Simulations 311

Model Inputs: Management Practices and Others 311

Model Outputs 311

Data Assimilation 311

Simulation of Agricultural Practices: EDCM as an Example 312

Net Primary Production (NPP) and Improvements in Crop Genetics and Agronomics …


National Climate Assessment Technical Report On The Impacts Of Climate And Land Use And Land Cover Change, Thomas Loveland, Rezaul Mahmood, Toral Patel-Weynand, Krista Karstensen, Kari Beckendorf, Norman Bliss, Andrew Carlton Jan 2012

National Climate Assessment Technical Report On The Impacts Of Climate And Land Use And Land Cover Change, Thomas Loveland, Rezaul Mahmood, Toral Patel-Weynand, Krista Karstensen, Kari Beckendorf, Norman Bliss, Andrew Carlton

School of Natural Resources: Faculty Publications

This technical report responds to the recognition by the U.S. Global Change Research Program (USGCRP) and the National Climate Assessment (NCA) of the importance of understanding how land use and land cover (LULC) affects weather and climate variability and change and how that variability and change affects LULC. Current published, peer-reviewed, scientific literature and supporting data from both existing and original sources forms the basis for this report’s assessment of the current state of knowledge regarding land change and climate interactions. The synthesis presented herein documents how current and future land change may alter environment processes and in turn, how …


Interior Least Tern Powerline Collision On The Lower Platte River, Lauren R. Dinan, Joel G. Jorgensen, Mary Bomberger Brown Jan 2012

Interior Least Tern Powerline Collision On The Lower Platte River, Lauren R. Dinan, Joel G. Jorgensen, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Collisions with electrical powerlines are a well-known documented cause of avian mortality (Avian Power Line Interaction Committee [APLIC] 1994, Savereno et al. 1996). Mortality caused by collisions with powerlines can be an important concern for many bird species, but is a serious conservation problem for threatened and endangered species because any mortality can have biological and legal ramifications (Janss 2000). Loss of individuals, particularly breeding adults, from an already small population may impede a species’ recovery by reducing reproduction and recruitment into the breeding population. The death of an individual from a threatened or endangered species as a result of …


Fish Assemblage Shifts And Population Dynamics Of Smallmouth Bass (Micropterus Dolomieu) In The Beaver Archipelago, Northern Lake Michigan: A Comparison Between Historical And Recent Time Periods Amidst Ecosystem Changes., Mark A. Kaemingk, Tracy L. Galarowicz, John A. Clevenger, David F. Clapp, Herbert L. Lenon Jan 2012

Fish Assemblage Shifts And Population Dynamics Of Smallmouth Bass (Micropterus Dolomieu) In The Beaver Archipelago, Northern Lake Michigan: A Comparison Between Historical And Recent Time Periods Amidst Ecosystem Changes., Mark A. Kaemingk, Tracy L. Galarowicz, John A. Clevenger, David F. Clapp, Herbert L. Lenon

School of Natural Resources: Faculty Publications

The ecological and economic importance of Great Lakes nearshore areas and the paucity of information on nearshore Lake Michigan fish assemblages prompted us to document changes that occurred from a historical time period (1969–1972, 1975, 1977, and 1984) to a recent period (2005–2008) in a nearshore northern Lake Michigan (Beaver Archipelago) fish assemblage, with an emphasis on smallmouth bass Micropterus dolomieu. From historical to recent periods, the Beaver Archipelago fish assemblage shifted from predominantly brown bullheads Ameiurus nebulosus to predominantly smallmouth bass. Relative abundance of brown bullheads and white suckers Catostomus commersonii declined from historical to recent time periods, as …


Priority Effects Among Young-Of-The-Year Fish: Reduced Growth Of Bluegill Sunfish (Lepomis Macrochirus) Caused By Yellow Perch (Perca Flavescens)?, Mark A. Kaemingk, Jeffrey C. Jolley, David W. Willis, Steven R. Chipps Jan 2012

Priority Effects Among Young-Of-The-Year Fish: Reduced Growth Of Bluegill Sunfish (Lepomis Macrochirus) Caused By Yellow Perch (Perca Flavescens)?, Mark A. Kaemingk, Jeffrey C. Jolley, David W. Willis, Steven R. Chipps

School of Natural Resources: Faculty Publications

1. When available, Daphnia spp. are often preferred by age-0 yellow perch and bluegill sunfish because of energetic profitability. We hypothesised that predation by age-0 yellow perch could lead to a midsummer decline (MSD) of Daphnia spp. and that priority effects may favour yellow perch because they hatch before bluegill, allowing them to capitalise on Daphnia spp. prior to bluegill emergence.

2. Data were collected from 2004 to 2010 in Pelican Lake, Nebraska, U.S.A. The lake experienced a prolonged MSD in all but 1 year (2005), generally occurring within the first 2 weeks of June except in 2008 and 2010 …


Phosphorus In Phoenix: A Budget And Spatial Representation Of Phosphorus In An Urban Ecosystem, Genevieve S. Metson, Rebecca L. Hale, David M. Iwaniec, Elizabeth M. Cook, Jessica R. Corman, Christopher S. Galletti, Daniel L. Childers Jan 2012

Phosphorus In Phoenix: A Budget And Spatial Representation Of Phosphorus In An Urban Ecosystem, Genevieve S. Metson, Rebecca L. Hale, David M. Iwaniec, Elizabeth M. Cook, Jessica R. Corman, Christopher S. Galletti, Daniel L. Childers

School of Natural Resources: Faculty Publications

As urban environments dominate the landscape, we need to examine how limiting nutrients such as phosphorus (P) cycle in these novel ecosystems. Sustainable management of P resources is necessary to ensure global food security and to minimize freshwater pollution. We used a spatially explicit budget to quantify the pools and fluxes of P in the Greater Phoenix Area in Arizona, USA, using the boundaries of the Central Arizona– Phoenix Long-Term Ecological Research site. Inputs were dominated by direct imports of food and fertilizer for local agriculture, while most outputs were small, including water, crops, and material destined for recycling. Internally, …


Monitoring Live Fuel Moisture Using Soil Moisture And Remote Sensing Proxies, Yi Qi, Philip E. Dennison, Jessica Spencer, David Riano Jan 2012

Monitoring Live Fuel Moisture Using Soil Moisture And Remote Sensing Proxies, Yi Qi, Philip E. Dennison, Jessica Spencer, David Riano

School of Natural Resources: Faculty Publications

Live fuel moisture (LFM) is an important fuel property controlling fuel ignition and fire propagation. LFM varies seasonally, and is controlled by precipitation, soil moisture, evapotranspiration, and plant physiology. LFM is typically sampled manually in the field, which leads to sparse measurements in space and time. Use of LFM proxies could reduce the need for field sampling while potentially improving spatial and temporal sampling density. This study compares soil moisture and remote sensing data to field-sampled LFM for Gambel oak (Quercus gambelii Nutt) and big sagebrush (Artemisia tridentata Nutt) in northern Utah. Bivariate linear regression models were constructed …


Bats In And Around Structures, Dennis M. Ferraro, Lisa Pennisi, Scott E. Hygnstrom, Stephen M. Vantassel Jan 2012

Bats In And Around Structures, Dennis M. Ferraro, Lisa Pennisi, Scott E. Hygnstrom, Stephen M. Vantassel

School of Natural Resources: Faculty Publications

No abstract provided.


The Collaborative Forest Landscape Restoration Program: A History And Overview Of The First Projects, Courtney A. Schultz, Theresa Jedd Jan 2012

The Collaborative Forest Landscape Restoration Program: A History And Overview Of The First Projects, Courtney A. Schultz, Theresa Jedd

School of Natural Resources: Faculty Publications

No abstract provided.


Predation, Herbivory, And Parasitism, Alison N.P. Stevens Jan 2012

Predation, Herbivory, And Parasitism, Alison N.P. Stevens

School of Natural Resources: Faculty Publications

No abstract provided.


Planet Protectors, A.P. Stevens Jan 2012

Planet Protectors, A.P. Stevens

School of Natural Resources: Faculty Publications

No abstract provided.


Dynamics Of Predation, Alison N.P. Stevens Jan 2012

Dynamics Of Predation, Alison N.P. Stevens

School of Natural Resources: Faculty Publications

No abstract provided.


Factors Affecting Global Climate, Alison N.P. Stevens Jan 2012

Factors Affecting Global Climate, Alison N.P. Stevens

School of Natural Resources: Faculty Publications

No abstract provided.


Estimating The Abundance Of Long-Billed Curlews In Nebraska, Cory J. Gregory, Stephen J. Dinsmore, Larkin A. Powell, Joel G. Jorgensen Jan 2012

Estimating The Abundance Of Long-Billed Curlews In Nebraska, Cory J. Gregory, Stephen J. Dinsmore, Larkin A. Powell, Joel G. Jorgensen

School of Natural Resources: Faculty Publications

Long-billed Curlews (Numenius americanus) are shorebirds of high conservation concern in North America. Populations have de­clined in the last 150 yr primarily due to habitat loss and conversion. We conducted a 2-yr study to estimate the density and state­wide abundance of breeding Long-billed Curlews in Nebraska during 2008 and 2009. Surveys were conducted during the prenest­ing period in April when Long-billed Curlews were likely to be detected. We used a simple random sample of roadside survey routes (N = 39), each consisting of 40 5-min point-counts at 800-m intervals. We modeled detection probability and found that wind …


2012 Interior Least Tern And Piping Plover Monitoring, Research, Management, And Outreach Report For The Lower Platte River, Nebraska, Mary Bomberger Brown, Joel G. Jorgensen, Lauren R. Dinan Jan 2012

2012 Interior Least Tern And Piping Plover Monitoring, Research, Management, And Outreach Report For The Lower Platte River, Nebraska, Mary Bomberger Brown, Joel G. Jorgensen, Lauren R. Dinan

School of Natural Resources: Faculty Publications

This document reports on our monitoring, research, management, and outreach activities during the past 12 months (2012). We prepared it to inform our partners, cooperating agencies, funding sources, and other interested parties of our activities and to provide a preliminary summary of our results.

The Lower Platte River and its major tributaries provide important nesting habitat for two state and federally protected bird species, the Interior Least Tern (Sternula antillarum athalassos) and Piping Plover (Charadrius melodus). The Tern and Plover Conservation Partnership (TPCP), based at the University of Nebraska-School of Natural Resources, and the Nongame Bird …


Use Of Partially Fenced Fields To Reduce Deer Damage To Corn, Aaron M. Hildreth, Scott E. Hygnstrom, Erin E. Blankenship, Kurt C. Vercauteren Jan 2012

Use Of Partially Fenced Fields To Reduce Deer Damage To Corn, Aaron M. Hildreth, Scott E. Hygnstrom, Erin E. Blankenship, Kurt C. Vercauteren

School of Natural Resources: Faculty Publications

White-tailed deer (Odocoileus virginianus) damage agricultural crops, often leading to significant economic losses for farmers. We used poly-mesh fence with wings to separate good deer cover from agricultural fields where crop damage by deer occurred primarily along this edge. In these cases, complete enclosure of the field with fencing may be unnecessary. The design used a 2.13-m-high polypropylene mesh fence erected along the wooded edge of a field with either 50-m or 150-m wings extending perpendicular from the fence line and wooded habitat. Fences reduced deer damage in cornfields 13.5% (F1,6= , P < 0.001). Average yield in fenced fields (10,211 kg/ha) was 1,708 kg/ha greater than in control fields, which, at US$0.155/kg, equals a net gain of US$265/ha. We found no difference in damage between fences with 50-m and 150-m wings (F …


Avian Influenza Virus Prevalence In Migratory Waterfowl In The Central Flyway, 2007–2009, Scott R. Groepper, Scott E. Hygnstrom, Mark P. Vrtiska, Thomas J. Deliberto Jan 2012

Avian Influenza Virus Prevalence In Migratory Waterfowl In The Central Flyway, 2007–2009, Scott R. Groepper, Scott E. Hygnstrom, Mark P. Vrtiska, Thomas J. Deliberto

School of Natural Resources: Faculty Publications

Highly pathogenic avian influenza (HPAI H5N1) poses risks to wild birds, poultry, and humans. Personnel with the United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, state game agencies, and tribal cooperators collected >36,000 migratory birds from 2007–2009 to test for HPAI virus. Species from the dabbling duck, diving duck, and geese and swans functional groups were collected in all 10 states of the Central Flyway. Numerous combinations of the 16 hemaglutinin (H) and 9 neuraminidase (N) subtypes were discovered, but no HPAI H5N1 was found. The dabbling duck functional group had significantly higher (p < 0.001) prevalence of AIV than other functional groups and should be the focus of future surveillance.


Utility Of Improvised Video-Camera Collars For Collecting Contact Data From White-Tailed Deer: Possibilities In Disease Transmission Studies, Michael J. Lavelle, Scott E. Hygnstrom, Aaron M. Hildreth, Tyler A. Campbell, David B. Long, David G. Hewitt, Jeff Beringer, K. C. Vercauteren Jan 2012

Utility Of Improvised Video-Camera Collars For Collecting Contact Data From White-Tailed Deer: Possibilities In Disease Transmission Studies, Michael J. Lavelle, Scott E. Hygnstrom, Aaron M. Hildreth, Tyler A. Campbell, David B. Long, David G. Hewitt, Jeff Beringer, K. C. Vercauteren

School of Natural Resources: Faculty Publications

Rapidly evolving electronic technology enables wildlife researchers to collect previously unobtainable data. To explore possibilities of using deer-borne cameras (DBCs) to collect behavioral data from an animal’s point of view, we constructed DBCs and deployed them on 26 adult male whitetailed deer (Odocoileus virginianus) within a closed population (405-ha fenced area) in southern Texas just prior to the breeding season during autumn 2010. Our DBCs consisted of global positioning system collars with attached motion-activated trail cameras. We obtained 21,474 video clips from 17 functional DBCs over a period of 14 days. Individual-based data are invaluable in disease and …


Mid-Contract Management Of Conservation Reserve Program Grasslands Provides Benefits For Ring-Necked Pheasant Nest And Brood Survival, Ty W. Matthews, J. Scott Taylor, Larkin A. Powell Jan 2012

Mid-Contract Management Of Conservation Reserve Program Grasslands Provides Benefits For Ring-Necked Pheasant Nest And Brood Survival, Ty W. Matthews, J. Scott Taylor, Larkin A. Powell

School of Natural Resources: Faculty Publications

Conservation Reserve Program (CRP) fields may provide good habitat for nesting and brood-rearing ring-necked pheasants (Phasianus colchicus) during early stages of succession. But, the success of hens in early successional CRP, relative to late successional CRP and other grassland habitats, has yet to be evaluated. The reproductive period is especially critical for populations of pheasants, and CRP’s benefits to hens and chicks may decrease as fields age because of loss of vegetative diversity, decrease in vegetation density, and accumulation of residual litter. During 2005– 2006, we evaluated spatial and temporal variation in nest and brood survival for radio-marked hen pheasants …


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

School of Natural Resources: Faculty Publications

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%) …


Spatial Heterogeneity Across Five Rangelands Managed With Pyric-Herbivory, Devan Allen Mcgranahan, David M. Engle, Samuel D. Fuhlendorf, Stephen L. Winter, James R. Miller, Diane M. Debinski Jan 2012

Spatial Heterogeneity Across Five Rangelands Managed With Pyric-Herbivory, Devan Allen Mcgranahan, David M. Engle, Samuel D. Fuhlendorf, Stephen L. Winter, James R. Miller, Diane M. Debinski

School of Natural Resources: Faculty Publications

1. Many rangelands evolved under an interactive disturbance regime in which grazers respond to the spatial pattern of fire and create a patchy, heterogeneous landscape. Spatially heterogeneous fire and grazing create heterogeneity in vegetation structure at the landscape level (patch contrast) and increase rangeland biodiversity. We analyzed five experiments comparing spatially heterogeneous fire treatments to spatially homogeneous fire treatments on grazed rangeland along a precipitation gradient in the North American Great Plains.

2. We predicted that, across the precipitation gradient, management for heterogeneity increases both patch contrast and variance in the composition of plant functional groups. Furthermore, we predicted that …


Estimating Seasonal Evapotranspiration From Temporal Satellite Images, Ramesh K. Singh, Shuguang Liu, Larry L. Tieszen, Andrew E. Suyker, Shashi B. Verma Jan 2012

Estimating Seasonal Evapotranspiration From Temporal Satellite Images, Ramesh K. Singh, Shuguang Liu, Larry L. Tieszen, Andrew E. Suyker, Shashi B. Verma

School of Natural Resources: Faculty Publications

Estimating seasonal evapotranspiration (ET) has many applications in water resources planning and management, including hydrological and ecological modeling. Availability of satellite remote sensing images is limited due to repeat cycle of satellite or cloud cover. This study was conducted to determine the suitability of different methods namely cubic spline, fixed, and linear for estimating seasonal ET from temporal remotely sensed images. Mapping Evapotranspiration at high Resolution with Internalized Calibration (METRIC) model in conjunction with the wet METRIC (wMETRIC), a modified version of the METRIC model, was used to estimate ET on the days of satellite overpass using eight Landsat images …


Gross Primary Production And Ecosystem Respiration Of Irrigated And Rainfed Maize–Soybean Cropping Systems Over 8 Years, Andrew E. Suyker, Shashi B. Verma Jan 2012

Gross Primary Production And Ecosystem Respiration Of Irrigated And Rainfed Maize–Soybean Cropping Systems Over 8 Years, Andrew E. Suyker, Shashi B. Verma

School of Natural Resources: Faculty Publications

The objective of this study is to examine interannual variability of carbon dioxide exchange and relevant controlling factors in irrigated and rainfed maize–soybean agroecosystems. The mean annual gross primary production (GPP) of irrigated and rainfed maize was 1796 ± 92 g C m−2 y−1 (±standard deviation) and 1536 ± 74 g C m−2 y−1, respectively. Mean annual GPP of soybean (average of irrigated and rainfed crops) was about 56% that of maize. Light use efficiency of maize and soybean during clear sky conditions were 1.96 ± 0.10 and 1.37 ± 0.06 g C MJ−1 …


Interannual And Spatial Impacts Of Phenological Transitions, Growing Season Length, And Spring And Autumn Temperatures On Carbon Sequestration: A North America Flux Data Synthesis, Chaoyang Wu, Alemu Gonsamo, Jing Ming Chen, Werner A. Kurz, David T. Price, Peter M. Lafleur, Rachhpal S. Jassal, Danilo Dragoni, Gil Bohrer, Christopher M. Gough, Shashi B. Verma, Andrew E. Suyker, J. William Munger Jan 2012

Interannual And Spatial Impacts Of Phenological Transitions, Growing Season Length, And Spring And Autumn Temperatures On Carbon Sequestration: A North America Flux Data Synthesis, Chaoyang Wu, Alemu Gonsamo, Jing Ming Chen, Werner A. Kurz, David T. Price, Peter M. Lafleur, Rachhpal S. Jassal, Danilo Dragoni, Gil Bohrer, Christopher M. Gough, Shashi B. Verma, Andrew E. Suyker, J. William Munger

School of Natural Resources: Faculty Publications

Understanding feedbacks of ecosystem carbon sequestration to climate change is an urgent step in developing future ecosystem models. Using 187 site-years of flux data observed at 24 sites covering three plant functional types (i.e. evergreen forests (EF), deciduous forests (DF) and non-forest ecosystems (NF) (e.g., crop, grassland, wetland)) in North America, we present an analysis of both interannual and spatial relationships between annual net ecosystem production (NEP) and phenological indicators, including the flux-based carbon uptake period (CUP) and its transitions, degree-day-derived growing season length (GSL), and spring and autumn temperatures. Diverse responses were acquired between annul NEP and these indicators …


An Alternative Method Using Digital Cameras For Continuous Monitoring Of Crop Status, Toshihiro Sakamoto, Anatoly A. Gitelson, Anthony L. Nguy-Robertson, Timothy J. Arkebauer, Brian D. Wardlow, Andrew E. Suyker, Shashi B. Verma, Michio Shibayama Jan 2012

An Alternative Method Using Digital Cameras For Continuous Monitoring Of Crop Status, Toshihiro Sakamoto, Anatoly A. Gitelson, Anthony L. Nguy-Robertson, Timothy J. Arkebauer, Brian D. Wardlow, Andrew E. Suyker, Shashi B. Verma, Michio Shibayama

School of Natural Resources: Faculty Publications

Crop physiological and phenological status is an important factor that characterizes crop yield as well as carbon exchange between the atmosphere and the terrestrial biosphere in agroecosystems. It is difficult to establish high frequency observations of crop status in multiple locations using conventional approaches such as agronomical sampling and also remote sensing techniques that use spectral radiometers because of the labor intensive work required for field surveys and the high cost of radiometers designed for scientific use. This study explored the potential utility of an inexpensive camera observation system called crop phenology recording system (CPRS) as an alternative approach for …