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Articles 3031 - 3060 of 4183

Full-Text Articles in Natural Resources and Conservation

In Situ Development Of Western Prairie Fringed Orchid Seeds, Protocorms, And Seedlings In Grazed And Non-Grazed Prairie Habitat, Bonnie Warner Alexander, Donald Kirby, Mario Biondini, Edward Dekeyser Jun 2010

In Situ Development Of Western Prairie Fringed Orchid Seeds, Protocorms, And Seedlings In Grazed And Non-Grazed Prairie Habitat, Bonnie Warner Alexander, Donald Kirby, Mario Biondini, Edward Dekeyser

The Prairie Naturalist

In 1989, the U.S. Fish and Wildlife Service listed the western prairie fringed orchid (Platanthera praeclara) as threatened. Although this orchid has been monitored for years, there is little scientific documentation of its biology, ecology, and phenology, nor the impacts of management activities on its populations. Our objectives were to document seed germination and seedling production rates after one year in situ, and compare seed germination in grazed and non-grazed prairie habitat in the Sheyenne National Grassland (SNG) in southeastern North Dakota. Of 18,717 planted seeds, we recovered 1,561 swollen embryos, 94 protocorms, and 51 seedlings. We documented no difference …


Ring-Necked Pheasant Nest Parasitism Of Sharp-Tailed Grouse Nests In Southwest North Dakota, Benjamin A. Geaumont, Kevin K. Sedivec, Christopher S. Schauer Jun 2010

Ring-Necked Pheasant Nest Parasitism Of Sharp-Tailed Grouse Nests In Southwest North Dakota, Benjamin A. Geaumont, Kevin K. Sedivec, Christopher S. Schauer

The Prairie Naturalist

Numerous investigators have reported observations of ring-necked pheasant (RNP; Phasianus colchicus) eggs in nests of other gamebirds and waterfowl species (Errington and Hamerstrom 1938, Westemeier et al. 1998, Hagen et al. 2002, Krakauer and Kimball 2009). Previously recorded hosts include wild turkey (Meleagris gallopavo; Schmutz 1988), northern bobwhite (Colinus virginianus; Westemeier et al. 1989), greater prairie-chickens (Tyrnpanuchus cupido; Westemeier et al. 1998), and lesser prairie-chickens (T. pallidicinctus; Hagen et al. 2002). The reported occurrence of nest parasitism during these studies has generally been low with the highest reported occurrences found in …


Early Winter Feeding On Elm Bark By Eastern Fox Squirrels Near The Western Range Terminus, Dessa K. Montgomery, Raymond S. Matlack Jun 2010

Early Winter Feeding On Elm Bark By Eastern Fox Squirrels Near The Western Range Terminus, Dessa K. Montgomery, Raymond S. Matlack

The Prairie Naturalist

Fox squirrels (Sciurus niger) feed on >30 different types of food across their extensive range ~Korschgen 1981) including tree buds, flowers, fruits, seeds, and, on occasion, bark. For a large portion of the year, fox squirrels rely heavily on tree seeds (Koprowski 1991). For three consecutive years (2007-2009), we observed fox squirrels feeding on bark of elm trees ( Ulmus sp.) on the campus of West Texas A&M University, Canyon, Texas. Squirrels began feeding on bark in late November shortly after leaves had fallen off the trees and continued almost daily throughout the winter. In late February, when …


Using Advancements In Cable-Trapping To Overcome Barriers To Furbearer Management In The United States, Stephen Vantassel, Tim L. Hiller, Kelly D. J. Powell, Scott E. Hygnstrom May 2010

Using Advancements In Cable-Trapping To Overcome Barriers To Furbearer Management In The United States, Stephen Vantassel, Tim L. Hiller, Kelly D. J. Powell, Scott E. Hygnstrom

School of Natural Resources: Faculty Publications

Harvest of furbearers through trapping has been challenged by anti-trapping organizations for centuries, with organizational goals often including prohibition of all forms of trapping. Challenges to trapping may also include dissention among state wildlife agencies, pro-hunting organizations, and pro-trapping organizations. Despite recent efforts by anti-trapping organizations and occasional dissention among consumptive-use groups, national trends in snaring regulations included less restrictive regulations through time. This positive trend may offer opportunities for state wildlife agencies and pro-trapping organizations to enhance the public image of trapping, increase recruitment of trappers, and reverse the increasing trend of wildlife damage and associated costs. We offer …


Winter Ecology Of Buggy Creek Virus (Togaviridae, Alphavirus) In The Central Great Plains, Charles R. Brown, Stephanie A. Strickler, Amy T. Moore, Sarah A. Knutie, Abinash Padhi, Mary Bomberger Brown, Ginger R. Young, Valerie A. O'Brien, Jerome E. Foster, Nicholas Komar May 2010

Winter Ecology Of Buggy Creek Virus (Togaviridae, Alphavirus) In The Central Great Plains, Charles R. Brown, Stephanie A. Strickler, Amy T. Moore, Sarah A. Knutie, Abinash Padhi, Mary Bomberger Brown, Ginger R. Young, Valerie A. O'Brien, Jerome E. Foster, Nicholas Komar

School of Natural Resources: Faculty Publications

A largely unanswered question in the study of arboviruses is the extent to which virus can overwinter in adult vectors during the cold winter months and resume the transmission cycle in summer. Buggy Creek virus (BCRV; Togaviridae, Alphavirus) is an unusual arbovirus that is vectored primarily by the swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) and amplified by the ectoparasitic bug’s main avian hosts, the migratory cliff swallow (Petrochelidon pyrrhonota) and resident house sparrow (Passer domesticus). Bugs are sedentary and overwinter in the swallows’ mud nests. We evaluated the prevalence of BCRV and extent of …


Vegetation Trends On A Waste Rock Repository Cap In The Northern Black Hills, Andrew C. Korth, Gary E. Larson, Lan Xu, Thomas E. Schumacher May 2010

Vegetation Trends On A Waste Rock Repository Cap In The Northern Black Hills, Andrew C. Korth, Gary E. Larson, Lan Xu, Thomas E. Schumacher

The Prairie Naturalist

We assessed successional trends, long-term vegetation sustainability, and soil surface protection during the 2005-2007 growing seasons on the 32-ha Ruby Gulch Waste Rock Repository cap. The cap consisted of 150 cm of rock and soil covering a polyethylene membrane which in turn covered mining waste rock in order to prevent leaching of heavy metals and acidic water into streams. Following construction in 2003, a contractor applied a grass-forb seed mixture to provide soil-surface protection especially for steeply sloped portions of the cap. In 2005, we established 56, 1-m2 plots, and 20, 20-m transects to annually measure canopy cover, basal …


Seasonal Variation In Terrestrial Insect Subsidies To Tropical Streams And Implications For The Diet Of Rivulus Hartii, David C. Owens May 2010

Seasonal Variation In Terrestrial Insect Subsidies To Tropical Streams And Implications For The Diet Of Rivulus Hartii, David C. Owens

School of Natural Resources: Dissertations, Theses, and Student Research

Terrestrial invertebrates subsidize fish diets in lotic ecosystems. Seasonality strongly influences terrestrial invertebrate abundance in temperate regions and alters their delivery to streams. Seasonal changes in the tropics are characterized by distinct wet and dry periods, with marked variation in invertebrate abundance. However, little is known about how these seasonal changes affect invertebrate subsidies and their ecological consequences for tropical streams. We measured the effect of rainfall and canopy density on terrestrial invertebrate falling input, as well as seasonal variation in falling input, benthic and drifting invertebrate, and Rivulus hartii (Hart’s Rivulus) diet composition during both the wet and dry …


2009 Vascular Plant Surveys In The Central Niobrara River Valley, Nebraska, Mary Ann Feist, Paul B. Marcum, Loy R. Philippe, Brenda Molano-Flores, Valerie Sivicek Apr 2010

2009 Vascular Plant Surveys In The Central Niobrara River Valley, Nebraska, Mary Ann Feist, Paul B. Marcum, Loy R. Philippe, Brenda Molano-Flores, Valerie Sivicek

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

The Niobrara River Valley in northern Nebraska is an important floristic area. It harbours a number of bryophyte, vascular plant, and animal species that are rarely found in close proximity to one another. Many of these species are more typical farther to the north, east, or west, but over time as climates have changed, have come to settle together in this valley (Kaul et al. 1988). The central Niobrara River Valley may be the most botanically diverse region of Nebraska. Approximately 580 of Nebraska’s roughly 2,000 vascular plant species have been documented for the Niobrara Valley Preserve (Schneider et al. …


Influence Of Canopy Cover, Nutrients, And Season On Stoichiometric Variation Of Epilithon In Neotropical Streams., Tyler J. Kohler Apr 2010

Influence Of Canopy Cover, Nutrients, And Season On Stoichiometric Variation Of Epilithon In Neotropical Streams., Tyler J. Kohler

School of Natural Resources: Dissertations, Theses, and Student Research

Light and nutrient availability are strong factors determining the nutrient composition of epilithon in temperate stream ecosystems. However, little work has been performed regarding this association in tropical streams. In our study, we investigated 1) how gradients of canopy cover and nutrients and 2) wet/dry seasonality influence epilithon standing stocks and nutrient quality. We surveyed 18 stream locations within six watersheds that varied in nutrient and light conditions during both the wet and dry seasons on the island of Trinidad to test these questions. Additionally, we sampled four stream reaches bimonthly for three years, thinning the canopy of two of …


An Artesian Well System In Beaver Crossing, Nebraska, It's Development And Demise, Mary Lanik Apr 2010

An Artesian Well System In Beaver Crossing, Nebraska, It's Development And Demise, Mary Lanik

Department of Environmental Studies: Undergraduate Student Theses

ABSTRACT

Nebraska has a veritable wealth of groundwater. The High Plains Aquifer underlies most of the state, and within its sand and gravel deposits, many interconnected aquifers provide fresh water for a variety of uses.

One of the most spectacular examples of this resource is the artesian well. Beaver Crossing, Nebraska was once home to one of the most prolific artesian systems in the state before its demise. Founded in the 1880’s, Beaver Crossing soon became known for its many artesian wells, that provided leisure activities and supported profitable business ventures such as small farming, ice production and aquiculture. Eventually …


A Proposed Plan For Managing Eastern Nebraska's Saline Wetlands, Vandhana Rabadinanth Apr 2010

A Proposed Plan For Managing Eastern Nebraska's Saline Wetlands, Vandhana Rabadinanth

Department of Environmental Studies: Undergraduate Student Theses

Abstract Eastern Nebraska’s saline wetlands play a major role in Nebraska’s environmental place in the world. Besides the role of scientific changes being important, education also is essential in the conservation of these wetlands. Through the observation of Salt Creek tiger beetle (Cicindela nevadica lincolniana) and soil electroconductivity, I propose that we need to reform Nebraska’s education system to help schools play a bigger part in environmental issues such as this one. There is a drastic trend in the correlations between Salt Creek tiger beetle populations and wetland degradation. Since many Lincoln residents have a limited knowledge of what is …


Droughtscape, Spring 2010, Kelly Smith Apr 2010

Droughtscape, Spring 2010, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

NDMC and NC Drought Council Team Up

Drought to Intensify in Northwest and Hawaii

International Work

Impacts Recorded in Hawaii and Western States

U.S. Drought Monitor Archives Enhanced

Low-Water Impact Surveys Completed

K-12 Drought Outreach


Minimum Riparian Buffer Width For Maintaining Water Quality And Habitat Along Stevens Creek, Sammi Bray Apr 2010

Minimum Riparian Buffer Width For Maintaining Water Quality And Habitat Along Stevens Creek, Sammi Bray

Department of Environmental Studies: Undergraduate Student Theses

ABSTRACT Riparian buffer zones are important sites of biodiversity, sediment trapping, pollutant removal, and hydrologic regulation that have significant implications for both people and wildlife. Urbanization’s influence on and need for adequate water quality increases the need for careful planning in regards to riparian areas. Wildlife are key components in the ecosystem functions of riparian zones and require consideration in peri-urban planning as well. This study reviews relevant literature to determine the recommended minimum riparian buffer width for maintaining water quality and habitat along Stevens Creek in Lincoln, Nebraska. Only sources that listed a specific purpose related to water quality …


Distribution Of Rain Gardens In Lincoln Nebraska: Are Rain Gardens More Likely To Be Built Near Bodies Of Water, Eric Voecks Apr 2010

Distribution Of Rain Gardens In Lincoln Nebraska: Are Rain Gardens More Likely To Be Built Near Bodies Of Water, Eric Voecks

Department of Environmental Studies: Undergraduate Student Theses

Abstract Rain gardens are an important tool in reducing the amount of stormwater runoff and accompanying pollutants from entering the city’s streams and lakes, and reducing their water quality. This thesis project analyzed the number of rain gardens installed through the City of Lincoln Nebraska Watershed Management’s Rain Garden Water Quality Project in distance intervals of one-eighth mile from streams and lakes. This data shows the distribution of these rain gardens in relation to streams and lakes and attempts to determine if proximity to streams and lakes is a factor in homeowners installing rain gardens. ArcGIS was used to create …


Herbicides And Amphibian Populations, Zach Shirk Apr 2010

Herbicides And Amphibian Populations, Zach Shirk

Department of Environmental Studies: Undergraduate Student Theses

Amphibians are a unique class of species that are found worldwide except Antarctica and Greenland. They range in size from a few millimeters to over six feet long. Amphibian’s habitats are as various as their size, but one thing in common is that amphibians require an aquatic location to breed. Amphibians live in deserts, mountain prairies, rain forest, wetlands, and almost everywhere in between. Amphibians are an integrated part of most natural ecosystems across the world. Amphibians are a critical part of many food chains; they provide the important link between secondary and tertiary consumers. Amphibians are indicator species in …


The Influence Of Partial Timber Harvesting In Riparian Buffers On Macroinvertebrate And Fish Communities In Small Streams In Minnesota, Usa, Christopher J. Chizinski, Bruce Vondracek, Charles R. Blinn, Raymond M. Newman, Dickson M. Atuke, Keith Fredricks, Nathaniel A. Hemstad, Eric Merten, Nicholas Schlesser Feb 2010

The Influence Of Partial Timber Harvesting In Riparian Buffers On Macroinvertebrate And Fish Communities In Small Streams In Minnesota, Usa, Christopher J. Chizinski, Bruce Vondracek, Charles R. Blinn, Raymond M. Newman, Dickson M. Atuke, Keith Fredricks, Nathaniel A. Hemstad, Eric Merten, Nicholas Schlesser

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Relatively few evaluations of aquatic macroinvertebrate and fish communities have been published in peer-reviewed literature detailing the effect of varying residual basal area (RBA) after timber harvesting in riparian buffers. Our analysis investigated the effects of partial harvesting within riparian buffers on aquatic macroinvertebrate and fish communities in small streams from two experiments in northern Minnesota northern hardwood-aspen forests. Each experiment evaluated partial harvesting within riparian buffers. In both experiments, benthic macroinvertebrates and fish were collected 1 year prior to harvest and in each of 3 years after harvest. We observed interannual variation for the macroinvertebrate abundance, diversity and taxon …


A Model‐Data Intercomparison Of Co2 Exchange Across North America: Results From The North American Carbon Program Site Synthesis, Christopher R. Schwalm, Christopher A. Williams, Kevin Schaefer, Ryan S. Anderson, M. Altaf Arain, Ian Baker, Alan Barr, T. Andrew Black, Guangsheng Chen, Jing Ming Chen, Philippe Ciais, Kenneth J. Davis, Ankur R. Desai, Michael Dietze, Danilo Dragoni, Marc L. Fischer, Lawrence B. Flanagan, Robert Grant, Lianhong Gu, David Hollinger, R. Cesar Izaurralde, Chris Kucharik, Peter Lafleur, Beverly E. Law, Longhui Li, Zhengpeng Li, Shuguang Liu, Erandathie Lokupitiya, Yiqi Luo, Siyan Ma, Hank Margolis, Roser Matamala, Harry Mccaughey, Russell K. Monson, Walter C. Oechel, Changhui Peng, Benjamin Poulter, David T. Price, Dan M. Riciutto, William Riley, Alok Kumar Sahoo, Michael Sprintsin, Jianfeng Sun, Hanqin Tian, Christian Tonitto, Hans Verbeeck, Shashi B. Verma Jan 2010

A Model‐Data Intercomparison Of Co2 Exchange Across North America: Results From The North American Carbon Program Site Synthesis, Christopher R. Schwalm, Christopher A. Williams, Kevin Schaefer, Ryan S. Anderson, M. Altaf Arain, Ian Baker, Alan Barr, T. Andrew Black, Guangsheng Chen, Jing Ming Chen, Philippe Ciais, Kenneth J. Davis, Ankur R. Desai, Michael Dietze, Danilo Dragoni, Marc L. Fischer, Lawrence B. Flanagan, Robert Grant, Lianhong Gu, David Hollinger, R. Cesar Izaurralde, Chris Kucharik, Peter Lafleur, Beverly E. Law, Longhui Li, Zhengpeng Li, Shuguang Liu, Erandathie Lokupitiya, Yiqi Luo, Siyan Ma, Hank Margolis, Roser Matamala, Harry Mccaughey, Russell K. Monson, Walter C. Oechel, Changhui Peng, Benjamin Poulter, David T. Price, Dan M. Riciutto, William Riley, Alok Kumar Sahoo, Michael Sprintsin, Jianfeng Sun, Hanqin Tian, Christian Tonitto, Hans Verbeeck, Shashi B. Verma

School of Natural Resources: Faculty Publications

Our current understanding of terrestrial carbon processes is represented in various models used to integrate and scale measurements of CO2 exchange from remote sensing and other spatiotemporal data. Yet assessments are rarely conducted to determine how well models simulate carbon processes across vegetation types and environmental conditions. Using standardized data from the North American Carbon Program we compare observed and simulated monthly CO2 exchange from 44 eddy covariance flux towers in North America and 22 terrestrial biosphere models. The analysis period spans ~220 site‐years, 10 biomes, and includes two large‐scale drought events, providing a natural experiment to evaluate …


Translocation To A Fragmented Landscape: Survival, Movement, And Site Fidelity Of Northern Bobwhites, Theron M. Terhune, D. Clay Sisson, William E. Palmer, Brant C. Faircloth, H. Lee Stribling, John P. Carroll Jan 2010

Translocation To A Fragmented Landscape: Survival, Movement, And Site Fidelity Of Northern Bobwhites, Theron M. Terhune, D. Clay Sisson, William E. Palmer, Brant C. Faircloth, H. Lee Stribling, John P. Carroll

School of Natural Resources: Faculty Publications

Habitat fragmentation, degradation, and loss have taxed early-successional species including the Northern Bobwhite (Colinus virginianus) and numerous grassland obligate birds. Translocation is often applied to counteract the consequences of habitat fragmentation through the creation, reestablishment, or augmentation of wild populations for the purposes of conservation, biodiversity maintenance. However, the implementation of these techniques is often conducted without valid experimental designs and therefore lacks robust, empirical data needed to evaluate and advance the knowledge and application of translocation. Despite the increasing amount of habitat management applied to patches among fragmented landscapes, a paucity of source populations often limits natural …


Upwelling Couples Chemical And Biological Dynamics Across The Littoral And Pelagic Zones Of Lake Tanganyika, East Africa, Jessica R. Corman, P. B. Mcintyre, B. Kuboja, W. Mbemba, D. Fink, C. W. Wheeler, C. Gans, E. Michel, A. S. Flecker Jan 2010

Upwelling Couples Chemical And Biological Dynamics Across The Littoral And Pelagic Zones Of Lake Tanganyika, East Africa, Jessica R. Corman, P. B. Mcintyre, B. Kuboja, W. Mbemba, D. Fink, C. W. Wheeler, C. Gans, E. Michel, A. S. Flecker

School of Natural Resources: Faculty Publications

We studied the effects of upwelling on nutrient and phytoplankton dynamics in the pelagic and littoral zones of Lake Tanganyika near Kigoma, Tanzania. During the dry season of 2004, a rise in the thermocline and sudden drop in surface water temperatures indicated a substantial upwelling event. Increases in concentrations of nitrate, soluble reactive phosphorus, and silica in the surface waters occurred simultaneously after the temperature drop. Within days, chlorophyll a concentrations increased and remained elevated, while inorganic nutrient concentrations returned to preupwelling levels and organic nutrient concentrations peaked. We observed parallel temporal patterns of water temperature, nutrient concentrations, and phytoplankton …


Recursive Streamflow Forecasting: A State-Space Approach, Jozsef Szilagyi, Andras Szollosi-Nagy Jan 2010

Recursive Streamflow Forecasting: A State-Space Approach, Jozsef Szilagyi, Andras Szollosi-Nagy

School of Natural Resources: Faculty Publications

No abstract provided.


Testing The Intergenerational Differences In Mental Boundaries, John E. Barbuto Jr., Stephanie Bryant, Lisa Pennisi Jan 2010

Testing The Intergenerational Differences In Mental Boundaries, John E. Barbuto Jr., Stephanie Bryant, Lisa Pennisi

School of Natural Resources: Faculty Publications

No abstract provided.


Locus Of Control, Sources Of Motivation, And Mental Boundaries As Antecedents Of Leader-Member Exchange Quality, John E. Barbuto Jr., Dayna Finch Weltmer, Lisa A. Pennisi Jan 2010

Locus Of Control, Sources Of Motivation, And Mental Boundaries As Antecedents Of Leader-Member Exchange Quality, John E. Barbuto Jr., Dayna Finch Weltmer, Lisa A. Pennisi

School of Natural Resources: Faculty Publications

No abstract provided.


Diurnal Fluctuations In Shallow Groundwater Levels And In Streamflow Rates And Their Interpretation: A Review, Zoltan Gribovszki, Jozsef Szilagyi, Peter Kalicz Jan 2010

Diurnal Fluctuations In Shallow Groundwater Levels And In Streamflow Rates And Their Interpretation: A Review, Zoltan Gribovszki, Jozsef Szilagyi, Peter Kalicz

School of Natural Resources: Faculty Publications

No abstract provided.


Complementary-Relationship-Based Evapotranspiration Mapping (Cremap) Technique For Hungary, Jozsef Szilagyi, Akos Kovacs Jan 2010

Complementary-Relationship-Based Evapotranspiration Mapping (Cremap) Technique For Hungary, Jozsef Szilagyi, Akos Kovacs

School of Natural Resources: Faculty Publications

No abstract provided.


Introduction To The Basic Drivers Of Climate, Alison P. Stevens Jan 2010

Introduction To The Basic Drivers Of Climate, Alison P. Stevens

School of Natural Resources: Faculty Publications

Climates on Earth vary from the warm, wet tropics to the cold, dry Arctic and Antarctic. What drives this variation?

Every day, we note the weather: temperature, rain, cloud cover, wind and humidity. Climate is the long-term prevailing weather in an area and is largely determined by temperature and precipitation. The climate in a desert is hot and dry. The climate in the tropics is warm and wet. The climate of a particular area is the largest determinant to the life found there. Climate is a key focus in ecology. Variations in climate include daily and seasonal cycles. Climatic variation …


Albedo Estimates For Land Surface Models And Support For A New Paradigm Based On Foliage Nitrogen Concentration, David Y. Hollinger, S. V. Ollinger, A. D. Richardson, T. P. Meyers, D. B. Dail, M. E. Martin, N. A. Scott, T. J. Arkebauer, D. D. Baldocchi, K. L. Clark, P. S. Curtis, K. J. Davis, A. R. Desai, D. Dragoni, M. L. Goulden, L. Gu, G. G. Katul, S. G. Pallardy, K. T. Pawu, H. P. Schmid, P. C. Stoy, Andrew E. Suyker, Shashi Verma Jan 2010

Albedo Estimates For Land Surface Models And Support For A New Paradigm Based On Foliage Nitrogen Concentration, David Y. Hollinger, S. V. Ollinger, A. D. Richardson, T. P. Meyers, D. B. Dail, M. E. Martin, N. A. Scott, T. J. Arkebauer, D. D. Baldocchi, K. L. Clark, P. S. Curtis, K. J. Davis, A. R. Desai, D. Dragoni, M. L. Goulden, L. Gu, G. G. Katul, S. G. Pallardy, K. T. Pawu, H. P. Schmid, P. C. Stoy, Andrew E. Suyker, Shashi Verma

School of Natural Resources: Faculty Publications

Vegetation albedo is a critical component of the Earth’s climate system, yet efforts to evaluate and improve albedo parameterizations in climate models have lagged relative to other aspects of model development. Here, we calculated growing season albedos for deciduous and evergreen forests, crops, and grasslands based on over 40 site-years of data from the AmeriFlux network and compared them with estimates presently used in the land surface formulations of a variety of climate models. Generally, the albedo estimates used in land surface models agreed well with this data compilation. However, a variety of models using fixed seasonal estimates of albedo …


A Black Hills-Madison Aquifer Origin For Dakota Aquifer Groundwater In Northeastern Nebraska, Randy Stotler, F. Edwin Harvey, David C. Gosselin Jan 2010

A Black Hills-Madison Aquifer Origin For Dakota Aquifer Groundwater In Northeastern Nebraska, Randy Stotler, F. Edwin Harvey, David C. Gosselin

School of Natural Resources: Faculty Publications

Previous studies of the Dakota Aquifer in South Dakota attributed elevated groundwater sulfate concentrations to Madison Aquifer recharge in the Black Hills with subsequent chemical evolution prior to upward migra¬tion into the Dakota Aquifer. This study examines the plausibility of a Madison Aquifer origin for groundwater in northeastern Nebraska. Dakota Aquifer water samples were collected for major ion chemistry and isotopic analysis (18O, 2H, 3H, 14C, 13C, 34S, 18O-SO4, 87Sr, 37Cl). Results show that groundwater beneath the eastern, un¬confined portion of the study area is distinctly different from …


Measuring Economic Impacts Of Drought: A Review And Discussion, Ya Ding, Michael J. Hayes, Melissa Widhalm Jan 2010

Measuring Economic Impacts Of Drought: A Review And Discussion, Ya Ding, Michael J. Hayes, Melissa Widhalm

School of Natural Resources: Faculty Publications

A comprehensive assessment of drought economic impacts provides critical information to rational decisions supporting drought mitigation policies and programs. The objective of this paper is to increase the understanding of the full scope of drought economic impacts and the associated quantitative assessment methodologies. To accomplish this, the paper reviews the literature of drought economic impact studies in both agricultural and non-agricultural sectors, summarizes the methods and data employed, compares the various results, and investigates the problems and limitations of previous studies. The paper concludes with a discussion of the challenges and directions of future improvement on drought economic impact assessment.


Algorithms For Remote Estimation Of Chlorophyll-Α In Coastal And Inland Waters Using Red And Near Infrared Bands, Alexander A. Gilerson, Anatoly A. Gitelson, Jing Zhou, Daniela Gurlin, Wesley Moses, Ioannis Ioannou, Samir A. Ahmed Jan 2010

Algorithms For Remote Estimation Of Chlorophyll-Α In Coastal And Inland Waters Using Red And Near Infrared Bands, Alexander A. Gilerson, Anatoly A. Gitelson, Jing Zhou, Daniela Gurlin, Wesley Moses, Ioannis Ioannou, Samir A. Ahmed

School of Natural Resources: Faculty Publications

Remote sensing algorithms that use red and NIR bands for the estimation of chlorophyll-α concentration [Chl] can be more effective in inland and coastal waters than algorithms that use blue and green bands. We tested such two-band and three-band red-NIR algorithms using comprehensive synthetic data sets of reflectance spectra and inherent optical properties related to various water parameters and a very consistent in situ data set from several lakes in Nebraska, USA. The two-band algorithms tested with MERIS bands were Rrs(708)/Rrs(665) and Rrs(753)/Rrs(665). The three-band algorithm with MERIS bands was in the form R3 …


Non-Destructive Estimation Pigment Content Ripening Quality And Damage In Apple Fruit With Spectral Reflectance In The Visible Range, Alexei E. Solovchenko, Olga B. Chivkunova, Anatoly A. Gitelson, Mark N. Merzlyak Jan 2010

Non-Destructive Estimation Pigment Content Ripening Quality And Damage In Apple Fruit With Spectral Reflectance In The Visible Range, Alexei E. Solovchenko, Olga B. Chivkunova, Anatoly A. Gitelson, Mark N. Merzlyak

School of Natural Resources: Faculty Publications

Modern non-destructive optical-reflectance-based techniques for estimation of pigment (chlorophyll, carotenoid, anthocyanin, and flavonol) contents, the rate of on- and off-tree ripening as well as for detection of common physiological disorders, such as sunscald, superficial scald, and water core, and other damages to apple fruit are an emphasis on the methods developed by the authors. The basic spectral features of fruit reflectance in the visible and near infra-red are briefly considered together with their implications for the development of algorithms for non-destructive pigment content assessment. The use of reflectance spectroscopy for estimating chlorophyll and carotenoid content as well as carotenoid/chlorophyll ratio …