Physical Sciences and Mathematics Commons^™

Scanning Electron Microscopic Study Of Quartz Sand Surface Features, Ash Hollow Formation, Ogallala Group, Western Nebraska, Patricia E. Helland, Robert F. Diffendal

Papers in Natural Resources

In field studies of the late Tertiary Ash Hollow Formation of the Ogallala Group in western Nebraska the alluvial deposits are composed of large volumes of sand and gravel up to large cobbles. Because the current understanding of the climate of the region at the time of deposition does not provide for a source for deposits of this character, a scanning electron microscopic study of the surface features on the quartz sand grains from these sediments was undertaken. Nine samples, collected from locations in Banner, Morrill and Keith Counties, were examined to see if they had one or more of …

Late Paleozoic Cyclic Sedimentation In Southeastern Nebraska: A Field Guide, Roger K. Pabian, Robert F. Diffendal

Papers in Natural Resources

People studying and collecting sedimentary rocks, minerals, and fossils in eastern Nebraska often find that locating rock exposures can be difficult. Most of the rolling hills in the eastern sixth of the state are underlain by thick, interlayered, glacial deposits, loess (windblown silt), and alluvium (stream-deposited sediments) of very young geologic age (fig. 1). These sediments cover the bedrock in most of that area.

Natural exposures and human excavations of bedrock are mostly confined to the sides and floors of stream valleys. However, in the southeasternmost counties of the state, the younger sediment cover is commonly thin or absent. Pawnee …

Plate Tectonics, Space, Geologic Time, And The Great Plains: A Primer For Non-Geologists, Robert F. Diffendal

Papers in Natural Resources

For most Americans, "The Great Plains" evokes images of grasslands, dust storms, prairie fires, Indians on horseback, cowboys and wheat lands, and perhaps flat valleys crossed by braided rivers carrying a heavy load of sand and gravel, extremes of weather, and a climate typified by an alternation of droughts and wetter periods. Geologists picture such general images, too, but they also see radical changes in the landscape over periods expressed in millions rather than hundreds of years. Geologically speaking, human activities on the Great Plains are too recent to have much of a place in the broad geologic history of …

Aerospace Monitoring Of Water Quality, Anatoly A. Gitelson, Ferenc Szilagyi

Papers in Natural Resources

The potential of using remote sensing for the detection of chlorophyll-a (CHL), dissolved organic matter (DOM), and suspended matter (SM) concentrations in coastal and inland waters was investigated using measurements of (ir)radiance spectra along with simultaneous earth-reference data. The range of CHL was 0.1 to 350 μg/l, SM was 0.1 to 43 mg/l, and DOM absorption at the 380 nm was 0.1 to 10^-1. Factor and signature analysis reveal allometric relationships between constituent concentrations C and functions of reflectance Z_k of the type C_k = aZ_k^b. Appropriate functions of R were found: Z …

Modeling Canopy Stomatal Conductance In A Temperate Grassland Ecosystem, Joon Kim, Shashi B. Verma

Papers in Natural Resources

No abstract provided.

Photoperiod Control Of Poplar Bark Storage Protein Accumulation, Gary D. Coleman, Tony H.H. Chen, Stephen G. Ernst, Leslie Fuchigami

Papers in Natural Resources

Bark storage proteins (BSPs) accumulate in the inner bark parenchyma of many woody plants during autumn and winter. We investigated the effect of a short-day (SD) photoperiod on the accumulation of the 32-kilodalton bark storage protein of poplar (Populus deltoides Bart. ex Marsh.) under controlled environmental and natural growing conditions. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and protein gel blot analysis revealed that 10 days of SD exposure (8 hours of light) resulted in a 20% increase in the relative abundance of the 32-kilodalton bark storage protein of poplar. After 17 days of SD exposure, the 32-kilodalton bark storage protein …

Windbreaks And Wildlife, Ron J. Johnson, Mary M. Beck, James R. Brandle

Papers in Natural Resources

Windbreaks can support wildlife that add beauty and pleasure to our lives. They also sustain birds that eat insect pests, improve hunting opportunities, and provide a focal point for family outdoor activities. The world around us would be less appealing without the stimulation - the color, sounds, tracks, and mystery - of wild creatures; windbreaks help wildlife and in some areas are essential to survival of the wildlife we enjoy. You can add wildlife benefits to windbreak plantings whether your main goal is to shelter crops, livestock, + roads, or a home or farmstead.

This publication provides an overview of …

Predicting Canopy Light-Use Efficiency From Leaf Characteristics, T. J. Arkebauer

Papers in Natural Resources

No abstract provided.

Modeling Canopy Photosynthesis: Scaling Up From A Leaf To Canopy In A Temperate Grassland Ecosystem, S. B. Verma

Papers in Natural Resources

No abstract provided.

How Windbreaks Work, James R. Brandle, Sherman Finch

Papers in Natural Resources

Windbreaks are barriers used to reduce and redirect wind. They usually consist of trees and shrubs, but may also be perennial or annual crops and grasses, fences, or other materials. The reduction in wind speed behind a windbreak modifies the environmental conditions or microclimate in the sheltered zone.

As wind blows against a windbreak, air pressure builds up on the windward side (the side towards the wind), and large quantities of air move up and over the top or around the ends of the windbreak. Windbreak structure – height, density, number of rows, species, composition, length, orientation, and continuity – …

Leaf Reflectance And Transmittance In Soybean And Corn, Elizabeth A. Walter-Shea, Blaine Blad

Papers in Natural Resources

No abstract provided.

Estimation Of Shortwave Hemispherical Reflectance (Albedo) From Bidirectionally Reflected Radiance Data, Elizabeth A. Walter-Shea, Blaine L. Blad

Papers in Natural Resources

No abstract provided.

Wbecon: A Windbreak Evaluation Model 1, James R. Brandle

Papers in Natural Resources

No abstract provided.

Windbreaks In Sustainable Agricultural Systems, Vernon C. Quam, John Gardner, James R. Brandle, Teresa K. Boes

Papers in Natural Resources

Sustainable agriculture is a system of whole-farm resource use balanced with whole-farm productivity. The overall level of productivity achieved is dependent upon the ability to coordinate and manage simultaneously the soil, water, plant, and animal resources within climatic and economic limits. Both the kind and amount of plants and animals supported by the system are important and play significant roles, both individually and collectively in maintaining a healthy farm environment. In the future, integrated systems will help reduce human impact on resources while providing sufficient supplies of high quality food and fiber.

Windbreaks provide protection for people, animals, buildings, crops, …

Windbreak Establishment, Patricia Boehner, James R. Brandle, Sherman Finch

Papers in Natural Resources

A successful windbreak planting depends on proper establishment and care during the first few years after planting. Time spent in site preparation, weed control, and replanting is repaid many times during the lifetime of the windbreak. Take no shortcuts in the planning and establishment of your windbreak.

Windbreaks are investments in the future value of your property. Each windbreak system is unique and your windbreak should be designed for your site and objectives. Your local conservation office can provide help in designing and installing your windbreak. These organizations can also help with recommendations on where to buy planting stock, and …