Physical Sciences and Mathematics Commons^™

Elm Trees And Elm Leaf Beetles: Patterns Of Herbivory, Cliff A. Lemen

School of Natural Resources: Faculty Publications

The rate of attack on elm seedlings by the Elm Leaf Beetle is affected by the seedlings position relative to adult elms. Those seedlings directly under adult trees suffer 580 times the insect attack from the beetles as seedlings not directly under adult elms. Excluding seedlings under adult elms, the number of egg masses found on an elm plant is directly proportional to its size. It was found that below a certain size seedlings were completely free from beetle attack.

Limitations In The Use Of Leaf Dry Weight And Leaf Number For Predicting Leaf Area Of Soybeans, S.N. Ogbuehi, J.R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Influence Of Windbreak-Shelter On Soybean Production Under Rainfed Conditions, S.N. Ogbuehi, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Influence Of Windbreak-Shelter On Soybean Production Under Rainfed Conditions, S.N. Ogbuehi, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Forestry For Wildlife Habitat Improvement. Nebraska Cooperative Extension Service Ec 81-1747, Ec 80-1747, Frank A. Hershey, Howard L. Wiegers

School of Natural Resources: Faculty Publications

Wildlife cannot exist without food and protective cover. Natural and planted woodlands contribute significantly to these essentials. This circular describes habitat needs of wildlife, recommends forestry practices for habitat improvement, and gives examples of practices to improve habitat for pheasant, quail, and deer.

Variety, rather than uniformity of vegetation, benefits most wildlife species. Management which results in a diverse plant community with many stages of growth can increase the numbers and species of wildlife. Techniques which create improved conditions for woodland wildlife are fundamentally the same as those designed to grow good timber.

Plant And Air Temperatures In Differentially-Irrigated Corn, B. L. Blad

School of Natural Resources: Faculty Publications

No abstract provided.

Mass And Energy Exchanges Of A Soybean Canopy Under Various Environmental Regimes, S. B. Verma

School of Natural Resources: Faculty Publications

No abstract provided.

Allocation Of Reproductive Effort To The Male And Female Strategies In Wind-Pollinated Plants, Cliff A. Lemen

School of Natural Resources: Faculty Publications

Amaranthus and several other wind-pollinated species of plants are used to test some of the theoretical models of relative reproductive effort towards the male and female sexes. Consistent with these models, in self-compatible, monoecious Amaranthus, Chenopodium, Digitaria, Setaria, and Lepidium, female effort represented over 90% of the total reproductive effort. Also consistent with predictions, Lolium, a self-incompatible wind-pollinated species, was found to have about equal male and female effort. A method is described here that should prove useful in quantifying male and female effort in both wind and insect-pollinated species of plants.

Relationship Between Relative Brain Size And Climbing Ability In Peromyscus, Cliff A. Lemen

School of Natural Resources: Faculty Publications

Eisenberg and Wilson (Evolution, 32:740-751, 1978) have documented an interesting relationship between the relative brain size of bats and the complexity of the habitat in which they forage. They found that bats that fly and forage through foliage have larger brains relative to their body size than those that forage in open air. Their explanation was that bats in the complex habitat must process more complex sonic information to navigate through the foliage. In order to do this a larger brain is required.

The Peromyscus of North America may offer a similar paradigm as far as habitat complexity …

Intrapopulational Morphological Variation As A Predictor Of Feedlng Behavior In Deermice, Richard A. Smartt, Cliff A. Lemen

School of Natural Resources: Faculty Publications

Within populations of animals that have determinate growth, all fully grown adults, even of one sex, are not identical. Both genetic and environmental factors are responsible for this variation. In recent years the importance of this variation has received much attention (Mayr 1963; Van Valen 1965; Fretwell 1969; Soule and Stewart 1970; Rothstein 1973). The important question asked has been, What effect does this morphological variation have on niche width and the ecology of a population? Implicit in many of these works is the concept that differences in the morphologies of population members can result in differences in their niches. …

Reflectorized Soybean Canopy In Relation To Transpiration And Herbicide Phytotoxicity, S.N. Ogbuehi, J.R.C. Leavitt, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Regional Tectonics And Seismicity Of Eastern Nebraska, Annual Report July 1980 - June 1981, R. R. Burchett

School of Natural Resources: Faculty Publications

This annual report presents and interprets the information obtained by the Conservation and Survey Division (Nebraska Geological Survey) during contract year July 1, 1980, to June 30, 1981, under contract NRC-04-76-3lS with the U. S. Nuclear Regulatory Commission. The information pertains to the geology, structure, tectonics, and seismicity of eastern Nebraska with emphasis on central Otoe County. Some of the information presented here results from a combination of studies begun in earlier years but the greater part results from studies begun during the contract year.

The scope of the studies is summarized as follows:

1. Rock outcrops in Otoe County …

The Rush Creek – Lisco Structural Basin, Garden And Morrill Counties, Nebraska, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

Detailed field mapping of outcrops in southern Garden and Morrill counties, Nebraska, has revealed a drop of more than 60 m (200 ft) in 4.8 km (3 mi) in the elevation of the contact between the Brule Formation and the Ogallala Group as exposed on the east side of Rush Creek. Beds of silt, sand, siltstone, and volcanic ash locally dip to the northwest at angles up to 8.5'. The contact between the two formations cannot be seen on the west side of Rush Creek but beds in the Ogallala Group there dip to the north and northeast. Rocks north …

A Gering Formation (Miocene) Pumice Conglomerate And Associated Beds From Broadwater, Nebraska, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

The Mitchell Pass Member of the Gering Formation was defined by Vondra, Schultz, and Stout in 1969 on the basis of exposures in the Wildcat Ridge area of western Nebraska. The basal part of the member in many areas of Wildcat Ridge is a pumice-pebble conglomerate bed. A newly discovered pumice-pebble conglomerate locality occurs north of Broadwater, Nebraska, some twenty miles east of the easternmost previously reported exposure of the pumice conglomerate at Redington Gap on Wildcat Ridge. Pumice samples from Redington Gap and Broadwater have the same index of refraction and similar inclusions. Beds above the conglomerate and below …

An Objective Forecast Method Developed For Lake Ontario Induced Snowfall Systems, K. F. Dewey

School of Natural Resources: Faculty Publications

A research effort was initiated in 1976 to develop an objective lake-effect snowfall forecast model for each of the Great Lakes. It is the purpose of this paper to present the development and evaluation of the forecast method which was created for the Lake Ontario induced snowfall systems. All Lake Ontario lake-effect days were identified for a 10-yead period prior to the 1976 snowfall season. Upper air surface observations were combined with overlake data for these lake-effect periods. The dominant predictors were derived through the diagnostic ability of stepwise multiple discriminant analysis. The final product of this research effort was …

Lake Erie Induced Mesosystems- An Operational Forecast Model, Kenneth F. Dewey

School of Natural Resources: Faculty Publications

All Lake Erie lake-effect days for a 10-year period prior to the 1976-77 snowfall season were utilized in the development of an operational lake-effect snowfall forecast model. Upper air and surface observation were combined with overlake data and analyzed, using stepwise multiple-discriminant analysis. A nine-predictor mesoscale forecast model resulted from this statistical test and its performance was evaluated during the 1976-77 and 1977-78 snowfall seasons. The results of this evaluation indicate that it is possible to predict six intensities of the Lake Erie lake-effect snowstorm using this mesoscale model.

Aerial And Crop Resistances Affecting Energy Transport, S. B. Verma, B. J. Barfield

School of Natural Resources: Faculty Publications

No abstract provided.

Turbulence Under Conditions Of Sensible Heat Advection, R. P. Motha, S. B. Verma, N. J. Rosenberg

School of Natural Resources: Faculty Publications

No abstract provided.

Exchange Coefficients Under Sensible Heat Advection Determined By Eddy Correlation, S. B. Verma

School of Natural Resources: Faculty Publications

No abstract provided.

An Objective Forecast Method Developed For Lake Ontario Induced Snowfall Systems, K. F. Dewey

School of Natural Resources: Faculty Publications

A research effort was initiated in 1976 to develop an objective lake-effect snowfall forecast model for each of the Great Lakes. It is the purpose of this paper to present the development and evaluation of the forecast method which was created for the Lake Ontario induced snowfall systems. All Lake Ontario lake-effect days were identified for a 10-year period prior to the 1976 snowfall season. Upper air and surface observations were combined with overlake data for these lake-effect periods. The dominant predictors were derived through the diagnostic ability of stepwise multiple discriminant analysis. The final product of this research effort …

The States And Natural Hazards, The Council Of State Governments, Robert Kuzelka

School of Natural Resources: Faculty Publications

No abstract provided.

Regional Tectonics And Seismicity Of Eastern Nebraska, R. R. Burchett

School of Natural Resources: Faculty Publications

This annual report presents and interprets the information obtained by the Conservation and Survey Division (Nebraska Geological Survey) during contract year July 1, 1979, to June 30, 1980, under contract NRC-04-76-3l5 with the U. S. Nuclear Regulatory Commission. The information pertains to the geology, structure, tectonics, and seismicity of eastern Nebraska with emphasis on the vicinity south of Omaha, Nebraska. Some of the information presented here results from a combination of studies begun in earlier years but the greater part results from studies begun during the contract year.

The scope of the studies is summarized as follows:

1. Rock outcrops …

Digital Demodulator-Correlator, James C. Fletcher, James W. Layland, Warren L. Martin, Arthur I. Zygielbaum, Richard M. Goldstein, William P. Hubbard

School of Natural Resources: Faculty Publications

Apparatus for demodulation and correlation of a code modulated 10 MHz signal is comprised of a sample and hold analog-to-digital (A/D) converter synchronized by a frequency coherent 40 MHz pulse to obtain four evenly spaced samples A1,B1A2 and B2 of each cycle of the signal, and means for adding, or subtracting, each sample to, or from, one of four accumulators to form the sums:

SI, = (A1-A2) M1

Sia=; (A1-A2) M2

S2, = (B1 - B2) M1

S2= (B1-B2) M2

where

M1 = 10 MHz Reference . Receiver Code A0' M2 = 10 MHz. Reference . Receiver Code A90'

M2 …

The Rush Creek Structure, Garden County, Nebraska, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

Detailed field mapping of surface outcrops in southern Garden County, Nebraska, has revealed a drop of 200 feet in three miles in the elevation of the contact between the Ogallala and pre-Ogallala (probably Brule) Formations exposed on the east side of Rush Creek. Beds of silt, sand, siltstone, and volcanic ash in the are a locally dip to the northwest at angles of up to 8½°. The contact between the two formations cannot be seen on the west side of Rush Creek but beds in the Ogallala Formation there dip to the north and northeast. The unusually long valley of …

Seed Size Selection In Heteromyids: A Second Look, Cliff A. Lemen

School of Natural Resources: Faculty Publications

The general conclusion of this paper is that heteromyids do not select seed sizes on the basis of their body size. My conclusion comes from the analysis of new data from central New Mexico, analysis of data in the literature on food habits of heteromyids, and a re-analysis of Brown and Lieberman (1973) and Brown (1975). All of these sources agree that no seed size selection exists.

Although no pattern of simple seed size selection was found, interesting differences were noticed among species. First, the tendency to husk appears to be related to the size of the rodent. Second, large …

Microhabitat Selection In Two Species Of Heteromyid Rodents, Cliff A. Lemen, Michael L. Rosenzweig

School of Natural Resources: Faculty Publications

An experiment was conducted to determine the microhabitat preferences of two heteromyid rodents, Dipodomys ordi and Perognathus flavus. This experiment used marked seeds and the atomic absorption spectrophotometer in order to study the environment as a mosaic of microhabitats. The results of our analysis indicate that these two heteromyids are microhabitat selectors. The preferences of the rodents are, D. ordi: grass habitat 0.0%, near grass habitat 22.5%, open habitat 77.4%, and P. flavus: grass habitat 46.2%, near grass habitat 32.2%, open habitat 21.4%. The overlap between the two species is only 0.43.

Local And Regional Components Of Sensible Heat Advection, Thomas W. Brakke, Shashi B. Verma, Norman J. Rosenberg

School of Natural Resources: Faculty Publications

Detailed knowledge of the advection of sensible heat is necessary to understand the energy balance of the evaporating surface in many parts of the world. Sensible hear advection can result from regional and/or local sources. The local and regional components of sensible heat advection (Aloc and Areg, respectively) are identified and their magnitudes in a semi-arid to sub-humid zone are established in the work reported here. Measurements of dry- and wet-bulb air temperature, wind speed and net radiation were made above an irrigated alfalfa field with relatively dry surrounding upwind at Mead, NE. A modified Bowen ratio-energy balance method which …

Shelter Effects On Growth And Yield Of Corn - Nebraska, U.S.A., James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Turbulent Exchange Coefficients For Sensible Heat And Water Vapor Under Advective Conditions, Shashi Verma, Norman J. Rosenberg, Blaine L. Blad

School of Natural Resources: Faculty Publications

Results are presented of micrometeorological measurements made over alfalfa and soybeans under conditions of sensible heat advection at Mead, Neb. The sensible heat advection phenomenon reported here is of a regional rather than a local nature. The exchange coefficient for sensible heat (Kh) is found to be generally greater than the exchange coefficient for water vapor (Kw). This result contradicts the usaul assumption of equality of Kh and Kw under nonadvection (lapse or unstable) conditions when the net transfer of both sensible heat and water vapor are away from the earth's surface. Under advective conditions, however, heat and water vapor …

Extreme Evapotranspiration By Irrigated Alfalfa: A Consequence Of The 1976 Midwestern Drought, Norman J. Rosenberg, Shashi Verma

School of Natural Resources: Faculty Publications

The rate of evapotranspiration by irrigated alfalfa at Mead, NE (41°09'N; 96°30'W, elevation 354 m) reached record levels in 1976. Evapotranspiration was measured with precision weighing lysimeters in a field 1.9 ha in size. Evapotranspiration ranged during the growing season from 4.75 to 14.22 mm day^–1 and exceeded 10 mm day­^–1 on one-third of the days studied. On each day of study the ratio of latent heat flux density (LE) to the sum of the net radiation and soil heat flux densities (Rn+S) was such that LE/ (Rn+S) > 1, indicating the occurrence of significant sensible heat advection. On …