Physical Sciences and Mathematics Commons^™

Geology Of Lake Mcconaughy Area, Keith County, Nebraska, Roger K. Pabian, Robert F. Diffendal, Frankie Gould

Papers in Natural Resources

Rocks cropping out along the North Platte River valley at Lake McConaughy provide a glimpse into Nebraska's geologic past. Here are excellent exposures of the Ogallala Group, which consists of continental sedimentary rocks deposited during the Miocene epoch of the Tertiary period of geologic time. This group of rocks extends throughout much of Nebraska (see geologic bedrock map on outside back cover) but is overlain in most places by younger stream and wind deposits of Pliocene(?) and Pleistocene age. Easily accessible, the Ogallala outcrops contain locally abundant fossils of seeds, casts of pedotubules, and occasional fossils of vertebrate animals such …

A Test Of Macroevolutionary Problems With Neontological Data, Cliff A. Lemen, Patricia W. Freeman

Papers in Natural Resources

Ricklefs (1980) suggested the use of neontological data to distinguish between puncuated equilibrium and gradualism as modes of evolution. This paper investigates his model and finds it contains oversimplifications that make any test difficult. We modify his model slightly and use it as a limited test of punctuated equilibrium by large morphological shifts at speciation. This test is applied to a data set of 110 species from two families of bats, the Emballonuridae and the Molossidae. We find no evidence of consistently large morphological shifts at the formation of subspecies, species or genera.

Review Of Bartlett, Great Surveys Of The American West, And Schubert, Vanguard Of Expansion: Army Engineers In The Trans-Mississippi West, 1819-1879, Robert F. Diffendal Jr.

Papers in Natural Resources

These two books outline the fascinating history of the exploration of the western United States by United States Army topographers and by civilian natural scientists from 1819 to 1879. These two groups, working either together under Army supervision or separately in military and civilian independent surveys, prepared topographic and geologic maps and natural history studies of most of the territory west of the Mississippi River. These maps and studies provided valuable information to settlers and to commercial and government groups involved in opening the west to development, and dispelled many myths concerning previously unexplored regions. They also helped lead to …

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

Papers in Natural Resources

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.

A Comparison Of Reproductive Strategies Among Marine Snakes, Cliff A. Lemen, Harold K. Voris

Papers in Natural Resources

(1) Gravid females representing fourteen species of marine snakes were collected from four localities along the coast of Malaysia in 1975. The average clutch size ranged from 2.9 to 17.8 but most species had between three and seven young. The number of young produced and the size of gravid Lapemis hardwickii differed significantly at two sites in the Straits of Malacca. Eight species showed a significantly positive relationship between the number of oviducal eggs and female weight. The rate of infertility among ten species ranged from 4.5 to 20%.

(2) Sex ratios in the collections varied significantly through time and …

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

Papers in Natural Resources

No abstract provided.

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

Papers in Natural Resources

No abstract provided.

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

Papers in Natural Resources

No abstract provided.

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

Papers in Natural Resources

No abstract provided.

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

Papers in Natural Resources

No abstract provided.

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

Papers in Natural Resources

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.