Biodiversity Commons^™

American Burying Beetle, Plant Richness, And Soil Property Responses To Collapse Of Juniperus Virginiana Woodlands With Fire, Alison Ludwig

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Grasslands are declining in the Great Plains due to land use changes, woody plant encroachment, and loss of historic fire cycles. Prescribed burn associations have utilized prescribed fire to collapse invading woodlands and allow the restoration of grasslands. This fire is considered “extreme” because it is capable of changing the structure and function of an ecosystem. Our study site is the Loess Canyons Experimental Landscape, a long-term, ecoregion-scale experiment to apply prescribed fire across the region to restore grasslands. The Nebraska Natural Legacy Project established the Loess Canyons ecoregion as a Biologically-Unique Landscape in 2005 with the state’s wildlife action …

Reorganization Of Surviving Mammal Communities After The End-Pleistocene Megafaunal Extinction, Anikó B. Tóth, S. Kathleen Lyons, W. Andrew Barr, Anna K. Behrensmeyer, Jessica L. Blois, René Bobe, Matt Davis, Andrew Du, Jussi T. Eronen, J. Tyler Faith, Danielle Fraser, Nicholas J. Gotelli, Gary R. Graves, Advait M. Jukar, Joshua H. Miller, Silvia Pineda-Munoz, Laura C. Soul, Amelia Villaseñor, John Alroy

School of Biological Sciences: Faculty Publications

Large mammals are at high risk of extinction globally. To understand the consequences of their demise for community assembly, we tracked community structure through the end- Pleistocene megafaunal extinction in North America.We decomposed the effects of biotic and abiotic factors by analyzing co-occurrence within the mutual ranges of species pairs. Although shifting climate drove an increase in niche overlap, co-occurrence decreased, signaling shifts in biotic interactions. Furthermore, the effect of abiotic factors on cooccurrence remained constant over time while the effect of biotic factors decreased. Biotic factors apparently played a key role in continental-scale community assembly before the extinctions. Specifically, …

Overview Of The Endangered Species Program, Glen Smart

Publications of the US Geological Survey

In the late 1950s and early 1960s, we became increasingly aware, as a Nation, of declining populations of birds and mammals. Rates of extinction appeared to be skyrocketing and the situation was becoming critical. The country needed to take action to reverse this trend. The Federal government began to show interest in the problem and acknowledged that it needed to intervene on a hands-on basis. The Washington, D.C., office of the U.S. Fish and Wildlife Service (USFWS) began to promote a program, championed by Dr. Ray Erickson, senior scientist at headquarters, to initiate captive research and propagation of birds and …

Fossil Crocodilians From The High Guajira Peninsula Of Colombia, And The History Of Neogene Crocodilian Diversity In Tropical South America, Jorge W. Moreno-Bernal

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The greatest diversity of Cenozoic crocodilians occurred during the Miocene in equatorial South America. However, the origin of this high diversity and its relationship to environmental factors are poorly understood. Most described species come from localities assigned to Laventan (13.8-11.8 Ma) and Huayquerian (9.0-6.8 Ma) South American land mammal ages (SALMAS), whereas the record is sparse in the early to middle Miocene and after the latest Miocene and Pliocene. Field research in the Castilletes (early Miocene-Pliocene) Formation in the High Guajira Peninsula of Colombia provides new fossil data on the origin of Neotropical crocodylian diversity. The Castilletes Formation crops out …

Recently Described Vulture One Of Several New Avian Species From The Ashfall Fossil Beds, Rick E. Otto

University of Nebraska State Museum: Programs Information

Several species of fossil bird are known from the Ashfall Fossil Beds. As of publication date, all represent previously undescribed species. In 2012, ornithologists Zhang, Feduccia and James described a vulture from isolated remains recovered from the Ashfall site in 1979. Similar in morphology to the Palm-nut Vulture (Gypohierax) of Africa, the relationship to the Ashfall vulture is unclear, and may represent an example of convergent evolution. The fossil vulture was designated Anchigyps voorhiesiin honor of paleontologist Michael Voorhies.

Bacterial Diversity In Biological Soil Crusts From Extrazonal Mountain Dry Steppes In Northern Mongolia, Anne Kemmling, Birgit Pfeiffer, Rolf Daniel, Michael Hoppert

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Biological Soil Crusts (BSCs), consisting of prokaryotes, microalgae, lichens, mosses and eventually small vascular plants, cover wide areas in arid and semi-arid environments. In the present study, the microbial diversity of these crusts was explored at extrazonal mountain steppe sites in the western Khentej (Northern Mongolia). At the study site the Siberian taiga borders on the Mongolian-Daurian forest steppe, resulting in a unique intermixture of the dark taiga, the light taiga, and forest steppe (DULAMSUREN 2004). Due to the presence of boreal, temperate and dauric elements the forest steppe is eminently rich in species (MÜHLENBERG et al. 2004).

BSCs in …

Geological Field Guide To The Cedar Point Biological Station, Keith County, Nebraska, Robert F. Diffendal Jr., Roger K. Pabian

School of Natural Resources: Faculty Publications

This field guide was produced by staff members of the Conservation and Survey Division of the University of Nebraska originally in 1979 at the request of Dr. Brent Nickol, former Director of the Cedar Point Biological Station. It is an introduction to the geologic history and paleoecology of the Cedar Point area intended for students, staff, and other persons using the camp. This revision has been made some 15 years after the first version to reflect changes in ideas resulting from new data collected during that time.

Users of this guide should take care when studying the rock exposures described …

Microorganisms And Soil Structure, T. M. Mccalla

Department of Agronomy and Horticulture: Faculty Publications

SUMMARY

Laboratory tests were made to determine the effectiveness of different compounds and microbial groups in increasing the stability of Peorian loess lumps against the action of falling water drops. The influence of these on percolation tests in the laboratory was also determined.

Many organic substances-dextrose, sucrose, starch, peptone, cullulose, and gum arabic-did not themselves contribute directly to soil-structure stability, though these substances do furnish energy material for soil microorganisms, which can convert them readily into either microbial tissue or decomposition products that increase soil-structure stability. Lignin, proteins, oils, fats, waxes, resin, and paraffin increased the stability of lumps of …

Vegetation Of The Northern Part Of Cherry County, Nebraska, William L. Tolstead

Conservation and Survey Division

Agricultural practices in the Great Plains of North America are now in a period of adjustment from a traditional agriculture initiated by pioneer farmers to a grazing economy based upon potentialities of climate and soil. The attainment of a proper system of land use has been retarded in many localities by the lack of definite information concerning the vegetation and its indicator significance. In this study of the vegetation of Cherry County, Nebraska, the interrelations between the plants and their environments are discussed, the dominant species are described, and changes in grasslands caused by seasons, grazing, and climatic cycles are …