In the Gulf Coastal Prairie and Marsh region of Texas, historic archaeological sites are often obscured by dense vegetation resulting in extremely limited surface visibility. In an environment such as this, historic sites can only be detected by the presence of above-ground features such as architectural remains and landscaping. Although not standard among cultural resource management firms, the use of historical aerial photography and informant interviews can be effective and efficient pre-field strategies for locating sites in this region. Identification of such sites is further enhanced by an in-depth understanding of the characteristic remains of pier and beam construction, which was commonly utilized in 19th-century southeast Texas farmsteads. Four 160-acre grants located in the Addicks Reservoir, Harris County, Texas were used as a case study to test the effectiveness and efficiency of these pre-field research strategies. Each of these tracts was associated with the mid 19th-century establishment of the German immigrant community of Bear Creek, and each tract contained the remnants of farmsteads where structures had often been removed or relocated leaving little above-ground remains to be discovered using standard survey techniques. A 1915 topographical map and a 1930 aerial photograph of the area were employed together with accounts of former residents and descendants of former residents that indicated locations of former farmsteads on each of these tracts. Additional archival research, including U.S. Army Corps of Engineers acquisition files for Addicks Reservoir, was conducted prior to a field “ground-truthing” survey of the properties. As a result, all six of the historic sites that appear on a 1930 aerial photograph of the area were located and documented. One historic site that appeared on a 1915 topographical map of the area but did not appear on the 1930 aerial photograph was not located.

The Eocene Clarno Formation, the Oligocene John Day Formation and basalts of the High Lava Plains are exposed in the Bear Creek Butte area in Central Oregon. In this area the Clarno Formation can be divided into a lower sequence composed of intermediate lava flows with intercalated mudflows and volcaniclastic sediments and an upper sequence of rhyolite and basalt flows and felsic ruffs. Separating the two units is a well developed saprolite. The change from intermediate to rhyolite-basalt volcanism reflects a change in the tectonic environment of the Cascade volcanic arc from compression to relaxation as subduction of the Farallon plate by the North American plate slowed, allowing extension of the continental plate margin to occur.

On the basis of three morphological characters (e.g., filament, width, chloroplast number, and type of cell end wall), six filament types of Spirogyra were collected along Bear Creek in the Santa Catalina Mountains near Tucson, Arizona. The occurrence and distribution of filament types showed seasonal and geographical patterns. Filaments were more frequently collected in early summer from pools at lower elevation. Growth of Spirogyra may be influenced by water temperature, pH, and water amount. Most filaments occurred more abundantly while water temperture and pH were relatively high. The number of filament types was greatest at sites with a semi-permanent water supply rather than in temporary and permanent pools. Of the six types of Spirogyra, Type V showed morphological and genetic changes through vegetative growth and sexual reproduction in a clonal culture in the laboratory. After 33 months culturing, a narrower filament-width group (Group II, 22.0 ± 1.1 μm) was produced in the original clone (Group I, 30.9 (+OR-) 0.7 μm). Groups I and II were homothallic and sexually compatible. Zygospores from the cross of I x II yielded germlilngs of Groups I, II, III (27.2 ± 1.0 μm) and a binucleate IV (44.9 ± 0.8 μm). Chromosome counts were: Group I (24), Group II (12), Group III (18), and Group IV (24, one nucleus). Relative nuclear-DNA fluorescence values increased as filament width and chromosome number increased. Cytologically, Group I is a tetraploid, Group II a diploid, and Group III a triploid. Systematically, Groups I, II and III key out to pirogyra singularis, S. communis, and S. fragilis, respectively, using Transeau's monograph on Zygnemataceae. These species are interpreted to be a species complex of S. communis (whose name has priority) with the ancestral haploid (x = 6) missing. Five years after isolation of the original strain in this species complex filaments corresponding to Groups I and II were found at the original collection site. The two field-collected groups were indistinguishable from the laboratory species complex in morphology and chromosome number. Homothallic conjunction within two field width groups yielded progeny similar to those from homothallic conjunction of groups in the laboratory species complex. Filament widths of progeny were generally within the width limits of respective parental groups. The four intergroup crosses between laboratory and field width groups were successful and yielded progeny representing Groups I, II, and III. The similarities in morphology, chromosome numbers, and reproductive behavior of laboratory and field width groups imply that the laboratory species complex of S. communis has a natural counterpart in the field.

This project uses a Geographic Information System (GIS) as a tool for estimating soil erosion on a watershed scale. A new and key tool for managing ecosystems in North America are resource management plans based on watershed areas. Watershed management plans are a response to widespread concern about the cumulative effects of nonpoint source pollution (such as agriculture pollution) on water resource quality.The primary objective of this project was to develop a method using GIS to estimate the annual gross erosion for each of the watersheds. Sediment delivery was calculated within each of the subwatersheds of Bear Creek, and the amount of sediment that potentially could be trapped by vegetative filter strips in each watershed was determined. The area that was used for the study site is the Upper Bear Creek watershed. The Bear Creek watershed is a subwatershed of the Loblolly watershed in Jay County, Indiana.The analysis determined that 99% of sediment was contributed from cropland. When vegetative filter strips were modeled, the sediment delivered to a load cell was substantially reduced. Cropland area required for vegetative filter strips would be 2.3% for the whole watershed. / Department of Natural Resources and Environmental Management