Thesis (M.A.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 156-167).

Several reports of widespread establishment of mesophytic vegetation within oak-hickory upland forests have been documented throughout the Central Hardwoods Region. Previous studies suggest deviations from historic disturbance regimes may be a primary driver of vegetation change, necessitating the use of Fire Regime Condition Class (FRCC) guidelines to measure changes in forest structure. Current parameters of forest structure and fuel loading were assessed within mature oak-hickory uplands throughout the ecological subsections of the Shawnee National Forest, including the Greater Shawnee Hills, Lesser Shawnee Hills, Cretaceous Hills, and the Illinois Ozarks. Present species importance values and forest structure were compared with reference conditions developed from General Land Office records(Fralish et al. 2002). Current uplands contained an average 214.72 ± 16.52 SE trees/ac and 103.37 ± 2.16 SE ft2 BA/ac, while reference stands harbored less than 90 trees/ac with a range of 16 and 120 ft2 BA/ac. Due to the high levels of fragmentation and a lack of large contiguous upland stands within the Shawnee National Forest, stand level criteria for FRCC values were developed as opposed to landscape level FRCC values which are commonly used. FRCC values determined during initial surveys were compared with plot level ratios of forest structure parameters regarding oaks:mesophytes and xerophytes:mesophytes, yielding clear relationships between species composition and FRCC values. Fuel loading (tons/ac) was assessed as a determinant of FRCC values, however a significant relationship between FRCC values and fuel loading was not discovered. Since widespread deviations from the historic fire regime have taken place since the early 20th century, Fire Regime Condition Class values were found to fall into the FRCC 2 and 3 categories without any stands representing FRCC 1. This determination requires future management practices to follow Fire Regime Condition Class guidelines. The study proved that mesophytic species have become established within all canopy strata, with a strong probability of gaining future dominance without active forest management. Although it is clear that forest structure has deviated from reference conditions, a strong oak-hickory overstory component found throughout the study area provides a potential resource to sustain future oak-hickory upland ecosystems.

Sagebrush shrubsteppe ecosystems have increasingly garnered attention as an endangered ecosystem. Ninety nine percent of all sagebrush ecosystems are thought to have been impacted by humans, and over 50% of grassland and shrubsteppe species are believed to be in decline. Most of the research on sagebrush ecosystems has been conducted at lower elevations and in large expanses of sagebrush. A considerable amount of sagebrush is found at higher elevations, often in meadows found within a forest matrix. The role of this high-elevation habitat is poorly understood. We conducted bird, small mammal, vegetation, and soil surveys in sagebrush-dominated mountain meadows within the Wasatch-Cache National Forest in northeastern Utah. Meadows ranged from 0.6 to 782 hectares in size and included an impressive list of associated plant species. We detected two sagebrush-obligate species and numerous shrubsteppe-associated species. Each species appears to respond to different habitat characteristics, but all species that showed a significant relationship with meadow size were more likely to occur in larger meadows. Many species showed no relationship with size, suggesting that while larger meadows were preferred by some species, small meadows could also play an important role as habitat. While sagebrush-dominated mountain meadows were important for some species, we also failed to detect a number of species of interest. In particular, Sage Thrasher, Sage Sparrow, and pygmy rabbit were not found within the study area. North American Breeding Bird data suggests that Sage Thrashers can be found nearby. It is likely that these birds are only found in large expanses, and none of our meadows were large enough to support them. Sagebrush-dominated mountain meadows appear to be an important supplement to large expanses of sagebrush shrubsteppe habitat, but are not substitutable for all species.

The rural west in this country faces increased national pressure concerning the iii management of natural resources on public lands. Issues regarding natural resource management are becoming more important as they continue to affect rural communities and capture the attention of a variety of interest groups. Natural resource managers are increasingly required to consider social dimensions of resource use and management. Lack of consideration in these areas can lead to dissatisfied, and even hostile, local residents and interest groups. Often land managers face criticism from many groups at once as a result of management decisions. This study analyzed a particular resource issue in a particular region of the west: grazing management in Catron County, New Mexico. The findings indicate a complex social structure with an historical base in natural resource dependence, and a personal independence from highly regulated grazing management. Changes in national legislation and changes in the Forest Service over time have contributed to the erosion of relationships between the Forest Service and ranchers and environmentalists. A socially informed, pragmatic and proactive approach to grazing management is currently lacking in Catron County.

Bison produce trails, wallows, and trample grounds, visible in satellite imagery disturbing ~27,500 m2 at Yellowstone National Park (YNP; in USA) and ~10,700 m2 in Białowieża National Forest (BNF; in Poland and Belarus), and, without anthropogenic land change, these mega-traces persist in sand-dominated substrates for 6-26 years. The average wallow size ranges from ~17-40 m2, whereas the average trample ground varies in size from ~140-300 m2. Trail segments typically extend for ~260-380 m, but the longest trails at YNP traverse >3 km. Estimates of track volume indicate for a standard herd of 200 animals, over a daily distance of 10 km ~4000 m3 is pediturbated. Low sinuosity values of 1.16-1.10 characterize trails, and wallows display high aspect ratios >0.7, helping distinguish bison traces on the landscape. During the Holocene, as many as 40 million bison inhabited North America, so this study provides a qualitative baseline for considering the geomorphic ability of large ungulates.Caliper measurements indicate the surface expression of simulated bison tracks varies depending on the moisture content of the medium. The slope of the marginal ridges (MR) in dry (0% moisture by volume), moist (~10% moisture by volume) and wet (saturated) sand differ around the track perimeter, although the minimum slope of the marginal ridge increases with moisture content (dry sand ~10 cm, moist sand ~40 cm, wet sand ~20 cm). The maximum MR slope (~80°) occurs in a moist substrate. The aspect ratio of prints in wet sand is 0.60, reflecting the most elliptical hoofprint, whereas moist sand displayed the most circular track with an aspect ratio of 0.76. The interdigital angle decreased by ~5° with increasing moisture (dry = 56°, wet ≈ 51°). Photos document in dry sand, deformation fronts 2-3 cm in height are present, whereas in moist sand, transverse and radial cracks are present. In wet sand, debris flows form. Ground-penetrating radar (GPR) imaging reveals subsurface anomalies interpreted as undertracks and normal micro-faults. In dry sand, two poorly-defined sets of undertracks with 1 cm relief are visible 3-4 cm beneath the tracking surface. Normal faulting is absent. In moist and wet sand, 4-5 sets of detailed undertracks showing 2-3 cm of relief deform sediments 7-8 cm in depth. Several normal faults are present in moist and wet hoofprints. Combined surface and subsurface observations may indicate the moisture content of paleo-tracking surfaces, particularly if the substrate is saturated. When hoofprints are formed in an unfrozen substrate, freezing increases preservation potential. Partially thawed tracks are resistant to deflation (wind erosion), maintaining outlines of digits and the medial pocket until late stages of deflation. Billions of ungulate traces formed in aeolian periglacial settings may be preserved. Tracks exposed to aeolian action exhibit higher heavy-mineral concentrations (HMC) along marginal ridges (MR), which are detectable using low-field bulk magnetic susceptibility (MS). In situ tracks from Delaware and Virginia (USA) display marginal HMCs 3.7-10x greater than background MS, whereas in laboratory, simulated hoofprints show marginal HMCs 1.7x above background MS. HMCs readily occur in nature, so MS measurements of tracking surfaces may quantitatively indicate the length or intensity of aeolian processes. This experiment demonstrates hoofprints indented through a <1 mm thick HMC and subsequently exposed to 1 min wind gusts of 5-10 m/s form HMCs on the scale of 10’s of µSI. Billions of ungulate tracks displaying marginal HMCs are probably preserved, potentially providing a detailed regional paleo-wind record. / Geoscience

Archaeological surveys using the subsurface testing method known as “shovel-testing” have been performed sporadically across the Bienville National Forest in central Mississippi. However; no research-oriented analysis has ever been performed for this area. The Bienville National Forest is located primarily in two physiographic regions: the Jackson Prairie and the Southern Pine Hills. These two regions are distinctly different in topography, soils, and vegetation. No settlement pattern study has been performed in the Jackson Prairie and it has been viewed as an area of low probability. Soils in this region are often heavy clays with high shrink/swell capabilities and poor drainage. In this thesis, I attempt to construct an initial analysis by looking at the duration of occupations and their placement in the landscape through time in order to determine whether the Jackson Prairie played any important role in the choice of habitation locations by prehistoric populations.

Usnea hirta and Xanthoparmelia cumberlandia are commonly used as bio-monitors of air quality. In order to more accurately and efficiently determine the distribution of these two sensitive indicator species, we have developed a probabilistic distribution map as a function of 9 macroclimatic and topographic variables for the White River National Forest, Colorado using Non-Parametric Multiplicative Regression (NPMR) analysis. Furthermore, we also developed a logistic regression (LR) model for X. cumberlandia in order to evaluate the strengths and limitations of the NPMR model. The best model for U. hirta included four variables - solar radiation, average monthly precipitation, average monthly minimum and maximum temperature (log β = 3.68). The presence rate for U. hirta based on field validated test sites was 45.5%, 65.4%, and 70.4% for low, medium, and high probability areas, respectively. The best model for X. cumberlandia generated by both NPMR and LR involved the same variables - solar radiation, average monthly maximum temperature, average monthly precipitation, and elevation as the best predictor variables (log β = 5.10). The occurrence rate for X. cumberlandia using the NPMR model was 32%, 44.4%, and 20% for the low, medium, and high probability areas respectively while the LR model had 26%, 50%, and 38% for low, medium and high probability areas respectively. Although the LR model predicted a smaller high probability area compared to the NPMR model there was substantial overlap between the two. The U. hirta model performed better than the X. cumberlandia model. The reduced performance of our model especially for X. cumberlandia may be due in part to the absence of field measured data in the development of the model. Our study also suggested that the northeast and western part of the forest should be preferentially considered for establishing future air quality bio-monitoring reference sites. Finally, in the future a well defined sampling design with sufficient sampling sites, field measured predictor variables, and microclimatic data should be used in the development of predictive models.

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