International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / We develop novel methods for compressing volumetric imagery that has been generated by single platform (mobile) range sensors. We exploit the correlation structure inherent in multiple views in order to improve compression efficiency. We show that, for lossy compression, three-dimensional volumes compress more efficiently than two-dimensional (2D) images. In fact, our error metric suggests that accumulating more than 9 range images in one volume before compression yields up to a 99% improvement in compression performance over 2D compression.

ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / The PAM representation was used to formulate a reduced-complexity detector for the Enhanced Flight Termination System (EFTS) whose performance is 5.6 dB better than limiter-discriminator detection when no phase noise is present and 3.4 dB better in the presence of expected phase noise in EFTS.

<p> With future climate change and increased water demand and scarcity in the Colorado River Basin, the Bureau of Reclamation estimates that the costs of salinity damage will increase for Colorado River users and will exacerbate the current salinity challenges. This study focuses on saline and sodic soils associated with the Mancos Shale formation in order to investigate the mechanisms driving sediment and salinity loads in the Price-San Rafael River Basin of the upper Colorado River. A Walnut Gulch rainfall simulator was operated with a variety of slope angles and rainfall intensities at two field sites (Price, Dry-X) near Price, Utah in order to evaluate how the amount and spatial distribution of vegetation affects salinity in runoff. For each simulated rainfall event, the time-varying concentrations of major cations, anions, and sediment in runoff were measured. Principal component analysis revealed that the two field sites are generally different in runoff water chemistry and soil chemistry, likely due to the difference in parent material and soil indicative of their location on different geologic members. The Dry-X site also has substantially greater total dissolved solids (TDS) and sediment in runoff, soil sodium absorption ratio (SAR), and soil cation exchange capacity (CEC) than the Price site. Despite these differences, a consistent positive linear relationship between the plot-averaged sediment and TDS concentration was found across both sites. The Rangeland Hydrology Erosion Model (RHEM) was calibrated to provide unbiased estimates of sediment in runoff from 23 runs of the rainfall simulator. RHEM simulated the plot-plot variability best at Dry-X compared to Price. Sensitivity analysis of the RHEM input parameters showed that the splash and sheet erodibility coefficient (Kss) and the effective saturated conductivity coefficient (Ke) had the largest influence on the model&rsquo;s sediment and discharge outputs, respectively. The regression that predicted TDS concentration from sediment was applied to RHEM outputs to show that the model could be used to provide salinity estimates for different storm intensities on this part of the Mancos Shale. The potential influence of vegetation canopy cover on sediment production from these two sites was inferred by running RHEM with canopy cover values ranging from 0% to 100%. This changed sediment output by 111% to -91% relative to the present vegetation cover. Measures of the geometry of soil and vegetation patches at Dry-X, such as fractal dimension index and proximity index, showed a relationship to error residuals from RHEM. As the vegetation becomes less isolated, more uniform, and the tortuosity of the bare soil area increases, observed sediment decreases relative to RHEM predictions. The results of this study will help land management agencies assess the feasibility of mitigation strategies for reducing sediment and salinity loads from the saline and sodic soils of the Mancos Shale formation and indicate a possible benefit to incorporating the parameters that describe the spatial pattern of vegetation in RHEM.</p>

9 pp. / Principles of obtaining and interpreting utilization data on rangelands / Rangeland monitoring is essential for making sound management decisions. Monitoring requires repeated measurements of the same attributes over time. Perhaps the earliest and most widespread rangeland management monitoring data collection protocol was the development and establishment of the Parker 3-step Method on U. S. Forest Service rangelands, beginning in 1948. This method collected both objective and subjective data and provided a scoring technique for assessment purposes. This paper describes the development of the Method and suggests ways to summarize the ecological attributes collected on Parker transects, analyze the data and reinterpret them based on trends in plant species abundance, composition and soil cover.

The objectives of this dissertation were to identify soil and vegetation changes due to grazing by livestock and to develop guidelines for monitoring the impact of livestock in the Sahelian zone of Africa. The study was conducted in eastern Senegal during 1983 to 1985. The basic methodology was a study of the process of degradation (retrogression) through the collection of data on soils and vegetation along a gradient of increasing livestock pressure. Two gradients were selected along piospheres. Each gradient was placed on a range site that had homogeneous state factors (climate, geology, and rainfall). The results show that the changes in the soil were confined to the top soil horizon. There was a negative correlation between livestock pressure and factors such as infiltration, percent nitrogen, and percent carbon, and a positive correlation between livestock pressure and the factors of bulk density, and phosphorous content. Changes in the vegetation community were dependent on the range site. On the sandy site, there was a linear, negative correlation between livestock pressure and the factors of plant density, plant cover and biomass. On the loamy range site, the changes in these factors along the gradient had a 2nd or 3rd order polynomial relationship. The effects of bush fires and short term droughts on the vegetation were also studied. Drought, in particular, has an impact that is similar to that of livestock pressure, and may compound the results. Multiple regression analysis and a Twinspan ordination program were used to select parameters and plant species that were highly correlated with the gradient, and could act as indicators of each stage of degradation. These indicators can be used to monitor the impact of livestock on rangelands. General parameters, such as total plant density, are less sensitive to drought-induced changes than the composition of indicator species, but the latter are easier to monitor. Both types of indicators can form the basis for a monitoring methodology that can be used in Africa at three management levels: the individual herder, extension agents and regional branches of the division concerned with rangelands, and policy makers at the ministerial level.

Foraging party and territory size of Heterotermes aureus (Snyder) were investigated on the Santa Rita Experimental Range south of Tucson, Arizona. A comparison of three techniques for delineating territorial extent suggested that the release and recapture of dyed termites was most useful, while agonistic behavior among termites may reflect past as well as current associations. Spatial and temporal patterns of termite attack on baits proved to be unreliable. Data obtained via the release and recapture of dyed termites indicated that most territories encompassed an area of several hundred to thousand square meters. These data sharply contrast with those obtained via spatial and temporal patterns of termite attack, which provided an estimate of 9.2 m² for average territory size. Although agonistic responses were useful for differentiating H. aureus colonies, the lack of this behavior among termites did not necessarily imply a current relationship, as they may have been from subgroups that previously had budded off from each other. These groups may be headed by neotenic reproductives, which were found for the first time under field conditions for this species. Data on foraging party size obtained via a mark-release-recapture technique indicated that many H. aureus colonies contained from ca. 50,000 to 300,000 foragers. However, the validity of these estimates is suspect because several of the assumptions of this technique were not met, i.e., marked individuals did not completely mix in the population, but their numbers tended to be more concentrated near release sites, and colonies may have represented open populations. However, exhaustive trapping data also indicated that colonies may contain tens or hundreds of thousands of foragers. As many as 100,000 foragers in a single colony were removed from fiberboard traps during a 1.5-year period. The average foraging party consisted of 1,456 individuals, of which 8.6% were soldiers.

Individual clumps of the perennial grass Bouteloua gracilis from which 25% or 75% of neighbors had been removed to a radius of 50 cm displayed significantly higher biomass production over one summer than did control plants. Neighbor removal also resulted in increased tiller production and flowering as compared to control plants. These results clearly demonstrate the importance of competition to B. gracilis in this system. In contrast, significant differences in predawn leaf water potential were found on only two of four sampling dates during the growing season. On the driest sampling date, increased variability in leaf water potential within treatments obscured the effect of treatment, even though the difference in mean leaf water potential between 75% removal and control treatments (0.35 MPa) was quite high. On the wettest sampling date, all plants appeared well-hydrated, and there was only negligible difference among treatments. In a second study, I examined the effect of near neighbors on the fecundity of an annual herb, Machaeranthera tanacetifolia (Asteraceae). Fecundity was negatively related to the number of neighbors within a biologically meaningful neighborhood radius for both conspecific neighbors and grass neighbors in 1984, and for grass neighbors in 1985. However, in no case did neighbors explain more than 6% of the variance in fecundity of M. tanacetifolia, and most plants produced few or no seeds regardless of the number of neighbors. I present a simple graphical model in which competition from neighbors serves as a necessary but not sufficient condition for high fecundity; other factors must also be favorable if a plant is to be successful. Application of this model to my data revealed that the amount of area occupied by neighbors had an important effect on fecundity for the subset of the population for which other conditions were inferred to be most favorable. As other conditions became less favorable, neighbors became less relevant to fecundity. I then discuss these results in terms of a general model of the interacting effects of competition and other factors, and distinguish four possible classes of outcome.

Most livestock and range management projects in the Sahelian countries of Africa have failed to achieve their objectives. Many reasons have been given to explain the failure, but these reasons usually fall short of covering the whole environmental picture and concentrate on the factors internal to the projects. They do not provide complete explanations of why pastoral programs fail because they tend to over-emphasize the isolation of pastoral communities from their wider societies and do not take into consideration the whole socio-economic and political environment. The purpose of this study was to more constructively explain why pastoral development projects succeed or fail. Pastoral projects funded by World Bank and USAID in six Sahelian countries of Africa were studied. Metaevaluation was used to study all of the factors affecting the outcome of pastoral projects. A survey of project evaluators and summaries of project reports and evaluation activities were used as the main sources of data. The results indicate that outcomes of pastoral projects do depend upon the technological, sociocultural, and environmental dimensions of the development situation. But the outcomes are more affected by the policies of governments and their institutions than by any other factor. Factors such as uncertain funding, conflicting goals and objectives, and complicated bureaucratic procedures, generally mean that projects are not implemented as planned, changes are made as the projects are implemented, or implementation never occurs.

The objective of this research was development and testing of a method for estimating cattle carrying capacities. A series of studies were conducted in developing this method. Range site and vegetation production data were grouped by topographic position and multiple linear regression equations were calculated for predicting vegetation production as a site deviated from the average case of a given range site. Overstory-understory relationships from the literature were adapted into overstory canopy cover classes for predicting understory production and tested on a variety of range sites. Use of these classes produced understory biomass estimates within 13% of measured biomass. Range condition class and understory aspect dominance by forage vs. non-forage species were investigated as estimators of forage value of the understory vegetation. Both were significantly related to amount of forage in the understory. However, understory aspect proved to be a better estimator when individual comparisons were examined. The previous findings, along with Soil Conservation Service range site guides, were used to calculate resource value ratings. Adjustment factors to be applied to the resource value ratings were calculated, using data from the literature, to account for the effects of slope and distance from water on forage utilization by cattle. These resource value ratings and adjustment factors form the basis of the carrying capacity estimation method. Pastures identified as properly utilized were used in testing the method developed. Pastures were mapped for range site, vegetation, slope and water location. Maps were converted to digital form and analyzed using the Map Analysis Package (MAP) computer program (Tomlin, 1975). Construction of a final range site-vegetation-slope-distance from water map, assigning of resource value ratings and adjustment factors, and computation of final carrying capacity estimates were accomplished using MAP. Carrying capacity estimates from the developed method were well correlated to estimates from ocular reconnaissance and area allowable use methods, r = .87 and .97, respectively, and with the actual use (perceived proper use), r = .95. These estimates were accomplished without intensive field sampling. The only information required was range site designation, amount of overstory canopy cover, understory aspect class, percent slope and water location.

No description available.