Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 20-23). Also available on the World Wide Web.

2 pp. / Other forest health publications / Pinyon needle scale (Matsucoccus acalyptus) are very small (0.5 mm) sucking insects that feed on pinyon, singleleaf pinyon, and foxtail pines in the southwestern United States. These insects can be effectively controlled using an integrated approach which includes sanitation, supplemental irrigation, and pesticides.

Revised; Originally Published: 2003 / 2 pp.

Thesis (Ph.D. - Geosciences)--University of Arizona. / Includes bibliographical references (leaves 248-263).

The assumption that each latewood ring in trees represents one year of growth was tested for Utah juniper (Juniperus osteosperma) and pinyon pine (Pinus edulis). Ring characteristics and growth rates were evaluated for 72 years of growth following scars of consistent date on all trees sampled. Errors in age and growth rate estimates based on ring counts were evaluated. Potential variation among observers was accounted for. Average error in ring counts was lowest when rings were counted on the fastest-growing portions of each cross-section. Errors for more than 40% of the junipers exceeded 10 percent with about half of the trees with more rings and half with less rings than actual years. Pinyons rarely had more rings than years and only 5% of the trees were missing more than 10% of the 72 annual rings. Percentage errors in growth rate estimates based on ring counts were similar to ring count errors for both species. Assigning junipers to age classes based on ring counts also can lead to error in assumed ages of trees. Assuming that ring count error for each tree for the 72 year period studied approximates potential error over the life of each tree, more than half of junipers older than 250 years would be assigned to the wrong age class when using 50 year age classes. Number of rings in junipers was highly correlated with growth rate. Competition from surrounding trees explained as much as 53% and 40% of the variation in growth rates of junipers and pinyons respectively. Relating growth rates and ring counts to ordinations of stand, site and soil characteristics indicated that trees with relatively fast growth rates or trees with the most rings tended to occur on gentle, north to northeast aspects with relatively better- developed soils. However, stand competition often had an overriding influence on growth. Presence of Koelaria pyramidata in the understory was generally an indicator of relatively favorable growing conditions for junipers. Results suggest the need for more caution in the use of ring counts for estimating ages or growth rates of Utah junipers and pinyons than has generally been used in the past, especially when drawing conclusions about specific individuals.

No description available.

Current global population growth and economic development accelerates the land cover conversion in many parts of the world and compromises the natural environment. However, the impacts of this land cover change on the hydrologic cycle at local to regional scales are poorly understood. The thesis presented here investigates the hydrologic implications of land use conversion in two different settings using two different approaches. The first study focuses in Southeast Asia and the expansion of rubber monocultures in a middle-sized basin. Field measurements suggest rubber has distinct dynamics compared to the area's native vegetation, depleting and exhausting the local water balance more than native vegetation. A phenology based evapotranspiration function is developed and used in a hillslope based hydrologic model to predict the implications of rubber expansion at a basin scale. The second study is centered in the semi-arid southwestern United States. This study challenges the traditional assumption that deforestation increases water yield at regional scales. Observations of water yield in basins affected by a regional piñon pine die-off show a decline in water yield during several years after die-off. These results suggest an increase in landscape sensitivity to vegetation disruption in semi-arid ecosystems as scale increases. Consequences of both studies have important implications for land and water managers in these different ecosystems.

5 pp. / Pine Bark Beetles, Cypress Bark Beetles / Hosts, description and life cycle of the pinon ips and signs of infection. Management practices include maintaining tree health, sanitation and chemical sprays. Thinning is the long term solution to stressed stands. Many ecological factors are significant when managing for pinon ips.

Revised; Original Published: 2006 / 5 pp.

The impetus for this research was the increasing threat of catastrophic wildfires resulting from the accumulation of fuels across the West. Guided by the priorities, goals, and guiding principles outlined by the national fire plan (NFP), the objective was to identify those areas within a pinyon-juniper woodland-dominated landscape with the highest hazard of catastrophic wildfire. The intent was to help managers prioritize proactive fuels management efforts outside of the wildland urban interface (WUI). Based on a management paradigm, constraints were placed on the data collection, analysis, and model development. A geographic information system (GIS) was used to create a hazard assessment at a landscape scale in Tintic Valley, Utah. Hazard categories were a classification of fuels based on crown cover of pinyon-juniper trees, utilizing remotely sensed data. The data set consisted of digital orthophoto quadrangle (DOQ) images from 1993. The methods were developed in three phases. Phase One resulted in a hazard assessment protocol. In Phase Two, data layers were created to further divide the hazard categories into more tractable management units. Phase Three, through the retrospective examination of recent wildfires, indicated the limitations and utility of the assessment technique. The protocol presented provides a relatively fast, inexpensive, and timely hazard classification technique for pinyon-juniper woodlands at a watershed level. It is intended to be used for coarse-scale assessments of fuel hazards for strategic planning purposes. While not appropriate for fire behavior predictions, this assessment can focus managerial efforts for additional tactical planning.