Treesearch

Proposes standard data definitions and format to facilitate the sharing of growth and yield permanent plot data for the development, testing, and improvement of tree or stand growth models. The data structure presented provides standards for documenting sampling design, plot location and summary descriptors, measurement dates, treatments, site attributes, and individual tree characteristics. Standardized species, crown class, tree class, and tree condition codes are defined for use in the Intermountain Northwest.

Few insects that live on whitebark pine (Pinus albicaulis) are considered pests or potential pests. Those that inhabit cones can cause reductions in reproduction of the tree by destroying seed crops. Decreases in food for animals ranging from squirrels to grizzly bears may also result. A single insect species, mountain pine beetle (Dendroctonus ponderosae) (MPB), may cause serious damage to whitebark pine over much of its range by killing mature trees. Through periodic epidemic outbreaks, the resultant tree killing causes reductions in seed cones and so decreases food supplies for various...

Includes 52 papers and 14 poster synopses that present current knowledge about ecosystems where whitebark pine and associated flora and fauna predominate. This was the first symposium to explore the ecology and management of these ecosystems, which are becoming increasingly important.

Includes 45 papers and accounts of field trips from a symposium focused on a recent shrub die-off phenomenon and a perennial problem, cheatgrass invasion, on western rangelands. Contributions also cover shrub establishment, shrub ecosystem ecology and physiology, and plant and shrub ecosystems.

Genetic variation among 62 populations of ponderosa pine was studied by comparing seedlings from all populations according to (1) growth and development of 4-yr-old seedlings in three disparate common gardens and (2) patterns of shoot elongation of 2-yr-old seedlings in a greenhouse. Genetic variation was detected among populations for 19 of the variables, most of which were intercowelated. Two principal components accounted for 60% of the total interpopulation variance. Multiple regression analyses were used to relate genetic variation in 19 variables and two principal components to the...

The proceedings is a collection of papers and posters presented at the Symposium on Effects of Fire Management of Southwestern Natural Resources held in Tucson, Arizona, November 15-17, 1988. Included are papers, poster papers and a comprehensive list of references on the effects of fire on: plant succession, cultural resources, hydrology, range and wildlife resources, soils, recreation, smoke management, and monitoring techniques pertinent to prescribed fire management in the southwestern United States.

I examined the relationships among brood survival in House Wrens (Troglodytes aedon) and Tree Swallows (Tachycineta bicolor) and rates of nest-box use, species interference, and nest predation. Tree Swallows nested in boxes in one of three woodlands occupied by House Wrens. Over a 4-year period, clutch mortality rates in swallows were significantly higher than those in wrens, but wrens on swallow-free plots had lower failure rates than wrens that coexisted with swallows. Though conspecifics interfered at 9 of 99 (9%) wren nests, predation was the major cause of wren nest failure, accounting...

An unbiased profile model, fit to diameter divided by diameter at breast height, overestimated volume of 5.3-m log sections by 0.5 to 3.5%. Another unbiased profile model, fit to squared diameter divided by squared diameter at breast height, underestimated bole diameters by 0.2 to 2.1%. These biases are caused by retransformation of the predicted dependent variable; the degree of retransformation bias depends upon choice of dependent variable in the regression model, variance of its prediction errors, and the bole position of the desired prediction. Retransformation biases were greatest...

The Kalman filter is a statistical estimator that combines a time-series of independent estimates, using a prediction model that describes expected changes in the state of a system over time. An expensive inventory can be updated using model predictions that are adjusted with more recent, but less expensive and precise, monitoring data. The concepts of the Kalman filter are explained with a simple, hypothetical example of estimating percentage of forest cover over time, using remote sensing and field plots from a forest inventory.

The primary objective of the 1990 Genetics/Silviculture Workshop was to review and discuss the virtues, concerns, and opportunities for applying the five regeneration harvest methods and their variations in forest management. The first two papers discuss population dynamics and the importance of understanding genetic variation. These are followed by the moderator's opening remarks, and papers by the silviculturists, geneticists, and research silviculturists for each of the five regeneration methods.