Lodgepole pines Pinus contorta (Douglas) were treated by girdling to assess the response by an endemic population of mountain pine beetle Dendroctonus ponderosae (Hopkins) (Coleoptera: Scolytidae). Capture in 'sticky traps' indicated that the beetles were attracted while in flight towards the wounded trees. A significant difference in the landing rates of bark beetles between the treated and untreated trees indicated that the beetles were able to distinguish wounded from non-wounded trees while still in flight. Pressure chamber readings demonstrated that water stress developed in the girded trees when compared to the non-girdled trees.

No description available.

Thesis (M.S.)--University of Nevada, Reno, 2007. / "May, 2007." Includes bibliographical references (leaves 54-57). Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2007]. 1 microfilm reel ; 35 mm.

Thesis (M.S.)--University of Wyoming, 2007. / Title from PDF title page (viewed on Feb. 24, 2009). Includes bibliographical references (p. 44-54).

Thesis (M.S.)--Oregon State University, 2005. / Printout. Includes bibliographical references (leaves 111-118). Also available on the World Wide Web.

The study was concerned with lodgepole pine, Pinus contorta Douglas and Engelmann spruce, Picea engelmannii Parry, particularly in the southern interior of British Columbia. Classifications of the forests of the Province as well as distribution, silvics, effects of fire upon succession, forest associations, and productivity classes of the two species were described. Sample plots were located in the Interior Douglas-fir and Engelmann Spruce - Alpine Fir Biogeoclimatic Zones. Hohenadl's form factor was used to compute volume growth by individual decades from stem analyses. On 124 plots, 137 trees were collected for stem analyses, 108 saplings were used for height - age studies, 100 point samples were made for determining basal area and stand volume and several hundred heights as well as diameters and borings at breast height, were taken. Thirty-four stand variables were subjected to multiple correlation analyses, particularly in regard to forest associations and growth of height, diameter at breast height and volume of the two species. Simple regressions were used to estimate height growth of several species on similar sites, and to compare several methods of volume calculation. Trees of the same diameter at breast height grown in different competitive positions (open, moderate to dense, and suppressed), contained different volumes. The largest volume of individual trees was found with trees grown in moderate to dense competitive position. Individual young lodgepole pines had a faster increment of height, diameter at breast height, and volume, than Engelmann spruces. This trend remained the same in yield tables based on individual tree studies and constructed for stands of good (average site index 100 ft. at 100 years), medium (average site index 70 ft. at 100 years), and poor (average site index 50 ft. at 100 years) productivity classes. The mean annual increment of volume of stands culminated earlier in lodgepole pine than in Engelmann spruce. The periods required were (in brackets are shown attained average diameters at breast height, total heights and volumes per acre). In the good productivity class in lodgepole pine 40 years (8.3 in., 58 ft., 6,700 cu.ft.) and in Engelmann spruce 75 years (10.0 in., 80 ft., 6,000 cu.ft.); in the medium productivity class in lodgepole pine 60 years (6.5 in., 50 ft., 4,600 cu.ft.) and in Engelmann spruce 130 years (9.0 in., 84 ft., 5,100 cu.ft.); in the poor productivity class in lodgepole pine 85 years (5.3 in., 45 ft., 3,100 cu.ft.) and in Engelmann spruce 150 years (6.3 in., 66 ft., 3,400 cu.ft.). Yield table volumes per acre in lodgepole pine were larger than those of Engelmann spruce, in the good productivity class, to the age of 120 years, in the medium productivity class to 150 years, and in the poor productivity class for an undetermined period. Present and suggested future trends of utilization and management of stands of the two species were reviewed. Generally, forest management in British Columbia shows a trend toward more intensive forest utilization, due to the increasing demand for wood. Smaller diameter trees and "smallwood" stands will be more and more frequently utilized. Utilization of whole trees, highly mechanized "harvesting" and transportation as well as intensified management of forest stands will compensate for increasing costs due to utilization of smaller diameters. Under intensive management, lodgepole pine deserves special consideration. It is as well-suited for artificial establishment of stands by planting as Engelmann spruce, but should cost less. Its value for the woodworking industry is similar to that of Engelmann spruce. However, on a rotation of maximal mean annual increment, its volume yield per acre unit will be higher than that of Engelmann spruce, and it should yield a higher rate of return on invested capital. / Forestry, Faculty of / Graduate

A study has been conducted with the objectives of (1) identifying weevils and their parasitoids emerging from infested lodgepole pine leaders, (2) determining emergence patterns of hosts and their parasitoids, and (3) obtaining further information on the biologies of the terminal weevils and their natural enemies in British Columbia. The major experiments and biological observations were carried out in young spaced lodgepole pine, (Pinus contorta Dougl. var. latifolia Engelm.), stands at Ellis creek, near Penticton, B.C. A total of 1046 infested leaders were collected. One-third of the terminals were dissected and the numbers of weevils and parasitoids at developmental stages were recorded. The remainder of the leaders were set up for individual rearing. Observations were also made on the feeding and ovipositional behavior of the weevils. Feeding habits of the parasitoids were also studied. Dissections showed that a few adult weevils emerge in the fall of the year of attack. The majority of adults overwinter as larvae but pupation also may occur prior to winter. In addition, dissections indicated that parasitism plays an important role in larval mortality of weevils. Weevils which emerged in the laboratory were identified as being of the following species: Pissodes terminalis Hopping, Magdalis gentilis LeC. and Cylindrocopturus sp. (COLEOPTERA: Curculionidae). M. gentilis is the first weevil species to emerge, in late May. This emergence is followed by that of P. terminalis from early June through mid-July, while Cylindrocopturus sp. emerges from early June through mid-July. P. terminalis attacks the current year's leaders, whereas adult M. gentilis and Cylindrocopturus sp. feed on foliage. All three weevil species utilize lodgepole pine terminal shoots for breeding. Larval feeding under the bark almost always results in the death of the terminal. The terminal weevils have a complex of natural enemies in British Columbia. Parasitoids belong to six families of the order Hymenoptera. The pteromalid Rhopalichus pulchripennis Crawford is the most widely distributed parasitoid species in the province. Two species of Eurytoma (Eurytomidae) ranked second in abundance. Emergence patterns of adult parasitoids are closely synchronized with that of their hosts. Parasitoids were observed feeding on pollen of flowering weeds in the field. This observation suggests that natural parasitoid populations could be enhanced by cultivating lupin, Lupinus sp., in lodgepole pine stands. It was concluded that every effort should be made to minimize weevil numbers in order to prevent formation of crooks, forks and stag-heads. Early emergence of M. gentilis suggests that leader clipping projects should be carried out by early spring. Further research is recommended to ensure correct association between parasitoids and host weevil species and to develop or establish methods for preservation of parasitoids for clipped leaders for release in the forest. / Forestry, Faculty of / Graduate

The longitudinal air permeabilities of the wood of 1116 specimens from 279 trees, two sapwood and two heartwood replicates, representing two varieties of lodgepole pine (Pinus contorta, vars. latifolia and murrayana) were measured with a steady state apparatus. It was found that the mean ratio of sapwood to heartwood permeability was ca. 10:1 for both varieties. The mean ratio of var. latifolia to murrayana was 1.5:5 and 1.75:5 for sapwood and heartwood, respectively. The most important source of variation following the difference between heartwood and sapwood was that among trees. Geographical locations, such as latitude and elevation did not significantly influence permeability. Tree size did, but only because the small trees (3 inch diameter) showed higher heartwood permeability and lower sapwood permeability than normal. Ca. 20 specimens of latifolia heartwood showed extremely high permeabilities. They were also deeply brown in color, which probably was caused by fungal or bacterial infestation. Pit pore size and number per cm² were determined for sapwood by making four permeability measurements, each at a different average pressure on each specimen. A mean pit pore radius of 1.5 µm and 1.3 µm for sapwood of var. latifolia and var. murrayana was calculated. The median values between 1200-1300 pit pores per cm² indicate an average rate of tracheid connection of 1.2-1.3%. Of the tested wood parameters including moisture content and specific gravity average ringwidth, only the permeability of var. latifolia was significantly correlated with moisture content for both heartwood and sapwood, with a negative correlation coefficient. Water retention measurements were carried out to relate the measured gas permeability of an individual specimen to its ability to absorb water. For both varieties the retention was significantly and quadratically correlated with sapwood permeability (R² = 0.286 and 0.224) and was linearly correlated with heartwood permeability (R² = 0.488 and 0.5775). The correlation factors for the regression between retention and the logarithm of permeability were 0.239 and 0.227 for sapwood and 0.447 and 0.420 for heartwood. / M.S.

To prevent the buildup of epidemic level mountain pine beetle populations, conditions of the stand environment they inhabit must be altered. Silvicultural treatment is the most effective means for doing this. Preventative treatments work best when applied while mountain pine beetle populations are still at the endemic population level. Therefore, information necessary for making decisions concerning mountain pine beetle populations in lodgepole pine stands needs to be included in the initial silvicultural prescription planning process, at a time before beetle populations reach outbreak numbers. In this dissertation, several quantitative descriptions of the mountain pine beetle/lodgepole pine relationship were investigated. Models were developed to 1) describe the temperature-dependent development of six mountain pine beetle life stages and 2) describe the amount of loss a stand could sustain if an epidemic level population were to occur in the stand. Concepts of mountain pine beetle risk rating were also discussed. These models and additional information pertaining to the mountain pine beetle/lodgepole pine relationship were incorporated into a knowledge-based system, the MPB Advisory System. This system was designed to help U.S. Forest Service silviculturists include decisions concerning mountain pine beetle populations in the stand management process. / Ph. D.

No description available.