A mathematical model has been developed to describe the growth of trees in stands of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) from age ten to age 100 years. An initial square pattern of spacing was assumed. At age ten years the trees were assumed to be open-grown, that is, growing in diameter at breast height at a maximum rate. A regression of d.b.h. on age was obtained from eighteen open-grown, Douglas fir trees measured on the Saanich Peninsula, Vancouver Island. The relationship derived from these data agreed with further data collected elsewhere in the coastal regions of British Columbia and Washington and in the interior of British Columbia. The d.b.h. growth of individual trees was predicted by five-year periods. Relationships between crown width and d.b.h. were calculated from data on 426 open-grown, Douglas fir trees. There was a close correlation between crown width and root spread for open-grown trees. A multiple regression equation was obtained for height of 869 trees on d.b.h. and basal area per acre. All regression equations calculated for use in the model, were highly significant statistically. The model is initiated with a matrix of 15 x 15 trees (or tree "locations”). The initial d.b.h. of each tree is specified and, from the crown width/d.b.h. regressions, the crown width of each tree is calculated. As long as the tree remains free of competition, this calculated crown width is reduced by 40 per cent by the reduction factor "REDFAC", to give the "competitive" crown width. This was because it was found that, in young Douglas fir plantations, there could be considerable overlapping of the crowns before d.b.h. growth was reduced. As soon as competition sets in the original 40 per cent reduction is systematically reduced. The proportion of the circumference of each tree that is occupied by the crowns of surrounding competitors is then calculated. This proportion indicates the amount of competition to which the tree is being subjected and varies between zero, if the tree is open-grown, and one or more, if the tree is completely enclosed by the surrounding competitors. If the reduction is sufficiently great, continued survival of the tree is considered unlikely, and the tree is assumed to have died. The periodic d.b.h. growth of the surviving trees is calculated at five-year intervals to age 100 years. All calculations are performed using am I.B.M. 7090 electronic computer. A summary of the structure of the stand can be printed out at the end of each five-year period if required. Height growth can be described by modifying the stand model by including an appropriate regression equation. Similarly, volume growth can be estimated by modifying the basic stand model. The mathematical model developed here satisfactorily describes the growth of Douglas fir stands on an individual tree basis, over a wide range of site conditions, stand densities, amounts and distributions of mortality and thinning regimes. Field data cannot be secured to evaluate the accuracy of all the tests made. However, there are no gross errors in absolute values and results are accurate proportionately. The model described here can aid the forester in managing Douglas fir stands in the Pacific Northwest. By simulating the growth of his stands from age ten to age 100 years in a few minutes he can study questions that would otherwise require several human generations to evaluate. / Forestry, Faculty of / Graduate

In Europe, the origin of older Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) plantations is generally unknown. The tracing of the probable origin of one Swiss and twenty Polish Douglas-fir stands was attempted. Cone and seed characteristics were measured on material collected from all twenty-one European stands, and compared with the displayed variation of the same characteristics from Douglas-fir growing in its natural range on the Pacific Coast of North America. A seed morphology test, as described by Allen (1960), was used to indicate the Coastal or Interior origin of the samples. Based on this test, the stands from Boezingen/Switzerland and from Purda Lesna/ Poland proved both to be of Coastal origin. A direct comparison of averages of six cone characteristics (width and length of cone scale, width of bract, length of first and second prong, and rating of bract) with the ranges of averages of these characteristics as they vary in climatic seed collection zones of the natural range (Yao [1971]) did not allow an unequivocal assessment of origin. From these comparisons, it could be concluded that cone scale and bract width are more influenced by the environment than the other characteristics. The six characteristics of cone morphology, one thousand-seed weight (measured or assessed on 124 samples from the natural range) and relative DNA content (measured on thirty-six samples of the Coastal part of the natural range) were used concurrently to perform discriminant analyses based on different subspecies, climatic and latitudinal groupings. The discriminant functions obtained were then used to classify the twenty-one provenances of unknown origin. Their origin was assessed at the intersection of the groups to which they were attributed in the different analyses. The low number of provenances, when compared with the immense natural range, and the low number of characteristics taken into consideration, did not allow a complete separation of the groups of provenances. Therefore, the assessment of origin based on cone and seed morphology is still to be considered with caution. Pre-established curvilinear regressions of relative DNA content of embryo cells on latitude in both Coastal and Interior Douglas-fir (El-Lakany and Sziklai [1971, 1972]), were used for inverse estimation of the latitude of origin. It could be established, by this method, that the stand from Boezingen/Switzerland originates between lat. 44° and 47°N on the Coast. When samples are sufficient from the unknown stand, as was the case for provenance Boezingen, seed characteristics and relative DNA content gave promising indication of the probable origin. / Forestry, Faculty of / Graduate

The practice of sustained-yield forest management requires the formulation of management plans designed to ensure the economic efficiency of the forest enterprise. Consequently a knowledge of the volume and value of timber in forest stands is of the utmost importance to foresters engaged in sustained-yield management. In this thesis an analysis of the quantity and value of the product yield from four natural stands of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) in British Columbia has been made. Average stand ages were 63, 86, 106 and 145 years with heights at 100 years of 160, 165, 175 and 165 feet, respectively. Logging and milling costs for what is regarded as typical coastal British Columbia operations were derived from the literature and from local sources. Lumber yields and values presented were obtained from the results of four mill studies of sample logs from the above stands. Value and volume of plywood and piling products obtainable were ascertained from the literature and from local sources. Linear programming techniques were used to determine the optimum joint-product yield from each of the stands. Financial rotations at two levels of establishment costs, and three interest rates, were examined and mathematical models of the relationship between tree value, tree volume and biological variables are presented. It was found that the net value per cubic foot of tree increased with tree size because of reduced handling costs per unit volume and better quality yield in the larger trees. At the level of costs and values used, and within limits of grade specifications, it is more profitable to produce piling from small trees, and plywood from large trees, rather than lumber. The linear programming solution to optimum product yield indicated that optimum conversion return for all stands was 5 cents per cubic foot greater than the lumber conversion return. Financial rotations, at 3 per cent compound interest on establishment costs and on the value of the growing stock, are between 60 and 70 years for these sites. At 65 years the margin for profit and risk in these stands varied from $1400 to $2000 per acre, increasing with degree of stocking. An increase in establishment costs did not affect the rotation age but reduced the net value per acre of the stand. Increasing the interest rate reduced both the rotation age and the net value per acre of the stand. Many biological variables were found to be significantly correlated with tree value and volume. However, regression models using only two or three variables were statistically as good as, and, from a practical point of view, much better than more involved models. Combinations of dbh, butt-log grade and crown class were the best two or three variable models for value prediction. Tree dbh and D²H rendered similar estimates of board-and cubic-foot volumes. It is considered that the volume and value of timber from these sites could be substantially increased by intensive forest management and complete utilisation of the productive capacity of the land. / Forestry, Faculty of / Graduate

Two dormancy induction trials were conducted in a private container nursery in Saanichton, British Columbia. The first study examined the effects of photoperiod induced dormancy on morphology, root growth and field performance of fall planted western hemlock (Tsuga heterophyl_1ji (Raf.)Sarg.) and Douglas-fir (Pseudotsuga menzi_esv[ (Mirb.) Franco) seedlings. Various periods of eight hour days, ranging from two to eight weeks, were applied throughout July and August 1983. Outplanting was done in late September. Survival and growth were assessed one year later. The second project investigated the effectiveness of short days, varying levels of moisture stress and a combination of both as dormancy induction techniques for Douglas-fir seedlings. The short day treatment was four weeks of eight hour days. Four levels of predawn moisture stress were: -5, -10, -15 and -25 bars. These classes respectively corresponded to control, light, medium and severe moisture stress levels. Short days and moisture stress were also combined whereby the four week period of short days followed the moisture stress treatments. These induction treatments were applied in July and August 1984. All seedlings were lifted in January 1985 and placed into cold storage for five weeks until March 1985. Morphology, root growth capacity, frost hardiness and dormancy intensity were assessed in January. Root growth capacity and dormancy intensity were again measured in March. In Study I, short days quickly initiated homogeneous budset in both species in approximately three weeks. The average height increment after treatment initiation was 3.7 cm in Douglas-fir and 4.2 cm in western hemlock. Short days reduced shoot dry weight and height. Caliper and root dry weight were unaffected. In September a surge in root growth occurred in hemlock seedlings treated with six or eight weeks of short days. The importance of early budset to allow increased root growth prior to a fall lift was demonstrated. Root growth capacity was similar among all treatments for both species. The planting survival of western hemlock seedlings increased with increasing weeks of short days. Control plants had 76% survival while the eight week regime had 91%. Survival was similar for all treated Douglas-fir seedlings. It ranged from 89% in the two week interval to 98% in the four week regime. One year height increment was significantly greater in the six and eight week short day treatments for both species. For hemlock, it ranged from 6.1 cm in the control plants to 10.4 cm in the six week trees. Douglas-fir height increment ranged from 6.4 cm for the control interval to 8.6 cm in the eight week regime. The six and eight week photoregimes produced the best quality hemlock seedlings for this study. Four weeks of short days appeared adequate for Douglas-fir. In Study II short days effectively initiated and maintained budset in Douglas-fir seedlings in four weeks. After six weeks from treatment initiation, a light to severe moisture stress was as effective in controlling height growth. A natural photoperiod with no moisture stress was least effective. In a comparison of all treatment combinations, only the control plants under a natural photoperiod were significantly larger in all morphological properties. Short days, moisture stress or a combination of both had similar effects on reducing height, caliper, shoot dry weight and root dry weight. Unstressed seedlings in a natural daylength had the highest value of root growth capacity. All other treatment combinations had significantly lower root growth capacity. Only the severe stress under a natural photoperiod significantly reduced root growth capacity compared to any other treatment. Short days accelerated bud burst in the January and March dormancy intensity tests. Frost hardiness was similar among all treatments. Selection of a regime which controlled height growth while maintaining seedling quality was not clearcut. A short photoperiod with no moisture stress was most effective in initiating budset. However, few morphological and physiological differences were evident between short day plants and light and medium stressed seedlings. / Forestry, Faculty of / Graduate

Bacterial galls on Douglas-fir (Pseudotsuga menzeisii [Mirb.] Franco), collected from the southern tip of Vancouver Island, the Greater Vancouver area and the Hope region of British Columbia, were generally globose in shape with rough, irregular surfaces and measured between 0.5 and 2.0 cm in diameter. The galls were generally located on the tips of branches or twigs of 10- to 20-year old Douglas-fir trees. The bacterial gall disease appeared to affect few Douglas-fir trees in the collection areas and bacterial galls were not found on any other coniferous species. Furthermore, there have been no reports of serious damage to natural forests in British Columbia due to bacterial gall disease. Young, greenhouse-grown Douglas-fir seedlings occasionally died if the tip of the main stem was artificially inoculated. Often new growing tips would be produced affecting the growth form of the seedlings. Two types of gall-forming Erwinia spp. were isolated from Douglas-fir galls. Typical isolates, tentatively identified by fatty acid analysis as Erwinia salicis, produced galls which were rough and irregular in shape composed of multiple outgrowths marked by a single or cross-shaped fissure. The atypical isolate, tentatively identified by fatty acid analysis as Erwinia herbicola subsp. herbicola, produced galls which were smooth and generally round in shape with the surface cracking as the gall expanded. Colonies of the typical isolates grown on casein-peptone-glucose media were characteristically round, slightly domed with somewhat concentric ridging observed near the margins of the colonies. Three to 4 day old colonies of the atypical isolates grown on casein-peptone-glucose media were characteristically round and concave while older colonies produced an extracellular slime and were more irregular in shape. In Luria Broth, the typical isolates grew at temperatures of up to 32°C while the atypical isolate grew at temperatures of up 34°C. The typical isolate was resistant to a wider range of antibiotics than the atypical isolate. Polyclonal antisera were produced against glutaraldehyde-fixed whole cells of both the typical T-2789 and atypical A-0181 gall-forming Erwinia isolates. The purified antisera were isolate specific as tested by immunodiffusion and an indirect ELISA against several different phytopathogenic bacteria including Pseudomonas syringae pv. syringae, Erwinia herbicola subsp. herbicola, Agrobacterium tumefaciens, Rhizobium leguminosarum and Erwinia carotovora subsp. carotovora. Plasmid profiles of the typical Erwinia isolates contained one band while the atypical isolate characteristically contained 4 to 5 bands which appeared to be different forms of at least one plasmid. Restriction digests of the typical isolates suggested a size of approximately 50 kb while complex digestion profiles were obtained for the atypical isolates because of the difficulty in isolating individual plasmid types. From visual estimates against Hindlll-digested lambda DNA, a size of between 10 and 20 kb was suggested for the fastest moving plasmid band of the atypical isolate. No homology was observed between the different plasmid types characteristic of the two isolates. The role of the plasmid DNA of the atypical isolate in pathogenesis was not determined because curing of the plasmid(s) was not successful using high temperature treatments plus chemical curing agents. Heat treatment experiments, in which the pathogen was selectively killed at various times after inoculation, demonstrated that the bacteria are required to be present for gall induction and continued development of the gall for both of the gall-forming Erwinia isolate types. Pathogenicity of the isolated bacteria was tested on 14 conifer species, other than Douglas-fir, including Abies, Chamaecyparis, Pinus and Thuja spp. The typical isolates were weakly pathogenic on Abies, Larix and Picea spp. The atypical isolate was weakly pathogenic on Abies, Chamaecyparis, Larix, Picea and Pinus spp. Due to the limited damage caused on the conifers tested and to their infrequent occurrence, these gall-forming pathogens do not appear to be of economic importance to the forestry industry. / Land and Food Systems, Faculty of / Graduate

Phellinus weirli (Murr.) Gilbertson is an important root rot of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in western North America. The effect of site and tree species on the growth of P. weirii along roots can be measured by inoculation using naturally infected root material or P. weirii cultured on sterile wood. This thesis reports the development of an inoculation technique using naturally infected root material to infect Douglas-fir and western hemlock (Tsuga heterophylla (Raf.) Sarg.). Intact naturally infected root sections of Douglas-fir used as an inoculum source resulted in P. weirii growing on approximately 87% of roots inoculated. Further inoculations were made using infected root sections split longitudinally with the exposed wood surface placed in contact with the host root. Subsequently an attempt was made to evaluate the influence of xeric, submesic and hygric sites, within the Demonstration area of the UBC Research Forest, Maple Ridge, on inoculation and growth of P. weirii along roots of Douglas-fir and western hemlock. Dry soil conditions experienced during the summer of 1978 reduced the expected number of successful infections of host roots to approximately 20%, 26 weeks after installation. All inoculations of a third series established after heavy rains in the late summer infected the roots of both Douglas-fir and western hemlock, verifying that the technique was successful when conditions were cool and moist. P. weirii inoculum used was collected from two sources, Haney and Surrey. Laboratory studies indicated incompatibility between the two sources when raised on agar media and field results indicated a longer retention of viable P. weirii in inoculum blocks from the Surrey source. / Forestry, Faculty of / Graduate

Cytokinin levels were determined by bioassay on a seasonal basis, for two species of dwarf mistletoes (Arceuthobium douglasii and Arceuthobium tsugense) and their respective hosts, Douglas-fir (pseudotsuga menziesii) and western hemlock (Tsuga heterophylla). The highest cytokinin levels occurred in early Spring for all of the samples studied. However, with the exception of the first growth segments of Douglas-fir, the levels of cytokinins detected were significantly greater in infected tissue and aerial shoots of the mistletoe than in the healthy tissue. Further studies were carried out on Spring and Winter samples to determine the kinds of cytokinins present. High performance thin layer chromatography and gas liquid chromatography results showed that zeatin riboside (ZR) was the only detectable cytokinin in Winter samples. ZR was also detected in all Spring samples excepting the aerial shoots of A. douglasii. Two other cytokinins were also detectable in Spring samples. Zeatin was present in aerial shoots from both dwarf mistletoes and in the infected fifth growth segments from Douglas-fir and in infected western hemlock tissue. Zeatin occurred in the healthy tissue only in first growth segments of Douglas-fir. The 2iPA was detectable in the aerial shoots of the dwarf mistletoe, in the fifth grmvth segments of Douglas-fir, and in the infected tissue from western hemlock. These results are discussed with particular reference to the role of cytokinins in the physiological interactions between the host and the parasite.

One serious problem faced by the forest industry in the Pacific Northwest is poor regeneration of commercial trees on land which is harvested and subsequently dominated by brush species. In Coastal Oregon, salmonberry is one of these brush species. Detailed investigations of field sites indicate that light intensity in the brush stands was low but sufficient for germination and early growth of Douglas-fir seedlings and soil moisture percentages and nutrient levels were high enough to support early Douglas-fir growth. Laboratory tests demonstrated the presence of leachable phytotoxins in the leaves of salmonberry. The hypothesis resulting from this study is that salmonberry releases a phytotoxin that in synergism with environmental stresses (i.e., light), suppresses germination and growth of Douglas-fir seedlings in the field.

The activation energy of Douglas fir wood char gasified in carbon dioxide was determined. Activation energies were found for chars that had been pyrolyzed in nitrogen at 600, 750, and 900°C. A thermogravimetric analyzer provided the weight versus temperature data used to obtain the activation energies. The Coats-Redfern integral method of kinetic analysis was used to extract the activation energies from the data. This method can be used to obtain an activation energy from a single weight versus temperature trace for a constant heating rate. An overall apparent activation energy of 723 ± 60 kl/mole and a natural log of the pre exponential factor of 68.8 ± 6.2 was determined from the data collected for all three chars. The different char preparation temperatures did not appear to affect the activation energy. / Master of Science

The use of nitrogenous fertilizers in agricultural and forestry practices coupled with increased fossil fuel combustion and resulting nitrogen (N) deposition across the landscape have contributed to a near doubling of N inputs to terrestrial ecosystems.  With such dramatic changes have come adverse environmental consequences including the acidification of soil and water resources and an increased rate of biodiversity loss in both flora and fauna.  A method of rapidly predicting ecosystem susceptibility to N loss across large spatial scales would facilitate the identification of those systems most likely to contribute to potentially adverse environmental impacts.  To begin the development of such a framework, this research utilizes study sites located throughout the geographic ranges of Douglas-fir (Pseudotsuga menziesii) and loblolly pine (Pinus taeda) to explore relationships between hyperspectral remote sensing, N stable isotope ratios ("15N) and growth response to nitrogenous fertilizer.  In both species multiple linear regression models relating leaf-level reflectance to "15N showed strong predictive capabilities, with some models explaining more than 65% of the variance in "15N.  Significant correlations between "15N metrics and growth response to N fertilization were also observed in both species.  Additional exploratory analysis of the inclusion of "15N metrics with other environmental and edaphic variables to predict fertilizer growth response showed an increase in model performance with the addition of the enrichment factor (EF ="15NFol - "15NSoil).  This research demonstrates the ability of hyperspectral reflectance to predict "15N and reveals the potential of "15N to be included in future models to predict fertilizer growth response. / Master of Science