Mycorrhizal colonization and types of mycorrhizae that formed on container-grown Douglas-fir, western hemlock, and western red cedar seedlings were determined in a nursery near Nanaimo, B.C. and under a range of field conditions on eastern Vancouver Island. Methods included a root clearing, bleaching, and staining procedure that allowed for accurate estimates of percentage colonization and some advantages in mycorrhiza characterization. The percentage of Douglas-fir and western hemlock short roots colonized by ectomycorrhizal fungi in the nursery was highly variable but over 99 percent of the mycorrhizae were formed by Thelephora terrestris. After one field season mycorrhizal colonization levels were between 72 and 93 percent on the new roots formed. The most difficult to regenerate site had the lowest percentage colonization and number of ectomycorrhizal types. T. terrestris mycorrhizae still had the highest relative abundance followed by Rhizopogon vinicolor (on Douglas-fir only), Cenococcum geophilum, Mycelium radicus atrovirens, Tujber-like, Sndogone-like, and 38 minor types of ectomycorrhizae. Some types of ectomycorrhizae were only present or common on specific sites. This included a type that formed spore-like structures on the mantle cystidia and a type that produced red-brown hyphal exudates. Douglas-fir seedlings artificially inoculated with R. vinicolor in an Oregon nursery were taller than control seedlings when outplanted but no height or weight difference was found after one field season. The 17 types of mycorrhizae that formed on the control seedlings were dominated in relative abundance by a type that was morphologically identical to that formed on the seedlings that were artificially inoculated with R. vinicolor. Western red cedar did not form mycorrhizae in the nursery but formed low levels of vesicular-arbuscular mycorrhizae in the field that included both fine and coarse endophytes. / Land and Food Systems, Faculty of / Graduate

The oceanic Juan de Fuca and Explorer plates are subducting beneath the continental America plate west of Vancouver Island. The Nootka fault zone, which separates these oceanic plates, experiences left-lateral shear due to the different rates of subduction for the Juan de Fuca (4 cm/yr) and the Explorer (<2 cm/yr) plates. Since 1918, six significant earthquakes (M= 5.3 - 7.2) have occurred in the region where the projection of this fault zone intersects central Vancouver Island. In this study two of the largest events are examined; the 1918 (Ms ≃ 7) and the 1957 (Ms ≃ 6) earthquakes. Prior to this research, no comprehensive studies of these events had been carried out. A total of 46 seismograms from 24 stations worldwide were obtained for the 1918 earthquake, and 138 seismograms from 46 stations were obtained for the 1957 earthquake. The preferred epicentre for the 1918 earthquake is 49.47°N, 126.24°W, with an estimated uncertainty of ±30 km. The preferred focal depth of 15 km indicates that this was a crustal earthquake. Magnitude estimates are Ms = 6.9 ± 0.3, mb, = 7.2 ± 0.4 and MI = 7.0, in agreement with previous studies. Surface wave analysis suggests this is a predominantly strike-slip earthquake occurring along either a NNW or an ENE striking fault. A seismic moment of 7.40x10²⁵ dyne-cm and a stress drop of 122 bars, indicative of an intraplate event, are estimated. The preferred epicentre for the 1957 earthquake is 49.65°N, 127.02°W with an uncertainty of ± 20 km. The estimated focal depth of 30 km suggests this event occurred in the subducting oceanic plate. Magnitude estimates are Ms = 5.9±0.2, rrif, = 6.3±0.3 and Mi = 5.7. Surface wave and P-nodal analyses indicate that this is a predominantly strike-slip earthquake; either dextral along a NNW striking fault, or sinistral along a ENE striking fault. The seismic moment is estimated to be 8.14x10²⁴ dyne-cm, and the stress drop to be 36 bars, which is indicative of an interplate event. The quality of these data does not allow for an unambiguous interpretation of these earthquakes in terms of seismotectonic models. However, the results of this study indicate that these earthquakes do not have normal or thrust mechanisms. The 1918 earthquake appears to be a crustal, intraplate event resulting indirectly from the complicated interaction of the Explorer, Juan de Fuca and America plates. The preferred epicentre, depth and stress drop for the 1957 earthquake are consistent with left-lateral motion between the Juan de Fuca and Explorer plates along the Nootka fault zone where it is being subducted beneath Vancouver Island. Uncertainties in the above parameters however, do not rule out the possibility of this being a crustal earthquake along a NW striking fault. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Headwater streams typically have no fish, owing to steep gradients and impassible barriers; therefore, scientific research and protection measures have been focused on fish bearing streams. The Scientific Panel for Sustainable Forest Practices in Clayoquot Sound (CSP) developed a channel classification system which is pertinent to all streams, fishless and fish bearing alike, and upon which management prescriptions in Clayoquot Sound, Vancouver Island, British Columbia are based (CSP, 1995). The CSP classification delineates channels according to four physical criteria: bed material, gradient, entrenchment, and width. The current study was undertaken to determine the efficacy with which the CSP classification system delineates small, steep streams, on the basis of channel geomorphic units within them, and to examine the benthic macroinvertebrate habitat capability of these geomorphic units. Falls, bedrock cascades, boulder cascades, rapids, chutes, riffles, glides, and pools were described according to their bed slope and dominant channel-material type and organization. In addition, the area of each geomorphic unit was measured. Seventeen streams were grouped into four CSP channel classes which were compared with respect to the mean relative proportion of class area in geomorphic units. Stratified random benthic samples were extracted from geomorphic units in order to investigate and to compare their habitat capability. "Alluvial channels" in the study exhibited only weak, very infrequent fluvial transport; therefore, they were termed semi-alluvial. In general, high gradient geomorphic units (i.e. bedrock and boulder cascades) were dominant in steep, largely non-alluvial channels. Lower gradient units (i.e. riffles and rapids) were common in semi-alluvial streams with more mild slopes. Accordingly, channel classes with opposing bed material and gradient designations exhibited notable differences with respect to relative proportions of geomorphic units while width and entrenchment designations exerted little influence on channel organization. Ultimately, only two of the four CSP classification criteria effectively systematized channels on the basis of channel geomorphic units within them. Abundance of benthic macroinvertebrates was greatest in riffles (≈100 individuals per two minute kick sample), followed by rapids (≈80 individuals/sample), pools (≈70 individuals/sample), boulder cascades (≈60 individuals/sample), chutes (≈50 individuals/sample), and lowest in bedrock cascades (≈25 individuals/sample). In addition, abundance of invertebrates in channels with ephemeral flow regimes was considerably lower compared to channels with seasonal or perennial flow regimes. Ordination of macroinvertebrate taxa showed that community structure of bedrock cascades and chutes were similar but different from other habitats. Similarly, the benthic macroinvertebrate community structure of channels with ephemeral flow regimes was very distinct.

An investigation was initiated in southern British Columbia during 1984 to determine the degree of similarity between populations of coho salmon, in terms of their demographic traits and exploitation patterns. Fourteen stocks of wild or hatchery origin were subject to coded-wire tagging in nine different streams located within a 150 km region of southeast Vancouver Island during 1985,1986, and 1987. Escapement enumeration and tag recovery were conducted during the 1985-1988 period in all streams by means of counting fences and stream surveys. A new mark-recapture model was formulated specifically for estimating escapement levels in natural streams where only a partial enumeration of spawners is possible. Estimates of the number of tags recovered in various sport and commercial fisheries were generated primarily on the basis of catch and sampling records extracted from the Mark-Recovery Program database, located at the Pacific Biological Station of the Canadian Department of Fisheries and Oceans. Estimates of sampling rates in the Strait of Georgia sport fishery were determined from simulation studies based on catch and sampling statistics associated with the Georgia Strait Creel Survey and Head Recovery programs. Populations were contrasted in terms of their juvenile migration patterns, smolt-to-adult survival, catch distributions, straying rates, escapement patterns, run composition, adult sizes, and exploitation rates. Considerable variation in smolt size and juvenile migration time was detected among populations each year. The most pronounced difference was the consistently shorter migration period of smolts released from public hatcheries. Estimates of ocean survival was highly variable across years and streams, and even among stocks within the same stream. No particular stock or stock type had consistently higher survival, but hatchery fish from the Big Qualicum River exhibited consistently lower survival. Considerable variation was observed in the duration and timing of various runs within the study area. On average, the contribution of strays to each spawning population was relatively small (< 2%), but strays could account for as much as 50% of the escapement to a given stream. Average exploitation rates were in the neighborhood of 80% each year, but were as high as 96% for some stocks. Substantial differences in exploitation rate were detected between stocks from the same stream, and between stocks from adjacent streams, but exploitation rates were not consistently higher or lower for any particular stock or stock type. The influence of specific factors upon straying rates, survival rates and exploitation patterns was estimated by means of log-linear models. Stock contributions to various fisheries appeared to be related to the release location, and two stock assemblages were identified within the study area based on the level of similarity among stocks in fishery contribution. Attempts to quantify the level of co-variation among stocks in survival and exploitation rates were hampered by the lack of sufficiently long time series of data, but preliminary results gave no indication of a high level of similarity among stocks or stock types. Still, it was possible to identify stocks which could be used as indicators of the general status of all stocks in the study area in terms of escapement trends, smolt-to-adult survival and exploitation rates. Based on the level of similarity observed, indicator stocks are considered to be useful stock-assessment tools, and can provide useful information for management purposes. / Science, Faculty of / Zoology, Department of / Graduate

It is generally accepted in British Columbia that Canada Land Inventory Class 1 to 4 lands are arable, yet in many instances commercial farms exist on lands of lower capability. A case study was done for an area (1.6 km * 2.9 km) southeast of Nanaimo, B.C. to determine if Canada Land Inventory Class 4 and 5 soils are biophysically suitable for Pyrus (pear) and Mai us (apple) orchards, and if such a development would be socioeconomically feasible. The critical biophysical conditions governing orchard development identified were climate (freeze free period, effective growing degree days, dormancy period and minimum winter temperature); soils (depth, drainage, texture/% coarse fragment content and topography); and groundwater availability for irrigation. The critical economic conditions were land tenure (Tree Farms and parcel size); current land use; and fruit yields and prices. While all biophysical conditions were favourable to apple orchards, the soils were found to be too coarse textured for pear orchards. Maps outlining the critical biophysical and socioeconomic conditions were prepared and overlayed. The composite map identified one area with realistic development potential for apple orchards. Although soils, land tenure, parcel size and current land use decreased the area available for orchards, the lack of groundwater for irrigation was found to be the most limiting factor to orchard development. Estimates of costs and returns for a 3.3 ha apple orchard over a 25 year period were done. Using these estimates, the net present value of the orchard was determined for three discount rates: 5%, 8% and 10%; and for five prices per kilogram: $0.15, $0.22, $0.33, $0.44 and $0.66. At prices of $0.15, $0.22, $0.33 and $0.44 (at discount rates of 10% and 8%), orchard establishment was not feasible. However, at prices of $0.44 (and discount rate of 5%) and $0.66, orchard establishment was feasible. / Science, Faculty of / Resources, Environment and Sustainability (IRES), Institute for / Graduate

Lead isotope compositions have been obtained from five major volcanic and intrusive rock suites and several ore deposits on Vancouver Island. Lead, uranium and thorium concentrations and strontium isotope ratios have been obtained for a subset of these samples. The rock suites examined are the Paleozoic Sicker Group, Triassic Karmutsen Formation, Jurassic Island Intrusions and Bonanza Group volcanic rocks, and the Eocene Catface intrusions. Isotope geochemistry of the Sicker Group is consistent with the interpretation that it formed as an island arc. Relatively high 207pb/204pb ratios indicate sediment involvement in the subduction process, which suggests that the Sicker Group formed close to a continent. Buttle Lake ore deposits display decreasingly radiogenic lead isotope ratios with time, suggesting that the associated magmas become increasingly primitive. This supports the hypothesis that these deposits formed during the establishment of rifting in a back-arc environment. Karmutsen Formation flood basalts display isotopic mixing between an ocean island-type mantle source and average crust. Isotopic evidence is used to support a Northern Hemisphere origin for these basalts. Mixing is apparent in the lead and strontium isotope signatures of the Island Intrusions and Bonanza Group volcanic rocks, between depleted mantle and crustal (possibly trench sediments) components. This is consistent with formation of these rocks in an island arc environment. Eocene Catface intrusions have relatively high 207pb/204pb indicating that crustal material was involved in their formation. There are two groups of plutons corresponding to an east belt and west belt classification. Galena from the Zeballos mining camp related to the Eocene Zeballos pluton indicates that the mineralization was derived from the pluton. Galena lead isotope data from Vancouver Island may be interpreted in a general way by comparison with data from deposits elsewhere of known age and origin. No single growth curve model can be applied. Lead isotope characteristics of Vancouver Island are clearly different from those of the North American craton, reflecting the oceanic affinities of this terrane. A new technique has been developed to compare 207pb/204pb ratios between samples with differing 206pb/204pb ratios. The procedure projects 207pb/204pb ratios along suitable isochrons until they intersect a reference value of 206pb/204pb. This technique can be used for interpreting lead isotope data from old terranes, in which lead and uranium may have undergone loss or gain, and if lead and uranium abundances have not been measured. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Headwater streams typically have no fish, owing to steep gradients and impassible barriers; therefore, scientific research and protection measures have been focused on fish bearing streams. The Scientific Panel for Sustainable Forest Practices in Clayoquot Sound (CSP) developed a channel classification system which is pertinent to all streams, fishless and fish bearing alike, and upon which management prescriptions in Clayoquot Sound, Vancouver Island, British Columbia are based (CSP, 1995). The CSP classification delineates channels according to four physical criteria: bed material, gradient, entrenchment, and width. The current study was undertaken to determine the efficacy with which the CSP classification system delineates small, steep streams, on the basis of channel geomorphic units within them, and to examine the benthic macroinvertebrate habitat capability of these geomorphic units. Falls, bedrock cascades, boulder cascades, rapids, chutes, riffles, glides, and pools were described according to their bed slope and dominant channel-material type and organization. In addition, the area of each geomorphic unit was measured. Seventeen streams were grouped into four CSP channel classes which were compared with respect to the mean relative proportion of class area in geomorphic units. Stratified random benthic samples were extracted from geomorphic units in order to investigate and to compare their habitat capability. "Alluvial channels" in the study exhibited only weak, very infrequent fluvial transport; therefore, they were termed semi-alluvial. In general, high gradient geomorphic units (i.e. bedrock and boulder cascades) were dominant in steep, largely non-alluvial channels. Lower gradient units (i.e. riffles and rapids) were common in semi-alluvial streams with more mild slopes. Accordingly, channel classes with opposing bed material and gradient designations exhibited notable differences with respect to relative proportions of geomorphic units while width and entrenchment designations exerted little influence on channel organization. Ultimately, only two of the four CSP classification criteria effectively systematized channels on the basis of channel geomorphic units within them. Abundance of benthic macroinvertebrates was greatest in riffles (≈100 individuals per two minute kick sample), followed by rapids (≈80 individuals/sample), pools (≈70 individuals/sample), boulder cascades (≈60 individuals/sample), chutes (≈50 individuals/sample), and lowest in bedrock cascades (≈25 individuals/sample). In addition, abundance of invertebrates in channels with ephemeral flow regimes was considerably lower compared to channels with seasonal or perennial flow regimes. Ordination of macroinvertebrate taxa showed that community structure of bedrock cascades and chutes were similar but different from other habitats. Similarly, the benthic macroinvertebrate community structure of channels with ephemeral flow regimes was very distinct. / Arts, Faculty of / Geography, Department of / Graduate

Around 1500 years ago, the Coast Salish peoples of southwestern British Columbia began to inter their dead within funerary petroforms. These burials, consisting of patterned arrangements of stone and soil built over the dead, marked a dramatic transition from below ground burials within the village, to above ground cemeteries located around village peripheries. This upward and outward movement of the dead is exemplified at the Rocky Point Peninsula on the southernmost tip of Vancouver Island. It is one of the largest mortuary landscapes on the Northwest Coast of North America, with 515 visible funerary petroforms distributed within and between two large neighbouring cemeteries. Catherine Bell’s (1992) notion of ritualization challenges us to consider what the building of funerary petroforms accomplished that previous funerary practices did not. While funerals are times of grieving, they may also be ritual actions in which the dead are transformed from corpse to ancestor and the family from mourner to inheritor. It was in the authority of tradition that funerary ritual served as a process for both enacting and contesting relationships of power within and between the two neighbouring communities at Rocky Point. Foregoing excavation, Coast Salish protocols of working with their dead challenged me to consider how the external and material attributes of funerary petroforms worked through space and time to produce a landscape inhabited by these durable, ancestral agents. Focusing on the mesoscale encompassing these two large cemeteries, this dissertation is an analysis of the depositional practices employed by the Rocky Point peoples in the burial of their dead. Tacking between an ethnographic thematic analysis of Coast Salish ritualization, a body of social theory, and the archaeological record, I used a novel suite of quantitative analyses to identify patterns in how these burials were made, in addition to how they were placed relative to one another on the landscape. Results point to a fundamental bifurcation in funerary petroform morphology and placement, in part, differentiating communities of ritual practice at Rocky Point. In particular, the results highlight the social significance of the spaces between the burials, as much as the burials themselves. This is exemplified by a perceptual paradox in which these above ground features, built according to shared dispositions of practice and placed on distinctive landscapes, are simultaneously and intentionally hidden from day-to-day movement between villages. This Rocky Point sense of monumentality speaks to the liminality of their most powerful dead, anchored at the threshold of the living. Funerary petroforms have a persistent power to entangle the living and the dead in oblique relationships of power. The resilience of this memory work, however, is not limited to the past. At Rocky Point and other cemeteries throughout the Salish Sea, these ancestral places provide living descendants with a tangible connection to family and community history. Possessing a durability that continues to enmesh people and places through time, funerary petroforms are one of the fulcrums upon which relations of power are presently balanced between Coast Salish and settler communities in British Columbia. / Graduate / dmathews@uvic.ca

Satellite-sensed Advanced Very High Resolution Radiometer (AVHRR) Sea Surface Temperature (SST) data over eight summers (1984-1991) were used to analyze the summer SST patterns of variability off the west coast of Vancouver Island. Empirical Orthogonal Function (EOF) analysis of the spatial variance for 133 nearly cloud-free summer images was performed. The first EOF mode, which resembled the mean of all images, showed a strong cool water band located at the northwest corner of Vancouver Island, a cool tongue extending seaward from the Strait of Juan de Fuca and a warm patch off Barkley Sound. The second mode revealed topographically controlled upwelling -- coolwater over the shelf region with its seaward boundary roughly following the 200-m depth contour, plus a cold eddy located just north of the Juan de Fuca Canyon. The third mode displayed cool water extending southwestward off Brooks Peninsula, while the fourth mode showed a cool water plume extending off Cape Scott at the northern tip of Vancouver Island. These 4 modes accounted for respectively, 33, 12, 10 and 5% of the SST variance. With the first 4 modes accounting for 60% of the total variance, the EOF method is highly effective in condensing the huge amount of satellite data. The temporal amplitude of the EOF modes revealed how the SST features changed as summer progressed. From these images, we also constructed an overall seasonal coolness index, which revealed the summers of 1986 and 1991 to have the coolest coastal water, with both summers immediately preceding an El Nino.

Root disease is a serious concern for the softwood timber industry. This thesis reports on the development of a root disease detection procedure that applies lidar data integrated with imaging spectrometer data. Photosynthetic pigments are frequently cited as one of the most responsive indicators of vegetation stress. This study estimated pigment content from needle and canopy reflectance and characterized the sensitivity of these pigments to a fungal-mediated stress. Samples were collected from the Greater Victoria Watershed District on Vancouver Island, BC, Canada. Lab reflectance measurements were made and pigments were extracted. Reflectance spectra were transformed into derivative spectra and a continuum removal band depth analysis was conducted. Reflectance metrics were generated and used in modeling pigment content. Chlorophyll-a was found to be significantly affected by the disease in the needle level portion of this study. The predictive power of reflectance attributes were assessed and yielded strong coefficients of determination (R2>0.80). Samples exhibiting stress responses affected by root disease were discriminated. It was determined that younger trees were more severely affected by the root pathogen than mature colonized trees. In the canopy level component of the study, chlorophyll-a was estimated through the application of partial least squares regression and achieved an R2 value of 0.82. Continuum removal metrics, which proved to be good estimators at the needle level, were found to be insufficient at the canopy level. Through the use of hyperspectral forest chemistry products, potential root disease sites can be identified. / Graduate