South Coastal British Columbia Research Articles

Adaptedness of Noble Fir (Abies procera Rehd.) Beyond Its Northern Limit

Abstract The adaptedness of noble fir (Abies procera Rehd.) beyond its northern limit was examined at 12 locations distributed throughout the Maritime, Submaritime, and Subcontinental climates in south coastal British Columbia. Ten-year testing results demonstrated large site effects. Noble fir planted in the Maritime climate survived better, grew faster, entered the period of accelerated growth earlier, and maintained a higher growth rate. In the Maritime climate, the reforestation range of noble fir can be extended considerably north of its current natural distribution and to lower elevations. Low winter temperature and growing-season soil moisture appear to be the major environmental factors limiting the species' expansion into more continental climates, and these factors must be considered in planting site selection. Provenance differences in both growth and survival were significant but small compared to site differences. Adaptive variation showed gentle geographic clines indicating that northern provenances were better adapted in the Maritime climate, whereas inland provenances were superior in the Submaritime climate. Lack of strong geographic patterns suggests that local environmental factors may be important to the adaptive variation of the species. The test results suggest that introduction of noble fir to British Columbia should be limited to the Maritime region, and that northern provenances, such as French Butte, McKinley Lake, and Stevens Pass in Washington are the primary seed sources. For. Sci. 40(3):412-428.

Growing season dry matter and macroelement accumulations in Willamette red raspberry and related soil-extractable macroelement measurements

Aboveground growth of Willamette red raspberry (Rubus idaeus L.) was destructively sampled and partitioned monthly in four growing seasons in 1980–1984 in south coastal British Columbia. This, together with chemical analyses of the plant parts and soil samples, was used to examine general macroelement dynamics. In each of the 4 yr, the plants (floricanes plus new canes) accumulated dry matter, N, P, K, Ca, Mg and Na rapidly during May to June and more slowly in September and October. Floricanes grew early in the season, with dry matter and macroelement uptake nearly complete by mid-summer then senesced after mid-summer with dry matter and nutrient loss. Most of this loss was leaves. New canes began to grow and take up macroelements later in the spring than floricanes and continued growth and uptake later into the fall. Growth and macroelement uptake patterns were inconsistent between years. A calculation, using October measurements, showed moderate quantities of N, P, K, Ca and Mg uptake by the plant on a unit area basis (107, 11, 102, 48 and 20 kg ha−1, respectively). Since maximum cane growth and macroelement uptake occurred at two different times, a minimum of two samplings (mid-summer for floricanes and autumn for new canes) are required to more accurately measure total aboveground biomass production and macroelement uptake. The precise time of sampling should match the growth stage of the plant and not calendar date as growth patterns differed from year to year. Key words: Nutrient uptake, nitrogen, phosphorus, potassium, calcium, magnesium, sodium, Rubus idaeus

Boron and Magnesium Fertilization of a Coastal Douglas-Fir Plantation

Abstract This study examines the role of boron and magnesium nutrition in the occurrence of severe growth distortion symptoms in Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) in the Skwawka River valley of south coastal British Columbia. Four fertilizer treatments including boron (2.25 kg B/ha), magnesium (42 kg Mg/ha), boron plus magnesium, and a control, were applied in conjunction with planting on a site believed to be deficient in these nutrients. After 5 growing seasons, only treatments containing boron (B and B+Mg) showed improved height growth over the control trees. The incidence of leader dieback, swollen leading shoots, and foliage distortion was significantly related to treatment with virtually no occurrence in plots treated with boron. Seedling uptake of applied boron was high, with foliar concentrations of 45 ppm found after the second growing season. Foliar B levels declined to 13-15 ppm after 5 growing seasons. No significant increase in foliar magnesium levels was detected for either of the magnesium treatments. The reduction in the incidence of leader dieback and shoot and foliar symptoms in seedlings treated with B indicate that these symptoms were the result of boron deficiencies. This is the first study to verify boron deficiency in coastal Douglas-fir through fertilizer trials. West. J. Appl. For. 8(2):48-53.

Row cover and population density effects on yield of bell peppers in south coastal British Columbia

Row cover and plant population density effects were studied at the Agriculture Canada Research Station, Agassiz, BC in 1988 and 1989. Bell pepper plants (Ace Hybrid) were transplanted into twin rows (0.45 m apart) on raised beds (1.8-m centers) at five population densities of 1.39, 1.85, 2.78, 5.56 and 11.1 plant m−2. For 7 wk in 1988 or 8 wk in 1989, subplots were either covered or not covered with slit clear polyethylene tunnels. A nonlinear regression model was used to define yield-population density responses. Row covers enhanced early and overall yields in 1988 and overall yield in 1989. Vegetative and reproductive yields (kg plant−1) declined with increasing plant population density. Yields were directly related to population density when measured on a land-area basis. Maximum fruit yield (7.9 kg m−2) was obtained at the highest population density. Treatment influences on fruit size were small and did not affect horticultural quality. An economic analysis showed that net returns were greatest with plants grown under row covers at the highest population density.Key words: Capsicum annuum L., field bell peppers, population density, row covers

Blood Parasites of Blue Grouse (Dendragapus Obscurus) In Western North America

Three hundred thirty-three blue grouse (Dendragapus obscurus) were examined for blood parasites from 11 sites: southern Yukon Territory, southeast coastal Alaska, northern and central interior British Columbia, south coastal British Columbia, northcentral Washington, southcentral Oregon, northwestern California, eastcentral Nevada, northwestern Colorado, and westcentral Montana. Three species of protozoan parasites (Leucocytozoon lovati, Haemoproteus mansoni, Trypanosoma avium) and a splendidofilariid nematode (Microfilaria sp. B) were found in nearly all locations. Prevalence levels were consistently high for L. lovati (92%). The other hematozoa were found less frequently (H. mansoni 29%; T. avium 46%; and microfilaria 29%). The range of these parasites in blue grouse was extended to a more northern (Yukon Territory) and more southern distribution (Nevada than previously reported. Ranges were also extended to blue grouse populations in Alaska, Washington, Oregon and California.

Seasonal colonization of winter wheat in South Coastal British Columbia by vesicular–arbuscular mycorrhizal fungi

Seasonal colonization patterns of vesicular-arbuscular mycorrhizal fungi at four sites were monitored in the roots of winter wheat through the October to August growing season, as were a variety of environmental factors which might influence these patterns. Fall colonization was observed at the two sites which were the most highly colonized at all five harvests. The other two sites were not colonized until late spring and never attained high levels of colonization. Soil phosphorus, soil moisture, and plant physiology were shown to be most highly correlated with these patterns, while temperature was not believed to be an important factor. Key words: endomycorrhiza, Glomus, Sclerocystis, Acaulospora, Scutellospora.

EFFECT OF COMPANION CROPS ON FORAGE ESTABLISHMENT IN SOUTH COASTAL BRITISH COLUMBIA

Field trials were conducted at the Agriculture Canada Research Station, Agassiz, B.C. from 1986 to 1988 to study, under south coastal British Columbia conditions, the use of companion crops in grass establishment. Orchardgrass (Dactylis glomerata L.), perennial ryegrass (Lolium perenne L.), or a mixture of the two was seeded with either oats (Avena sativa L.) or barley (Hordeum vulgare L.) as a companion crop, or as sole crops with weeds either allowed to grow or controlled by herbicide. First cut yields were highest and second cut yields lowest in the establishment year whenever a companion crop was used. Companion crops had no effect on third cut yield in the establishment year, nor on yield the following year. Total yield in the establishment year was highest whenever a companion crop was used due to the higher forage yield of annual cereals than perennial grass at first cut. Proportion of weeds in the first cut was lowest with a companion crop and highest where grass was seeded alone without herbicide. Crude protein content of the first cut was lowest with a companion crop while establishment method had no effect on crude protein content of subsequent cuts. In the second year crude protein content of the forage was highest with ryegrass and lowest with orchardgrass particularly if sprayed with herbicide. A companion cereal crop can be used when seeding forage grasses in south coastal British Columbia, and there is no advantage to using a herbicide for weed control on forage seedlings grown without a companion crop.Key words: Companion crop, establishment, forages, British Columbia

AN EVALUATION OF THE T-SUM METHOD FOR EFFICIENT TIMING OF SPRING NITROGEN APPLICATIONS ON FORAGE PRODUCTION IN SOUTH COASTAL BRITISH COLUMBIA

Seven field trials were conducted over 3 years (1984–1986) at two locations (Agassiz and Oyster River) in south coastal British Columbia to determine forage response to 100 kg N ha−1 applied at various time intervals in the spring according to the accumulation of average air temperatures above 0 °C from 1 Jan. (T-sum). A T-sum of 200 has been reported to be the optimum time for N application in western Europe and the United Kingdom. Both urea and ammonium nitrate were applied at the Oyster River location, while only ammonium nitrate was applied at Agassiz. First-cut forage dry matter production responded to the timing of N application in a variety of ways in the seven trials, with a decrease in growth as N was applied later in the season in most cases. In one trial, dry matter production was lowest at T-100 and T-150 compared to later times of application. Although there were variations among the trials, overall the highest yields occurred when N was applied at T-200 to T-300. Crop quality (%N or crude protein content), however, tended to increase as N was applied later in the season. Recovery of N in the plant and soil at harvest was relatively uniform for all times of N application and the distribution of extractable inorganic N in the soil profile suggested little N leaching. The dominant form of inorganic N found in the soil was ammonium. The cool soil temperatures and flush of plant and microbial activity probably contributed to the apparent lack of leaching and response of the grass to the N applied at various times early in the growing season. The timing of N application in the spring resulted in varying residual effects, whether N was applied or not after the first cut.Key words: N fertilization, yield, quality, timing, N recovery

EFFECT OF NITROGEN, PHOSPHORUS AND POTASSIUM ON WEED EMERGENCE AND SUBSEQUENT WEED COMMUNITIES IN SOUTH COASTAL BRITISH COLUMBIA

The effect of fertilizer on weed emergence and subsequent weed communities was studied in a greenhouse and in the field. In greenhouse experiments, N at 100 kg ha−1 stimulated grass emergence but had no effect on broadleaf weeds. Emergence of broadleaf weeds was suppressed by 200 kg ha−1 and that of grasses by 300 kg ha−1. Emergence of cabbage (Brassica oleracea L.), carrot (Daucus carota L.) was suppressed by 100 kg N ha−1 while suppression of emergence of corn (Zea mays L.), wheat (Triticum sativum L.) and cucumber (Cucumis sativus L.) was less pronounced. In field experiments, N applied in early April increased the number of corn spurry (Spergula arvensis L.) seedlings. After several weeks, lady’s-thumb (Polygonum persicara L.) assumed biomass dominance in 1986 while lamb’s-quarters (Chenopodium album L.) was dominant in 1987 and 1988 on plots that received N. Corn spurry was the dominant weed in number and biomass on plots with no N. When fertilizer was applied in late May, a number of weed species emerged evenly across the various treatments; however, towards maturity, lamb’s-quarters dominated in amount of biomass where N was applied, while corn spurry and shepherd’s-purse (Capsella bursa-pastoris L.) dominated the plots with no N. Phosphorus had a small effect and K had no effect on weed communities and there were no significant interactions. When different rates of fertilizer were tested, emergence of corn spurry was stimulated by 100 kg N ha−1 but was suppressed by higher rates. Results from these experiments have demonstrated that weed emergence and subsequent weed communities in south coastal British Columbia can be greatly altered by fertilizer.Key words: Fertilizer, nitrogen, phosphorus, potassium, weed emergence, weed communities

Estimating Site Index of Douglas-Fir (Pseudotsuga menziesii [Mirb.] Franco) from Ecological Variables in Southwestern British Columbia

Abstract Relationships were examined between Douglas-fir site index (at 50 years breast height age), understory vegetation, and site classification units based on 88 sample plots from south coastal British Columbia. Analysis of variance showed differences in site index (P < 0.01) among the site units. Of the regression models tested, the one based on site units plus indicator species groups was most successful in predicting site index (R² = 0.87, SE = 2.96 m, and 75% of cases classified within 3 m of actual site index). The models using indicator species alone as variables had consistently poorer performance, which we attribute largely to inherent variation in understory vegetation. Further testing of the models over a wider range of sites and in earlier seral stages is suggested. For. Sci. 35(1):50-63.

THE DYNAMICS OF INORGANIC NITROGEN IN A FRASER VALLEY SOIL WITH AND WITHOUT SPRING OR FALL AMMONIUM NITRATE APPLICATIONS

Nitrogen in fallow soil in four field trials was monitored at Agassiz to examine the response of N processes under humid weather conditions of south coastal British Columbia. Inorganic N in the soil profile of control and ammonium-nitrate-treated plots were compared at various time intervals. In two trials (Spring-78 and Spring-81) treatments were applied in late May and in two (Fall-79 and Fall-82) in early November. Leaching of spring-applied N was quite limited during the spring and summer. In the Spring-78 trial, there was negligible nitrate movement until September whereas in the Spring-81 trial there was some movement in June. In the Spring-81 trial, upward movement of nitrate was detected in late August. Nitrate leaching in the summer of 1981 was associated with an unusually high amount of precipitation during June. Leaching of nitrate was significant in late October to December. Nitrogen applied in early November showed extensive leaching by late December. The ammonium appeared to have been nitrified quickly to enable leaching of the applied N as nitrate. Leaching of nitrate appeared to be associated with net water surpluses (precipitation less pan evaporation). Clay fixation of applied ammonium was detected immediately after fertilizer application in the fall but not in the spring trials. The applied ammonium that was fixed by clay was apparently released during the monitoring period. An increase of surface acidity due to ammonium nitrate application was detected in the Fall-79 trial. Comparison of nitrate leaching with long-term precipitation and pan-evaporation records shows that there is low risk of nitrate leaching during the spring and summer but high risk during the fall and winter in south coastal British Columbia. It was concluded that residual inorganic N after the growing season would not be available for crop growth in the spring due to nitrification and leaching over the winter. Development of a soil test for N would have to concentrate on the potential of the soil to mineralize soil N in the spring and early summer. Key words: Nitrogen leaching, nitrogen transformations, clay fixed NH4+, nitrification, fall nitrogen application

The effects of guard rows on variety test results of maize

A 2-year field experiment was conducted in south coastal British Columbia to study the effect of shading in single and triple row plots on the testing results for maize hybrids. Seven early maturing and eight late maturing varieties were planted at separate locations in single and three row plots. The four variables studied were whole crop dry matter % (above ground portion), dry matter yield (t/ha), grain content % and % lodging. The precision of dry matter yield estimates for late varieties was higher for means from center rows than from single plots. Since the statistical significance of this result was marginal and precision did not improve for early varieties or for other variables, the practical importance of this is unclear. Differences in dry matter yields among hybrids differed significantly between single and side rows for early varieties but not for late varieties or between single and center rows. It was concluded that proper randomization and orientation of rows would reduce shading effects in single row plots to levels which are unimportant relative to experimental precision.

Epiphytic vegetation on Acer macrophyllum: a multivariate study of species-habitat relationships

Multivariate methods were used to examine epiphytic species composition on the lower trunk of Acer macrophyllum at five sites in south-coastal British Columbia, Canada. Differences in species composition and abundance between sites were attributed mainly to variation in relative humidity and light conditions. Bark chemistry differences accounted for only a small portion of the observed variation in epiphytic composition between sites. Within sites, compositional variation was examined over 0.5–5 m from ground level on the upper, vertical, and lower trunk surfaces of leaning trees. Compositional variation of the epiphytic vegetation with height and inclination tended to be more strongly developed at drier sites. Furthermore, at all sites compositional variation tended to be greater on upper (wetter) than on lower (drier) surfaces. Particular epiphytic species tended to occur in similar locations on the trunk surface at different sites, suggesting that some microhabitat specialization has occurred. Observed distributional shifts of epiphytic species appeared to be greatest among sites differing widely in prevailing microenvironmental conditions.

Differences in Morphology between Wild and Hatchery Populations of Juvenile Coho Salmon

Abstract To assess the degree of morphological divergence between wild and hatchery-reared juvenile coho salmon (Oncorhynchus kisutch), juveniles from five hatcheries and five wild populations in south-coastal British Columbia were studied. The morphology of hatchery coho salmon was significantly less variable than the morphology of wild-reared juveniles with respect to individual characteristics and overall body form. Populations that were close geographically tended to be similar morphologically in wild-wild and hatchery-hatchery comparisons, but not when wild and hatchery populations were compared together. A principal components analysis suggested a distinct grouping of juvenile coho salmon into hatchery and wild morphological types. Discriminant function analysis and jackknifed classification procedure indicated that juvenile coho salmon could be classified as either hatchery or wild in origin with over 90% accuracy. The morphological differences and the reduced variation of hatchery juveniles observ...

Variation in Burst and Prolonged Swimming Performance Among British Columbia Populations of Coho Salmon, Oncorhynchus kisutch

Burst swimming tests, using both wild and laboratory-reared juvenile coho salmon, Oncorhynchus kisutch, from three streams (two south coastal British Columbia and one interior), indicated that in the first few hundredths of a second of a "fast-start" the coastal juveniles attain greater burst velocities than similar sized interior juveniles. Interior (Coldwater River) juveniles had greater swimming stamina than individuals from the two coastal streams: Wade and Morrison creeks. The differences in stamina performance were demonstrated to be inherited. The differences in swimming performance between coastal and interior are related to differences in body form; coastal coho have deep, robust bodies, while interior juveniles are more fusiform. The differences in swimming performance between coastal and interior coho salmon are probably adaptive and related to differences in the energetic demands of their freshwater migrations and perhaps to different levels of predation in coastal and interior streams.

Epidemiology of dwarf mistletoe in western hemlock stands in south coastal British Columbia

Surveys of seven western hemlock (Tsugaheterophylla) stands in south coastal British Columbia using fixed-radius plots assessed dwarf mistletoe (Arceuthobiumtsugense) infection intensity level and spatial distribution patterns. Regression analysis indicated a close relationship between the plot infection index (average dwarf mistletoe rating of trees in a plot) and the percentage of infected trees. Plot infection index reached 4.0 when all trees in a plot were infected. Infected trees were either associated with widely spaced infection centers or were more or less evenly distributed throughout the stand. Spatial distribution pattern and spread rate were related to (i) the severity and distribution pattern of the initial inoculum sources, (ii) the manner of stand regeneration and resulting stand structure, and (iii) the presence of barriers to spread such as a high nonhost component and drastic slope increases. Tree mortality from dwarf mistletoe averaged 0.6% (range, 0–1.8%) and was much lower than mortality from other causes. On average, 9.3% of the trees had large dwarf mistletoe caused swellings on the lower third of the bole.

Ordination of epiphytic bryophyte communities in a wet-temperate coniferous forest, South-Coastal British Columbia

Three coniferous tree species (Pseudotsuga menziesii, Tsuga heterophylla, and Thuja plicata) at Capilano Canyon, British Columbia, were studied for their epiphytic communities. Quantitative data were obtained for fourteen bryophyte species by sampling at heights of 0.5 m, 1 m and 2 m above ground level. Scapania bolanderi is an abundant and widely distributed species; Dicranum fuscescens, Bazzania denudata, Lepidozia reptans and Hypnum circinale are also common. An environmentally uniform study area was chosen to minimize the effects of factors other than bark and elevation on the distribution of epiphytes. In general, tree species are similar in terms of their epiphytic assemblages, but ordination methods using quantitative data exposed compositional variation that may be explained by differences in microclimate and bark-type. In this respect, the results point the way to further studies to examine epiphyte associations in closer detail, and to relate these associations to specific factors in the microenvironment.

A palynological study of postglacial vegetation changes in the University Research Forest, southwestern British Columbia

The postglacial vegetation history of the University of British Columbia Research Forest was investigated using percentage and absolute pollen analysis, macrofossil analysis, and radiocarbon dating. A marine silty clay deposit records the oldest (12 690 ± 190 years before present (B.P.)) assemblage of terrestrial plant remains so far recovered from the postglacial of south-coastal British Columbia. Lodge-pole pine (Pinus contorta) dominated this early vegetation, although some Abies, Picea, Alnus, and herbs were also present. Sediment cores from two lakes were also studied. The older is Marion Lake, where five pollen assemblage zones are recognized, beginning with a previously undescribed assemblage of Pinus contorta, Salix, and Shepherdia in clay older than 12 350 ± 190 B.P. The pollen diagram from Surprise Lake (11 230 ± 230 B.P.) is divided into three pollen zones which show the same major trends of vegetation change as the Marion Lake diagram.The first report of the postglacial vegetation history of cedar (Thuja and perhaps Chamaecyparis) in southwestern British Columbia is presented from pollen and macrofossil analyses.At about 10 500 B.P. in both lakes, pollen of Douglas fir (Pseudotsuga menziesii) began a rapid increase, probably in response to climatic amelioration. The palynological evidence, supported by well-preserved bryophyte subfossils, suggests that humid coastal conditions have prevailed in the study area since about 10 500 B.P., with virtually no evidence for a classical Hypsithermal interval between 8500 B.P. and 3000 B.P.