ALBERT

Description: The effects of self-pollination in white spruce, Piceaglauca (Moench) Voss, were examined in 20 trees in three populations. The most drastic effect is the increased frequency of empty seeds which averages over 90%, and is 5 to 22 times higher than that from comparable cross-pollinations. The average numbers of embryonic lethal equivalents, although highly variable for individual trees, averaged 8.0, 9.1, and 12.9 for the three populations. Self-pollination also resulted in slightly lower germination and reduced survival. The total number of lethal equivalents affecting seed yield, germination, and survival to age 17 years is estimated as 12.6. The effect of selfing on growth becomes evident at age 2 years and increases to age 17 years when seedlings from self-pollinations averaged 44.5% shorter and 63.7% smaller diameter than seedlings from unrelated matings.

Description: The salinity tolerance of six annual crop species, wheat, oats, barley, rye, flax and rapeseed, were determined on saline soils that occur north of the Quill Lakes in the northeastern corner of the agricultural area of Saskatchewan. The relative merits of a salt-tolerant grass-legume mixture were also given consideration. The effects of salt stress on spring-sown cultivars became most apparent following exposure to hot, dry summer weather. In contrast, maximum salt tolerance for both winter wheat and winter rye was a function of winterkill. The winterhardiness of both winter annuals was reduced by saline conditions, but winter rye was more adversely affected than winter wheat. Large decreases in seed yield, plant dry weight and height occurred before the effects of increased soil conductivity were expressed for hectoliter weight, 1000-kernel weight, date of maturity, protein content and oil content. Among the spring and winter annual cultivars considered, Bonanza barley and Garry oats demonstrated the greatest salt tolerance. However, where severely saline conditions occurred, mixtures of salt-tolerant perennial grasses and alfalfa proved to be more productive than either barley or oats. The salinity tolerance of all cultivars was greater for years with more favorable growing conditions. It was apparent that stress factors, such as soil salinity, cold, heat, drought, etc., have a cumulative effect in reducing crop performance. This observation emphasizes the importance of minimizing all stress factors when attempting to crop saline soils. Detailed soil analyses indicated that where salts were a problem, the level of salinity was extremely variable, often changing dramatically over short distances. This extreme variability made it difficult to assess the magnitude of the salinity problem. In this regard, crop performance, especially plant height, provided a good indicator for identifying saline areas for purposes of soil testing.

Description: Between 1974 and 1981, the cross black spruce (Piceamariana (Mill.)B.S.P.) × Sitka spruce (P. sitchensis (Bong.) Carr.) was attempted on over 2000 black spruce strobilis on 39 trees. Of 58 different tree × pollen combinations attempted, 48 yielded viable seeds. Species crossability, although highly variable on an individual-tree basis, averages about 5%. Hybrid seeds have slightly poorer germination and produce more abnormal seedlings than nonhybrid seeds. The hybrid seedlings are intermediate between the parents for most taxonomic characters and are clearly distinguishable from the parents on the basis of bud scale shape and serrations. Within-family variation in growth is higher in hybrid than in nonhybrid families, and most hybrid families contain a few exceptional seedlings. Methods of mass producing these exceptional seedlings are discussed. It is suggested that black spruce and Sitka spruce should be placed in different subsections of section Omorika, genus Picea.

Description: Starch gel electrophoresis was used to survey for genetically determined enzyme mobility differences among 297 megagametophytes of red pine (Pinusresinosa Ait.) from five widely separated geographical sources. Consistent and reproducible enzyme banding patterns were observed with five of the seven isozyme systems assayed. No variation in band mobility was observed in any of these systems. This result stands in contrast with those reported from surveys of allozyme variation in other coniferous species but is consistent with the low degree of genetic variation observed in red pine for higher levels of genetic organization. It is concluded that red pine is genetically depauperate.Possible explanations for restricted genetic diversity are discussed. The most plausible explanation suggests that red pine was at sometime, possibly during the Pleistocene, reduced to a small refugial population and has yet to reestablish equilibrium heterozygosity.

Description: Natural inbreeding and relatedness among neighboring trees were studied in several central New Brunswick populations of white spruce (Piceaglauca (Moench) Voss). Coefficients of relationship (r) were estimated by comparing the self-, neighbor-, open-, and unrelated-pollination effects on percent full seed. The estimates were 0.29 and 0.28 for neighbor and open pollinations, respectively. The effects of natural inbreeding on juvenile traits, e.g., germination and early growth, were slight while the effect on height growth increased with age at least to age 7 years. Neighboring white spruce trees growing in natural stands appear to be related at about the half-sib level (r = 0.25). Based on percent full seed, open-pollination approximates a level of inbreeding expected from trees related at a level well above that of half-sibs. Differential selection at the pre-embryo to early seedling stages results in progenies again related at the half-sib level. It is suggested that an inbreeding equilibrium exists in natural stands of white spruce and that this equilibrium approximates that expected from half-sib matings (F = 0.125). The inbreeding equilibrium is controlled, at least in part, by the frequency of lethal genes in the populations.

Description: Survival and total height of red spruce (Picearubens Sarg.) at ages 15 and 22 years from seed are reported. Twelve provenances distributed from North Carolina to Quebec were grown in three experiments each in Ontario, Quebec, and New Brunswick; seven additional provenances were only partially represented. Variance, correlation, and regression analyses were made. Results at both ages were very similar. Provenance differences in survival were small at individual sites and significant only when the results from all nine sites were combined. Provenance differences in height were well expressed and significant in each of the three groups of tests, with northern provenances growing best. Several provenances were also relatively stable and performed well from site to site. Correlation and regression analyses showed that variation in height was more closely related to the degree of introgressive hybridization with black spruce (Piceamariana (Mill.) B.S.P.) than to latitude, elevation, or precipitation at the place of seed origin. These results were conditioned by development on open sites which are not typical red spruce sites.In contrast with expectations when the study was initiated, it is now apparent that provenances from the southern Appalachian Mountains in West Virginia and North Carolina are less variable than expected and not suitable for reforestation in Canada.

Description: Seed collected from 30 stands of black spruce, 15 upland and 15 lowland, was tested by germination, nursery performance at two nurseries, and field planting at three locations; results were measured to the 5th and 10th year after planting.Significant differences (seed size, germination, seedling size, survival, and height growth) were found between the three geographical locations: Cochrane, Geraldton, and Thunder Bay. Only very minor differences were found between upland and lowland types. Strong significant differences were found between individual collection stands, indicating that superior stands for seed collection could be located and preserved.

Description: A tree-concentric procedure is presented to eliminate edge effect statistical bias for horizontal point sampling. For known forest populations, the exact mean of the unbiased (adjusted for edge effect) and biased (unadjusted for edge effect) estimators of a forest characteristic can be determined along with the exact bias. Edge-effect bias is investigated for three forests that vary in area, four basal area factors (BAF), and three forest characteristics. Exact and estimated results based on 5000 random points were compared. Edge effect bias increases as the BAF decreases and varies with forest size, size and spatial distribution of trees, percentage of edge trees, and forest characteristic. The variance of the biased estimator was always smaller than the variance of the unbiased estimator. Using mean square errors, the biased estimator was found to be, in general, more accurate and the distortion of probability statements caused by the bias negligible for small to moderate sample sizes, especially for larger BAF's and certain forest characteristics.

Description: Effects of inbreeding in a natural population of black spruce (Piceamariana (Mill.) B.S.P.) were studied using progenies from self-, open-bag, open, and pollen-mix pollinations. Self-pollination resulted in significant reductions in seed set and early height. The numbers of embryonic lethals were estimated comparatively by using two different models. Based on full seed data, the population carried an average genetic load of five to seven embryonic lethal equivalents per zygote. The total number of lethal equivalents, acting from the time of pollination through age 6 years, ranged from about six to eight. The role of polyembryony in maintaining heterozygosity is discussed. Significant differences among female parents with respect to seed weight, percent germination, and 2- and 6-year heights indicated substantial variation owing to additive genetic and maternal effects. Relative self-fertility in the species, although generally high, varied widely among parents.

Description: A procedure is presented to eliminate edge-effect statistical bias for fixed-area circular plots when sampling forest areas. For known forest populations, the exact mean of the unbiased (adjusted for edge effect) and biased (unadjusted for edge effect) estimates of a forest characteristic can be determined along with the exact bias. Edge-effect bias is investigated for three forests that vary in area, four plot sizes, and three forest characteristics. Exact and estimated results based on 5000 random points were compared. Edge-effect bias increases with plot area and varies with forest size, spatial distribution of trees, percentage of edge trees, and forest characteristic. The variance of the biased estimator was always smaller than the variance of the unbiased estimator. Using mean square errors, the biased estimator was found to be more accurate and the distortion of probability statements caused by the bias negligible for moderate sample sizes and small-plot areas.