The susceptibility of white spruce, Piceaglauca (Moench) Voss, leaders to damage by the spruce bud moth, Zeirapheracanadensis Mut. & Free., was assessed for 72 half-sib families at four half-sib family test sites and in one seedling seed orchard in New Brunswick. Trees of intermediate height (1.5–3.75 m) were the most damaged, and damage in one year was positively correlated to damage in the next. During 2 consecutive years, half-sib family explained only 1% of the variation in damage when all four test sites were analysed together. However, half-sib family explained between 2.9 and 7.9% of the variation in damage at individual sites. At the four test sites, mean growth reductions of trees in the two most susceptible families were estimated to be approximately 30% higher than those of trees in the two least susceptible families. When all 72 families were ranked with respect to height, trees in the most susceptible and least susceptible families were ranked very poorly and highly, respectively. This suggested that trees in more susceptible families were smaller because of damage by the spruce bud moth. However, this pattern was observed at all sites, including one where bud moth damage was negligible. Thus even in the absence of damage by the spruce bud moth, trees in these least susceptible families had a greater growth rate, in terms of height, than trees in the most susceptible families. This indicates that selection for plant traits reducing susceptibility to bud moth may be compatible with breeding programs attempting to improve height growth. Implications of these results for tree improvement programs are discussed.

Seed mass is an adaptive trait affecting species distribution, population dynamics and community structure. In widely distributed species, variation in seed mass may reflect both genetic adaptation to local environments and adaptive phenotypic plasticity. Acknowledging the difficulty in separating these two aspects, we examined the causal relationships determining seed mass variation to better understand adaptability and/or plasticity of selected tree species to spatial/climatic variation. A total of 504, 481 and 454 seed collections of black spruce (Picea mariana (Mill.) B.S.P.), white spruce (Picea glauca (Moench) Voss) and jack pine (Pinus banksiana Lamb) across the Canadian Boreal Forest, respectively, were selected. Correlation analyses were used to determine how seed mass vary with latitude, longitude, and altitude. Structural Equation Modeling was used to examine how geographic and climatic variables influence seed mass. Climatic factors explained a large portion of the variation in seed mass (34, 14 and 29%, for black spruce, white spruce and jack pine, respectively), indicating species-specific adaptation to long term climate conditions. Higher annual mean temperature and winter precipitation caused greater seed mass in black spruce, but annual precipitation was the controlling factor for white spruce. The combination of factors such as growing season temperature and evapotranspiration, temperature seasonality and annual precipitation together determined seed mass of jack pine. Overall, sites with higher winter temperatures were correlated with larger seeds. Thus, long-term climatic conditions, at least in part, determined spatial variation in seed mass. Black spruce and Jack pine, species with relatively more specific habitat requirements and less plasticity, had more variation in seed mass explained by climate than did the more plastic species white spruce. As traits such as seed mass are related to seedling growth and survival, they potentially influence forest species composition in a changing climate and should be included in future modeling of vegetation shifts.

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A commentary onChallenging Easter Island's collapse: the need for interdisciplinary synergies by Rull, V.,

[Du Roil K.Koch), which were clonal seed orchards and controlpollinated progeny tests. Production from the seed orchards has been regular and heavy. In only 15 years, most reforestation stock was being grown from orchard seed. Early results from black spruce and jack pine realized gain tests indicate increases of 12 to 20% in volume growth by using genetically improved seed. This is double the prediction that was made when the program started. Stem straightness ofjack pine trees has been improved by 25%. Second-generation programs of black spruce and jack pine are well underway and production from these orchards is steadily increasing. Indications are that gains from using this seed will be substantial. An ongoing research and development program has contributed to a more effective breeding program, has increased seed production, and has given further insights into wood quality. The success of the Council's program is due to excellent participation and team work by government, university and industrial agencies and their long-term commitment.

a limited seed supply, sensitivity to hard water and excessively large branches (especially at wider spacing) are drawbacks.Despite growing on a wide range of sites, red pine is remarkably uniform in taxonomic and morphological characteristics, a rare feature amongst pines (Holst 1975, Boys et al. 2005. Studies on red pine populations from Quebec (Simon et al. 1986), Ontario, New Brunswick and Nova Scotia (Fowler and Morris 1977), and isolated populations in Newfoundland (Mosseler et al. 1991(Mosseler et al. , 1992 ABSTRACTSurvival, total height and diameter at breast height (DBH) were measured in the fall of 2005 in a 48-year-old red pine (Pinus resinosa Ait.) provenance trial growing in northwestern Ontario. There was significant variation in both height and diameter among the 23 provenances. Generally, westerly provenances performed well while those from the Maritime Provinces exhibited relatively poor growth. Considering that the plantation is at the northern biological range of red pine, survival was high, averaging 96% after 48 years. Provenances with the best growth rates exceeded a volume of 420 m 3 ha -1 . Some provenances from Minnesota and Wisconsin as well as Fort Frances, Ontario exhibited superior growth and should be considered as seed sources for future planting programs in northwestern Ontario.Key words: red pine, provenance test, survival, diameter, height, volume, Northwestern Ontario RÉSUMÉ Le taux de survie, la hauteur totale et le diamètre à hauteur de poitrine (dhp) ont été mesurées à l'automne 2005 dans une plantation de pin rouge (Pinus resinosa Ait.) âgée de 48 ans destinée à faire l' essai de différentes provenances de semis et située dans le nord-ouest de l'Ontario. On a relevé une variation significative tant au niveau de la hauteur que du diamètre parmi les 23 provenances. De façon générale, les provenances occidentales ont bien performé tandis que celles issues des provinces de l' Atlantique ont démontré une croissance relativement décevante. En prenant en considération que la plantation est située à la limite nordique de l'aire de distribution biologique du pin rouge, le taux de survie s' est révélé être élevé, atteignant une moyenne de 96 % après 48 ans. Les provenances ayant les meilleurs taux de croissance ont atteint un volume supérieur à 420 m 3 ha -1 . Certaines provenances du Minnesota et du Wisconsin ainsi que de la région de Fort Frances en Ontario ont démontré une croissance plus importante et devraient être retenues comme sources de semences pour les prochains programmes de plantation à être réalisés dans le nord-ouest de l'Ontario.

Genetic gains based on a genetic test using clonal replicates were compared to those based on a test using seedlings at the same gene diversity and testing effort levels using POPSIM™ Simulator. Three testing and deployment strategies targeting for white spruce (P. glauca [Moench] Voss) and black spruce (P. mariana (Mill.) B.S.P.) in New Brunswick were compared: seedling test with clonal seed orchard deployed as seedlings (CSO_ST), clonally replicated test with clonal seed orchard deployed as seedlings (CSO_CRT), and clonally replicated test deployed as a clone mix (MVF). The breeding populations (BP) were formed by balanced within-family selection and the production populations (PP) were selected by strong restriction on relatedness, i.e., no parent in common. Compared to the seedling test, the clonally replicated test resulted in faster accumulation of additive effects but quicker loss of additive variance in the BP, and this is particular true in the case of lower narrow-sense heritability or less non-additive genetic variance. The quicker loss in BP additive variance was overcompensated for by its faster accumulation in BP additive effect, resulting in higher gain in the clonally replicated test based PPs. Compared to the CSO_ST, the gain superiority of the CSO_CRT increased with generations, decreasing narrow-sense heritability or reducing the amount of non-additive variance. Implementing MVF was the most effective in terms of gain in most simulated cases and its superiority over the CSO_ST increased with generations, decreasing narrowsense heritability, or increasing non-additive genetic variance. Overall results demonstrated significant advantages of using clonally replicated test both for BP advancement and PP selection in most of the scenarios, suggesting that clonally replicated test should be incorporated into current spruce breeding strategies.

Height and diameter distributions between improved and unimproved (checklot) seedlots for white spruce [Picea glauca (Moench) Voss] and black spruce [Picea mariana (Mill.) BSP] were compared using the two-parameter Weibull function. Individual tree height at age 5Á15 years and diameter at breast height at age 15 years that were collected from two series of large-plot realized gain tests were used for this purpose. For both species, improved seedlots did not significantly (a 00.05) change the shape parameter of the distributions relative to their checklots, suggesting that an overall shape value will be adequate to predict tree size distributions of various improved seedlots. The most important finding was that seedlot influenced the scale parameter (related to the range of the distribution) significantly, but from a practical viewpoint, only those scale values of the higher rated seedlots (i.e. seedlots collected from a rogued seed orchard or superior families) were significantly higher (a 00.05) than those of the respective unimproved seedlot. The changes in scale value of the alternative improved seedlots relative to the checklot (D Scale ) were comparable in magnitude to the respective realized genetic gains, suggesting that tree improvement effects on the scale value can be adjusted by realized genetic gains. The results also suggest that site and age significantly affected the scale value; in general, D Scale became larger at earlier ages or on better sites. The findings reported here will be used in the development of yield functions for genetically improved white and black spruce in New Brunswick.