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Western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings grown in two different container cavities that received four different dormancy induction treatments, short (SD) or long days (LD) in combination with moisture stress (D) or no stress (W) in the greenhouse, and lifted and placed in cold storage (November, January, or March), were planted on two adjacent coastal reforestation sites in British Columbia and monitored for survival and morphological development. Survival was greatest in seedlings grown in the larger cavities in the greenhouse, in seedlings lifted in March, and in seedlings not treated to moisture stress. Seedling shoots had more stem units on the southeast than the northwest site, but the amount varied with nursery treatment. Seedlings from the LD treatments produced more stem units during free growth and lammas growth than those from the SD treatment. Nevertheless, most shoot growth was predetermined in the buds during nursery culture, accounting for a minimum of 67% of the final number of stem units. Stem unit length (SUL) was longer in seedlings on the southeast site than on the northwest site for those treated to LD in the nursery. Seedlings treated to short days showed the reverse pattern (SDW) to this, or were unaffected by site (SDD). Shoots and needles were shortest for seedlings from the SDD treatment and for those lifted in November. Shoot growth was greatest for seedlings lifted in March and for those treated with LD, mainly owing to their longer SUL. Lammas growth was most frequent in seedlings from the smaller cavities, and in those from the November and March lifts.

Western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings grown in two different container cavity sizes that received four different dormancy induction treatments, short (SD) or long days (LD), in combination with moisture stress (D) or no moisture stress (W), in the greenhouse, and lifted and placed in cold storage (November, January, or March) were planted on two adjacent coastal reforestation sites on Vancouver Island, British Columbia, and monitored for phenological responses during the first growing season. The SD seedlings flushed sooner and began bud development later than the LD seedlings, although the effect on flushing was small for those lifted in March. Moisture stress and SD together in the greenhouse reduced shoot elongation rates but had little impact on field bud development. Cold storage of seedlings lifted in November and January delayed flushing, reduced shoot elongation rates, and advanced bud development compared with the March-lifted stock. The influence of cavity size was generally small on most variables measured. Shoot elongation was slightly faster on the southeast site than on the northwest site, whereas bud development was more rapid on the northwest site. The effect of site on date of flushing varied with nursery treatment.

A ventilated, transient-type porometer was designed to nondestructively measure the average stomatal conductance of conifer seedlings. The porometer consists of a low-power microprocessor unit and a stainless steel chamber which encloses the seedling. Conductance is calculated from the measured rate of increase in chamber relative humidity above the ambient level. Consequently, chamber air does not have to be dried prior to measurement. Direct readout of stomatal conductance is provided by means of a liquid crystal display and a serial (RS232) port. Porometer calibration over a range of humidities showed that the effective chamber volume was consistently 25% larger than the actual chamber volume. Stomatal conductance measurements made on Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings using the porometer agreed well with average values obtained with a ventilated diffusion porometer using four needle samples. The porometer proved to be very convenient to use in a forest clearcut environment, with the measurement procedure taking about 1 min. Measurements can be made on a seedling over the growing season because the use of the instrument causes no injury to stem, branches, and needles.

Experiments on field-grown and potted trees investigated the effect of timing of gibberellin A3 treatment in relation to natural day length on flowering and sex expression in Chamaecyparisnootkatensis. When gibberellin A3 treatment began was more important than the number of weekly sprays (two to eight), and the optimal time of treatment was similar for promotion of seed and pollen cone buds. The optimal treatment time was independent of photoperiod or its direction of change, but instead appeared to be related to a specific stage of ontogeny during early development of the bud apex. Trees growing at progressively lower elevations attained this stage earlier in spring, suggesting that the mechanism triggering initiation of bud development involved heat sums. A higher concentration of gibberellin A3 was required to initiate seed cone buds (200 mg•L−1) than pollen cone buds (100 mg•L−1), and the average weekly dosage was more important than whether gibberellin A3 was applied weekly or biweekly. Young, potted trees within a greenhouse flowered more profusely than larger but similarly treated field-grown trees, indicating that the species is a good candidate for containerized seed orchards.

A preliminary investigation of the use of mitotic indexing for quantifying root system activity in Pseudotsugamenziesii (Mirb.) Franco and Abiesamabilis (Dougl.) Forbes seedlings during the fall of 1981 indicated that the technique was sensitive enough to detect seasonal variability in both species.

Stem analysis of 14 cast coast Vancouver Island mixed stands of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and shore pine (Pinuscontorta Dougl. ex Loud. var. conforta) indicated that shore pine was taller and contained more volume per tree up to 80 years of age than Douglas-fir. Shore pine–Douglas-fir mixed stands could significantly increase fibre yields from these sites if pine were utilized as a thinning crop.