Seed Stratification of Engelmann Spruce and Lodgepole Pine: The Effect of Stratification Duration and Timing of Surface-drying

Based on the speed and completeness of laboratory germination and nursery bed emergence, the present study showed that for both Engelmann spruce (Picea engelmannii [Parry] Engelmann) and lodgepole pine (Pinus contorta Dougl.): (1) longer stratification generally improved the rate, and in some cases completeness, of germination more so under a cool temperature (15 °C/5 °C) regime than under a warm, standard temperature (30 °C/20 °C) regime emphasizing its importance for early spring outdoor sowing under suboptimal germination temperatures, (2) for a given stratification period, surface-drying at the end of stratification was at least as effective as surface-drying prior to or during stratification, and (3) stratification periods of 6 weeks or longer were generally the most effective. A 6- to 8-week stratification with seeds surface-dried at the end of stratification is recommended for nursery sowing of both species. Key Words: stratification, pinus contorta, Picea engelmanni, laboratory germination, nursery bed emergence.

Natural and Advance Regeneration of Engelmann Spruce and Subalpine Fir Compared 21 Years After Site Treatment

The mean height of Engelmann spruce (Picea engelmanni Parry) advance growth 21 years after release by overstorey harvesting and residual tree felling, was eight times that of natural regeneration established following brush blade scarification. Subalpine fir (Abies lasiocarpa (Hook.) Nutt.) advance growth was nine times taller than natural regeneration established on scarified soil. Mean current annual height increment of Engelmann spruce and subalpine fir advance growth was 39 and 34 cm, respectively, compared with only 7 cm for natural regeneration on scarified soil. The performance gap does not appear to be narrowing. The poor performance of natural regeneration on mineral soil exposed by blade scarification is attributed to removal of organic and top mineral soil horizons beyond the immediate reach of seedlings. These soil layers remained available to the advance growth. Consideration should be given to preserving advance growth when scarification may be inappropriate.

CONSTITUTION OF THREE HEMICELLULOSES FROM THE WOOD OF ENGELMANN SPRUCE (PICEA ENGELMANNI)

An arabino-4-O-methylglucuronoxylan (10:70:12), a water-soluble galactoglucomannan (1:1:3), and an alkali-soluble galactoglucomannan (0.2:1:3) have been isolated in yields of 8.0, 1.0, and 8.1% from the wood of Engelmann spruce (Picea engelmanni). The xylan consisted of a linear framework of (1 → 4)-linked β-D-xylose residues to which were directly attached single side chains of (1 → 2)-linked 4-O-methyl-α-D-glucuronic acid and (1 → 3)-linked α-L-arabinofuranose residues. The galactoglucomannans were both composed of a backbone of (1 → 4)-linked β-D-mannose and β-D-glucose residues, some of which carried directly attached side chains of (1 → 6)-linked α-D-galactopyranose residues. Partial hydrolysis of the water-soluble galactoglucomannan yielded, among other oligosaccharides, a trisaccharide composed of galactose, glucose, and mannose residues. It is concluded that the main polysaccharides in the wood of Engelmann spruce are the same as those in most other gymnosperms. In the bark of this tree, the water-soluble galactoglucomannan is replaced by one or several polysaccharides of an entirely different composition.

GROWTH AND SURVIVAL OF ENGELMANN SPRUCE AND ALPINE FIR ON SEED SPOTS AT BOLEAN LAKE, B.C., 1954-59

Seed spots established in the spring of 1953 were remeasured in August 1959. Variables included Engelmann spruce (Picea Engelmanni Parry) and alpine fir (Abies lasiocarpa (Hook.) Nutt.); two site types—wet (VO) and dry (VM); three degrees of light—full shade, part shade, and full sun; and five seedbeds—mineral soil, burn, moss, litter, and rotted wood. The observed data on survival and growth are further evidence of the need to provide adequately disturbed seedbeds to ensure reproduction of Engelmann spruce and alpine fir. The poor survival, even with first-year screening, and slow juvenile growth of these species suggest that planting may have advantages over direct seeding.