Publications

The defining feature of each forest is the organism that humanity generically designates as ‘tree’ [...]

This study investigated the carbon (C) content in b oles of twenty western hemlock ( Tsuga heterophylla (Raf.) Sarg.) trees. Bole samples were obtained from southern Vancouver Island in British Columbia (Conuma River, south of Muchalat Lake, Apple River, and Harris Creek) from a Western Forest Products Inc. management area, during the summer of 2003. Disks (10 centimeters thick) were o btained from the top of live crown (TLC), the base of live crown (BLC), and at breast height (BH) of each tree . By elemental analysis, C content of 20 genotypes had a mean of ~53.5% (w/w), standard error of the mean [SEM] 0.1). Since the variation in each tree was so small, and the SEM for each of the positions within the bole was 0.1 a nd 0.2, we conclude that there was only slight vari ation among genotypes at the 99% level of confidence in the thr ee positions within the bole. Considerable addition al research is needed in order to have accurate estimates of total C content in any tree, and given that there is var iation in C content within tree species, and in order to accoun t for C in any forest stand, total C content should be estimated by integrating each individual tree component.

Using one purification procedure, endogenous indol-3-ylacetic acid (IAA), a known regulator of vascular development in woody plants, was characterized by capillary gas chromatography–mass spectrometry in developing secondary xylem of 6 conifers, 16 hardwoods, and 4 additional species of woody plants indigenous to the northern temperate zone. The results suggest IAA may be ubiquitous throughout the Tracheophyta.

Alkali-insoluble cellulose and water-soluble polysaccharide production by wild-type Acetobacter xylinum colony and liquid cultures was investigated. The mass of cellulose exceeded that of soluble polysaccharides in liquid cultures while the reverse situation occurred in colony cultures. The soluble polysaccharide fraction, 3 × 10 5 to 5 × 10 5 in molecular weight, was found by DEAE-Sephacel chromatography to be a complex of several acidic, nitrogenfree polysaccharides. One acidic polysaccharide was predominant in the complex, and gas–liquid chromatography and mass spectrometry showed this to contain glucose, rhamnose, mannose, and glucuronic acid in molar ratio of 6:1:1:1, respectively. 13 C and 1 H nuclear magnetic resonance spectra are presented for this major polysaccharide component. Several minor, soluble, acidic polysaccharides were related in chemical composition to the major soluble polymer. The relation of these soluble polysaccharides to cellulose biogenesis is discussed.

Gišogenesis, otherwise known as secondary-xylem development, was investigated in an old-growth upland population of white spruce (Picea glauca (Moench) Voss) trees having morphologically diverse crowns and growing on a south slope north of East Fork Creek bordering never-glaciated Yukon Beringia. After tree felling, trunks were segmented into one-metre lengths. In the laboratory, widths of xylem layers were measured across the four cardinal directions at each height, followed by Pearson’s product momentum correlations to evaluate variation in historical gišogenetic vigour within and between trees. Substantial variation was found, and it cannot readily be explained in terms of differences in extrinsic environment. Physiological differences in intrinsic gišogenetic regulation within a genetically diverse population, comprising both refugia and recent recruits, is proposed as a probable explanation, thus emphasizing the individuality of each tree’s internal control over how it responds to the extrinsic environment. Further investigations within Yukon Beringia may yield insight into evolutionary diversification of gišogenesis.