Publications

This paper contains a description of the only known non-banded bark in the geologic record. The bark is attached to a branch of the Araucarioxylon arizonicum tree that was found recently in the Late Triassic Chinle Formation (~ 220 Mya) in Arizona. In the fossil the vascular cylinder is almost totally enclosed in rough bark 2–11 mm in thickness. The inner bark is less than 1 mm thick and comprises a very narrow zone of presumed phloem containing infrequent fibers. The outer bark varies in thickness up to 10 mm, and consists of curving lenses of sequent periderm free of both dilation tissue and resin canals but is quite unlike the banded bark of Araucaria heterophylla . Wide zones of very thin-walled rectangular parenchyma cells arranged in radial files and groups of thin-walled spongy parenchyma, and small clusters as well as solitary sclerenchyma occur in the rhytidome. The vascular cambium contains 1–4 fusiform cells per radial file. Uniseriate rays are common in the secondary xylem and extend to the cambial zone. Small (1 mm in diameter), simple tunnels in the bark and wood indicate that the branch was attacked by phytophagous insects. A possible petrified beetle larva similar in form and size to Anobium is associated with these tunnels.

The natural range of Porsild spruce (Picea glauca var. porsildii Raup), a white spruce variety distinguished by its smooth bark and resin blisters, has long been considered to be restricted to northwestern North America, but here it is noted that the same phenotype exists in wild stands in Ontario, Quebec, and Atlantic Canada. No record of Porsild spruce trees yet exists in the region between Alberta and western Ontario, or anywhere in the United States other than Alaska. The forestry community is requested to document any encounters with Porsild spruce in unmanaged stands, in order that its full range can be established. History and potential scientific importance of Porsild spruce are given consideration.

Tree mortality is becoming more common in wild forests, plantations, and orchards. Remedial or preventative counteracting measures are limited because, before the onset of overt dying, reliable methods to distinguish intrinsically healthy trees from unhealthy trees are lacking. Survivotypes within dead populations can nevertheless be identified and conserved in support of achieving suitably adapted future forests.

Radial files of tracheids having changing orientations were traced through serial tangential sections to deduce events in fusiform cambial cells (FCCs) associated with spiral grain formation. Within an induction bridge of phloem and cambium sloping diagonally across a stem girdle in Pinus contorta Dougl. ssp. latifolia, repetitive, homologously sloping, pseudo-transverse anticlinal divisions in FCCs were a primary event contributing to FCC orientation changes. Imperfect periclinal divisions (IPDs) in FCCs also contributed. In Picea glauca (Moench.) Voss, IPDs and FCC elongation interacted to change tracheid orientation during natural spiral grain development. In both natural and induced reorientations, small numbers of adjoining FCCs changed their orientation abruptly while the greater population of FCCs changed orientation less rapidly. These sites of abrupt reorientation are termed "microdomains."not available

Abstract The determination of phenols based upon coupling with 4-aminophenazone in the presence of an alkaline oxidising agent has been examined. The importance of pH has been studied and a suitable buffering agent has been recommended. The reactivity of many phenols of pharmaceutical interest has been investigated and the application of the method to a number of pharmaceutical preparations is described.

Between the Klondike Plateau and Yukon–Tanana highlands of Yukon and Alaska, respectively, current maps explain glaciated alpine locales and periglacial areas in terms of localized Pliocene–Pleistocene montane ice caps, alpine glaciers, and periglacial changes. However, this region’s plateau topography is populated with long undulating ridges having wide flattened tops; it contrasts with relief of other regions of northwestern North America also affected by ice caps, cryoplanation, and erosion over similar duration during the same epochs. This region has received minimal research and appears to present a new opportunity for resolving outstanding glaciological and stratigraphy issues. The glaciological history is reviewed, placing particular emphasis upon the low-elevation ridges within the “unglaciated” region, suggesting that those ridges are relict arête/cirque remnants. Sites of subalpine glacial grooving and mountaintop planing are also identified, and a conglomeratic red bed containing erratic clasts is described. All indications point to the “unglaciated” region having been glaciated before late Pliocene. Two working hypotheses are proposed: (1) The landscape once supported a range of young mountains that became glaciated then overridden and pared to a plateau by an ice sheet. (2) Following deglaciation, an extended period of paraglacial activity removed most of the former drift and excised new valleys to give the region an unglaciated appearance, which thereafter became modified into its present state by local montane/alpine glaciations, interglacial cryoplanation, periglacial gelifraction, and erosion. In addition to Pliocene–Pleistocene glaciations, a northeastward advancing Miocene ice sheet seems plausible and, on the basis of paleographic considerations and lithology, a Cretaceous glaciation evidently is also not out of the question.

Endogenous indol-3yl acetic acid (IAA) was characterized by combined gas chromatography – mass spectroscopy (GC–MS) in inactive cambia of Pinus contorta Dougl. and Larix decidua Mill, during winter, and IAA levels were estimated by GC–MS in buds, needles, and the tissues comprising the inactive cambial region of P. contorta during late autumn and winter. Supplementary IAA estimates were obtained for cambia of Acer pseudoplatanus L., L. decidua, Populus × canadensis 'Robusta,' and Quercus robur L. IAA levels in cambial tissue of lodgepole pine were higher than those in similar-aged tissue of hardwoods throughout the winter.Both winter disbudding and defoliating treatments reduced levels of endogenous IAA in the cambial region of lodgepole pine. Moreover, exogenous [ 14 C]IAA and [ 14 C]sucrose were transported downward in the stem during winter. Microscopy suggested functional sieve cells to be present during winter, and the moisture content of the cambial region of lodgepole pine was more than twice that of overwintering hardwoods.Thus, the vascular cambium of P. contorta probably is not dependent upon a supply of IAA from extending shoots and growing needles for its reactivation in spring. The findings also suggest that IAA production and export from metabolically active buds and mature needles may occur during winter.