Davidsonia - Volume 14

Index to Volume 14

Tue, 25 Oct 2005 17:26:42 -0700

Abstract or Summary:

An index of authors, titles, illustrations and keywords for Davidsonia Volume 14.

Davidsonia Volume 14, Number 4, October 2003

Tue, 25 Oct 2005 17:23:59 -0700

Abstract or Summary:

Davidsonia - A Journal of Botanical Garden Science. Volume 14, Number 4, October 2003

Editorial - Davidsonia Volume 14, Number 4

Tue, 25 Oct 2005 17:16:44 -0700

Abstract or Summary:

Editor Iain Taylor writes about the importance of studying the small scale ecological systems, which occur in British Columbia and the importance of these fragmented environments to the biodiversity of the province.

Autumn Colours - Nature's Canvas is a Silk Parasol

Tue, 25 Oct 2005 17:01:54 -0700

Abstract or Summary:

The variety and widespread nature of leaf colour change in autumn has led to investigation of the biochemical pathways and compounds responsible. The synthesis of bright red colouration initiated by longer nights prior to leaf abscission in deciduous species points to some adaptive value for this expensive ephemeral trait. It is hypothesized that during the breakdown of the unstable chlorophyll and the dismantling of the nutrient-rich photosynthetic apparatus, red anthocyanins provide a more biochemically parsimonious alternative to the elaborate xanthophyll system. This alternative enables leaves to screen out excess light energy and circumvent photooxidative damage to leaf cells, while allowing photosynthesis to persist at low rates in support of metabolic processes and phloem loading required for nutrient resorption from leaves.

A Floristic and Ecological Analysis at the Tulameen Ultramafic (serpentine) Complex, southern British Columbia, Canada

Tue, 25 Oct 2005 17:00:15 -0700

Abstract or Summary:

While distinct floristic and ecological patterns have been reported for ultramafic (serpentine) sites in California and Oregon, those of British Columbia are muted which is thought to be related to the moderating influence of increased precipitation, a short time since glaciation, and the presence of non-ultramafic glacial till over ultramafic sites. Despite these factors, we found clear floristic and ecological differences with respect to soil type at our study site on Grasshopper Mountain, part of the Tulameen ultramafic complex in southern British Columbia. Ultramafic soils support 28% of the local species richness and host more rare taxa than non-ultramafic soils. Many species show patterns of local restriction to or exclusion from ultramafic soil habitats. Patterns of plant family diversity also show differences between substrates.

The North America Red Raspberry - A Genetic Resource Awaiting Exploitation

Tue, 25 Oct 2005 16:51:35 -0700

Abstract or Summary:

Rubus idaeus L., the red raspberry consists of two subspecies, R. idaeus subsp. strigosus Michx, which is native to North America and far eastern Asia, and R. idaeus subsp. vulgatus Arrhen, which is native to Europe and Asia Minor. The subspecies are usually referred to as R. strigosus and R. idaeus, respectively. Neither is adequately represented in the red raspberry breeding gene pool. This paper describes efforts to find potentially useful parents with disease or insect resistances from previously unexploited selections of R. strigosus. Selections with resistances to aphid, root rots, and cane diseases were identified and have been incorporated into the Pacific Agriculture Research Centre’s breeding programme. Several derivatives of the selections have the potential to become cultivars with entirely new sources of resistances.

November in the Garden

Tue, 25 Oct 2005 16:46:54 -0700

Abstract or Summary:

The November installment of Judy Newton's popular series describing what to see at the UBC Botanical Garden each month of the year.

Gleanings

Tue, 25 Oct 2005 16:43:05 -0700

Abstract or Summary:

The Editors of Davidsonia highlight some of the most interesting and important titles from the thousands of recently published papers in the plant sciences.

Davidsonia Volume 14, Number 3, July 2003

Mon, 24 Oct 2005 15:04:35 -0700

Abstract or Summary:

Davidsonia - A Journal of Botanical Garden Science. Volume 14, Number 3, July 2003.

Editorial - Davidsonia Volume 14, Number 3

Mon, 24 Oct 2005 15:00:02 -0700

Abstract or Summary:

Editor, Iain Taylor writes about the importance of peer review in science journals.

Taxonomy in Conservation Biology: The Enigmatic Vancouver Island Beggartick

Mon, 24 Oct 2005 14:50:04 -0700

Abstract or Summary:

During conservation status report work on Bidens amplissima, many plants were found that resembled B. amplissima but lacked the trilobed leaves ascribed to the species. Herbarium investigations revealed that most plants with this form had been identified as B. cernua because of this lack of trilobed leaves. However, these plants more closely resembled B. amplissima than B. cernua in other leaf and achene characters. Multivariate statistical analysis of morphological characters from herbarium specimens unambiguously separated them into two groups. One group was B. cernua, and the other, including all the unlobed and trilobed-leaved specimens, was B. amplissima. Recognition of unlobed B. amplissima has resulted in an increase in the number of localities for the species, a range extension for the species into Washington State with its addition to the flora of the United States, and loss of its endemic status in British Columbia. This discovery was important for assessment of the status of B. amplissima and has broad conservation implications. Our results highlight the need for careful review of the taxonomy of species, particularly within difficult taxonomic groups, when conducting status assessments. Primary data re-evaluation may be critical where status designation has implications for both landowners and governments, and where conservation and protection policies are presently evolving.

Silver Firs in UBC Botanical Garden

Mon, 24 Oct 2005 14:45:03 -0700

Abstract or Summary:

The forty or so species in the genus Abies Miller are distributed widely around the Northern Hemisphere, with centres of diversity occurring in southern Europe, Asia, the Himalayas and western North America. UBC Botanical Garden has a small but significant collection consisting primarily of local and Asian species, but has identified the genus as one of its target groups and there are plans to expand the collections. As a group, the silver firs are easily recognizable; they are mostly densely pyramidal in youth, with conspicuously whorled branches, flattened needles and neat, upright cones, which are produced with the greatest frequency on older plants. The common name derives from the often highly visible whitish, wax-covered stomatal bands on the undersides of the needles of many species.

Pesticides, Plant Introductions and Organic Gardening: Ethical Issues Facing Horticulture

Mon, 24 Oct 2005 14:37:30 -0700

Abstract or Summary:

This paper is a discussion of impacts arising from use of pesticides, introduction of new plants for horticulture and the increasing interests in ‘organic’ gardening. Consideration of these practices in a broad context of benefits and harm allows us to begin addressing commercial and public perceptions from an ethical perspective. Past experience with all forms of herbicides, insecticides, fungicides and biological control agents points to a need for a greater effort to learn from the past. Introduction of new cultivated material cannot be fully predicted to be free of invasive risks. The increasing complexity and generally low level treatment of human and industrial waste makes it increasingly difficult to assume that ‘natural’ soils are as pristine as we may like to think in moving towards ‘organic’ gardening practices. Biomagnification of toxic materials in soil by food plants may compromise their perceived safety of such ‘organic’ production.

August in the Garden

Mon, 24 Oct 2005 14:34:53 -0700

Abstract or Summary:

The August installment of Judy Newton's popular series describing what to see at the UBC Botanical Garden each month of the year.

Gleanings

Mon, 24 Oct 2005 14:28:49 -0700

Abstract or Summary:

The Editors of Davidsonia highlight some of the most interesting and important titles from the thousands of recently published papers in the plant sciences.