|BOTANICAL ELECTRONIC NEWS|
No. 143 September 12, 1996
This year's BOTANY BC took place from July 18 to July 20 in Fort St. James and Prince George. The topic this year was Vegetation of Special Habitats and included a bus trip from Prince George down the Rocky Mountain Trench to Valemount.
Many thanks to Craig Delong and other organizers of this year's Botany BC. They outdid themselves by showing us such a vast array of ecosystem types that one participant was heard to wonder whether we were still on the same planet! Imagine seeing this within 2 days: serpentine ridge (Murray Ridge - 1445 m), limestone mountain (Mt. Pope at 750 m elevation), black spruce/tamarack bog, willow forests, beautiful Rubus chamaemorus (Cloudberry) bog, inland wetbelt oldgrowth forest, and sand dunes.
This year's BOTANY BC had a slightly different format due to the bus trip: two full days in the field were combined with evening lectures. There were excellent talks by Dr. Art Kruckeberg on the relationship between plants and serpentine geology [see abstract below], Dr. Hugues Massicotte on mycorrhizal fungi, and Trevor Goward's enlichening talk on indicator lichen species in inland oldgrowth forests. These "antique" forests occur nowhere else on the planet, and Trevor gave an articulate and impassioned plea for the preservation of these threatened ecosystems. [Abstracts of Dr. Massicotte's talk and Trevor Goward's "antique" forests will be posted in the next BEN.]
Rare plant discoveries were made, among them blue-listed Pellaea atropurpurea, Woodsia glabella, and Carex tonsa, and yellow-, or "watch"-listed Aspidotis densa.
Thanks again to Craig et al for organizing this memorable trip. Join us for an alpine BOTANY BC next July. Possibly at beautiful Cathedral Lakes.
[ Ultramafic rocks - igneous rocks in which there is an abnormally high content of ferromagnesian silicates, but which contain no feldspar... Chambers Science and Technology Dictionary ]
In Western North America, ultramafics occur with decreasing abundance from California, Oregon, Washington, to British Columbia. The greatest concentration of ultramafics, mostly as serpentinized peridotite, are in northwestern California and southwestern Oregon.
Soils weathered from ultramafic rocks are either devoid of vegetation (barrens) or support sparse but often distinctive floras. Cation exchange capacities range from 5.2 to 43 milliequivalents per 100 grams of dry soil; pH values are around neutral (6.0 to 8.8); Mg/Ca quotients are invariably greater than 1.0; and deficiencies of nitrogen and phosphorus are common. Tissue analysis of serpentine plants often reveals high concentrations of magnesium and nickel.
Vegetation on ultramafic soils takes the form of distinctive variants of conifer-hardwood forest, chaparral, or grassland. Often the serpentine (S) vegetation is sharply delimited from adjacent non-serpentine (NS) types, both by physiognomy (e.g. chaparral on serpentine, forest on nearby nonserpentine), and by species composition. The most striking contrast in vegetation (S vs. NS) are in California and Oregon. Contrasts in S-NS vegetation are lessening in the Pacific Northwest, possibly because of increased precipitation, or the short post-Pleistocene history in the region, or both. A similar lessening of contrasts in S-NS vegetation was noted in the United Kingdom.
Floras on ultramafic soils can be strikingly unusual. Three types of floristic elements can be found: (1) serpentine endemics, (2) local or regional indicator species, and (3) bodenvag species, taxa widespread on S and NS habitats. Also many NS taxa may be excluded from adjoining S soils.
The greatest concentration of species endemic to serpentine is in the Klamath-Siskyou mountain complex of northwestern California and southwestern Oregon, with secondary concentrations in the North Coast and South Coast ranges and the Sierra Nevada of California. Endemics occur in all life-forms: trees and shrubs (e.g., Cupressus sargentii, Quercus durata, Ceanothus jepsonii), herbaceous perennials (e.g., Calochortus tiburonensis, Fritillaria liliacea, Lilium bolanderi); and annuals (e.g., Streptanthus batrachopus, Layia discoidea, Clarkia franciscana). Endemics belong to genera abundantly represented in the regional flora.
Widespread species that appear as local or regional indicators of serpentine include trees like Calocedrus decurrens and Pinus jeffreyi, shrubs (e.g., Heteromeles arbutifolia, Adenostoma fasciculatum, Ceanothus cuneatus) and herbs (e.g., Streptanthus glandulosus, Darlingtonia californica, Aspidotis densa, Xerophyllum tenax).
Indifferent or bodenvag species are often racially differentiated into tolerant and intolerant biotypes.
The fauna on western North American serpentines has received but scant attention, and merits closer study. Butterfly species are known to be closely tied to serpentine plants as food sources; one instance of plant mimicry of butterfly eggs is cited.
The evolution of a serpentine flora may involve a variety of speciational routes. The most probable sequence for diploid taxa could involve (1) genetic preadaptation to serpentine within a NS species; (2) racial fixation of the preadapted genotype; (3) further morphological and physiological divergence yielding an infraspecific variant; (4) attaining species status by further genetic and ecological isolation. This sequence is illustrated by Streptanthus, a genus of western North America crucifers, with varying degrees of fidelity and narrow endemism to California and Oregon serpentines. A more rapid mode of speciation on serpentine, saltational speciation by catastrophic selection, has been proposed.
Adaptation to ultramafic soils is likely to involve both physiological and morphological modifications. Xerophytism, nanism, glaucescence, plagiotropism and colour changes (anthocyanic, chlorotic) are frequent attributes of serpentine species. A few species possess the ability to accumulate over 1000 micrograms/gram of nickel in their foliar dry matter (hyperaccumulators).
Western North American serpentines have been exploited for minerals, timber, grazing and agriculture, with consequent effects on their flora. Mining for mercury, nickel and chromium, as well as geothermal power developments, have created the greatest disturbance to them. Only modest efforts have been made to preserve samples of serpentine vegetation. Some state and federal wilderness areas include serpentine vegetation; other serpentine areas are 'protected' either by neglect or because they are valued as watershed areas. A very few natural areas specifically for serpentine vegetation have been established in the three Pacific Coast states. None are known for British Columbia.
Make up a 1 per cent solution of dimethylglyoxime in ethanol. Soak a box of 4-5 cm filter papers in solution. Allows papers to dry in a fume hood, or overnight in a low temperature (30 - 40 deg.) oven.
Use in field: Moisten (water) paper, then crush plant tissue between folded paper. Turns RED if 1000 ppm or greater.
[The only hyperaccumulator of nickel so far reported from northwestern North America is Arenaria (=Minuartia) rubella. Cf. Kruckeberg, A.R. et al. 1993. Madrono 40: 25-30.]
Coastal Mountain College of Healing Arts presents an extension course "First Nations' Herbal Materia Medica" instructed by Brian Compton, Ph.D.
Native British Columbian medicinal plants have been used for a variety of purposes by indigenous peoples for centuries but have only recently begun to be systematically and comprehensively examined and evaluated by scientists for their antibiotic and antifungal properties. This combined with the growing public interest in herbal medicine and research into new formulations makes this course of vital interest to individuals in the product research and manufacturing sectors.
This 10 week course provides an introduction to the botanical, phytochemical, therapeutic and cultural attributes of 100 species of native medicinal flora. The course will also explain their relation to the traditional healing beliefs and practices of various First Nation cultures of North America.
The program will be taught by Brian Compton, Ph.D., ethnobotanist and honourary research associate at the University of British Columbia. He has done extensive field studies in North and South America. With over 10 years of teaching experience, Dr. Compton presently teaches a course on "Ethnobiology of British Columbia's First Nations" at First Nations' House of Learning.
The course will feature:
Course Date: Monday nights from October 7 to December 10, 1996
Course Tuition: CND$ 375.00
Deadline For Registration: October 5, 1996
To Register or For More Information
Submissions, subscriptions, etc.: email@example.com.
BEN is archived on gopher freenet.victoria.bc.ca. The URL is:
gopher://freenet.victoria.bc.ca:70/11/environment/Botany/ben. Also archived at http://www.ou.edu/cas/botany-micro/ben/