| BEN |
| BOTANICAL ELECTRONIC NEWS |
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| ISSN 1188-603X |
| No. 213 January 19, 1999 | aceska@victoria.tc.ca Victoria, B.C. |
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The Alaska Rare Plant Forum will hold its annual meeting on April 8 and 9 in Anchorage at the office of the Chugach National Forest in the Calais II Building at 3301 'C' Street, Suite 300. Anyone interested in rare plants of northern regions is invited to attend or to give a presentation.
We are also soliciting speakers and agenda items. Agenda items could include the results of your 1998 field work, descriptions of your field trips, proposals for 1999 field work and presentations describing your ongoing botanical work. If you would like to give a presentation, please send your name, a brief description of your presentation and the presentation's approximate length. We also would appreciate hearing about any topics that you would like to see added to the agenda. Please send this information to:
We will send out an agenda in mid-March. Please contact us if you need any additional information, you wish to give a presentation, or if you have ideas for agenda items. Exciting botanical work is taking place in our part of the world, so we look forward to a particularly interesting meeting of the Alaska Rare Plant Forum.
The University of Saskatchewan invites applications for a faculty position in plant taxonomy/biodiversity at the level of Assistant Professor, commencing July 1, 1999.
This is a tenure-track position in the Department of Biology, with a joint appointment in the Department of Plant Sciences.
Requirements include a Ph.D., preferably with teaching experience. The successful applicant will be responsible for teaching courses such as introductory plant taxonomy and for curatorship of the W.P. Fraser Herbarium.
In accordance with Canadian immigration requirements, priority will be given to Canadian citizens and permanent residents. The University of Saskatchewan is committed to the principles of Employment Equity and welcomes applications from all qualified candidates.
Send curriculum vitae and the names, addresses and telephone or fax numbers of at least three referees to:
The closing date for applications is February 15, 1999.
This position as advertised is subject to budgetary approval.
Recently a species of moss called Rhytidiadelphus triquetrus was reported for the first time in New Zealand. It was found in the township of St Arnaud, next to the Nelson Lakes National Park, which is about 1 hours drive south of Nelson, at the northern end of the Southern Alps. I am informed by Dr. Allan Fife of Landcare Research that Rhytidiadelphus triquetrus occurs in boreal forests in the northern hemisphere where it is "a widespread and ecologically important component of the ground cover."
Dr. Fife has expressed the concern that this species is a potentially serious invader of undisturbed native forest such as beech and manuka scrub. Although New Zealand material is probably exclusively male (it is a dioecious moss), he has pointed out that the related R. squarrosus, also exclusively male in New Zealand, has spread throughout Westland, Southland and parts of Otago in the last 25 years. However, unlike R. triquetrus, this species has not shown the ability to invade intact native forest.
In the past the invasive potential of non-vascular plant species has largely been overlooked. However there is an increasing acknowledgement of the threat posed by marine algae, and concern has been raised over invasive mosses overseas. For several reasons I am particularly concerned about mosses when compared to many other weeds:
I plan to look at this further to find out how far the moss has spread and whether it will be controllable, or need to be controlled. My feeling on this is that if it is eradicable then it should be eradicated, as this has the appearance of a problem that could become intractable very rapidly.
I would be interested to know if anybody has any experience at all with invasive mosses, or has heard anything about management of exotic moss species. I would be interested to know any control techniques which have been used for mosses (whether or not they have worked).
Any ideas or comments would be much appreciated.
This work is the first comprehensive, syntaxonomic overview of North American boreal forest vegetation, a massive undertaking by any standard. The authors compiled a total of 2084 releves, of which they themselves gathered 204, assembling the remainder from published raw data from Alaska to Labrador. All of the new releves are presented in releve tables, and the entire data set is summarized in synoptic tables, to arrive at 37 associations, 10 alliances and 4 orders, an example of the utility of the Braun-Blanquet approach in creating overviews of large areas. The authors take this one step further by comparing their North American releves with 3273 releves obtained from European, Japanese and Korean literature, to form the most comprehensive floristic overview of circumpolar boreal forest vegetation ever undertaken. They conclude that the circumpolar boreal forests have so much in common, they must be summarized in the same class as described for the coniferous forests of the Alps, Vaccinio-Piceetea Br.-Bl. 1939.
Central to the survey is the construction of a hierarchical comparison of forest vegetation based on floristics. Those with only distant familiarity with Braun-Blanquet methods, might recall that construction of the hierarchies is a process of systematic and iterative comparison of sample plots (releves) to identify floristic patterns -- not unlike the methods used to distill plant species from morphological patterns. The second step is the construction of a hierarchy based on similarities of the communities to each other. An association is delimited from a series of closely similar vegetation samples; similar associations are grouped into alliances, and likewise they into orders and classes. Since vegetation ecologists very early began evolving widely diverging views of what constitutes an association and how hierarchies are constructed, a group of far-sighted vegetation scientists from over a dozen countries formed a commission to draft a rigid set of classificatory rules to avoid chaos in the system, most recently revised by Barkman et al. (1986).
Peinado and his colleagues are to be commended for adhering to this code throughout their work. They have taken many of the long, nomenclaturally invalid association names such as Ptilio (crista-castrensis) - Gymnocarpio (dryopteridis) - Abieto (lasiocarpae) - Piceetum glaucae and shortened them in accordance with the code to more manageable binomials. They combine closely related communities into consolidated association and propose synonymies. They designate type releves for their associations and type associations for their alliances and orders, so that if they should ever need to be split, the splitter will know which half of the association maintains the original name -- an important small step almost always overlooked in our regional vegetation studies.
In their descriptions of the syntaxa (vegetation types of various rank), Peinado and his colleagues do not leave out a general overview of the causal environment, providing useful tables of soils and climatic characteristics associated with he individual associations. Notwithstanding, it is apparent that the central objective of their work is the systematic comparison of vegetation types -- syntaxonomy in the strict sense.
While there are certainly technicalities of the classification, such as the inclusion of peripheral Pacific Northwest syntaxa in a classification meant for the boreal forest, which could be criticized, I think it is important to draw attention to this work as a milestone in the development of phytosociology in North America. My sharpest criticism of the authors is their near-failure to engage the many vegetation ecologists who work in the region of their study, who are the potential beneficiaries of their classification, the users on the ground, the link between the abstract and the concrete. Vegetation classification is not an end in itself, but a tool to interpret the landscape, to make responsible conservation and natural resource management decisions. Peinado and his colleagues are encouraged to bridge this gap, both through presenting their classification in the light of forest management considerations, and explaining how their classification differs from those available to vegetation ecologists in the region today. If they do not, their survey of boreal forest vegetation, as well as the promised forthcoming surveys of western North American vegetation, may join the ranks of the numerous other phytosociological classifications which failed to make themselves useful, which sit today shelved in the company of other esoteric dissertations on the dusty bookshelves of our university libraries.
References:
This is a synopsis of the classification of boreal coniferous forests published by Peinado et al. (1998) - see Toby Spribille's review above. Peinado et al. recognized the following orders (ending -etalia), alliances (-ion), and associations (-etum) in boreal North America. These forests belong to the class (-etea) Vaccinio-Piceetea described from Europe by Braun-Blanquet et al.
References: