| BEN |
| BOTANICAL ELECTRONIC NEWS |
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| ISSN 1188-603X |
| No. 250 May 21, 2000 | aceska@freenet.victoria.tc.ca | Victoria, B.C. |
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(Abstract of the paper presented at the symposium on "Vegetation Classification and Mapping in the Rocky Mountains," Glacier National Park, Montana, 29 June - 2 July 1999)
Several thousand plant associations have been formally defined in monographs in the last five decades in the United States. Most of the associations in the western U.S. were defined as "climax plant community types" as part of developing a habitat type site classification system. During the 1990's, considerable effort has been devoted to developing a standard National Vegetation Classification System (NVCS) of existing vegetation. This has generated considerable debate on relationships among established "potential natural vegetation associations" and "existing vegetation associations".
I suggest that the conceptual framework of "association" set forth in 1910 still provides a solid theoretical foundation. However, the ideal "association" is not yet apparent and will not be until an adequate database exists to represent all the vegetation variation (floristics and physiognomy) for a full range of physical environments (habitats) within a geographic area. With such a database, a vegetation scientist may be able to discern and explain how vegetation varies in relation to succession, disturbance (natural and man-caused), and physical environments.
The first obvious step in this long process toward a standard NVCS may be to acknowledge that the "associations" used to derive habitat type classifications are really "late-successional associations" and therefore do represent "existing vegetation"! Another step is to make full use of existing databases, mainly from relatively undisturbed late-successional communities. An example for 1001 Montana forest stands is provided. Obviously, a major gap is the lack of data for early successional stages and disturbed communities. Those few databases that provide a good sample of all successional stages within restricted environmental conditions should be very useful examples of what a NVCS might look like. An example for western Montana forest stands is provided.
In the 1910 context, we must deal with three very different criteria (floristics, physiognomy, and habitat conditions). Requiring uniformity in all three simultaneously could idealistically lead to defining more associations than most of us can imagine! If the purpose of the classification is to simplify in order to make meaningful abstractions, the words "relatively uniform" take on special meaning. One possible solution is to focus first on standardizing one criterion at a time for analysis. Then meaningful comparisons can be made to the other criteria.
This spring a new organization was formed, Northwest Lichenologists (NWL).
NWL is a nonprofit corporation dedicated (1) to promote and encourage professional development, growth, and renewal, (2) to enhance the visibility of the profession, (3) to maintain and promote high standards of performance by all members of the profession. We plan to promote these goals through training and certification programs.
One of the first activities of NWL is a certification program.
Why is there a certification program?
Our initial certification program is for macrolichens in the oceanic Pacific Northwest (west of the Cascade Crest in Oregon, Washington, northern California, and British Columbia).
The first round of certification is currently planned to occur on June 3-4, 2000, at the H. J. Andrews Experimental Forest, Blue River, Oregon. Certification exams will be offered at least once per year. Future locations will be set each year by the Board of Directors. NWL will contract the services of qualified instructors to administer the examinations.
Read more about NWL and the certification program at: http://www.proaxis.com/~mccune/nwl.htm
When I first started making notes this review was in danger of degenerating into a discussion of the British Class system as it applied to gardening and readers may still detect traces of this. But to get down to the book itself, it is an out and out scientific monograph - that is, a carefully planned, detailed examination and revision of the subject by a scientist. Note 'scientist', not gardener. This implies a certain rigour, even stiffness in the writing style and treatment. Of course we need a periodic scientific revision of each genus to get us back to fundamentals. Then, out of these treatment can come more gardenly books with an easier approach and more concentration on horticultural matters. I am sure there will be spin-off from this book.
This book originated as a Ph.D. thesis and elements of this can be detected in occasional obsessive detail - for instance six and half pages of synonyms for the common snowdrop, Galanthus nivalis. The book fits in well with other publications produced in the Monograph series at Kew. The author is currently a research botanist at the Royal Botanic Gardens, Kew working on the wild coffees of Madagascar.
The earlier great monograph on the subject is F.C. Stern's 1956 Snowdrops and Snowflakes, published by the Royal Horticultural Society and some degree of comparison is in order. Stern's book is in itself a classic of its time - a model of how to treat a subject. For the past 45 years it has been very much revered as the standard treatment. It includes Leucojum which Davis does not. Looking back I can see that our world of snowdrops was moulded by Stern's views. He was at the time one of Britain's leading rock garden authorities.
In a very real sense Stern studies were confined by World War II and its continuation the Cold War. What he had to work on was largely material in cultivation in British gardens collected before 1939. Most of the regions where snowdrops grow were in socially and militarily unstable regions such as Greece, Turkey and Syria, or no-go areas behind the Iron Curtain with travel forbidden to foreigners.
By contrast Davis' work can be regarded as the "peace dividend" we were promised when the Cold War ended in 1990. Davis was able to travel extensively in Greece, Turkey and the Caucasus. He examined in the field and in institutions species which were not (and still are not) in cultivation in our gardens.
The extraordinary differences between these two monographs can be ascribed to the material available to each author and to the differences in training and approach. Sir Frederick Stern was an English gentleman with a career in the military, an expert gardener but no knowledge of the subtleties of botanical science. Aaron Davis is a scientist trained in modern techniques. The difference shows. The newer book is startlingly different both because of its approach and in the large amount of new material available.
Between these two comes an intermediary to whom considerable credit must be given. In then Soviet Union, starting in the 1960's, Z.T. Artiushenko worked on Russian snowdrops producing a monograph in Amaryllidaceae SSSR in 1970. She eventually enlarged her studies to all to all the then known species. This eastern point of view and her access to material from behind the Iron Curtain led to a radical reappraisal of what existed in wild. Artiushenko wrote several articles on snowdrops many readily available but her views never really filtered down to the level of the gardening public. It was to reconcile her more revolutionary ideas with the traditional views of Stern that Davis' monograph was undertaken.
Among the major differences between Stern's and Davis' monographs are the number of species recognized and the names affixed to them. Stern recognized 12 species, Davis recognizes 18 but these exclude four from Stern's list.
By not referring to the literature or examining the original herbarium specimens on which the names are based Stern completely reversed the usage of certain names. His biggest mix-up was in using the name "Galanthus elwesii" for specimens of G. gracilis. This is a big problem because the Sternian concept of "G. elwesii" is now the universally accepted idiom. It is so embedded in our vocabulary, trade and literature that to change back to the proper usage would cause endless confusion. So Davis bows to the inevitable and formally conserves Stern's use of "Galanthus elwesii."
A name that has disappeared is Galanthus caucasicus, long cultivated and the stated parent of many garden hybrids. Davis contends that the plant of gardens given that name is simply the early-flowering variety (var. hyemalis) of G. elwesii. The plant in question has a single terminal green spot on the inner petals. He maintains that G. elwesii during cultivation has given rise to single-spot forms which have mistakenly been designated "G. caucasicus."
To illustrate how complicated some of the naming problems are I can add that there is a wild plant from the Caucasus also called G. caucasicus but now named G. alpinus. This latter includes the triploid clone var. bortkewitschianus, previously regarded as a hybrid or a species in its own right.
Readers' heads will be spinning over naming problems and in places this book is not easy reading. However I think that Davis' revision is going to be very influential over the next few years. The new names will gradually filter down to the garden level. Meanwhile don't take at face value any label in a nursery.
About three quarters of the book is concerned with descriptions of the species, the history of their discovery, their distribution and naming problems. Other chapters discuss pollination, anatomy, cytology, ecology, pests and diseases. There is a useful chapter on how to cultivate them (they do better in the ground than in pots) and the propagation section includes a detailed account of chipping and twin scaling (contributed by Ronald MacKenzie).
One chapter sure to interest gardeners is that on cultivars. Some 118 cultivars are described with their origin and chief characteristics set out. This is a valuable section. My only regret is that it is still difficult to put a name to an unnamed specimen. I mention this because of the old hybrids persist for long periods in gardens, whereas their labels decay.
In terms of illustrations there are excellent photographs of the species most taken in their natural habitat, some in gardens.
Christabel King was commissioned to do the illustrations and produced a black and white page of the general habit of a snowdrop with enlarged dissections of the parts. Her colour plates I think are a missed opportunity. Each shows a clump of plants in flower, some with, some without, bulbs. However, unlike the black and white plate there are no dissections of flower parts shown. This is in a group where details of the markings on the inner petals are of crucial importance. In fact, rather than show an enlarged flower, or part of a flower, with a different form of mark, two of the species have been given duplicate plates for the rather trivial reason of showing a different marking. There is a long history at Kew of botanical illustration and many of the paintings produced have had dissected parts incorporated. These are after all scientific illustrations not bedroom decoration.
To sum up this is one of the most radical revisions of any group to come out in recent years and the book is a must-have for any grower of temperate bulbs.