| BEN |
| BOTANICAL ELECTRONIC NEWS |
|---|
| ISSN 1188-603X |
| No. 310 May 9, 2003 | aceska@victoria.tc.ca | Victoria, B.C. |
|---|
An invasive alien race of Phragmites australis (Cav.) Trin. ex Steud. is considered a threat to North American biodiversity. The native race has reddish instead of yellow lower stem internodes, but these lower parts are often not available and quailitative assessments are sometimes difficult. Thus, identification of races is problematic, but is urgently needed for evaluation of the problem and for monitoring and management. Measurements of first glume length were made for 223 plants which included 1 to 11 plants from each of 58 population samples gathered from throughout the eastern portion of southern Ontario. Based on correlation with stem color, plants with first glume lengths above 4.2 mm belong to the native North American race, while those below 3.5 mm belong to the alien Eurasian race. The overlapping area of 3.5 to 4.2 mm included 22.4% of the sample. This result, along with inflorescence and non-color stem differences as well as ecological and geographic corre- lates, supports Fernald's recognition of the North American native plants as Phragmites australis var. berlandieri (Fourn.) C.F. Reed.
An economically important plant serving as a source of food and materials, Phragmites australis has yet to be fully exploited as a crop (Small and Catling, 2001). Despite its economic potential, much recent interest has been focused on the fact that it is a pest; clones of P. australis form dense monocultures that reduce native biodiversity, especially in tidal and inland freshwater marshes (Chambers et al., 1999; Meyerson et al., 2000). In eastern Ontario, where samples of P. australis for this study were collected, there has been an overall increase in P. australis abundance and distribution, particularly along roadsides (Schueler, 2000; Catling et al., 2003). The aggressive race of P. australis now occurring in many parts of North America is apparently more closely related to Eurasian populations. The introduction of this race may have taken place 150 years ago on the Atlantic coast of the United States, while the native race is believed to have been present in North America for thousands of years (Saltonstall, 2002).
Native biodiversity was found to rebound following removal of alien Phragmites australis (Meyerson et al., 2000). Thus, monitoring and management can be applied to the problem. Marks et al. (1994) reviewed various management strategies that have been employed to control P. australis; these include burning, chemical control, cutting, grazing, dredging, draining, and manipulation of water level and salinity. In addition, research is now being carried out to find biological control agents for P. australis, as herbivores of this plant are much more numerous in Europe than in North America (Tewksbury et al., 2002). Monitoring and work aimed at management and control require accurate identification; the invasive alien race should not be confused with the possibly declining native race that is not a biodiversity threat.
Qualitative characters of the races have already been determined (Blossey, 2002; Catling et al., 2003). Among these, the color of the stem internode and associated characters have proven strongly correlated with ecological characteristics suggesting native and introduced races. Furthermore, older herbarium specimens all have red stems while more recent collections include specimens with yellow stems suggesting a recent invasion of the yellow-stemmed race (Catling et al., 2003). Distinguishing races based on qualitative characters alone can be problematic because it requires judgements and observations at specific times, while the use of quantitative floral characters of longpersisting inflorescences provides a potential solution to these problems. We undertook this study to determine whether a quantitative character, length of first glume, is correlated with the recently identified stem color races. Glume length was suggested to distinguish North American and European races by Fernald in 1932.
Measurements of first glume length were made for 223 plants including 1 to 11 plants from each of 58 population samples. The samples were gathered in fall of 2002 from throughout the eastern portion of southern Ontario including an area extending from Ottawa southeast to Brighton and from Tweed east to Alexandria.
Some collected specimens were sent to the "Phragmites Diagnostic Service" (Blossey, 2002), to be identified as native or alien. Then, based on this assessment, it was possible to identify the remaining samples and reliably establish two groups of the 223 plants for morphological analysis. This identification was based on stem color (reddish stems were identified as native, while brown or yellow stems were considered to be introduced).
Measurements were made using a dissection microscope with an ocular measuring scale. For each inflorescence, the spikelet to be measured was selected from a portion of a branch from the lower middle of the inflorescence. This branch portion normally contained 2 to 5 spikelets from which a complete and opened spikelet with visible rachilla hairs was selected. The lengths of the glumes were measured from the articulated base of the glume at the point where the two sides of the glume joined together (and the rachilla at the base of the glume was no longer visible), to the tip of the glume.
Alien plants with yellow or brownish stems had first glumes ranging from 2.3 to 4.2 mm and native plants with reddish or reddish-purple stems had first glumes ranging from 3.5 to 6.4 mm. The overlapping area of 3.5 to 4.2 mm included 22.4% of the sample.
Variation within this worldwide cosmopolitan species has resulted in descriptions of many subspecies and varieties (Small and Catling, 2001). Fernald (1950) described the North American "Phragmites communis var. berlandieri (Fournier) Fernald" as a taxon with longer glume lengths than those of Eurasian plants. It was noted that the first glumes of the North American variety ranged from 4 to 6 mm with a mean length of 4.6 mm, while first glumes of the Eurasian variety ranged from 2.5 to 5 mm with a mean length of 3.5 mm (Fernald, 1950). These lengths are comparable to the results obtained in this study of native North American P. australis plants and introduced Eurasian P. australis plants now growing in eastern Ontario.
Recently this North American variety has not been recognized (e.g. Clevering and Lissner, 1999; Scoggan, 1978; Gleason and Cronquist, 1991). Citing Clayton (1967), Dore and McNeill (1980) suggested that the distinction was of doubtful validity considering variation in glume size throughout the world. However, it appears that there is a significant quantitative morphological difference between native and alien races of Phragmites australis in eastern Ontario (and possibly throughout a large portion of North America) that can be used in identification to supplement qualitative characters. These differences, along with ecological and geographic correlates and apparent reproductive isolation of the two races (Catling et al., 2003) suggest the recognition of the North American race as a subspecies or variety, as recommended by Fernald (1932, 1950). Study over a broad area of North America is needed to confirm this suggestion. In the mean time, those interested in invasive aliens may wish to experiment with the following key:
Bill (William J.) Cody retired as a Research Scientist in 1987. He then became an Honorary Research Associate. He completed his Flora of the Yukon Territory in 1996, that work being recognized by the Canadian Botanical Association with their prestigious Lawson Medal in 1997. He has written several extensive articles on additions to both the Yukon and the Northwest Territories floras. However these research accomplishments are only a small part of his continuing work much of which is spent helping others. He has helped everyone with everything and is often the first to respond to the doorbell, despite the fact that his office is furthest from the door! He proofreads, provides extensive information and consultation, and helps with hundreds of identifications each year. He also assists herbarium visitors and service personnel. He has mounted, labelled and repaired many thousands of specimens. In addition he has helped to organize and process thousands of specimens in storage and has made material available for the international exchange program. The online catalogue of type specimens is maintained by Bill. For 55 years he has served as business manager for the Canadian Field-Naturalist, the major publication covering field biology in Canada. This outstanding contribution of volunteer work was recognized recently with a Queen's Golden Jubilee Medal (2002). Always ready with a song or a pun, Bill's cheerful disposition has also contributed a great deal to the herbarium operation.
Gerry (Gerald A.) Mulligan has served as president of the Canadian Botanical Association and Director of Entomology, Botany and Mycology (50 scientists and a few hundred staff) on the Central Experimental Farm of Agriculture and Agri-Food Canada. He retired as Director and Research Scientist in 1987 and continued to pursue his work on the Brassicaceae as an Honorary Research Associate. Since retirement he has made many major contributions. Several new species were discovered and described and several papers were written including a major monograph on the genus Arabis. Many thousands of identifications have been provided to other researchers and planners. Gerry has revised and reorganized the Brassicaceae portion of the DAO vascular plant herbarium collection (40,000 specimens), and he also revised much of the material in several other collections. Many storage shelves of specimens had been collected 30 years ago as part of a major study of the Genus Arabis, but were not labelled and incorporated in the collection because they could not be identified. Gerry identified all this valuable backlog and made sure that it went into the collection to become available to researchers worldwide. Through his effort the DAO collection of Arabis has become one of the best in the world. He contributed to the development of the very impressive Brassicaeae database which was one of the first databases to make essential information from the DAO herbarium widely available. Gerry has also assisted staff with consultations on weedy plants, revised his book on common weeds of Canada and made much information on poisonous plants available on the web: http://res2.agr.gc.ca/ecorc/poison/index_e.htm
Ardath Francis came to work as a volunteer at DAO in 1990. She contributed extensively to research on taxonomy of the Wheat family, classification of pasture grasses, and work on the Mustard family. In the latter case she entered label data for over 14000 DAO specimens verified by Gerry Mulligan for the Brassicaceae of Canada database developed with Dr. Suzanne Warwick. Ardath recently translated the ecology text and other information for the french version. An exceptional bibliographer, she gathered and synthesized information from both the herbarium and the library to support research. This provided an example of the close association between an herbarium collection and a botanical library as primary tools in the identification and classification of plants. During her time as a volunteer, Ardath also assisted with the Inventory of Canadian Agricultural Weeds. Through expert assistance in proofreading, gathering and checking information and sharing of knowledge of other languages (Latin, German and Russian) she has been a great asset. Ardath contributed extensively to the herbarium theme of collection improvement by helping to reorganize thousands of specimens into adequate space and helping with repair. In addition to an outstanding record of 13 years of daily help to others, Ardath has won recognition for the botanical research associated with DAO through publishing a review of early agriculture in North America and participating in several publications in the Biology of Canadian Weeds series.
BEN readers might like to know that my 6,000-word biographical essay on Theodora Cope Stanwell-Fletcher (1906-2000) was recently published. Dr. Stanwell-Fletcher, who had a PhD in ecology from Cornell, did pioneering ecological work with her husband John Stanwell-Fletcher in the Driftwood Valley region of British Columbia in the years 1937 to 1941. Their letters, notes and collections are held by the British Columbia Museum in Victoria. She wrote three books on the Canadian north, the best known of which is *Driftwood Valley* (1946). This lovely book remains in print having been re-issued by Oregon State University Press (Corvallis) in 1999 [see BEN # 235].
My essay, entitled "Driftwood Valley: Epitaph for a Wilderness, New LIfe for a Literary Classic," appears in *ISLE* (Interdis- ciplinary Studies in Literature and Environment), Volume 9.2 (Summer 2002), pages 101-114.
Dr. Stanwell-Fletcher died in Pennsylvania on January 15, 2000 at the age of 94 [see BEN # 243]. She was member of the well-known Cope family of Philadelphia which included Edward Drinker Cope. It is interesting to note that Theodora was almost an exact contemporary of G. Ledyard Stebbins.
Robin Wall Kimmerer's book Gathering Moss is a delight. Robin invites the reader to see things a bit differently, to take a look at things from a moss's perspective. Although this is not a field guide, Robin introduces us to a variety of different mosses and their haunts. Robin uses these moss examples to illustrate major ecological principals such as succession, gap dynamics, intermediate disturbance hypothesis, r versus K strategies, sexual versus vegetative reproduction, and symbiotic relationships. I must confess that part of the pleasure for me was that I know many of the people and places that Robin mentions in her book. However, I truly enjoyed her unique perspective on mosses and the world; she speaks as a biologist, a woman, a mother, and a Native American.
This book should appeal to a wide range of readers, from seasoned moss nuts to new ecology students to general readers interested in natural history.
[Robin Wall Kimmerer is an Associate Professor on the faculty of Environmental and Forest Bilogy at the State University of New York, College of Environmental Science and Forestry. She has published numerous articles on the biology and ecology of mosses, as well as articles on traditional Native American knowledge of natural world.]
Title: Primary Succession and Ecosystem Rehabilitation.
Date: March, 2003.
Authors: Lawrence R. Walker (University of Nevada, Las Vegas) and Roger del Moral (University of Washington).
Publisher: Cambridge University Press, Cambridge UK, New York, N.Y. 442 pages, including a glossary, index and references.
ISBN 0-521-80076-5 [hard cover] Price: US$130.00
ISBN 0-521-52954-9 [soft cover] Price: US$50.00
Link to Cambridge University Press Web Page: http://www.cup.org/
Natural disturbances such as lava flows and landslides, and human- damaged habitats such as pavements and mine wastes usually leave little biological legacy. This book provides the first comprehensive summary of how plant and animal communities develop under the harsh conditions that follow dramatic and devastating disturbances. The authors examine, summarize and synthesize basic principles that determine ecosystem development and apply the general rules to the urgent practical need for promoting more efficient reclamation of damaged lands. They demonstrate that succession not deterministic, rather pathways are affected by stochastic processes, landscape position and priority effects. Initial disturbances often result in alternative stable stages.
This book was written for those concerned with disturbance of any kind, landscape dynamics, restoration ecology, invasion biology, or the assembly of communities. It is an authoritative text for graduate students and will serve as a valuable reference for professionals in both the public and private sectors involved in land management and restoration.
One service provider returned BEN # 309 to me with the following message:
The Message with the above mentioned subject [BEN # 309] was blocked from delivery. Please review the message for any content deemed 'inappropriate' for business communications. If you feel this message is error, please contact: postmaster@abcdefg.com
I really felt that this message was error and I got the following explanation and apology from the postmaster:
I found your message, and what stopped it was the number of times 'amateur' was used. Based on the content of your message, it was not inappropriate at all. Please feel free to resend the message to the original recipient. It should now be delivered with no problem. Please accept my apology in this matter.