| BEN |
| BOTANICAL ELECTRONIC NEWS |
|---|
| ISSN 1188-603X |
| No. 331 June 16, 2004 | aceska@victoria.tc.ca | Victoria, B.C. |
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[These are the excerpts from the article published in the Natural Areas Journal 8(4): 238-243 - and they are posted in BEN with the author's permission. Although this paper was published in 1988, it is still relevant, even 16 years after it appeared. - AC]
Transplantation of threatened or rare plants into suitable protected sites has been proposed as an acceptable conservation strategy (e.g., IUCN 1986, Falk 1987). The most straightforward approach introduces rare plants into a location similar to the one at risk. A restoration site would be the wisest choice, but regardless of where the transplants are placed, a natural area must not be manipulated to accommodate them. Why disturb one assemblage of plants in an attempt to relocate others? The large number of rare and endangered species is a result of society's cavalier approach to natural areas in the past. Continued insult to ecosystems will only aggravate the situation and create even more rare entities.
Conservationists are very concerned about rare species, but the inherent values of habitat and communities, while given lip- service, are not equally appreciated. In addition to their role as a haven for particular species, ecosystems themselves are of value and must be perpetuated. As discussed by Whitney (1987) and others, they serve as reference points or benchmarks, outdoor research laboratories, sources of germplasm, and element of natural and cultural heritage. Because of the necessary functions that ecosystems perform, it is senseless to interfere with them for any reason. This is particularly true since there is no guarantee that rare species will be actually "saved" as a result of the disturbance.
Some types of research depend on undisturbed conditions. Insidious changes in ecosystems due to transplantation or other manipulations can confound an unsuspecting investigator attempting to understand basic biological phenomena. Chater (1987) learned accidentally that what he had regarded as a range extension of the uncommon Polystichum aculeatum was actually a transplant of unknown origin made by a botanist some years previously. Such unsuspected introductions could give spurious results in studies of nutritional and moisture requirements, allelopathic interactions, or factors controlling distribution.
Another consideration is that in the course of inserting new individuals or floristic elements into a natural area, something previously established often is displaced. Any interference is bound to impinge on the complex interrelationships within an ecosystem. Also we could be wrong about what constitutes an appropriate introduction.
Even when it is believed that transplantations are being made into an area where a species once grew naturally, mistakes can be made not only about the proper provenance but about a satisfactory microhabitat or even the suitability of the area itself. An introduction can be slowly eliminated if it is ill-equipped for a site; it can disadvantage other elements in the community if it becomes aggressive in the new setting.
An example of error in judgment can be seen in two parks in southern Ontario where oak savannas were deliberately planted with pine (mainly Pinus strobus). The savanna origins of the stands were not understood, and it was believed that pines previously occurred there. After all, one area had long been known as "the Pinery." As a result of an extensive planting operation that took place in the 1950's, 1960', and 1970's, sites now have degenerated to dense, near monocultures of pine with only a few of the original species surviving. In one park a locally rare herb, Lupinus perennis has been essentially eliminated along with the rare Karner blue butterfly that feeds upon it (Crabe et al. 1988). To prevent the loss of more savanna species and the destruction of one of the rarest ecosystems in Ontario, expensive and labour-intensive pine removal has become necessary to restore the community.
Introduction of pine into parks in southern Ontario was a major effort extending over a period of many years, but lesser introductions also can have an effect. Introductions of even a single fertile individual could ultimately generate a burgeoning population and the full impact of an apparently minor introduction might not be felt until decades or even centuries later (Egler 1983).
Limited availability of funds is often given as a reason for resorting to alternative conservation methods rather than simply setting aside nature reserves. However, alternative approaches can be very expensive when they are properly executed. An example is the substantial cost of creating artificial vernal pools in California to mitigate the effects of urbanization on natural pools; Zedler and Black (1988) concluded that it is not necessarily cheaper to create artificial communities than to preserve the natural one that are to be destroyed.
.....
Since funds are usually limited they should be spent where prospects of success are greatest. Private yards and gardens are ephemeral and not recommended by the World Wildlife Fund Plant Conservation Roundtable (1986). Even constitutional gardens are unreliable as a permanent repository of rare plant due to policy changes over time. As directors come and go, commitments change and old collections disappear to make room for new.
There are also many biological reasons why transplantation could fail and many indications that it does, though much of this evidence is unpublished. For example, in a local provincial park several interesting plants were moved so that the public could see them more easily. The park naturalist noted that while transplants persisted at first, they usually did not increase in number. Gradually most species declined and twenty years later were gone (T. Crabe pers.comm.). All attempts to transplant a threatened Canadian population of Buchnera americana totally failed (A.H. Rider pers. comm.); transplanting a distance of even 100 m did not work. Most transplants fare poorly when placed in previously established communities (Lape 1985) and according to Egler (1983) "do best in good Bare Soil."
Better known transplant examples include the rare sedge, Schoenus ferrugineus, in Scotland. Individuals from the last remaining population were moved to avoid inundation of the original habitat (Morton 1982). Though they were moved only a few meters up a lakeshore the transplants persisted for just a short time before they died out. The species is now thought to be extinct in Britain.
[Several more examples of mostly unsuccessful transplants (Cranston & Valentine 1983, Hall 1987, Holland 1980, Hope Simpson 1987, Lape 1985, and May et al. 1982) follow in the original paper.]
Obviously many wild plants flourish in gardens and may persist there for many years; however, success with any given species is not predictable (Keddy 1983). Detailed environmental requirements are not usually known, and even if every aspect of the physical support system could be suitably reproduced, it would be almost impossible to assemble the appropriate genotypes of microbes, insects, plants, and other biological associates in the natural community. Rare plants often have an extremely narrow ecological amplitude, and this may well be the reason why they are rare. What appear to be negligible differences between growing conditions at the original location and some chosen transplant site may be critical ones that preclude establishment.
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[In the next sections of the article Dianne Fahselt discussed "False Sense of Security," and "Undermining of Preservation Efforts." ]
Transplantation is not, of course, universally inadvisable. Clearly it can be a valuable tool for the stabilization of disturbed areas (e.g., Diamond 1985, Falk 1987) such as dune systems, eroding roadsides, mine tailings, and old fields, and some of the more successful revegetation projects do involve the use of native species (Miayawaki et al. 1988). Such applications are commendable, as long as valuable natural areas are not depleted in the course of supplying stock for reestablishment and as long as the finished product is not regarded as a satisfactory replacement for a long-established and finely tuned natural ecosystem. As pointed out by Zedler & Black (1988) artificial habitat cannot replace natural habitat.
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In spite of the problems associated with it, transplantation is used along with seeding to culture rare species, as recommended by the Canadian Plant Conservation Program, the Center for Plant Conservation in the United States, and similar organizations in other countries. However, this should be done only if it is impossible to prevent relevant habitats from being destroyed and only if plants are transferred to locations other than natural areas.
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Our lab here in Neuchatel (Switzerland) is preparing a worldwide molecular phylogeny of Impatiens.
We have students from China and Madagascar, and others doing fieldwork in Africa and SE Asia. So, oddly enough, we are most underrepresented in North American material.
I would be happy to exchange material of North American Impatiens species with North American botanists. I would be interested in a specimen voucher, and leaves dried in silica-gel for our molecular analyses. For the leaves in silica-gel, the more the better, but say 10-15 leaves should be more than adequate.
1. Impatiens noli-tangere L. [Alaska USA, BC, CANADA, WA, OR]
Syn.: I. occidentalis Rydb.
2. Impatiens aurella Rydb. [NW USA]
3. Impatiens ecalcarata Blank. [NW USA]
4. Impatiens capensis Meerb. [NE USA]
Syn.: I. biflora Walter
Syn.: I. fulva Nutt.
Syn.: I. nortonii Rydb.
5. Impatiens pallida Nutt. [NE USA]
6. Impatiens mexicana Rydb. [Veracruz, MEXICO]
7. Impatiens turrialbana (Donn.) Sm. [COSTA RICA]
1. Impatiens balfourii Hook.f.
2. Impatiens balsamina L.
3. Impatiens glandulifera Royle
Syn.: I. roylei Walp.
4. Impatiens parviflora DC.
5. Impatiens walleriana Hook.f.
There is a species in Mexico and one in Costa Rica, so I'm trying to get them as well. The American species of Impatiens came essentially from within Asian groups, at least according to the 2 species samples so far.
It would be great to get samples of all the native and introduced species from North America, as well as the hybrids.
Many thanks,
Jason
Dr. Jason R. Grant
Laboratoire de botanique ‚volutive,
Institut de botanique
Faculte‚ de Sciences, Universite de Neuchatel
Rue Emile-Argand 11, Case Postale 2 CH-2007
CH-2007 Neuchatel SWITZERLAND
Tel: (+41) [0] 32 718 3958 /or 2344 (secr. 2353)
FAX: (+41) [0] 32 718 3001
jason.grant@unine.ch
jasonrgrant@hotmail.com
Those that have worked throughout the province of British Columbia have understood the wide diversity of wetlands that occur here. Finally, a book has been produced that provides a comprehensive look at wetland plant communities.
This beautifully designed and illustrated book provides description of wetland ecosystems in a variety of classes and also includes ecosystems often not considered in other documents including floodplains, riparian and transitional wetlands. The book also includes wise management actions in terms of range management, forestry and values for wildlife habitat.
Over 100 wetland, riparian, floodplain, shallow- water and transition site associations are each described in a one page summary that includes information about provincial distribution, vegetation and site characteristics, and a photograph. Many excellent photos are used to help illustrate the major wetland classes. Line drawings of common wetland plants are sprinkled throughout the book.
The introduction to the book provides information on the wetland classes, including environmental characteristics. It also describes the Biogeoclimatic Ecosystem Classification with its various levels, taxonomic conventions, and provides tools for identification of wetlands (including keys and summaries).
A section on conservation and management issues provides a look at sensitivities and values of wetlands in terms of range management, forestry management and wildlife use of wetlands.
For those familiar with the edatopic grid used in the Biogeoclimatic Ecosystem Classification (BEC), which combines, in this case, actual soil moisture regime and soil nutrient regime, this guide adds an interesting modification that also includes 5 classes of pH (acidity/alkalinity), and a Hydrodynamic Index that has 5 classes of vertical and lateral water movement in the soil.
I would highly recommend this book to get an understanding of the many wetland types in the province and how to manage for values associated with them.