| BEN |
| BOTANICAL ELECTRONIC NEWS |
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| ISSN 1188-603X |
| No. 252 July 1, 2000 | aceska@freenet.victoria.tc.ca | Victoria, B.C. |
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Ottawa scientist Dr. Erich Haber has been recognized by the Canadian Wildlife Federation with the prestigious Roland Michener Conservation Award. Erich Haber, 56, currently develops databases and reports for nationally rare plants, algae, wildlife areas and migratory bird sanctuaries for the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), a national organization. [Dr. Haber's project IPCAN - Invasive Plants in Canada - was described in BEN # 181, January 10, 1998. See http://infoweb.magi.com/~ehaber/ipcan.html]
Dr. Haber immigrated to Canada from Yugoslavia with his family in 1951. He grew up in Toronto, moving to Ottawa in 1971, where he worked as a research scientist with the Canadian Museum of Nature until 1993. He has worked with the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) since 1982, co-chairing the vascular plants, mosses, and lichens species specialist group. He is one of the committee's longest-serving members.
The Roland Michener Conservation Award is given every year since 1978 to an individual who has demonstrated a commitment to conservation.
Congratulations, Erich!
Polyploidy, the possession of multiple sets of chromosomes, is common amongst plants. It has considerable evolutionary significance as an abrupt mechanism of speciation as it results in an instant establishment of reproductive isolation from ancestral taxa. Most important crop plants, such as maize or wheat, are polyploids.
Molecular techniques have been used to infer that the genetic diversity in polyploids is mainly due to multiple origins (i.e. the evolution of the same species several times), leading to the claim that "the multiple origin of polyploids is the rule and not the exception" (Soltis & Soltis, 1993). However, the quality of molecular data and the assumptions used for their interpretation require critical examination. Indeed, the evidence for multiple origins in most allozyme studies is equivocal and other explanations are possible. Genetic variation in polyploids may be a result of:
In order to avoid interpretational problems, we propose the following list of conditiones sine qua non, to explain the genetic variation in polyploids:
Given this set of requirements, it is clear that limits are placed on the types of polyploids that can be investigated effectively. For more recently evolved polyploids (neopolyploids), it is more likely that the ancestral diploids will still exist, so that studies of the natural history, experimental hybridisation and tests of breeding systems can be carried out, and direct comparisons made of genetic variation and morphology.
Research in the Molecular Biology Laboratory in the Department of Botany [The Natural History Museum, London] aims to address many of the questions raised above. The fern genus Asplenium (Spleenworts) comprises some 50 taxa in Europe and extensive cytological studies and morphological comparisons have demonstrated that half of the European taxa are diploid and the other half are polyploids derived from these diploids (Lovis, 1977). Accessibility of material and invaluable information obtained by classical methods make Spleenworts a model genus to investigate and reconstruct patterns and processes of polyploid evolution using biochemical and molecular methods.
At the moment the jury is still out on the question as to whether "the multiple origin of polyploids is the rule and not the exception".
References:
In spring 1998 I taught a course on the identification of grasses, sedges and rushes at the University of Victoria (UVIC) as a part of the university Restoration of Natural Systems Program. Tim Johnsen, a student in that course, brought me a sedge (collected at the UVIC campus) that turned out to be Carex tumulicola Mack. that had not been reported from British Columbia at that time. Once alerted to this species, we found it at several other locations:
Voucher specimens are deposited in UBC, duplicates in DAO, UC, UVIC and WTU.
In the herbarium of the Royal B.C. Museum (V) we found several specimens of Carex tumulicola collected in 1990 by T.C. Brayshaw on Cattle Point, Oak Bay. All Dr. Brayshaw's specimens came from two clumps at the top of an eroded bank W of the geographic marker (T.C. Brayshaw, personal communication). We visited the site in 1999 and the two clumps of C. tumulicola are still growing there.
In neighbouring Washington State, Carex tumulicola occurs on San Juan Islands (Fred Weinmann, pers. comm.) and in a remnant of the grassland prairie in Port Townsend (Binda Colebrook, pers. comm.). It is a sedge associated with Garry oak (Quercus garryana) habitats.
Carex tumulicola belongs to the subgenus Vignea, section Bracteosae. The species that belong to this section are caespitose, have pistilate flowers with two stigmas and their bisexual spikes are androgynous, i.e., they have male flowers in the upper part, and the female flowers in the lower part of the spikes. Carex hoodii, the most common relative of C. tumulicola, occurs in British Columbia generally south of 55-th parallel. Another member of this group, Carex vallicola, has been reported from British Columbia only recently from the Ashnola River Valley (Douglas et al., 1998).
The following key can serve to identify Carex tumulicola and other species of sect. Bracteosae in British Columbia:
Reference:
Although the dimensions of editions 1 (1988) and 2 are nearly identical, edition 2 is much longer (434 vs. 708 pages). Revision is thorough, with five new chapters (see the *-marked entries in the Contents). The 13 chapters from edition 1 have "new tables, illustrations, chapter sections, and references," whereas all 18 chapters now have "information on habitat loss and the restoration and preservation programs that are mitigating these losses." A definite downside in the new edition, which is particularly inexcusable in that the price rose to $120.00 from $49.00 in 1988, is the heavier inking of many diagrams and especially the muddy reproductions of the photos carried over from edition 1. Nevertheless, this is an outstanding and landmark book that belongs on the shelf of everyone teaching even a regional course on community ecology. This work is a fine memorial to W.D. Billings (1910-1997).
Contents (new chapters marked with *): L.C. Bliss on arctic tundra & polar desert biome; D.L. Elliott-Fisk on taiga, boreal forest; R.K. Peet on forests & meadows Rocky Mts.; J.F. Franklin & C.B. Halpern on Pacific Northwest forests; Barbour & R.A. Minnich on California upland forest & woodlands; K.E. Keeley on chaparral; N.E. West & J.A. Young on intermountain valleys & lower montane slopes; J.A. MacMahon on warm deserts; P.L. Sims & P.G. Risser on grasslands; H.R. Delcourt & P.A. Delcourt on eastern deciduous forests; N.L. Christensen on vegetation of south-east Coastal Plain; * C.J. Richardson on freshwater wetlands; * I.A. Mendelssohn & K.L. McKee on salt marshes & magroves; W.D. Billings on alpine vegetation; * A. Velazquez et al. on Mexican temperate vegetation; * A.E. Lugo et al. on the Caribbean; G.S. Hartshorn on tropical & subtropical vegetation of Mesoamerica; * L.L. Loope on vegetation of Hawaiian Islands; Indices.